TWI516615B - Discoloration resistant copper alloy and copper alloy member - Google Patents

Description

Resilience-resistant copper alloy and copper alloy member

The present invention relates to a discoloration-resistant copper alloy which is brass color and has discoloration resistance, and a copper alloy member using the discoloration-resistant copper alloy, relating to workability and mechanical properties such as hot workability, cold workability, and pressability. A discoloration-resistant copper alloy excellent in properties and excellent in antibacterial property and bactericidal property, and a copper alloy member using the discoloration-resistant copper alloy.

The present application claims priority based on Japanese Patent Application No. 2013-199475, filed on Sep

Conventionally, copper alloys such as Cu-Zn have been used for various applications such as piping equipment, construction materials, electric/electronic devices, daily necessities, and mechanical components. Among the building materials, from the viewpoint of aesthetics, it is required to be discolored in the use of decorative/construction metal parts such as handrails, door handles, western tableware, and keys. In order to meet the requirements, the surface of the copper alloy product is coated with a resin such as nickel/chromium plating or colorless coating.

However, the plating product peels off on the surface of the plating product due to long-term use. Moreover, the color tone of the coated product changes over the years and has a coating film. The problem of divestiture occurred. Further, since the plating product and the coated product are not in contact with the copper alloy, the antibacterial property (bactericidal property) of the copper alloy is impaired.

When the content of Zn exceeds 15 mass% or 20 mass% in a copper alloy such as Cu-Zn, it has a brass color. However, if a protective film such as a plating layer or a coating is not formed and used as a decorative material in the surface state of the blank, it is also affected by the environment in which it is placed, and it becomes brownish brown or reddish brown in a short period of time. Further, in the case of discoloration, it is not uniformly discolored, and the environment, the parts, and the parts are discolored due to discoloration or unevenness in color tone, and the state in which the first metallic luster is beautiful cannot be maintained.

Conventionally, as a copper alloy having a material having discoloration resistance, a white Cu-Ni-Zn alloy having a gloss similar to that of a plating layer and an aluminum bronze having a gold color have been proposed.

As such a Cu-Ni-Zn alloy, for example, JIS C 7941 contains Cu (60.0 to 64.0 mass%), Ni (16.5 to 19.5 mass%), Pb (0.8 to 1.8 mass%), and Zn (remaining portion). Free cutting of nickel and silver. Further, Patent Document 1 discloses that Al (5 to 9 mass%), Ni (1 to 4 mass%), In (0.005 to 0.3 mass%), Mn (0.1 to 0.5 mass%), and Co (0.001 to 0.01 mass) are disclosed. %), Be (0.0025~0.2mass%), Ti (0.001~0.01mass%), Cr (0.05~0.2mass%), Si (0.001~0.5mass%), Zn (0.005~0.5mass%) and Sn( One or two of 0.003 to 0.4 mass%, and an aluminum-copper alloy containing the remaining portion of Cu and unavoidable impurities.

Moreover, conventional copper alloys have an antibacterial effect (bactericidal action). In hospitals and other medical institutions, infections such as Staphylococcus aureus and Pseudomonas aeruginosa which are resistant to biomass and the like are often called in-hospital infections. and, Infectious diseases such as influenza spread throughout the world, and diseases caused by bacteria or viruses become problems.

For example, in hospital infections, the path of the bacteria that cause the cause is various, and it is conceivable that the patient who is in contact with the bacteria, the other patient, or the medical personnel contact the place where the bacteria are attached, and the pathogen spreads in the hospital. The bacteria are killed or reduced by setting the objects that the patient and the medical personnel are in contact with as copper alloys. Moreover, it is necessary to reduce the nosocomial infection by severing the infection path. Specifically, it is expected that the handles of the doors, the lever handles, the door handles, and the like, which are installed in the yard, or the fences, guardrails, and nursing carts provided on the bed are made of copper alloy, thereby reducing the diffusion path of bacteria. In the case of influenza, etc., it is possible to prevent the use of various bacteria and viruses by using an antibacterial (bactericidal) copper alloy in a member that is in contact with a large number of people in a public institution such as a train, a bus, or a park. Infection.

(previous technical literature)

(Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 2004-143574

However, the copper alloy disclosed in JIS C 7941 contains a large amount of Ni and Pb, and has problems in terms of health and hygiene, and thus its use is limited. Ni is a cause of strong Ni allergy especially among metal allergies. Further, since Pb is known as a harmful substance, there is a problem in the use of a building metal part such as a handrail that directly contacts human skin, and a home electric appliance or the like as a daily product. In addition, when a large amount of Ni is contained, workability such as hot rolling properties and punchability is changed. Poor, and Ni is expensive, and the manufacturing cost is increased, so the use is limited.

In addition, the copper alloy disclosed in Patent Document 1 contains an aluminum alloy containing 5 mass% or more of Al, and is excellent in discoloration resistance, but has poor workability such as rolling. Therefore, it is mainly produced as a casting material, and it is difficult to process it into a thin plate or the like. Further, in the case of bending such as bending, for example, the 90-degree bending or the like lacks ductility, and therefore cold workability such as cracking in the bent portion is inferior. Further, there is a problem that the antibacterial property is weakened by the formation of an oxide film of aluminum on the surface, and the antibacterial property is lost in long-term use.

Further, if a usual copper alloy is actually used in a handle, a lever handle, a door handle, or the like, a difference in hue is generated in a portion in contact with the human body and a material in the non-contact portion as time passes. In long-term use, the part that is in contact with the human body is more slowly formed, or even if the color-changing layer is formed, it is removed by physical effects such as abrasion caused by human contact, thereby The difference in hue between the parts (the part that has less contact with the human body) becomes more apparent, and it is hard to say that it is excellent in appearance. Further, since the human body contacts the material and the sweat, sebum or the like of the human body adheres to the material, the color difference is generated by the surface condition of the portion in contact with the human body by the effect of promoting or delaying the discoloration based on the adhered substance. Further, the discoloration also differs depending on the environment in which the material is used, and the higher the temperature/high humidity, the more likely it occurs, and the portion where water droplets (including rainwater or the like) adhere is remarkably present, and at this time, discoloration occurs in a very short period of time. Therefore, most of the copper alloy handles used for such applications are coated with a copper alloy surface by plating, a colorless coating, or the like, so that it is difficult to cause discoloration.

A copper alloy is a non-ferrous metal that is not found in other metals. It is representative of copper red reddish orange, brass (Cu-Zn alloy) yellow or nickel silver (Cu-Ni-Zn). Alloy) silver white and so on. As described above, the copper alloy is a material having various hues by adding an element. As described above, when it is used under conditions of contact with a human body, it differs depending on the alloy, but discoloration is difficult to avoid. In particular, red-orange copper and yellow brass discolor in a very short time, but because of the color tone that other metals do not have, these colored copper alloys are sometimes used from the viewpoint of art, design, or aesthetics. material. However, in order to prevent discoloration, a resin film such as a colorless coating layer is coated (coated) on the surface, and thus the antibacterial property (bactericidal property) is not exhibited.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a color tone having a yellow color (brass color), and excellent in workability such as hot workability, cold workability, and punchability, and further, discoloration resistance and antibacterial property. A discoloration-resistant copper alloy excellent in (sterilization) and a copper alloy member using the discoloration-resistant copper alloy.

In order to solve the above problems, the inventors of the present invention have studied the composition and metal structure of a brass alloy having a brass color, and as a result, obtained the following findings.

In the Cu-Zn-Sn-Al alloy, although depending on the content of each additive element, when a material such as hot rolling or hot pressing becomes a high temperature, a β phase appears in the matrix to reduce the deformation resistance in hot rolling, and hot rolling The deformation energy becomes excellent. However, if a β phase having an area ratio of more than 0.9% or a γ phase exceeding an area ratio of 0.7% is present at normal temperature (room temperature), the ductility is deteriorated, and cold workability such as cold rolling or cold drawing in the next process is not only performed. It deteriorates, and the discoloration resistance and the like also deteriorate. Moreover, in the pipe processing, the processing such as bending and flatness having a small radius of curvature is also deteriorated. In addition, it also has an adverse effect on corrosion resistance, dezincification corrosion, stress corrosion cracking difference. Further, since the β phase which appears in the Cu-Zn-Sn-Al alloy contains Sn and Al, it is harder and more brittle than the β phase of the Cu-Zn alloy.

Further, in the Cu-Zn-Sn-Al alloy, a β phase occurs when processing is performed at a high temperature such as hot rolling or hot pressing, and a γ phase appears from the β phase by an eutectoid reaction depending on cooling conditions. Compared with most of the α phase of the matrix, the γ phase hard phase has more Zn content than the β phase, and Sn and Al are also more than twice as large as the β phase, so that it is a hard and brittle phase. When the area ratio of the γ phase exceeds 0.7%, the material lacks ductility similarly to the β phase, and the cold workability is lowered. Further, although the influence is small as compared with the β phase, the corrosion resistance such as dezincification corrosion is lowered, and the discoloration resistance is also deteriorated. Further, when the γ phase exceeds 0.7%, the ductility of the material remarkably decreases, and if it is used for a member to which an impact is applied, the possibility of cracking increases. The same applies to the Cu-Zn-Sn-Al-Ni alloy in which a part of Sn and Al is substituted by Ni, and the metal structure in the matrix affects various properties of the material.

Further, the Cu-Zn alloy is generally processed by hot rolling or hot pressing after heating the ingot produced by casting to a high temperature. Thereafter, a product of a desired size is obtained by repeatedly performing heat treatment such as rolling or drawing in cold rolling and plastic working such as annealing. A material having poor hot workability such as a Cu-Sn alloy and a Cu-Zn-Ni alloy is produced by continuous casting to produce a thinner (rolled piece) or finer (extruded) size casting than an ingot, and thereafter, Manufacturing is performed by cold working. Although the ingot is also dependent on the mold, it can be manufactured in an amount of about 10 tons per hour. In continuous casting, the cross-sectional area is smaller than that of the ingot, so the amount of production per hour is reduced to one-tenth. Therefore, in terms of manufacturing cost, ingot manufacturing is lower than that by continuous casting, and most copper alloys are manufactured by hot working after manufacturing an ingot. Cu-Zn-Sn-Al alloy is also associated with Cu-Zn Similarly, the alloy can be produced by hot rolling or hot-pressing ingots, and can be produced by continuous casting. When a small amount of product is required, manufacturing by continuous casting may be advantageous in terms of cost.

As described above, although the amount of each element added and the manufacturing conditions are affected, the β phase which occurs when the material becomes high temperature is converted into the γ phase during the cooling process, and the β phase remains at the normal temperature, and the respective phases individually exceed the area. The rate is 0.7% (γ phase), 0.9% (β phase), and when the area ratios of the β phase and the γ phase are set to (β)% and (γ)%, respectively, if 2×(γ)+(β) When the total amount exceeds 1.5%, the cold workability is lowered by the decrease in ductility in cold rolling, and the discoloration resistance and corrosion resistance may be deteriorated.

Further, the solid copper alloy forms an active oxygen group such as hydrogen peroxide and a reactive radical on the surface thereof, and this active oxygen group acts on the cell membrane and DNA of the bacteria, thereby exhibiting antibacterial property (bactericidal property). On the surface of the copper alloy which forms the active oxygen group, copper contributes to the oxidation/reduction reaction and reacts with water or the like existing in the atmosphere. Further, in the case of the antibacterial property (bactericidal property) when the liquid is brought into contact with the copper alloy, the contacted liquid reacts with the copper alloy to elute the copper ions. These reactions are the same as the corrosion of the so-called copper alloy, and when the antibacterial property (bactericidal property) is exhibited, a corrosion reaction is caused on the surface of the copper alloy. The surface corrosion of the copper alloy is responsible for the discoloration of the copper alloy. As described above, the antibacterial property (bactericidal property) is substantially opposite to the discoloration resistance, and the effect of improving discoloration resistance and attenuating antibacterial property (bactericidal property) are related. That is, the discoloration resistance and the antibacterial property (bactericidal property) are not both. In order to have such opposite characteristics, a relational expression of Zn, Sn, and Al, and a relational expression of Sn and Al are important.

The present invention has been completed based on the above findings of the present inventors. that is, In order to solve the above problems, the following inventions are provided.

The discoloration-resistant copper alloy according to the first aspect of the present invention contains 17 to 34 mass% of Zn, 0.01 to 2.5 mass% of Sn, 0.005 to 1.8 mass% of Al, and 0.0005 to 0.030 mass% of Pb, and the remainder contains Cu. And inevitable impurities, the content of Zn [Zn] mass%, the content of Sn [Sn] mass%, and the content of Al [Al] mass% have 24 [Zn]+5×[Sn]+3×[Al] 40 relationship, and the content of Sn [Sn] mass% and the content of Al [Al] mass% have 1.2 [Sn]+2×[Al] In the relationship of 4.0, the discoloration-resistant copper alloy is a metal structure in which the area ratio (γ)% of the γ phase of the α phase matrix and the area ratio (β)% of the β phase have 0. 2×(γ)+(β) In the relationship of 1.5, a γ phase having an area ratio of 0 to 0.7% and a β phase of 0 to 0.9% are dispersed in the α phase matrix.

In the discoloration-resistant copper alloy according to the first aspect of the present invention, the content of Zn, Sn, Al, and Pb is within the above range, and the relationship between Zn, Sn, and Al, and the relationship between Sn and Al are respectively defined as described above. Within the range, it is brass. In addition, the discoloration resistance and the antibacterial property (bactericidal property) can be achieved, and the discoloration resistance can be improved in a state in which the excellent antibacterial property (bactericidal property) of the copper alloy is maintained.

Further, since the area ratio of the γ phase and the β phase in the α phase matrix is defined as described above, workability, discoloration resistance, and corrosion resistance can be improved.

The discoloration-resistant copper alloy according to the second aspect of the present invention contains 17 to 34 mass% of Zn, 0.01 to 2.5 mass% of Sn, 0.005 to 1.8 mass% of Al, 0.0005 to 0.030 mass% of Pb, and 0.01 to 5 mass%. Ni, the remainder contains Cu and unavoidable impurities, and the content of Zn [Zn] mass%, the content of Sn [Sn] mass%, the content of Al [Al] mass%, and the content of Ni [Ni] mass% have twenty four [Zn]+5×[Sn]+3×[Al]-0.5×[Ni] The relationship of 40, and the content of Sn [Sn] mass%, the content of Al [Al] mass%, and the content of Ni [Ni] mass% have 1.2. 0.7 × [Ni] + [Sn] + 2 × [Al] In the relationship of 4.0, the discoloration-resistant copper alloy is a metal structure in which the area ratio (γ)% of the γ phase of the α phase matrix and the area ratio (β)% of the β phase have 0. 2×(γ)+(β) In the relationship of 1.5, a γ phase having an area ratio of 0 to 0.7% and a β phase of 0 to 0.9% are dispersed in the α phase matrix.

In the second aspect of the present invention, in the discoloration-resistant copper alloy, Ni is substituted for a part of Sn and Al in the discoloration-resistant copper alloy of the first aspect described above. Here, the content of Zn, Sn, Al, Pb, and Ni is set within the above range, and the relationship between Zn, Sn, Al, and Ni, and the relationship between Sn, Al, and Ni are respectively within the above ranges. Therefore, the discoloration resistance can be improved in a state in which the excellent antibacterial property (bactericidal property) of the copper alloy is maintained. Further, by adding Ni, the discoloration resistance and the corrosion resistance can be further improved.

Further, since the area ratio of the γ phase and the β phase in the α phase matrix is specified as described above, workability, discoloration resistance, and corrosion resistance can be improved.

Further, the discoloration-resistant copper alloy according to the third aspect of the present invention further contains 0.01 to 1.0 mass% of Si and 0.01 to 0.5 mass% of Ti and 0.01 in the first and second aspect of the discoloration resistant copper alloy. ~1.5 mass% of Mn, 0.001 to 0.09 mass% of Fe, and 0.0005 to 0.03 mass% of Zr, the content of Zn [Zn] mass%, the content of Sn [Sn] mass%, and the content of Al [Al]mass%, content of Si, Ti, Ni, Mn, Fe, and Zr [Si]mass%, [Ti]mass%, [Ni]mass%, [Mn]mass%, [Fe]mass%, and Between [Zr]mass% has 24 [Zn]+5×[Sn]+3×[Al] +2.5×[Si]+1.0×[Ti]-0.5×[Ni]+0.5×[Mn]+0.2×[Fe]+0.1×[Zr 〕 40 relationship.

According to the third aspect of the present invention, the discoloration-resistant copper alloy is appropriately added with elements such as Si, Ti, Mn, Fe, and Zr within the above range depending on the intended use, whereby desired characteristics can be obtained. Resin-resistant copper alloy. Further, even when these elements are added, the relationship between Zn, Sn, Al, Ni, Si, Ti, Mn, Fe, and Zr can be set within the above range to maintain excellent antibacterial properties of the copper alloy. The state of (bactericidal) improves the discoloration resistance.

Further, the discoloration-resistant copper alloy according to the fourth aspect of the present invention further contains 0.005 to 0.09 mass% of P and 0.01 to 0.09 mass% of Sb and 0.01 in the first to third aspect of the discoloration resistant copper alloy. Any one or more of As of 0.00.0 mass% and Mg of 0.001 to 0.03 mass%.

According to the fourth aspect of the present invention, the discoloration-resistant copper alloy is appropriately added with elements such as P, Sb, As, and Mg within the above range depending on the intended use, whereby discoloration having desired characteristics can be obtained. Copper alloy. Further, since the content of these elements is relatively small, and the influence on the antibacterial property (bactericidal property) and the discoloration resistance is small, it is not necessary to consider the relationship with Zn, Sn, Al, or the like.

The discoloration-resistant copper alloy according to the fifth aspect of the present invention is used in the form of a welded pipe, a forged product, or a casting in the above-described first to fourth aspect of the discoloration-resistant copper alloy.

The discoloration-resistant copper alloy according to the fifth aspect of the present invention is used in the form of a welded pipe, a forged product, or a casting, and can be widely applied as a member of various products.

In the discoloration-resistant copper alloy according to the sixth aspect of the present invention, in the discoloration-resistant copper alloy of the first to fifth aspects, the viable cell rate after 10 minutes in the antibacterial test is equal to or lower than the viable cell rate of pure copper. .

The discoloration-resistant copper alloy according to the sixth aspect of the present invention has the same antibacterial property as or superior to pure copper, and can be applied to medical institutions, public facilities, and sanitary management facilities (for example, foods, cosmetics, and pharmaceuticals). The components of the product used in, etc.).

The copper alloy member of the present invention is configured by joining a base material composed of a discoloration-resistant copper alloy formed of the discoloration-resistant copper alloy in the first to fifth aspects described above to another member. The other members are, for example, the discoloration-resistant copper alloy of the present invention and general copper and copper alloys, iron steel materials, metal materials such as stainless steel and aluminum alloy, resins, wood, and the like, and products using the discoloration-resistant copper alloy are used according to the purpose. The material of the various components.

In the copper alloy member having such a configuration, since the above-described discoloration-resistant copper alloy is used as a substrate, discoloration of the substrate can be suppressed, and the antibacterial property (bactericidal property) is excellent, and it can be used for various purposes.

Specific examples of the copper alloy member of the present invention include a door handle, a door handle, a door push plate, an armrest, a bed fence, a side panel, a table top, a chair backrest, a member for nursing the handle of the handcart, a grip of the pen, and a keyboard. , mouse, sink, rings, building materials, etc.

According to the present invention, it is possible to provide a color tone having a yellow color (brass color), and excellent workability such as hot workability, cold workability, and punchability, and discoloration resistance excellent in both discoloration resistance and antibacterial property (bactericidal property). Copper alloy and use The copper alloy member of the discoloration resistant copper alloy.

Hereinafter, the discoloration-resistant copper alloy according to the embodiment of the present invention will be described. Further, in the present specification, the element mark with parentheses as in [Zn] indicates the content (mass%) of the element.

Further, in the present embodiment, a plurality of composition indexes are defined as follows using the method of expressing the content. Further, in the composition index f1, when the content of each of the unadded elements and Sn, Al, Si, Ti, Ni, Mn, Fe, and Zr is less than 0.01 mass%, it is considered that the value of the composition index f1 is hardly affected. , set to []=0.

Composition index f1=[Zn]+5×[Sn]+3×[Al]+2.5×[Si]+1.0×[Ti]-0.5×[Ni]+0.5×[Mn]+0.2×[Fe]+ 0.1×[Zr]

Composition index f2=[Sn]+2×[Al]

Composition index f3=0.7×[Ni]+[Sn]+2×[Al]

Composition index f4=[Sn]×[Al]+0.1×[Ni]

The discoloration-resistant copper alloy according to the first embodiment of the present invention contains 17 to 34 mass% of Zn, 0.01 to 2.5 mass% of Sn, 0.005 to 1.8 mass% of Al, and 0.0005 to 0.030 mass% of Pb, and the remainder contains Cu. And inevitable impurities, the content of Zn [Zn] mass%, the content of Sn [Sn] mass%, and the content of Al [Al] mass% have 24 [Zn]+5×[Sn]+3×[Al] 40 relationship, and the content of Sn [Sn] mass% and the content of Al [Al] mass% have 1.2 [Sn]+2×[Al] The relationship of 4.0. That is, in the discoloration-resistant copper alloy of the first embodiment, the composition index f1 is set at 24 F1 Within the range of 40, the composition index f2 is set at 1.2. F2 Within the scope of 4.0.

In addition, the discoloration-resistant copper alloy according to the first embodiment having the above composition is referred to as a first invention alloy.

The discoloration-resistant copper alloy according to the second embodiment of the present invention contains 17 to 34 mass% of Zn, 0.01 to 2.5 mass% of Sn, 0.005 to 1.8 mass% of Al, 0.0005 to 0.030 mass% of Pb, and 0.01 to 5 mass%. Ni, the remainder contains Cu and unavoidable impurities, and the content of Zn [Zn] mass%, the content of Sn [Sn] mass%, the content of Al [Al] mass%, and the content of Ni [Ni] mass% have twenty four [Zn]+5×[Sn]+3×[Al]-0.5×[Ni] The relationship of 40, and the content of Sn [Sn] mass%, the content of Al [Al] mass%, and the content of Ni [Ni] mass% have 1.2. 0.7 × [Ni] + [Sn] + 2 × [Al] The relationship of 4.0. Further, in the present embodiment, it has 0.3 [Sn] × [Al] + 0.1 × [Ni] The relationship of 1.4. That is, in the discoloration-resistant copper alloy of the second embodiment, the composition index f1 is set at 24 F1 Within the range of 40, the composition index f3 is set at 1.2. F3 Within the scope of 4.0.

In addition, the discoloration-resistant copper alloy of the second embodiment having the above composition is referred to as a second invention alloy.

The discoloration-resistant copper alloy according to the third embodiment of the present invention further contains 0.01 to 1.0 mass% of Si, 0.01 to 0.5 mass% of Ti, and 0.01 to 1.5 mass% of Mn in the first and second invention alloys. 0.001 to 0.09 mass% of Fe, 0.0005 to 0.03 mass% of Zr, and the content of Zn [Zn] mass%, Sn content [Sn] mass%, Al content [Al] mass%, Contents of Si, Ti, Ni, Mn, Fe, and Zr [Si]mass%, [Ti]mass%, [Ni]mass%, [Mn]mass%, [Fe]mass%, and [Zr]mass% Between 24 [Zn]+5×[Sn]+3×[Al]+2.5×[Si]+1.0×[Ti]-0.5×[Ni]+0.5×[Mn]+0.2×[Fe]+0.1×[Zr 〕 40 relationship. That is, in the discoloration-resistant copper alloy according to the third embodiment, the composition index f1 is set at 24 F1 Within the range of 40. Further, the composition indexes f2 and f3 are respectively set within the ranges defined in the first embodiment or the second embodiment described above.

In addition, the discoloration-resistant copper alloy according to the third embodiment having the above composition is referred to as a third invention alloy.

The discoloration-resistant copper alloy according to the fourth embodiment of the present invention further contains 0.005 to 0.09 mass% of P, 0.01 to 0.09 mass% of Sb, 0.01 to 0.09 mass% of As, and the alloy of the first to third inventions. 0.001 to 0.03 mass% of any one of Mg or more. Here, since P, Sb, and As are small in content and have little influence on characteristics, the composition index f1 is not considered. Therefore, in the discoloration-resistant copper alloy according to the fourth embodiment, the above composition index f1 is also set at 24. F1 Within the range of 40. Further, the composition indexes f2 and f3 are respectively set within the ranges defined in the first embodiment or the second embodiment described above.

In addition, the discoloration-resistant copper alloy according to the fourth embodiment having the above composition is referred to as a fourth invention alloy.

Further, the discoloration-resistant copper alloy (the first to fourth invention alloys) according to the first to fourth embodiments of the present invention has the following metal structure: area ratio (γ)% and β phase of the γ phase of the α phase matrix. The area ratio (β)% has 0 between 2×(γ)+(β) In the relationship of 1.5, a γ phase having an area ratio of 0 to 0.7% and a β phase of 0 to 0.9% are dispersed in the α phase matrix.

Hereinafter, the reason why the component composition and the composition indexes f1, f2, f3, and f4 and the metal structure are defined as described above will be described.

(Zn: 17 mass% or more and 34 mass% or less)

Zn is a main element in the alloy of the present invention, which has improved mechanical strength such as tensile strength and endurance, discoloration resistance, and workability, and has an effect of further improving various characteristics by the synergistic effect with Sn and Al. Further, it is an element which further enhances the effect of antibacterial property (bactericidal property) and is important in securing the characteristics of the copper alloy. Further, the copper alloy containing a large amount of Zn is superior in discoloration resistance and strength to copper alloy having a high concentration of pure copper and copper, and is excellent in or superior in antibacterial property (bactericidal property). In addition, Zn is also an essential element in order to exhibit a yellow color (a yellowish hue or a brass color) of the characteristic hue of the alloy of Cu, that is, brass. According to the content of Zn, Sn, Al, etc. (the remainder of Cu), the β phase appears, and the possibility of remaining the β phase at room temperature (room temperature) is increased, and the area ratio of the β phase is different, but it is possible to produce Problems such as poor workability and corrosion resistance. In addition, depending on the cooling conditions, the γ phase is generated from the β phase by the eutectoid reaction, and when the γ phase is present in the matrix, the workability and corrosion resistance in cold rolling are the same as the β phase. Getting worse. This is also the same in the portion where the bonding by brazing and brazing is performed by high temperature heating. In addition, the welded pipe is formed into a circular shape by using a roll (model) to form a strip product (a product obtained by winding a raw material into a coil of a tape shape), and the both ends thereof are joined by welding, thereby obtaining a pipe and a welded portion. The portion is heated to a high temperature and partially exceeds the melting point. Moreover, since the material thickness (the wall thickness in the pipe) is thin, the cooling rate when air-cooled (air-cooled) after welding is faster, and the welded portion and its vicinity (the welded width is centered at a width of 10 mm (one side is 5 mm). The heat-affected part of the part) is likely to remain in the β phase. In addition, the welding of the welded pipe has a method of heating and butt welding using a high frequency induction heating coil, and borrowing Various methods such as joining a welded portion by direct TIG welding. However, the welding method is not limited to these, and any method of welding/joining can be applied to the method of being able to weld both ends of the material after the roll is formed. In brazing, there is also a method of brazing in a furnace using a conveyor belt furnace, and a method of manually brazing a brazed portion in a combustion furnace, which is called manual brazing. In any case, the brazed portion is heated to a temperature above or below the melting point of the solder, for example, a temperature of 800 degrees or more. Further, in the case of manual brazing, as in the case of welding, the heated portion is quenched, and the β phase tends to remain.

Further, although the copper alloy has excellent antibacterial property (bactericidal property), its action depends on the content of copper, and the content of copper is at least 60 mass% or more, and 70 mass% or more is preferable. However, it was confirmed in the experiment that the antibacterial property (bactericidal property) depends not only on the content of copper but also on the amount of Zn and the amount of Sn and Al. In particular, the amount of Zn is 17 mass% compared with the copper alloy having a high Cu content. The antibacterial property (bactericidal property) of the above or 20 mass% of the copper alloy is improved. In other words, in the alloy of the present invention, the antibacterial property (bactericidal property) is further improved by the effect of multiplication of a certain amount or more of Zn, Sn, and Al. Further, if the content of Zn is less than 17 mass%, the color tone of the alloy is also slightly reddish. Pure copper is a so-called red-orange copper color, but the copper-toned copper alloy has poor discoloration resistance compared to a yellow-colored brass material having a large amount of Zn. In view of the discoloration resistance, the content of Zn is approximately 20 mass% or more, and the performance is excellent in combination with the synergistic effect with Sn and Al. When placed in the same environment, it was observed that, for example, a copper-colored copper alloy exposed to light at 60 ° C and a relative humidity of 95% for 8 hours turned into a brownish-colored discoloration, and the surface became dull, whereas yellow (brass) The copper alloy maintains the metallic luster at the initial stage of exposure, and no obvious observation is observed. Discoloration or the like is improved by the Zn-containing discoloration resistance.

The content of Zn is 17.0 mass% or more, more preferably 18.0 mass% or more, more preferably 20.0 mass% or more, and most preferably 21.0 mass% or more from the viewpoint of mechanical properties, antibacterial property (bactericidal property), and color tone of the alloy.

However, if the content of Zn exceeds 34.0 mass%, more β phase appears in hot rolling (material temperature is high temperature), which contributes to workability in hot rolling, and on the other hand, ductility and bending in cold rolling The properties, corrosion resistance, stress corrosion cracking resistance, and discoloration resistance are deteriorated, and the antibacterial property (bactericidal property) is also saturated or worse. Further, in the case of manufacturing a welded pipe or during brazing, a β phase tends to occur, and there is a high possibility that a large γ phase exists. The content of Zn is preferably 32.0 mass% or less, more preferably 30.0 mass% or less and 28.0 mass% or less. In addition, when the content of Zn is less than 17.0 mass% (the content of Cu is increased), the mechanical strength is lowered, and the workability and moldability in hot rolling are deteriorated, depending on the contents of Sn, Al, etc., but The antibacterial property (bactericidal property) is deteriorated. Further, the burrs at the time of cold working such as press working in cold rolling become large.

These various characteristics have a large influence on the composition index f1 to be described later, and the workability, corrosion resistance, discoloration resistance, mechanical strength, and the like also vary depending on the value of the index.

(Sn: 0.01 mass% or more and 2.5 mass% or less)

Sn not only has a large effect on the discoloration resistance, but also has an effect of easily generating β at the high temperature and reducing the deformation resistance at a high temperature. In addition, it also contributes to the punching properties such as corrosion resistance, mechanical strength, and press working. However, in the Cu-Zn alloy containing Sn, the γ phase increases, and the presence of the γ phase affects the rolling properties, workability, corrosion resistance, and discoloration resistance in cold rolling. When copper alloy is packaged When Sn is contained, for example, when it is observed from a corrosive surface such as tap water, an oxide of Sn or the like is preferentially formed in a severe environment, and a composite oxide with an oxide of copper or another element acts as a stable protective film. This plays a large role in corrosion resistance. The formation of the oxide is corrosion, that is, the material is discolored, so the oxide of Sn also affects the discoloration. When used in the atmosphere, Sn is also preferentially formed as an oxide or a component in the atmosphere (a compound having corrosive sulfur oxides and chlorides) as such a compound. However, in the atmosphere, unlike water, it is not formed by a thick film but by an extremely thin film. Therefore, it is visually confirmed that a large change in color tone is not observed. The discoloration resistance is improved by the protective effect of the film. If the protective effect of the film is too strong, the antibacterial property (bactericidal property) may be affected. However, the above discoloration resistance or antibacterial property (bactericidal property) is added together with Al in the presence of an appropriate amount of Zn. Further improvement is made, and the balance of components based on the composition index f1 and the like becomes important.

In order to exhibit the above effects, Sn needs to be 0.01 mass% or more, preferably 0.1 mass% or more, more preferably 0.3 mass% or more, and most preferably 0.5 mass% or more. On the other hand, when it is less than 0.01 mass%, the effects of discoloration resistance and antibacterial property (bactericidal property) are small, and the effects on mechanical strength, corrosion resistance, and the like are also small.

On the other hand, when the content of Sn exceeds 2.5 mass%, not only the discoloration resistance and the corrosion resistance are saturated, but also the γ phase at a normal temperature (the β phase at a high temperature is increased), and the weldability including the welded pipe is exhibited. Cold workability, bending workability in cold rolling, corrosion resistance, and the like are deteriorated. Therefore, the content of Sn is 2.5 mass% or less, preferably 2.0 mass% or less, more preferably 1.8 mass% or less, and 1.5 mass% or less. The best. Further, the relationship between the discoloration resistance, the antibacterial property (bactericidal property), and the structure (β phase, γ phase) is closely related to the composition indexes f1 and f2 described later, and in particular, the relationship formula with Al is the composition index f2, f3, and f4. It is an important factor for various characteristics. Although the effect of the single effect is small, the multiplication effect by the coexistence with Al is high, and various characteristics such as discoloration resistance and antibacterial property (bactericidal property) are improved in the composition range satisfying the relationship of f2.

Further, Sn has almost no influence on the color tone within a preferred range within the range specified above.

(Al: 0.005 mass% or more and 1.8 mass% or less)

Al has a great effect on the discoloration resistance similarly to Sn. The formation of an Al-based oxide is one of the active elements which are less energy-intensive and easily oxidized. An extremely thin oxide film is formed on the surface by the addition of Al, whereby the discoloration resistance is improved. On the other hand, when a thin oxide film is formed on the surface and the discoloration resistance is improved, the antibacterial property (bactericidal property) may be hindered, but the antibacterial property (bactericidal property) can be maintained by the combination of Zn and Sn which are appropriately blended. Not damaged. Further, there is an effect of increasing the occurrence of the β phase at a high temperature, and also contributes to deformation resistance and deformation energy at a high temperature, and the strength is also improved. However, although it depends on the Zn and Sn contents, the addition of Al makes the β phase easy to form, and thus there is a possibility that the workability in cold rolling causes a problem. In addition, the viscosity of the molten metal is lowered by the addition of Al, the castability is improved, and the effect of the vapor of Zn generated during casting and welding is suppressed. Similarly, the weldability at the time of welding can be improved, and a strong welded pipe or joined structure can be obtained. On the other hand, if a large amount of Al is contained, an oxide film is easily formed, but the oxide film is strongly thickened, and the presence of the film restricts the display of antibacterial property even if the bacteria adhere to the surface (sterilization) The contact between the base material (blank) of the copper alloy and the bacteria, and the antibacterial property (bactericidal property) is lowered. Further, when it is actually used in the atmosphere or the like, corrosion of a surface such as oxidation occurs, and the oxide film formed on the surface by the etching contributes to discoloration resistance, but the antibacterial property (bactericidal property) is further deteriorated. Conditions may not show antibacterial (bactericidal). When a large amount of Al is contained during welding, the weldability is deteriorated by the formation of a strong oxide film (oxide) of Al.

In order to exhibit the above effects, Al needs to be 0.005 mass% or more, preferably 0.1 mass% or more, more preferably 0.3 mass% or more, and most preferably 0.4 mass% or more. On the other hand, when it is less than 0.005 mass%, the oxide film formed on the surface is reduced, and the effect of discoloration resistance is small.

On the other hand, when the content of Al exceeds 1.8 mass%, the discoloration resistance is improved by the formation of a strong oxide film, but the antibacterial property (bactericidal property) or weldability is inhibited. 1.7 mass% or less is preferred, 1.6 mass% or less is more preferable, and 1.5 mass% or less is most preferable. Further, similarly to Sn, the composition indexes f1, f2, f3, and f4 have a large influence on characteristics, organization, and the like.

Further, Al has almost no influence on the color tone within a preferred range within the range specified above.

(Pb: 0.0005 mass% or more and 0.030 mass% or less)

Pb is contained in order to improve workability such as shearing and polishing such as press. In the Cu-Zn-Sn-Al alloy in which the metal structure is α single phase, Pb hardly dissolves at room temperature. Zn, Sn, Al, etc. (the remainder is Cu) within the above composition range, the composition index f1, f2 are in the appropriate range, during cooling after hot rolling or hot pressing, cooling during heat treatment, or welding of welded tubes Pb is mainly precipitated at the grain boundary after cooling of the heated portion after post-forging and after brazing. The Pb Since it is finely precipitated in the form of Pb particles, workability such as shearing and polishing such as press is improved.

In order to exhibit the above effects, Pb is preferably 0.0005 mass% or more, and 0.001 mass% or more is preferable. On the other hand, when the content of Pb is too large, the alloy has poor influence on the ductility, hot rolling properties, weldability, flat workability of the welded pipe, and bendability. The content of Pb is 0.030 mass% or less, preferably 0.015 mass% or less, more preferably 0.009 mass% or less. In particular, Pb is a hazardous substance and therefore less desirable.

Next, Ni added to the alloy of the second invention will be described.

(Ni: 0.01 mass% or more and 5 mass% or less)

In addition to ensuring discoloration resistance, the Ni system also suppresses the formation of important elements of the β phase and the γ phase generated during welding and hot working. The effect of the discoloration resistance by Ni instead of the Sn and Al described above. That is, Sn and Al improve the discoloration resistance by forming a stable film such as an oxide on the surface of the material, but Ni also forms a composite oxide with Cu and other elements to contribute to discoloration resistance. Although depending on the amount of Ni added, even if Ni is added separately to the Cu-Zn alloy, the effect of improving the discoloration resistance is lower than that of Sn and Al, which contributes to discoloration resistance by co-addition with Sn and Al. .

Here, when the content of Ni exceeds a certain amount, it is related to the deterioration of fluidity during casting and the amount of Sn, Al, and Zn. However, surface cracking and edge cracking of hot rolling may occur, and hot workability may change. difference. In addition, the press formability is lowered, and the possibility of causing allergies (Ni allergies) is increased, and the color of the brass is far from the difference, and it becomes white. However, if the content of Ni is small, the effect of improving discoloration resistance is small. Therefore, when Ni is added, the content of Ni is 0.01 mass% or more, and 0.3 mass% or more is preferable. In particular, when the effect of Sn and Al is replaced by Ni, when the total content of Sn and Al is 0.02 mass% or more and 0.5 mass% or less (the content of Sn [Sn] mass% and Al content [Al] is 0.02. [Sn]+[Al] 0.5), the content of Ni for obtaining characteristics such as good discoloration resistance is preferably 1.5 mass% or more. When Sn and Al and Ni are added together, the discoloration resistance and the like are exhibited. However, when the content of Sn and Al is small, if the Ni content is also decreased, the effect on the discoloration resistance is reduced, and the Ni content is set to 1.5 mass% or more, the amount of decrease in the effect of Sn and Al on discoloration resistance and the like can be compensated by the addition of Ni.

On the other hand, the content of Ni is 5.0 mass% or less from the viewpoint of Ni allergies or hot rolling properties of a copper alloy having a brass color. 4.0 mass% or less is preferred, and 3.0 mass% or less is most preferred. Further, Ni contributes less to the antibacterial property (bactericidal property), and the composition indexes f1, f3, and f4 indicating the mixing ratio with Zn, Al, and Sn become important.

Next, Si, Ti, Mn, Fe, and Zr added to the alloy of the third invention will be described.

(Si: 0.01 mass% or more and 1.0 mass% or less)

The addition of Si has an effect of increasing the β phase at a high temperature, and the deformation resistance and the deformation energy at a high temperature are increased. However, if a large amount is contained, the β phase is increased, and a large amount of β phase remains at normal temperature (room temperature). By adding together with Sn and Al, γ is also increased (also affected by cooling conditions). Moreover, the mechanical strength is also improved, but the elongation is lowered, and the balance between the strength and the elongation is deteriorated. When it is 0.01 mass% or less, the effect of discoloration resistance is small, and when it is more than 1.0 mass%, it is effective in discoloration resistance, but not only the β phase is precipitated, but It also deteriorates the balance between mechanical strength and elongation.

From the above, when Si is added, the content of Si is preferably 0.01 mass% or more and 1.0 mass% or less, and preferably 0.01 mass% or more and 0.5 mass% or less.

(Ti: 0.01 mass% or more and 0.5 mass% or less)

Ti does not dissolve much in the Cu-Zn-Sn-Al alloy but forms a part of precipitates such as Ti ₂ Cu. Although the addition of Ti contributes to the discoloration resistance, when a large amount is present, the amount of precipitates increases, and although the strength is contributed, the elongation value decreases. Further, the entrapment of the oxide during casting is a problem, and a special melting method such as vacuum melting is required. When the amount is less than 0.01 mass%, the effect of discoloration resistance is small, and if it exceeds 0.5 mass%, the mechanical properties may be deteriorated, and the casting yield is also deteriorated.

From the above, when Ti is added, the content of Ti is preferably 0.01 mass% or more and 0.5 mass% or less, and preferably 0.01 mass% or more and 0.2 mass% or less.

(Mn: 0.01 mass% or more and 1.5 mass% or less)

Mn is a person who improves strength and wear resistance and improves flexibility and punchability. On the other hand, if the content of Mn is too large, hot rolling properties are inhibited. Further, Mn alone has a small effect on discoloration resistance or antibacterial property (bactericidal property), and depending on the case, the antibacterial property (bactericidal property) may be inhibited, and the mixing ratio with Cu, Zn, Al, and Sn becomes important ( Composition index f1). Further, by containing Mn, the fluidity of the molten metal can be improved. From these viewpoints, when Mn is added, the content of Mn is preferably 0.01 to 1.5 mass%, and preferably 0.1 to 1.0 mass%. Further, the co-addition of Mn and Si forms a compound of Mn-Si, which hinders cold workability, and therefore it is necessary to avoid this. When Si and Mn are simultaneously added, it is preferable to set Si to 0.05 mass% or less and Mn to 0.5 mass% or less.

(Fe: 0.001 mass% or more and 0.09 mass% or less)

Fe has an effect of refining crystal grains during annealing. In particular, the crystal grains of the welded portion of the welded pipe are made thinner, and high strength can be obtained in the welded pipe. When the welded pipe is subjected to bending, the surface is not It becomes rough and becomes a smooth state. In order to obtain such an effect, Fe needs to be 0.001 mass% or more. Further, even if it is contained in an amount exceeding 0.09 mass%, the above-described effects are saturated, and the workability in cold rolling is rather lowered.

From the above, when Fe is added, the content of Fe is 0.001 mass% or more and 0.09 mass% or less.

(Zr: 0.0005 mass% or more and 0.03 mass% or less)

Zr has an effect of refining the hot-rolled material and the crystal grains during annealing, and in particular, by improving the weldability by co-addition with P, the crystal grains of the welded portion of the welded pipe are made thinner, and the welded pipe can be made higher. The strength at the time of performing the bending process does not become rough and becomes a smooth state. In order to obtain such an effect, Zr needs to be 0.0005 mass% or more. Further, even if it is contained in an amount of 0.03 mass% or more, the above-described effects are saturated, and when it is cast, it is introduced in the form of an oxide, which causes adverse effects such as casting defects.

From the above, when Zr is added, the content of Zr is 0.0005 mass% or more and 0.03 mass% or less.

Next, P, Sb, As, and Mg added to the alloy of the fourth invention will be described.

(P: 0.005 mass% or more and 0.09 mass% or less)

P improves corrosion resistance and improves fluidity of molten metal. In order to exert this effect, the content of P needs to be set to 0.005 mass% or more. And, excessive P The content adversely affects the ductility in cold rolling and hot rolling, so the content of P is set to 0.09 mass% or less.

From the above, when P is added, the content of P is 0.005 mass% or more and 0.09 mass% or less.

(Sb: 0.01 mass% or more and 0.09 mass% or less)

Like P, Sb is also added to improve corrosion resistance. In order to obtain this effect, the content of Sb needs to be 0.01 mass% or more. Further, even if it contains an amount of 0.09 mass%, the effect corresponding to the content is not obtained, and the ductility is rather lowered. Further, since Sb may adversely affect the human body, the content is preferably 0.05 mass% or less.

From the above, when Sb is added, the content of Sb is preferably 0.01 mass% or more and 0.09 mass% or less, and preferably 0.01 mass% or more and 0.05 mass% or less.

(As: 0.01 mass% or more and 0.09 mass% or less)

Like P, As is added for the purpose of improving corrosion resistance. In order to obtain this effect, the content of As needs to be 0.01 mass% or more. Further, even if it contains an amount exceeding 0.09 mass%, the effect corresponding to the content is not obtained, and the ductility is rather lowered. Further, since As may have an adverse effect on the human body, the content is preferably 0.05 mass% or less.

From the above, when As is added, the content of As is 0.01 mass% or more and 0.09 mass% or less, and 0.01 mass% or more and 0.05 mass% or less is preferable.

(Mg: 0.001 mass% or more and 0.03 mass% or less)

The use of scrap as a part of the raw material in the copper alloy is often the case, and the S (sulfur) component is sometimes contained in the scrap. When the scrap containing the S component is used as an alloy raw material to manufacture a product, Mg can remove S in the form of MgS. Ingredients. Even if the MgS remains in the alloy, it does not adversely affect corrosion resistance, discoloration resistance, and the like. Further, when the S component is in the form of MgS, the punchability is improved. If the plastic containing the S component is used without adding Mg, S tends to exist in the grain boundary of the alloy, which may contribute to grain boundary corrosion, and thus, corrosion resistance and discoloration resistance are also lowered. However, it is possible to effectively prevent grain boundary corrosion by adding Mg. In order to exert this effect, the content of Mg needs to be set to 0.001 to 0.03 mass%. Since Mg is easily oxidized, if it is excessively added, it is oxidized during casting to form an oxide, whereby the viscosity of the molten metal is increased, and casting defects such as entrapment of oxide may occur.

From the above, the content of Mg when Mg is added is 0.001 mass% or more and 0.03 mass% or less.

(Cu: the remaining part)

The residual components of Cu-based Zn, Sn, and Al (excluding unavoidable impurities) are included for the balance of these main elements. Cu is an element that is important for improving the mechanical strength such as tensile strength and endurance of a copper alloy and ensuring properties such as antibacterial property (bactericidal property). Although it is a residual component, the content of Cu for exhibiting various characteristics is 64.0 mass% or more, 65.0 mass% or more is preferable, 70.0 mass% is more preferable, and 72.0 mass% or more is most preferable. On the other hand, when the content of Cu exceeds 81.0 mass%, the mechanical strength is lowered, and workability such as hot rolling properties and moldability is deteriorated, and not only the antibacterial property (bactericidal property) is deteriorated, but also the discoloration resistance is lowered. Further, the content of Cu is 81.0 mass% or less, preferably 80.0 mass% or less, more preferably 78.0 mass%, and most preferably 77.0 mass% or less.

(inevitable impurities)

Further, examples of the unavoidable impurities include Cr, Ag, Ca, Sr, Ba, Sc, Y, Hf, V, Nb, Ta, Mo, W, Re, Ru, Os, Se, Te, Rh, and Ir. , Pd, Pt, Au, Cd, Ga, In, Li, Ge, Tl, Bi, S, O, Be, N, H, Hg, B and rare earths. It is preferable to contain such inevitable impurities in an amount of 0.5 mass% or less based on the total amount. When a large amount of unavoidable impurities are contained in an amount of 0.5 mass% or more based on the total amount, the metal structure is affected, and corrosion resistance, antibacterial property (bactericidal property), and the like are lowered, and the elongation is lowered to cause cold working. The property is lowered, and the deformation resistance in hot rolling is increased, etc., and therefore it is not preferable. In addition, it is inevitable that the impurities represent elements that are deliberately not included.

(composition index f1)

The content of Zn [Zn] mass%, the content of Sn [Sn] mass%, the content of Al [Al] mass%, the content of each of Si, Ti, Ni, Mn, Fe, and Zr [Si] mass%, [Ti 】mass%, [Ni]mass%, [Mn]mass%, [Fe]mass%, and [Zr]mass%, the relationship obtained by multiplying each element by a factor and the numerical value thereof in the welded pipe, The area ratio of the β phase and the γ phase existing in the metal structure of the plate, the rod, the forged part, and the casting is affected, and the cold workability (plastic processing such as cold rolling and cold drawing), the bending workability of the welded pipe and the plate, Strength, corrosion resistance, discoloration resistance, and antibacterial property (bactericidal property) have an effect. Thereby, the composition index f1 is an important relational expression that comprehensively quantifies these characteristics and properties.

If the value of the composition index f1 is less than 24, the deformation resistance in hot rolling such as hot rolling, hot pressing or hot forging is increased. Further, the strength of the material is low, and the discoloration resistance is also lacking, and the press workability is also deteriorated. In hot rolling, heating is predetermined by a rolling mill The ingot of temperature (for example, a plate thickness of 190 mm) is rolled to gradually reduce the thickness of the plate. However, in a rolling mill having a small power, since the deformation resistance is large, the processing rate in one large rolling pass cannot be taken. Therefore, the number of rolling passes of the processing bar is increased, and the material is thinned and the material length becomes long in the latter half of the hot working (when the hot rolling is performed until the final thickness becomes about 12 mm, the hot rolling is 25 mm or less). The hot rolling process takes a long time. Therefore, the temperature drop of the material is increased, and the deformation resistance is increased, so that it is not possible to increase the load of the rolling mill, and it is not possible to obtain a desired thin and thick material and the like, which adversely affects the hot rolling property. Further, when the content of each element represented by Zn, Sn, and Al and the total aggregate content obtained by weighting each element are low, the discoloration resistance is not sufficient. Similarly, the antibacterial property (bactericidal property) is also poor. Further, the workability at the time of shearing such as press working such as burrs is likely to occur. Moreover, the strength of the material is lowered, and when it is used for a member requiring strength, it is necessary to thicken the thickness of the material, and there is also a problem in terms of cost. Further, when the value of the composition index f1 is low, the thermal conductivity is improved, the weldability is deteriorated, the mechanical strength is lowered, and the balance with the ductility is deteriorated. The copper alloy has good thermal conductivity. If the thermal conductivity (instead of electrical conductivity, the thermal conductivity is proportional to the electrical conductivity, that is, the electrical conductivity), the heat is diffused during welding or brazing. Since it is necessary to perform heating over a wide range, weldability/brakeability is deteriorated. In order to perform good soldering and brazing, it is preferable to convert the conductivity to 25% or less.

As described above, from the viewpoints of hot rolling properties, press workability, and strength, the value of the composition index f1 is 24 or more, 26 or more is preferable, and 28 or more is more preferable, and 29 or more is preferable.

If the value of the composition index f1 exceeds 40, hot rolling, hot pressing, tube welding, and heat The area ratio of the β phase in the high temperature state such as forging increases, and the area ratio of the β phase and the γ phase at normal temperature (room temperature) also increases. Therefore, the strength of the material is improved, but the balance between the strength of the material (tensile strength) and the elongation is deteriorated, and M1 = σ × (1 + ε / 100) as a relational expression (σ is a value indicating tensile strength, ε To indicate the value of the stretch rate) becomes smaller. In addition, the hot rolling deformation resistance value is small and the hot workability is improved by the increase in the β phase, but the β phase and the γ phase remain in the structure at normal temperature (room temperature), whereby the cold workability is remarkably lowered. In the processing such as cold rolling and cold-rolling drawing, and in cold rolling such as bending work of pipes and sheets, the ductility is lowered, and cracking occurs during processing, or a sufficient processing rate or the like is not obtained. Further, the corrosion resistance, that is, the dezincification resistance and the stress corrosion cracking property are deteriorated. Similarly, when the numerical value becomes the upper limit, the discoloration resistance is not saturated, but falls. In addition, the characteristic of the copper alloy, that is, the antibacterial property (bactericidal property) is not saturated, but decreases.

Further, the welded pipe is manufactured by resistance electric welding, but the weldability is deteriorated, and the yield at the time of manufacturing the welded pipe is deteriorated. Further, the temperature of the welded pipe locally rises, and the thickness of the pipe becomes thin as it is melted, and the area ratio of the β phase and the γ phase which are occupied by the metal structure of the welded pipe is increased due to the rapid cooling rate. The welded pipe is sometimes used by applying a 90° bend (for example, a radius of curvature of 40 mm) and a complicated bending process, causing a problem that the bent portion is broken or cannot be processed into a predetermined curved shape. In the bending process, if the bending portion is heated or the like, the bending process can be performed without causing cracking, but the strength of the portion is lowered. Further, since the portion to be heated is annealed, the crystal grain size is grown, and problems such as roughness, strength, and fatigue may occur during bending. Moreover, resistance to discoloration, corrosion and antibacterial (sterilization Sexuality) also deteriorates, which in turn leads to disadvantages such as increased costs. Further, in the manufacture of the welded pipe, if the value of the composition index f1 is higher than 40, the β phase or the γ phase remains in the joint portion and the portion of the heat to be welded, and the subsequent manufacturing process is cold rolling and cold. There is a problem in pulling. Further, the discoloration resistance and the antibacterial property (bactericidal property) are deteriorated.

As described above, in consideration of discoloration resistance, antibacterial property (bactericidal property), cold workability, flexibility, and the like, the composition index f1 has a value of 40 or less, 38 or less is preferable, 36 or less is more preferable, and 34 or less is most preferable. On the other hand, in consideration of hot rolling properties, press workability, and strength, the value of f1 is 24 or more, 26 or more is preferable, and 28 or more is more preferable, and 29 or more is most preferable.

That is, the composition index f1 is set at 24 F1 Within the range of 40, set at 26 F1 38 is preferred, located at 28 F1 Further within the scope of 36 is set at 29 F1 The range of 34 is the best.

However, in the composition index f1, a large coefficient is given to Sn and Al. The main reason is that both Sn and Al have a large influence on discoloration resistance, corrosion resistance, and antibacterial property (bactericidal property), and Sn is segregated during local melting at the time of welding, and a small amount of segregation occurs. The β phase and the γ phase remain in the Sn, and the amount of the β phase and the γ phase increases while the concentration increases. Further, in the hot working, the β phase and the γ phase are likely to remain. Further, since the β phase containing a large amount of Sn and the γ phase are weak and hard, the cold workability and the bending workability are affected. Al exhibits the same tendency as Sn on the metal structure, but to a lesser extent, the weldability has a positive effect, and the influence of Sn is alleviated. In particular, the multiplication effect of Sn and Al is imparted to each of the properties including the discoloration resistance and the antibacterial property (bactericidal property) which are the subject of the present invention.

In the addition of Ni in the alloy of the second invention, the coefficient of the composition index f1 is small, Negative. Compared with the effect of multiplication of Sn and Al, the discoloration resistance is small but has a certain effect, and therefore depends on the content of Ni. Further, Ni has an effect of suppressing the formation of the β phase and the γ phase during the hot working and the welding based on Sn and Al. In particular, when the composition index f1 shows a large value, Sn and Al are contained instead of Sn, thereby maintaining discoloration resistance, and it can be utilized for the suppression of the formation of the β phase and the γ phase. The coefficient is small, and its effect seems to be small. However, by effectively using Ni, workability can be improved, and discoloration resistance and antibacterial property (bactericidal property) can be improved.

Further, among the Si, Ti, Mn, Fe, and Zr added to the alloy of the third invention, various properties such as workability, discoloration resistance, and antibacterial property (bactericidal property) are affected. Therefore, in the composition index f1, Each element is multiplied by a coefficient and added.

On the other hand, the content of P, Sb, As, and Mg added to the alloy of the fourth invention is smaller than that of other elements, and has a large influence on mechanical properties, corrosion resistance, discoloration resistance, and the like. The influence of the organization is small (i.e., the coefficient is 0 or a number close to 0), and therefore is not included in the relationship constituting the index f1.

Further, regarding the impurities which are inevitably contained, when the total amount of impurities is less than 0.5 mass%, there is almost no influence on the composition index f1. When the total unavoidable impurity mass exceeds 0.5 mass%, the content of unavoidable impurities is set to [X] mass%, f1 = [Zn] + 5 × [Sn] + 3 × [Al] + 2.5 × [Si] +1.0 × [Ti] - 0.5 × [Ni] + 0.5 × [Mn] + 0.2 × [Fe] + 0.1 × [Zr] + [X] The value is set at 24 F1 Within 40 limits.

(composition index f2)

Although Sn and Al are also related to the amount of Zn, the value of the composition index f2 is based on Al: 0.01 to 1.8 mass%, and Sn: 0.01 to 2.5 mass%, with Al. The synergistic effect with Sn has a large influence on discoloration resistance, corrosion resistance, and antibacterial property (bactericidal property), and thus affects the weldability, hot workability, cold workability, bending workability, and press working. Processability.

When the value of the composition index f2 = [Sn] + 2 × [Al] is less than 1.2, the discoloration resistance is not greatly affected, the punching property such as press working is deteriorated, and the antibacterial property (bactericidal property) is also deteriorated. . On the other hand, when the value of the composition index f2 exceeds 4.0, the discoloration resistance is improved, but the antibacterial property (bactericidal property) is lowered, and the weldability, hot workability, cold workability, and bending workability are also lowered. Further, when Al and Sn are added together, Al is imparted with a coefficient larger than Sn because a small amount of Al contains an effect particularly on discoloration resistance, but as a large amount of Al is contained, antibacterial property (bactericidal property) starts to be impaired. From the viewpoint of such characteristics, the value of f2 is preferably 1.3 or more, more preferably 1.5 or more. Further, 3.5 or less is preferable, and 3.2 or less is more preferable. In addition, from the viewpoint of the effect of multiplication of Al and Sn, if it contains 0.4 mass% or more of Al and 0.5 mass% or more of Sn, respectively, it has a remarkable effect.

That is, the composition index f2 is set at 1.2. F2 Within the scope of 4.0, set at 1.3 F2 The range of 3.5 is better, set at 1.5 F2 Further within the scope of 3.2 is further preferred.

Further, regarding the impurities which are inevitably contained, when the total amount of impurities is less than 0.5 mass%, there is almost no influence on the composition index f2. Even when the total unavoidable impurity amount exceeds 0.5 mass%, the composition index f2 is within the above range.

(composition index f3)

For example, in the alloy of the second invention, when a part of Al or Sn is replaced by Ni, if the composition index f3 = 0.7 × [Ni] + [Sn] + 2 × [Al] is 1.2. F3 In the range of 4.0, the alloy is excellent in discoloration resistance, corrosion resistance, and antibacterial property (bactericidal property), and is excellent in punching workability such as hot workability, cold workability, bending workability, and press working. Further, from the composition index f3, it is understood that Ni has a lower effect of discoloration resistance and the like than Al and Sn, and it is necessary to contain a large amount of Ni, but the coefficient is small.

Similarly to the composition index f2, the composition index f3 is 1.2 or more, and 1.3 or more is preferable, and 1.5 or more is more preferable from various characteristics. On the other hand, it is 4.0 or less, 3.5 or less is preferable, and 3.2 or less is more preferable.

That is, the composition index f3 is set at 1.2. F3 Within the scope of 4.0, set at 1.3 F3 The range of 3.5 is better, set at 1.5 F3 Further within the scope of 3.2 is further preferred.

Further, regarding the impurities which are inevitably contained, when the total amount of impurities is less than 0.5 mass%, there is almost no influence on the composition index f3. Even when the total unavoidable impurity amount exceeds 0.5 mass%, the composition index f3 is within the above range.

(composition index f4)

Further, when Sn and Al are coexisted as described above, it contributes to various characteristics such as discoloration resistance, antibacterial property (bactericidal property), and strength, and the composition index f4 = [Sn] × [Al] + 0.1 × [Ni] Become an important factor. Further, when Ni is not added, the composition index becomes f4 = [Sn] × [Al].

When the composition index f4 is less than 0.02, even if the combination of Sn and Al is added, the discoloration resistance, strength, and the like are not sufficient. Thereby, the composition index f4 is 0.02 or more, 0.1 or more is preferable, 0.2 or more is further more preferable, and 0.3 or more is most preferable. another On the other hand, when the composition index f4 exceeds 1.8, the effect of the addition and multiplication by the common addition is not saturated, but a disadvantage such as a decrease in cold workability occurs. Thereby, the composition index f4 is 1.8 or less, 1.6 or less is preferable, 1.4 or less is further preferable, and 1.3 or less is most preferable.

That is, the composition index f4 is set at 0.02. F4 Within the range of 1.8, set at 0.1 F4 The range of 1.6 is better, set at 0.2 F4 Better in the range of 1.4, set at 0.3 F4 The best range of 1.3.

Further, regarding the impurities which are inevitably contained, when the total amount of impurities is less than 0.5 mass%, there is almost no influence on the composition index f4. Even when the total unavoidable impurity amount exceeds 0.5 mass%, the composition index f4 may be within the above range.

(metal organization)

The β phase has a different area ratio due to the amount of Zn (amount of Cu), the amount of Sn, and the amount of Al, and the value of the composition index f1 becomes important. With respect to the β phase, when the amount of Zn is 32.5 mass% or more from the 2-element equilibrium state diagram of Cu-Zn in the Cu-Zn alloy, it occurs when the material temperature becomes high. The β phase appears in a high temperature state, and changes from the β phase to the α phase at the stage of cooling the material, so that the β phase is reduced. In addition, when the amount of Zn is 39 mass% or more, the β phase does not disappear even at normal temperature. However, when it is manufactured by a general manufacturing method, it is in an unbalanced state, and the Zn amount of the remaining β phase is not shifted to the low concentration side as shown in the equilibrium state diagram. Further, Sn and Al are elements which cause the β phase to easily appear at a high temperature. In addition, since Sn and Al are formed into a metal structure and a phase structure which are further separated from the equilibrium state in the production to be used in actual use, the composition of Zn, Sn, Al, or the like is determined in accordance with the composition index f1 and the like.

The β phase has a function of lowering the deformation resistance at a high temperature in the copper alloy and improving workability and deformation energy in hot rolling. However, when the β phase exists in the matrix at a normal temperature (room temperature), the β phase is harder and the strength is higher than that of most of the α phase of the matrix, so that the cold workability is lowered. Compared with the α phase, more β, Al is distributed in the β phase, so it is harder. Specifically, in plastic working such as bending processing or rolling in cold rolling, cracking occurs in a portion where the curvature radius of curvature is extremely large, or edge cracking occurs in cold rolling (breaking of the end surface portion of the ingot). Moreover, compared with the α phase, the corrosion resistance is very poor, and it also causes the dezincification corrosion and the stress corrosion cracking. In particular, when the β phase is large, the β phase in the rolled material and the extruded material may be continuous in parallel with the rolling direction or the extrusion direction, and the corrosion depth may be increased due to the continuous β phase having poor corrosion resistance. Moreover, it also has a bad influence on discoloration resistance and antibacterial property (bactericidal property). In addition, in the Cu-Zn-Sn-Al alloy, the β phase which occurs at a high temperature is converted into the α phase by cooling or is converted into the α phase and the γ phase in the same manner as the Cu—Zn alloy, and is subjected to the amount of Zn and Sn, Al. The influence of quantity is related to the composition index f1, f2, f3, and f4.

On the other hand, when shearing such as press working is performed by the presence of the β phase, a small amount of β phase and a γ phase described later are good. Compared with the α phase having a low Zn concentration, and containing no Sn, Al or even a small amount of the α phase, the Zn concentration is high and satisfies the conditions of f2, f3, and f4, and contains α, Al, and α. The phase, that is, the α phase in a state immediately before the occurrence of the β phase, improves the punchability even if the β phase or the γ phase is not contained. Further, by the presence of a trace amount of the β phase, the effect of suppressing the grain growth of the α phase of the matrix when the temperature of the material such as heat treatment rises is increased, and as a result, the crystal grains become small. The grain affects the mechanical properties (strength), and the smaller the crystal grain size, the higher the strength. Thus, various characteristics are affected by the presence of the β phase.

Similarly, the metal structure which satisfies the composition indexes f1, f2, f3, and f4 and is in a state immediately before the occurrence of the β phase is excellent in discoloration resistance and antibacterial property (bactericidal property) of the alloy containing only the α phase, and bending workability And the weldability is also good.

From the above, the area ratio of the β phase at normal temperature (room temperature) is preferably 0.9% or less and less than 0.5%, more preferably about 0% or 0%. That is, in order to achieve the object of the present invention, from the viewpoint of the metal structure, only the metal phase of the α phase immediately before the β phase appears, or the matrix is the α phase and contains the β phase of about 0.1% in area ratio. The metal structure is good.

The γ phase is produced by the transformation of the β phase occurring at a high temperature into an α phase and a γ phase by an eutectoid reaction. The γ phase is hard and exhibits fragile properties compared to the β phase described above. The γ phase formed of a Cu-Zn-Sn-Al alloy (for example, a γ phase composed of 50 mass% Cu-40 mass% Zn-10 mass% (Sn+Al)) is harder because it contains a large amount of Sn and Al. . Therefore, when compared with the area ratio of the same amount, γ has a large influence on the elongation at the time of the tensile test, and the cold workability is lowered. Further, although the corrosion resistance of the γ phase is better than that of the β phase, it is inferior to the α of the matrix, and therefore causes a decrease in overall corrosion resistance (dezincification corrosion, stress corrosion cracking, etc.). The γ phase is also observed in the Cu-Zn2 element alloy, which occurs when the amount of Zn is 48.9 mass% or more, but in the Cu-Zn-Sn-Al alloy, it is different from the γ phase of the Cu-Zn2 alloy. Containing Sn and Al is more rigid and fragile, and has a greater impact on cold workability. In addition, a small amount of γ phase improves press formability.

The γ phase is affected by the amount of Zn and the amount of Sn and Al in the same manner as the β phase. In order to set the amount of the appropriate γ phase, the values of the composition indexes f1 and f2 need to be in a good range, which is important from various characteristics. . And, if the angle of the area ratio of the γ phase is In terms of degree, it needs to be 0.7% or less, less than 0.4% is preferable, and 0% or 0% is more preferable. From the viewpoint of the metal structure, in order to improve the discoloration resistance and the antibacterial property (bactericidal property) and to improve the bending workability and the weldability, the metal phase of the α phase immediately before the γ phase appears, Or the metal structure in which the matrix is an α phase and contains a γ phase of about 0.1% in terms of area ratio is good.

When the β phase and the γ phase are present at normal temperature (room temperature), as described above, the cold workability and the corrosion resistance are adversely affected. If the β phase and the γ phase are simultaneously present at normal temperature (room temperature), the multiplication effect is greater than that of the case where it exists alone. In view of this effect, when the area ratio of the γ phase is (γ) and the area ratio of the β phase is (β), if the area rate index f5 = 2 × (γ) + (β) exceeds 1.5, The cold workability and the corrosion resistance are deteriorated, and it is necessary to obtain various characteristics for the following.

Accordingly, the area ratio index f5 is 1.5 or less, 1.2 or less is preferable, and the value of f3 is preferably 1.0 or less, more preferably about 0% or 0%.

Further, in the alloy of the present invention, the area ratio of the β phase in the matrix of the α phase is preferably 0 to 0.9%, preferably 0 to 0.5%, and the metal structure in the presence or absence of the β phase is preferable. However, the concentration of the grain boundary of the α phase and the phase boundary of α-β is higher than the concentration of Zn, Sn, Al, and other unavoidable impurities which promote the formation of the β phase, and corrosion resistance and the like become unstable and need to be enhanced. To do this, add Mg, Sb, As, P. Further, it is assumed that the β phase contains a β' phase which is produced by an order-disorder transition.

Here, in the discoloration-resistant copper alloy (the alloy of the first to fourth inventions) according to the first to fourth embodiments of the present invention, the viable cell rate after the passage of 10 minutes in the antibacterial test is equal to or lower than the viable cell rate of pure copper. . That is, it has the same antibacterial property (bactericidal property) as or superior to pure copper.

Here, the live bacteria rate is evaluated by a test method according to JIS Z 2801 (antibacterial processed product - antibacterial test method / antibacterial effect).

(Strength/Extension Balance Index M1)

In addition, in the discoloration-resistant copper alloy (the first to fourth invention alloys) of the first to fourth embodiments of the present invention, when the tensile strength σ and the elongation ε are taken, the strength/elasticity balance index M1 is considered. σ × (1 + ε / 100) is preferred.

If it is high-strength, it can realize thinning and weight reduction of the product to be used, and it is advantageous in terms of cost. However, the high-strength material has a small elongation value, and the plastic workability such as cold workability and bending processing is poor, so that strength and stretch are obtained. The balance of the rate becomes important. When the strength/elasticity balance index M1=σ×(1+ε/100) is 440 or more, the balance of strength and elongation is good, and cold workability, bending work, strength, and the like can be ensured to the minimum necessary. Further, it is preferable that the strength/elasticity balance index M1 is 490 or more.

(average crystal grain size)

Further, in the discoloration-resistant copper alloys (the alloys of the first to fourth inventions) of the first to fourth embodiments of the present invention, it is preferable to consider the average crystal grain size.

The average crystal grain size affects the punching property, the bendability, the strength, the corrosion resistance, and the like, and therefore 0.003 to 0.070 mm (3 to 70 μm) is preferable. When the average crystal grain size is more than 0.070 mm, roughening (roughness) may occur when bending processing or the like is performed. Further, the shape and the burrs are severe at the time of punching, and roughness is generated in the vicinity of the punching portion, and the quality of the product is deteriorated. In addition, the strength is lowered, and when it is used for an armrest and a door handle, the strength is insufficient and becomes a problem, and the fatigue is also deteriorated. Since the thickness (thickness) needs to be increased due to insufficient strength, weight reduction cannot be achieved, and corrosion resistance and discoloration resistance tend to be deteriorated. 0.050mm or less is preferred. The best is below 0.040mm. On the other hand, when the average crystal grain size is less than 0.003 mm, there is a problem in flexibility, and 0.005 mm or more and further preferably 0.010 mm or more. Further, in the case of a welded pipe in which the cold-drawn welded state is not performed, strength is required for use, and therefore the average crystal grain size of the raw material of the welded pipe is preferably 0.005 to 0.020 mm.

Next, a method for producing a discoloration-resistant copper alloy (the alloy of the first to fourth inventions) according to the first to fourth embodiments of the present invention, and a method for producing a copper alloy member and a copper alloy member comprising the alloy of the first to fourth inventions will be described. .

Depending on the content of Zn, Sn, and Al, the β phase may occur at a high temperature during hot working, from the β phase to the α phase from the high temperature region to the cooling phase, or by the eutectoid phase to the α phase and the γ phase. The reaction produces a gamma phase. In order to set the amount of the β phase and the γ phase which are present in a non-equilibrium state to a predetermined amount or less in the final sheet or the welded tube, it is necessary to set the total amount of the β phase and the γ phase to 5% in the stage after the hot working. Hereinafter, it is preferable to set it as 3% or less. The starting temperature of hot working such as hot rolling depends on the composition, but it is 760 to 930 ° C, and the rolled material is finished to a thickness of 10 to 20 mm. If it is an extruded material, it is extruded to a predetermined size. When it is a rolled material, after hot rolling, it is subjected to annealing, cold rolling, and annealing. When the cold-rolled material is subjected to heat treatment (annealing softening heat treatment) by a continuous annealing cleaning line, it is not necessary to heat to a high temperature range such as hot rolling and hot pressing at a maximum temperature of 550 to 780 ° C during annealing, and the heating time is also In a short time, the β phase in the matrix does not increase. However, in the case of batch annealing, if the first annealing is performed at a temperature of 450 ° C or lower, the γ phase may increase, so care is required. It is preferred to carry out batch annealing under conditions of 480 ° C or higher.

In hot forging, if the material temperature is set to a high temperature, the deformation resistance is lowered, and further When the β phase occurs at a high temperature, the deformation resistance at a high temperature is lowered, and the deformation energy is improved. Therefore, the material temperature is adjusted up to 700 to 880 ° C. In the case of hot forging, when the β phase is contained in a large amount of 10% or more, the β phase is reduced by setting the cooling rate from forging to 650 ° C to 3 ° C / sec or less or 10 ° C / sec or less. In addition, in hot forging, although the cooling rate depends on the shape of the forging, the thinner portion of the forged material has a faster cooling rate, and the thicker portion has a slower cooling rate, if the faster portion When the cooling rate is 1 ° C / sec or less, the overall β phase is reduced.

When the welded pipe is formed, the joint portion of the welded pipe instantaneously becomes in a molten state, so that the β phase is likely to occur. Further, when bonding is performed by welding, brazing, or the like, the welded portion is instantaneously melted, and the brazed portion is heated to a temperature of 800 ° C or higher, so that the β phase is likely to occur. Further, when the thickness is thin, the cooling condition is fast, and the β phase tends to remain. Therefore, it is necessary to set the ratio of the β phase and the γ phase in the metal structure of the blank of the welded pipe to 0% or less.

Here, the discoloration-resistant copper alloys (the first to fourth invention alloys) of the first to fourth embodiments of the present invention are used, for example, in lever handles, door handles, etc. used in hospitals and public facilities, nursing carts or settings. For the fences and guardrails of the bed, these pipes are used more. In these applications, the pipe is subjected to 90-degree bending, flattening, riveting, etc., and when used as a fence, guardrail, or lever handle, a large load is applied during use, thus requiring high strength and ductility. And safety, antibacterial (bactericidal). In the case of this alloy, it is preferable to use a welded pipe (electric resistance welded pipe) as a pipe material, and it is not necessary to say that the welded pipe is excellent in discoloration resistance and antibacterial property (bactericidal property), and also requires good weldability, and the strength of the welded pipe is high, and strength/ Excellent balance of ductility. In the alloy of the present invention, by satisfying each element The composition range, the composition index f1, f2, f3, and f4, the area ratio index f5, and the requirements of the occupied area of the β phase and the γ phase can have the above characteristics.

Further, as the evaluation of the welded pipe, the expansion test, the flat test, and the 180° bending test can be applied. In the expansion test, the welded pipe was expanded to 1.25 times the diameter of the original welded pipe without cracking, and in the flat test, the welded portion was flattened to a thickness of 3 t (3 times the wall thickness: t is the pipe material) At the wall thickness, there is no crack in the welded portion, thereby demonstrating that the welded portion is strong. When the welded pipe is bent at 180 degrees, no crack is generated within three times the diameter of the bending R, and there is no problem in actual use. Further, it is preferable that the tensile strength of the welded pipe is 350 MPa or more, more preferably 400 MPa or more, or the endurance is 120 MPa or more, 150 MPa or more is preferable, and more preferably 200 MPa or more, it can be said that the strength is good, and iron Compared with the pipe made, the thickness can be reduced.

By each manufacturing method, it is heated to 700 to 930 ° C in high temperature heating, that is, hot working (rolling, extrusion, forging, etc.), or the composition of the billet satisfies the composition index f1 although it is instantaneously melted in the welded pipe. Thereby, the β phase and the γ phase are limited to a predetermined amount. In addition, when the β phase is large, the mechanical strength is improved, but the elongation is lowered, the balance between the strength and the elongation is deteriorated, the cold workability is deteriorated, and the antibacterial property (bactericidal property) and corrosion resistance are also brought. Bad influence. In order to reduce the area ratio of the β phase, various characteristics can be improved by setting the composition index f1 or the like in an appropriate range.

Door handles and elbows, etc., are sometimes made of forged parts and require no breakage under a suitable forging load. In the alloy of the present invention, it is possible to provide forging properties, discoloration resistance, and antibacterial properties by satisfying the composition range of each element, the composition indexes f1, f2, f3, and f4, the area ratio index f5, and the area occupied by the β phase and the γ phase. Sex (sterilization Sex).

As described above, the welded pipe is used for guardrails, fences, and the like, but these are joined by pipes, and are welded by pipes, forged pieces, plates, rods, wires, castings, etc. of the same kind and different materials as the pipes. , soldering (soldering), brazing, etc., to form one component (such as a guardrail). Therefore, at least in the alloy of the present invention, bonding property, weldability, solderability, and brazing property are required to be good. In the alloy of the present invention, by satisfying the composition range of each element, the composition index f1, f2, f3, and f4, the area ratio index f5, and the area occupied by the β phase and the γ phase, it is possible to provide detachability, discoloration resistance, and antibacterial properties. Sex (bactericidal).

As described above, the discoloration-resistant copper alloy (the alloy of the first to fourth inventions) of the first to fourth embodiments of the present invention has discoloration resistance, corrosion resistance, and antibacterial property (bactericidal property), and a welded pipe can be produced. Forged parts, good jointability and good mechanical strength and ductility, so they can be suitably used for door handles, door handles, door pushers, armrests, bed fences, side panels, table tops, chair backs, nursing cart handles, pens Stationery such as grips, keyboards, mice, sinks, rings, switches, switch covers, wall materials used in elevators, etc.

The embodiment of the present invention has been described above, but the present invention is not limited thereto, and can be appropriately modified without departing from the scope of the technical idea of the invention.

[Examples]

Hereinafter, the results of the confirmation experiment performed to confirm the effects of the present invention are shown. The following examples are intended to illustrate the effects of the present invention, and the configurations, procedures, and conditions described in the examples are not intended to limit the technical scope of the present invention.

A sample was produced by changing the manufacturing process using the first invention alloy, the second invention alloy, the third invention alloy, the fourth invention alloy, and the copper alloy of the comparative composition. For the comparative copper alloy, C1020, 2600 specified in JIS H 3100 and C4622 specified in JIS H 3250 were used.

The manufacturing process P1 is carried out by laboratory tests for the purpose of inspecting the influence of the composition, and is formed into a rolled material in the process P1-1, and an extruded material is produced in the process P1-2.

The manufacturing process P2 is aimed at manufacturing a rolled material in a mass production facility, and is aimed at investigation in a welded pipe.

The manufacturing process P3 is aimed at producing an extruded material in a mass production facility, and is aimed at investigation of forging, brazing, welding, and the like.

The manufacturing process P1-1 was carried out as follows.

A raw material obtained by adjusting various components of electrolytic copper, electrolytic zinc, high-purity Sn, Al, and other commercially available pure metals by electric furnace melting. Thereafter, the molten metal was poured into a metal mold having a width of 70 mm, a thickness of 35 mm, and a length of 200 mm to obtain a plate-shaped ingot of the test sample. The plate-shaped ingot was subjected to cutting to remove the entire surface portion of the casting and the oxide, and a sample having a width of 65 mm, a thickness of 30 mm, and a length of 190 mm was produced. The ingot was heated to 800 ° C, hot rolled in three passes to a thickness of 8 mm, and cooled by air cooling and forced air cooling using a cooling fan. After the oxide on the surface of the hot-rolled sample was removed by grinding, it was rolled to a thickness of 1.0 mm by cold rolling, and a continuous furnace (manufactured by Koyo Thermo Systems Co., Ltd.: 810A) was used in a nitrogen atmosphere. The furnace set temperature and the feed rate were changed, whereby the heat treatment was carried out under the condition that the maximum reaching temperature was 650 ° C and the holding time in the temperature region of the temperature 50 ° C lower than the highest reaching temperature to the highest reaching temperature was 0.3 min. These heat treatments are assumed to be connected The annealing line is continuously manufactured to produce a mass material, and the heat treatment can be performed under the same heat treatment conditions as the continuous annealing line. After the heat treatment, it was further cold rolled to 0.9 mm (processing rate: 10%), and this was used as a sample.

The manufacturing process P1-2 is carried out as follows.

A raw material obtained by adjusting various components of electrolytic copper, electrolytic zinc, high-purity Sn, Al, and other commercially available pure metals by electric furnace melting. Thereafter, molten metal was injected into a metal mold having a diameter of 100 mm × a height of 200 mm to obtain a rod-shaped ingot. The rod casting block was subjected to cutting to remove the entire surface portion of the casting and the oxide, and a sample having a diameter of 90 mm and a height of 190 mm was produced. The sample was heated to 800 ° C and extruded through a 500 ton press extruder to a diameter of 21 mm to obtain a bar having a length of 2000 mm. The extruded rod was drawn to a diameter of 20 mm to obtain a cold drawn material (processing rate: 9.3%).

The manufacturing process P2 is performed as follows.

The plate-shaped ingot having a thickness of 190 mm, a width of 840 mm, and a length of 2000 mm was prepared by dissolving a raw material adjusted to a predetermined composition by a trough type low frequency induction heating furnace, and the ingot was heated to 800 ° C and hot rolled to a thickness of 12 mm ( 13 rolling passes). After surface-cutting each surface of the rolled material (thickness: 11.2 mm), it was processed to 1.0 mm by cold rolling. The material was subjected to heat treatment on the continuous annealing line at a maximum temperature of the heat-treated material of 650 ° C and a holding time of 0.3 min in a temperature range from a temperature 50 ° C lower than the highest reaching temperature to the highest reaching temperature. The heat-treated material was cut into a width of 87 mm and 80 mm by a slitter to prepare a billet (blank) of the welded pipe.

Regarding the manufacture of the welded pipe, the welding method is carried out in the following two types. The width of the billet is different depending on the welding method. When it is added by a high frequency induction heating coil When heat is used to manufacture a welded pipe, a heat-treated material (annealed material) having a width of 87 mm and a thickness of 1.0 mm is used, and a heat-treated material (annealed material) having a thickness of 1.0 mm and a thickness of 1.0 mm is used for TIG welding. . When the welded pipe is manufactured by the high-frequency induction heating coil, the billet strip is supplied at a feed speed of 60 m/min, and is plastically processed into a circular shape by a plurality of rolls, and the material becomes a cylindrical material by a high frequency induction heating coil. Heating is performed and joining is performed by butting the ends of the billet. The bead portion of the joint portion was removed by cutting using a turning tool (cutting tool), thereby obtaining a welded pipe having a diameter of 25.4 mm and a wall thickness of 1.08 mm. Considering the change in wall thickness, when the welded pipe is formed, a few percent of the cold working is actually performed. When the welded pipe is manufactured by TIG welding, the billet strip is supplied at a feed rate of 2 m/min, and the plate shape is plastically deformed into a circular shape by a plurality of rolls (the same heating method as the high frequency heating coil) The both end faces were brought into contact, and Ar gas was supplied to the portion while being joined by TIG welding. The bead portion of the welded portion is removed by in-line cutting by a turning tool (cutting tool). By this method, a welded pipe having a diameter of 25.4 mm and a wall thickness of 1.0 mm was obtained. In addition, in the welded pipe manufactured by the induction heating coil, the wall thickness was changed, but there was almost no change in the TIG welding.

Further, in order to evaluate various characteristics, the rolled material after heat treatment on the continuous annealing line was rolled by cold rolling to have a sheet thickness of 0.9 mm (processing rate: 10%).

Further, for C2600 (70Cu/30Zn brass) and C1020 (oxygen-free copper) having a plate thickness of 1 mm as a comparative material, the furnace set temperature and the feed rate were adjusted in a nitrogen atmosphere using a continuous furnace, thereby maximizing the temperature. Temperature of 650 ° C, 50 ° C lower than the highest reaching temperature to the highest temperature reached The heat treatment was carried out at a holding time of 0.3 min in the degree region. Each of the heat-treated sheets was cold-rolled to a sheet thickness of 0.9 mm (processing rate: 10%).

The manufacturing process P3 is performed as follows.

A bar ingot having a diameter of 240 mm and a length of 700 mm was prepared by dissolving a raw material adjusted to a predetermined composition by a trough type low frequency induction heating furnace, and the ingot was heated to 800 ° C, and the diameter was made by an extruder of 3,000 tons. 21mm extruded material. The extruded material was cold drawn to a diameter of 20 mm (machining rate: 9.3%) to obtain a drawn material.

The drawn material was cut to a length of 200 mm and heated in an oven to 800 ° C, so that hot forging was the shape of the door handle (L shape). The cooling rate at 800 ° C to 650 ° C after forging was 1.5 ° C / sec.

C4622 (63Cu-35.9Zn-1.1Sn) having a diameter of 21 mm was produced as a comparative material by the same process as the manufacturing process P3, and cold-drawn to a diameter of 20 mm (processing rate: 9.3%).

Make No.1~8, 1-1~1-12, 2-1~2-10, 3-1~3-6, 4-1, 4-2, No.A1~A7 by process P1-1 , A9~A11, A1-1, A1-2, A2-1~A2-4, A3-1~A3-5, A4-1, A4-2 and No.B1, B2, made by process P1-2 No. 9 to 11, 1-13 to 1-15, 2-11, 3-7, 3-8, No. A8, A12, A13, and No. B3, and perform hot workability, microstructure observation, and mechanical property measurement , resistance to discoloration test, corrosion resistance test, etc.

Further, No. 12, 13, and 17 were produced by Process P2, and after heat treatment by a continuous annealing cleaning line, a rolled material having a thickness of 0.9 mm by cold rolling (processing rate: 10%) and a heat-treated material were obtained. The welded pipe is processed to test the welded pipe. In the same manner as the process P1-1, the hot workability and the group are applied to the rolled material. Weaving observation, mechanical property measurement, discoloration resistance test, corrosion resistance test, and the like. In addition to the above, the welded pipe was subjected to tests such as flatness test and expansion test to evaluate the robustness of the welded pipe and evaluation of weldability.

The extruded material (pull material) of No. 14, 15, 16 was produced by the process P3. In the same manner as the process P1-2, the evaluation, the brazability test, and the trial production of the forged product were carried out, and the forgeability and the structure of the forged product were confirmed.

<hue and color difference>

The surface color (color tone) of the copper alloy evaluated in the discoloration resistance test to be described later is measured by the object color according to JIS Z 8722-2009 (measurement method of color - reflection and transmission of object color), and The L*a*b* color system specified in JIS Z 8729-2004 (color display method - L*a*b* color system and L*u*v* color system) is displayed.

Specifically, the L, a, and b values were measured by SCI (including specular reflection light) using a spectrophotometer "CM-700d" manufactured by Konica Minolta, Inc. The color difference based on JIS Z8730 (color display method - color difference of object color) is calculated from each L*a*b* measured before and after the test (ΔE={(ΔL*) ² +(Δa*) ² + (Δb*) ² } ^1/2 : ΔL*, Δa*, Δb* is the difference between the two object colors), and is evaluated by the magnitude of the chromatic aberration. In addition, the L*a*b* measurement before and after the test was measured at three points, and the average value thereof was used.

<Discoloration resistance test 1: high temperature and high humidity atmosphere test>

In the discoloration resistance test for evaluating the discoloration resistance of the material, each sample was exposed to an atmosphere having a temperature of 60 ° C and a relative humidity of 95% using a constant temperature and humidity chamber (Huimoto Chemical Co., Ltd. HIFLEX FX2050). The test time was set to 24 hours. After the test, the sample was taken out and the material before and after the exposure was measured by a spectrophotometer. The surface color was measured by L*a*b*, and the color difference was calculated and evaluated. The smaller the color difference is, the smaller the color tone change is, and therefore the discoloration resistance is excellent. As the evaluation of the corrosion resistance, the value of the color difference was set to "A": 0 to 4.9, "B": 5 to 9.9, and "C": 10 or more. The color difference indicates the difference between the respective measurement values before and after the test. The larger the value, the more the color tone before and after the test is different, and when the color difference is 10 or more, it is possible to visually confirm that the color change is sufficient, and it can be judged that the discoloration resistance is inferior.

The discoloration resistance was similarly evaluated for C2600 (brass: 70Cu-30Zn), C1020 (oxygen-free copper: 100Cu), and C4622 (naval brass: 63Cu-35.9Zn-1.1Sn) as comparative materials. In addition, regarding the discoloration resistance of the bar shape, the drawing material having a diameter of 20 mm was cut perpendicularly to the longitudinal direction to 50 mm, and the surface of the width of 20 mm × the length of 50 mm was surface-dried using #1200 waterproof sandpaper. Grinded for testing. The material of the plate shape was a material obtained by setting a 10% cold-rolled material to a length of 150 mm × a width of 50 mm, and surface-grinding the surface of the material in a dry manner using a #1200 waterproof sandpaper for testing.

C2600 and C1020 are subjected to anti-rust treatment (treatment using a commercially available anti-rust liquid for copper alloy) which is carried out in a general copper alloy manufacturing company. In the rust-preventing treatment, after the surface of each material was degreased by acetone, it was immersed in an aqueous solution containing 0.1 vol% of a commercially available copper alloy anti-rust liquid heated to 75 ° C and having a main component of benzotriazole for 10 seconds. Thereafter, washing with water, washing with hot water, and finally drying the material by blast drying. It is similar to the anti-rust treatment conditions (production) of a general copper alloy. Further, the C4622 and the inventive alloy were subjected to an exposure test without performing antirust treatment.

<Discoloration resistance test 2: Indoor exposure test>

Taking into account the fact that it will be used as a push board, limited by Mitsubishi Shindo The interior door of the building in the company's Sambo Plant is affixed with a 10% cold-rolled material cut into a 150 mm long x 50 mm horizontal plate and the surface discoloration is confirmed. Prior to exposing the material to be tested, the surface was surface-polished dry using #1200 waterproof sandpaper and exposed to room temperature (with air conditioning) for 1 month. The push plate is used at least 100 times/day under conditions in which the human hand is in contact (1 contact time is about 1 second). The surface color of the material before and after the exposure was measured by L*a*b* by a spectrophotometer, and the color difference was calculated and evaluated. In the same manner as the high-temperature and high-humidity atmosphere test, the evaluation criteria were evaluated by setting the value of the color difference to "A": 0 to 4.9, "B": 5 to 9.9, and "C": 10 or more. The C2600 anti-rust treatment material and the C1020 anti-rust treatment material were also subjected to an exposure test in the same manner as the comparative material and evaluated.

<punchability>

The punching and punching test was carried out by a punching jig having a punching machine having a diameter of 57 mm and a die, and by a 200 kN hydraulic universal testing machine (AY-200SIII-L manufactured by TOKYO TESTING MECHINE INC.). The copper alloy plate was held in the upper portion of the mold having a circular circular hole, and punched at a speed of 5 mm/sec from the upper portion toward the lower portion. The material of the piercer and the die was SKS-3, the gap with the puncher was 3%, the taper of the die was 0°, and it was implemented in a state of no lubrication. The sample evaluated was set to 10% cold rolled material.

A sample having a width of 5 mm and a length of 10 mm was cut out from the end portion of a circular copper alloy plate having a diameter of 57 mm, and the sample was filled with a resin, and observed from the end of the copper alloy plate in a vertical direction by a metal microscope. Determine the height of the burrs. Regarding the punching of the sample, the "flash height" was calculated by averaging 4 points divided in the 90 direction. The lower the "burr height", the higher the evaluation of the punchability (punching property), and the evaluation was performed from the measured value of the "burr height". Evaluation of stamping property (punching property) A: less than 5 μm, B: less than 5 to 10 μm, and C: 10 μm or more. The smaller the burr height, the better the punchability, and if it is "A" of less than 5 μm, it can be judged to be good.

<bending>

Regarding the bendability, the sample was subjected to a 180-degree bend described in JIS Z 2248 (Metal Material Bending Test Method), and the condition of the bent portion was determined. In the 180 degree bending test, a sample having a thickness of 0.9 mm which has been subjected to 10% cold rolling is used, and a length of 50 mm and a width of 10 mm are cut in a direction parallel to the rolling direction, and bending is performed in a direction perpendicular to the rolling direction. The bending radius (R) of the bent portion was set to 0.45 mm, and a 180 degree bend (ta is a plate thickness) of R/ta = 0.5 was performed. At the time of evaluation, the bent portion (bending portion) was visually observed, and it was assumed that A: no wrinkles or small wrinkles, B: large wrinkles, C: rough feeling, and D: cracking.

It is judged that "A" (no wrinkles or small wrinkles) which is not hindered by the bending process is judged to be excellent in bending property, and evaluation of B or more without cracking (cracking) is preferable. In addition, when it is difficult to visually determine the scale of the wrinkles, as shown by the bending processability evaluation method of the copper and copper alloy thin strips of JBMA (Technical Standard of Japan Extension Copper Association) T307: 1999, it is enlarged to 50 by a metal microscope. The bending portion (bending portion: width 10 mm) was observed and judged. Further, when the grain of the material is coarsened, the bending process is performed, and although there is no crack in the periphery of the bent portion, a large roughness (surface roughness) is generated, and these materials cannot be used. The evaluation of the sample which gave a rough feeling was set to "C".

<welding property>

Generally, the strip-shaped product which becomes a billet is formed into a circular shape by gradually plastic working in the width direction by a forming roll, and then induced to generate heat by a high-frequency induction heating coil or by butt-joining the both ends thereof by TIG welding. Engaging, thereby manufacturing a welded pipe. The joint portion is so-called pressure-bonded, and the pressure is locally heated to cause the butt portion to be instantaneously melted and joined at both ends, and the joint portion is formed by abutting the excess material to form a large weld bead. The part is continuously cut and removed to the inside and outside of the tube by the cutting blade. However, when the diameter of the welded pipe is φ 15 mm or less, when it is a small diameter, the cutting tool inserted into the inside is also pointed, and sometimes the part of the bead cannot be removed by sufficient cutting, and the bead portion is not in all the welded pipes. Cutting removal. The joint property of the welded portion is inferior due to the adhesion of the butted portion. The evaluation of the weldability was carried out by a flat test described in the welded pipe of copper and copper alloy of JIS H 3320. A sample of about 100 mm is taken from the end of the welded pipe, and the sample is sandwiched between two flat plates, and the distance between the flat plates and the flat plate is three times the thickness of the pipe wall, and the welded portion of the welded pipe at this time is placed. The flat bending was performed so as to be a curved front end in a direction perpendicular to the compression direction, and the state of the welded portion bent by visual observation was visually observed. In addition, welded pipes are used for flat bending. The evaluation was set to A: no defects such as cracks and micropores were observed, B: no fine cracks were observed (the length of cracking was less than 2 mm in the longitudinal direction of the tube), and C: partial cracking was observed (cracking cracking) The length is 2 mm or more in the longitudinal direction of the pipe).

The evaluation of the welded portion of the welded pipe was carried out not only by the flat test described above but also by the expansion test and the 180° bending test. The expansion test was carried out by the method described in JIS H 3320. In the expansion test, a conical tool with a apex angle of 60° was pressed at one end of a sample cut into a 50 mm welded tube, and expanded to become 1.25 times the outer diameter (that is, by expanding, the end portion) The diameter becomes The diameter of 1.25 times of 25.4 mm was 31.75 mm), and the crack of the welded portion was confirmed by visual observation. A: No defects such as cracks and micropores were observed, B: fine cracks were observed (the welded portion was not divided), and C: the welded portion was cracked and evaluated.

In the 180° bending test, the welded pipe was cut to 300 mm, and 180° bending was performed using a CNC bending machine (manufactured by Chiyoda Industrial Co., Ltd.). The welded portion was bent as a portion having the outermost diameter when the 180° bending was performed, and the condition of the welded portion was visually confirmed. In addition, the diameter of the curved portion (welded portion) after the bending process was set to 76.2 mm which was three times the diameter, and was bent and evaluated. When a defect such as a crack or a micropore is not observed, "A" is observed, and a defect such as a crack or a micropore can be seen as "C" for evaluation.

Further, regarding the weldability, a welded pipe having a diameter of 25.4 mm was cut into 150 mm, and both ends of the cut welded pipe were butted, and a copper alloy welded bar (JIS Z 3341 YCuSi A 2.4Si-Cu) was added. : The front part of the element mark indicates mass%), and the welding is performed along the entire circumference by TIG welding. The tensile strength of the welded pipe was measured by stretching a pipe having a total length of 300 mm to breakage by a tensile tester (Shimadzu AG-X). Moreover, the cross-sectional area at the time of obtaining the tensile strength was made into the cross-sectional area of the welded pipe (not the cross-sectional area of the welded part). When the tensile strength of the butt welded welded pipe exceeds 70% of the tensile strength of the welded pipe (holding state) which is not butt welded, it is set to A, 50 to 70% or more is set to B, and it is smaller than the case. It is set to C, B is set to have weldability, and A or more is set to be excellent in weldability.

<hard solderability>

Cut the 20mm diameter drawing rod into a length of 50mm, on the cut surface The center uses a drill to open a hole having a diameter of 5 mm, and a rod of C1100 (toughness copper) having a diameter of 4.8 mm is placed in the drill hole. This portion was heated by a burner, and brazing was carried out using a phosphor-containing copper solder (JIS Z 3264 BCuP-4 7.2P-5Ag-Cu: the front portion of the element mark represents mass%).

The tensile test of the brazed sample was carried out using a tensile tester (Shimadzu AG-X), and the brazing property was set to be good at the C1100 other than the brazed portion, and the brazing portion was broken. The situation was evaluated as poor. The clamping portion of the tensile test (the portion holding the sample in the testing machine) was C1100 having a diameter of 20 mm and a diameter of 4.8 mm.

Further, each sample before brazing was subjected to acetone degreasing, and brazing was performed in a fluxless state.

<crystal grain size>

Regarding the crystal grain size, a metal microscope (EPIPHOT300 manufactured by Nikon Corporation) was used in a direction parallel to the rolling direction of a 10% cold-rolled sample having a deformation amount of 150 times (appropriately changed to 500 times according to the crystal grain size). And the metal structure of the cross section parallel to the drawing direction of the bar having a diameter of 20 mm (the deformation amount of 9.3%) was observed by JIS H 0501 (comparison of crystal grain size test method) The α phase grains of the measured metal structure were measured. Further, the crystal grain size (α phase crystal grain) is an average value of any three points.

In the metal structure of the forged product, the portion from the forged surface in the thickness direction of 1/5 was measured in the same manner as the area ratio of the β phase and the γ phase described later, and the average value of the three points was obtained.

< Area ratio of β phase and γ phase>

The area ratios of the β phase and the γ phase were determined as follows. By a metal microscope (ECLIPSE MA200 manufactured by Nikon Corporation), a cross section parallel to the rolling direction of the 10% cold-rolled sample and a φ20 mm drawn material (deformation amount) at 500 times (field of view 270 μm × 220 μm) 9.3%) The metal structure of the cross section of the bar parallel to the drawing direction was observed, and the image processing software "WinROOF" was used to perform the binarization of the β phase and the γ phase of the observed metal structure. The ratio of the area of the β phase to the area of the entire metal structure is taken as the area ratio. Further, the metal structure was measured for three fields of view, and the average value of each area ratio was calculated.

The portion of the welded pipe which was separated by 5 mm in the circumferential direction around the welded portion was measured in the thickness direction from the outer surface by 1/5. For the forged part, the portion from the forged surface in the thickness direction of 1/5 was measured. Further, the metal structures of the welded pipe and the forged part were measured for three fields of view, and the average value of each area ratio was calculated.

When it is difficult to discriminate the β phase or the γ phase by a metal microscope of 500 times, it is obtained by an FE-SEM-EBSP (Electron Back Scattering Diffraction Pattern) method. That is, the FE-SEM was JSM-7000F manufactured by JEOL Ltd., and TSL solutions OIM-Ver.5.1 was used for the analysis, and the phase diagram (Phase diagram) of 500 times the analysis magnification was obtained. That is, the α phase shows the crystal structure of the FCC (face-centered cubic lattice), and the β phase and the γ phase take the crystal structure of the BCC (body-centered cubic lattice). Although the β phase and the γ phase have the same crystal structure, the interatomic distance and the lattice constant are different, and thus each phase can be discriminated.

<Hot workability>

The hot workability was evaluated by the fracture state after hot rolling. Visual inspection When the appearance is observed, the damage is not caused by the hot rolling, or the crack is fine (3 mm or less), which is excellent in practicality and is represented by "A", and the slight edge crack of 5 mm or less is present throughout the entire length. 5 or less is practical and is represented by "B", and it is difficult to apply a large crack of more than 5 mm or a small crack of 3 mm or less to more than 6 parts (a large repair is required in actual use). ) is indicated by "C". In addition, the hot rolling deformation resistance was large and it was not possible to roll to the predetermined thickness (8 mm in P1-1) in the number of rolling passes in hot rolling, and it was evaluated as "C" in practical difficulty. Moreover, those who were evaluated as "C" basically discontinued the subsequent tests.

<Cold workability>

Regarding the cold workability, the fracture state (the fracture state of the cold-worked material) after cold-rolling the hot-rolled material at a high processing rate of 80% or more was evaluated. It is practically excellent in the case where the visual appearance is such that there is no damage such as cracking, or even if it is broken (3 mm or less), it is represented by "A", and it is practical to produce edge cracks of more than 3 mm and 5 mm or less. As indicated by "B", it is difficult to apply a large cracker of more than 5 mm and is represented by "C". This evaluation is based on the cracking caused by the ingot, and the crack which can be visually judged in advance in hot rolling is excluded, and the crack generated in the hot rolling is excluded, and the length of the crack generated in the cold rolling is judged. Moreover, those who were evaluated as "C" basically discontinued the subsequent tests.

<Antibacterial (bactericidal) 1>

The evaluation of the antibacterial property was carried out by a test method based on JIS Z 2801 (antibacterial processed product - antibacterial test method / antibacterial effect), and the test area (film area) and contact time were changed to evaluate. The bacteria used for the test were set to Escherichia coli (strain storage number: NBRC3972), and pre-cultured at 35±1° C. using a 1/500 NB dilution (the method of pre-culture was the method of 5.6.a described in JIS Z 2801). In Escherichia coli, a liquid having a bacterial count adjusted to 1.0 × 10 ⁶ /mL was used as a test bacterial solution. The test method is as follows: The sample cut into a 20 mm square is placed in a sterilized culture vessel, and 0.045 mL of the aforementioned test bacterial solution (Escherichia coli: 1.0×10 ⁶ /mL) is dropped, and a film having a diameter of 15 mm is covered, and the lid of the culture vessel is covered. . The culture vessel was cultured in an atmosphere of 35 ° C ± 1 ° C and a relative humidity of 95% for 10 minutes (inoculation time: 10 minutes). The cultured test bacterial solution was washed out by 10 mL of SCDLP medium to obtain a washed bacterial solution. The bacterial solution was washed with a phosphate buffered physiological saline solution every 10 times, and a standard agar medium was added to the bacterial solution, and cultured at 35 ± 1 ° C for 48 hours, and the number of colonies was measured when the number of colonies (number of colonies) was 30 or more. And find the number of viable bacteria (cfu / mL). The number of bacteria at the time of inoculation (the number of bacteria at the start of the bactericidal test: cfu/mL) was compared with the number of viable cells of each sample, and it was evaluated as A: less than 10%, and B: less than 10 to 33%, C. : 33% or more. The sample obtained by the evaluation of A or more (that is, the number of viable cells at the time of inoculation and the number of viable cells of the evaluation sample was less than 1/3) was judged to be excellent in antibacterial property (bactericidal property). The culture time (inoculation time) was set to be shorter for 10 minutes because the effectiveness of the antibacterial (bactericidal) was evaluated. The sample to be evaluated was a 10% cold rolled sample having a deformation amount. Further, in pure copper (C1020), the number of bacteria after 10 minutes in the above test method was 33% of the number of inoculated bacteria. From the above considerations, the material of Evaluation A or Evaluation B becomes excellent in antibacterial (bactericidal) equal to or higher than pure copper (C1020), that is, the same or lower viable rate after 10 minutes from inoculation, which is excellent. Antibacterial (bactericidal). Further, the material having a rod shape is formed on a cross section cut in a direction perpendicular to the longitudinal direction. The material of the plate shape was cut to 20 mm × 20 mm.

<Antibacterial (bactericidal) 2>

After measuring the surface color of the exposed material of the above-mentioned discoloration resistance test 2 (exposed as a push plate of the interior door of Mitsubishi Shindo Co., Ltd.), it was cut into a square of 20 mm by using the above-mentioned large intestine. The test bacteria liquid of Bacillus was subjected to a sterilization test, and the bactericidal property (bactericidal property) of the sample after long-term use was evaluated. The test method and evaluation method are the same as those of the above-described bactericidal (antibacterial) 1 evaluation method.

<Corrosion resistance>

Corrosion resistance was evaluated by a dezincification corrosion test based on ISO 6509:1981 (Corrosion of metals and alloys determination of dezincification resistance of brass). In the test, the sample was kept in a 1% copper dichloride aqueous solution heated to 75 ° C for 24 hours, and the metal structure in the vertical direction was observed from the exposed surface, and the depth of the portion with the highest degree of dezincification corrosion was measured (maximum dezincification) Corrosion depth). When the maximum dezincification corrosion depth is 200 μm or less, it is set to "A", and when it exceeds 200 μm, it is set to "C".

<Tensile test>

The rolled material after the heat treatment process (the sample before cold rolling), the 10% cold rolled sample, the extruded bar, and the bar after drawing (Re: 9.3%) are respectively processed into JIS Z2201: metal material Ten test piece of tensile test piece (rolled material: width 25 mm, distance between punctuation points 50 mm) and test piece No. 4 (bar material: diameter 14 mm, distance between punctuation points 50 mm), by 200 kN hydraulic universal testing machine (TOKYO TESTING A tensile test was carried out by AY-200SIII-L manufactured by MECHINE INC. Also, the welded pipe will be maintained in a welded state (diameter 25.4 mm, wall thickness 1.08 mm) Or 1.0 mm) as JIS Z2201: Test piece No. 11 of a tensile test piece of a metal material (a distance between punctuation points of 50 mm: the test piece is kept cut from the pipe), and a cored bar is placed in the clamp portion by 200 kN A tensile test was carried out by a hydraulic universal testing machine (AY-200SIII-L manufactured by TOKYO TESTING MECHINE INC.). Tensile strength, elongation, and 0.2% endurance were measured by a tensile test. In addition, the endurance described in the specification indicates the endurance at a permanent elongation of 0.2% by a small residual elongation method described in JIS Z2241: Metallic material tensile test method.

In addition, when the tensile strength is σ (MPa) and the elongation is ε (%), the strength/extension balance index M1 = σ × (1+) is defined as an index indicating the balance between strength and ductility. ε/100).

In addition, in the manufacturing process P2, in addition to the rolled material after the heat treatment process (the sample before cold rolling) and the 10% cold rolled sample, the rolled material after the heat treatment process: billet strip (width 111 mm) The welded pipe manufactured by the thickness of 1.0 mm was subjected to a tensile test. The results are shown in the column of tensile test results of a 10% cold rolled sample in the form of a tape ( ).

<Electrical conductivity>

The conductivity was measured using SIGMATEST D2.069 (manufactured by FOERSTER JAPAN Limited). Among the various rolled materials, the surface of the cold-rolled material (Re10%) and the bar (φ20 mm cold drawn material: Re9.3%) were measured at a measuring frequency of 480 kHz in a direction cut in a direction perpendicular to the extrusion direction.

The composition and evaluation results are shown in Tables 1 to 10.

The test results are as follows.

A first invention alloy (the discoloration-resistant copper alloy in the composition range described in Patent Application No. 1), if the composition index f1 is 24 F1 Within the range of 40, the composition index f2 is 1.2 F2 In the range of 4.0, the hot workability and the cold workability are also good. In the metal structure of the cold-rolled material, the ratio of the β phase and the ratio of the γ phase are respectively 0.9% or less and 0.7% or less, and the average crystal grain size is also 30 μm or less. . Therefore, the mechanical properties (strength) are high and there is also an elongation ratio, and the strength/expansion balance index, that is, M1 is also 480 or more, showing a high value. In addition, the discoloration resistance is good, and workability such as punching property and flexibility is also excellent, and the antibacterial property (bactericidal property) is the same as or better than that of pure copper (C1020), and the corrosion resistance is also good.

It is understood from the composition indexes f1 and f2 that when these factors fall within a preferable range, the discoloration resistance and the antibacterial property (bactericidal property) are further excellent, and the composition indexes f1 and f2 are comparatively advantageous for each characteristic. Great impact. No. A1 and A9 in which f1 exceeds the appropriate range have many β phase and γ phase, and there is a problem in cold workability, and discoloration resistance and workability are inferior. On the other hand, No. A3 and A4 in which f1 is lower than the appropriate range have a large deformation resistance in hot working, and therefore cannot be pressed down to a predetermined thickness. No. A4 has a high deformation resistance, and there is a problem in pressing, but Pb sometimes exceeds an appropriate range, resulting in a large edge crack, and there is a problem in hot workability.

The brass material (C2600), which is a comparative material, has good sterilizing properties, but is inferior in discoloration resistance, and has workability in punchability and the like. Pure copper (C1020) is discolored in a short period of time, and has poor discoloration resistance and low workability such as punching property. Further, as described above, regarding the antibacterial property (bactericidal property), the ratio of the number of viable cells after the test is 33% at the time of inoculation, which is the same as or worse than the alloy of the first invention. The intensity is also weak (the value of M1 is small). Naval brass (C4622) has a low balance of strength/extension before cold drawing, and there is also a problem with discoloration resistance. Moreover, there is also a problem in corrosion resistance (dezincification resistance).

In No. A1 and A9 in which the content of Zn is more than the range of the present invention, the composition index f1 is also larger than the range, and therefore, the ratio of the β phase and the γ phase in the metal structure is 2% or more, which is large, and cold workability (by There is a problem that the cold rolling produces a large crack. As a result, although the strength is relatively high, the elongation value is low, the strength/extension balance index M1 is low, and the discoloration resistance, the bending property, and the corrosion resistance are generated. A larger problem is a problem when used as a discoloration-resistant copper alloy.

In No. A3 in which the content of Zn is less than the range of the present invention, the composition index f1 is also smaller than the range, and the deformation resistance at the time of hot rolling is increased, and it is impossible to roll to a desired thickness.

In No. A2 in which the content of Sn is more than the range of the present invention, the composition index f2 is larger than the range, and although there is no β phase in the metal structure, the γ phase is large, and therefore, a large crack occurs during cold rolling. Therefore, the elongation rate also decreases, and M1 also becomes a small value, and the bending property and the corrosion resistance cause a large problem. On the contrary, in No. A1-1 in which the content of Sn is less than the range of the present invention, the composition index f4 is smaller than the range, and although there is no γ phase, the tensile strength is low, and M1 is also a small value, and the discoloration resistance and rushing are small. Cutting processability creates problems.

In No. A4 in which the content of Pb is more than the range of the present invention, although f1 is small, a large crack occurs during hot rolling, so that cold rolling of the next process cannot be performed.

On the contrary, in No. A6 in which the content of Pb is less than the range of the present invention, there is almost no influence on mechanical properties, discoloration resistance, and antibacterial property (bactericidal property), but the burr height at the time of punching test is large, and punching is performed. There is a problem with processability.

In No. A5 in which the content of Al is more than the range of the present invention, the composition index f2 is also large, and the β phase ratio in the metal structure is high. Further, since there is a large amount of Al, the antibacterial property (bactericidal property) of the sample which is exposed to a long period of time is particularly deteriorated. In No. A8 in which the content of Al is less than the range of the present invention, the values of the composition indexes f2 and f4 are small, the crystal grains are large, the tensile strength is small, and M1 is small. Moreover, the discoloration resistance is poor.

The second invention alloy (the discoloration-resistant copper alloy in the composition range described in Patent Application No. 2) is composed of Ni instead of a part of Sn and Al in the above-described first invention alloy, if the composition index f1 is 24 F1 Within the range of 40, the composition index f3 is 1.2 F3 In the range of 4.0, hot workability, cold workability, and mechanical strength (balance index of strength/stretching ratio) are also good, and it is possible to obtain not only workability such as punching property but also excellent sterilizing property and corrosion resistance. Even if Ni and Ni are replaced by Ni, the various characteristics are the same level, and there is no problem. In particular, if the composition index f4 is at 0.02 F4 Within the range of 1.8, the above characteristics are further improved.

In No. A7 having a composition index f3 of more than 4.0, the Ni-Al-based intermetallic compound deteriorates hot workability, and thus a large crack is generated.

In No. A8 in which the content of Si is more than the range of the present invention and the composition ranges f2 and f4 are out of the range, a large edge crack occurs in hot rolling. This is because the composition indices f2 and f4 exceed the upper limit and the content of Si is large. Although the hot workability was evaluated by C, only the edge of the hot rolled material was removed by milling with a grinder, and cold working was performed and various evaluations were performed. In addition, the cold workability was also evaluated as C, which caused a large crack. Since the β phase and the γ phase are large in the metal structure, the ductility (stretching ratio) is small, and the M1 of the annealed material is reduced, and the flexibility, the antibacterial property (bactericidal property), and the corrosion resistance are deteriorated.

In No. A11 in which the content of Ni is more than the range of the present invention and the composition index f3 is also out of the range, hot workability is deteriorated, and a large crack is generated.

The third invention alloy (the discoloration-resistant copper alloy in the composition range described in Patent Application No. 3) further contains 0.01 to 1.0 mass% of Si and 0.01 to 0.5 mass% of Ti in the first and second invention alloys described above. Any one or more of 0.01 to 1.5 mass% of Mn, 0.001 to 0.09 mass% of Fe, and 0.0005 to 0.03 mass% of Zr, and the composition index f1 is set at 24 F1 Within the range of 40, the composition index f2 is set at 1.2. F2 Within the range of 4.0, or the composition index f3 is set at 1.2 F3 Alloy in the range of 4.0.

In these alloys, the discoloration resistance, workability, antibacterial property (bactericidal property), and discoloration resistance are affected by the composition index f1, f2, or f3, but are substantially the same as those of the first invention alloy and the second invention alloy, and mechanical properties. (Strength) is further improved, and M1 is increased.

In No. A10 in which the content of Sn and Si is less than the range of the present invention and the content of Ti is more than the range of the present invention, the elongation is small, M1 is also decreased, and processing in cold rolling such as cracking is caused in bending workability. Poor sex. Further, since Sn and Si are small, as a result, the antibacterial property (bactericidal property) becomes poor.

No. A3-1 in which Si, Ti, and Zr are smaller than the range of the present invention, and No. A3-2 in which Mn and Fe are smaller than the range of the present invention exhibit substantially the same mechanical properties (strength) as those of No. 1 having a similar composition, The discoloration resistance, the bactericidal property, and the like are not observed, and it is not observed that each of the properties is improved by the addition of the elements.

On the other hand, in No. A10 in which Ti exceeds the range of the present invention, cracking occurs in bending workability, and workability causes a problem. In the No. A3-3, A3-4 and A3-5 in which Si, Fe, Ti, Zr and Mn respectively exceed the scope of the present invention, β phase, γ There are many problems in the cold workability and the corrosion resistance, and the ingot defects caused by the entrapment of oxides such as Zr and Ti cause deterioration of hot workability and hot workability due to a large amount of Mn. Deterioration and large-scale edge cracking, etc., have problems in processability and characteristics.

In the alloy of the first aspect of the invention, the discoloration-resistant copper alloy further contains 0.005 to 0.09 mass% of P, 0.01 to 0.09 mass% of Sb, 0.01 to 0.09 mass% of As, and 0.001 to 0.03 mass%. Any one or more of Mg. The various characteristics are affected by the composition indexes f1, f2, etc., but the discoloration resistance, the bactericidal property, and the like are improved as compared with the first invention alloy or the like, and the effect of adding an element is not observed. In No. A4-1 in which P, Sb, and As were less than the appropriate range of the present invention, although the composition was slightly different, various characteristics similar to those of No. 4 of the similar composition were exhibited, and the effect based on the added element was not observed. On the other hand, in No. A4-2 containing P and Mg which are more than the appropriate range of the present invention, ingots which are excessively cracked during hot working due to excessive P, and oxides which also generate Mg are formed. Problems such as defects and hot workability have arisen.

In the first invention alloy, the second invention alloy, and the third invention alloy, the billet is produced by mass production trial production, and the welded pipe is experimentally produced, and the welded pipe has good robustness (flat test, expansion test, and 180-degree bending). The area ratio of the β phase and the γ phase in the structure near the welded portion is also small, and there is no problem. Further, it was confirmed that there was no problem in the weldability (butt welding). Both tensile strength and elongation are excellent, and the balance is also good. Further, the welded pipe of the second invention alloy (No. 17 in the present drawing) is produced by heating using a high frequency induction coil and TIG welding. No matter which method is used to manufacture the welded pipe, the welded pipe has good robustness (flat test, expansion test, 180° bending), and the structure is α single. There is also no problem with the phase, and the tensile strength, the elongation and the balance are also excellent.

Further, a hot forging was experimentally produced from an extruded material, and corrosion resistance, texture, and the like were confirmed, and there was no problem in any of the samples.

Thus, it was confirmed that various inventive alloys were able to obtain materials satisfying various characteristics for the strip products, the board products, and the welded tubes manufactured therefrom. Further, the bar (extruded material) can be manufactured satisfactorily, and the hot forging or the like can be produced without any problem.

In addition, when the average crystal grain size is within the range, it is affected by the composition index f1 or the like, but the mechanical properties are also good. When the thickness is large, the roughness is generated during the bending process, and the workability is problematic.

As described above, it has been confirmed that the compositional indexes f1, f2, f3, and f4 of various inventive alloys contribute not only to the area ratio of the β phase and the γ phase, but also to the discoloration resistance and workability, and also contribute to the antibacterial property (sterilization). Corrosion resistance, if it is within the range given in the scope of the patent application, a discoloration-resistant copper alloy excellent in various properties can be obtained.

[Industrial availability]

The discoloration-resistant copper alloy according to the present invention and the copper alloy member using the discoloration-resistant copper alloy have a yellow (bronze) color tone, and are excellent in workability such as hot workability, cold workability, and pressability, and can be improved. Resistance to discoloration, antibacterial and bactericidal properties.

Claims (19)

A discoloration-resistant copper alloy characterized in that the discoloration-resistant copper alloy contains 17 to 34 mass% of Zn, 0.01 to 2.5 mass% of Sn, 0.005 to 1.8 mass% of Al, and 0.0005 to 0.030 mass% of Pb, and the remainder The part contains Cu and inevitable impurities, and the content of Zn [Zn] mass%, the content of Sn [Sn] mass%, and the content of Al [Al] mass% have 24 [Zn]+5×[Sn]+3×[Al] 40 relationship, and the content of Sn [Sn] mass% and the content of Al [Al] mass% have 1.2 [Sn]+2×[Al] In the relationship of 4.0, the discoloration-resistant copper alloy is a metal structure in which the area ratio (γ)% of the γ phase of the α phase matrix and the area ratio (β)% of the β phase have 0. 2×(γ)+(β) In the relationship of 1.5, a γ phase having an area ratio of 0 to 0.7% and a β phase of 0 to 0.9% are dispersed in the α phase matrix. A discoloration-resistant copper alloy characterized in that the discoloration-resistant copper alloy contains 17 to 34 mass% of Zn, 0.01 to 2.5 mass% of Sn, 0.005 to 1.8 mass% of Al, 0.0005 to 0.030 mass% of Pb, and 0.01. ~5mass% of Ni, the remainder contains Cu and unavoidable impurities, Zn content [Zn]mass%, Sn content [Sn]mass%, Al content [Al]mass%, and Ni content [Ni]mass Between 24% [Zn]+5×[Sn]+3×[Al]-0.5×[Ni] The relationship of 40, and the content of Sn [Sn] mass%, the content of Al [Al] mass%, and the content of Ni [Ni] mass% have 1.2. 0.7 × [Ni] + [Sn] + 2 × [Al] In the relationship of 4.0, the discoloration-resistant copper alloy is set to have a metal structure in which the area ratio (γ)% of the γ phase of the α phase matrix and the area ratio (β)% of the β phase have 0. 2×(γ)+(β) In the relationship of 1.5, a γ phase having an area ratio of 0 to 0.7% and a β phase of 0 to 0.9% are dispersed in the α phase matrix. The discoloration-resistant copper alloy according to claim 1 or 2, wherein the discoloration-resistant copper alloy further contains 0.01 to 1.0 mass% of Si, 0.01 to 0.5 mass% of Ti, and 0.01 to 1.5 mass%. Any one or more of Mn, 0.001 to 0.09 mass% of Fe, and 0.0005 to 0.03 mass% of Zr, Zn content [Zn] mass%, Sn content [Sn] mass%, and Al content [Al] mass% Contents of Si, Ti, Ni, Mn, Fe, and Zr [Si]mass%, [Ti]mass%, [Ni]mass%, [Mn]mass%, [Fe]mass%, and [Zr]mass% Between 24 [Zn]+5×[Sn]+3×[Al]+2.5×[Si]+1.0×[Ti]-0.5×[Ni]+0.5×[Mn]+0.2×[Fe]+0.1×[Zr 〕 40 relationship. The discoloration-resistant copper alloy according to claim 1 or 2, wherein the discoloration-resistant copper alloy further contains 0.005 to 0.09 mass% of P, 0.01 to 0.09 mass% of Sb, and 0.01 to 0.09 mass%. As and 0.001 to 0.03 mass% of any one or more of Mg. The discoloration-resistant copper alloy according to claim 3, wherein the discoloration-resistant copper alloy further contains 0.005 to 0.09 mass% of P, 0.01 to 0.09 mass% of Sb, 0.01 to 0.09 mass% of As, and 0.001 to 0.03 mass% of any one of Mg or more. The discoloration-resistant copper alloy according to claim 1 or 2, wherein The above-mentioned discoloration-resistant copper alloy is used in the form of a welded pipe, a forged product, or a cast piece. The discoloration-resistant copper alloy according to claim 3, wherein the discoloration-resistant copper alloy is used in the form of a welded pipe, a forged product, or a cast. The discoloration-resistant copper alloy according to claim 4, wherein the discoloration-resistant copper alloy is used in the form of a welded pipe, a forged product, or a cast. The discoloration-resistant copper alloy according to claim 5, wherein the discoloration-resistant copper alloy is used in the form of a welded pipe, a forged product, or a cast. The discoloration-resistant copper alloy according to claim 1 or 2, wherein the viable cell rate after 10 minutes in the antibacterial test is equal to or lower than the viable cell rate of pure copper. The discoloration-resistant copper alloy according to claim 3, wherein the viable cell rate after 10 minutes in the antibacterial test is equal to or lower than the viable cell rate of pure copper. The discoloration-resistant copper alloy according to claim 4, wherein the viable bacteria rate after 10 minutes in the antibacterial test is equal to or lower than the viable cell rate of pure copper. The discoloration-resistant copper alloy according to claim 5, wherein the viable cell rate after 10 minutes in the antibacterial test is equal to or lower than the viable cell rate of pure copper. The discoloration-resistant copper alloy according to claim 6, wherein the viable cell rate after 10 minutes in the antibacterial test is equal to or lower than the viable cell rate of pure copper. The discoloration-resistant copper alloy according to claim 7, wherein the viable cell rate after 10 minutes in the antibacterial test is equal to or lower than the viable cell rate of pure copper. The discoloration-resistant copper alloy according to Item 8 of the patent application, wherein the viable cell rate after 10 minutes in the antibacterial test is equal to or lower than the viable cell rate of pure copper. The discoloration-resistant copper alloy according to claim 9, wherein the viable cell rate after 10 minutes in the antibacterial test is equal to or lower than the viable cell rate of pure copper. A copper alloy member characterized in that it is joined to a base material composed of a discoloration-resistant copper alloy according to any one of claims 1 to 17 and other members. The copper alloy member according to claim 18, wherein the copper alloy member is used as a door handle, a door handle, a door push plate, an armrest, a bed fence, a side panel, a table top, a chair back, and a nursing trolley. Handle members, pen grips, keyboards, mice, sinks, rings, switches, switch covers, and building materials.