WO2007077645A1 - Titanium alloy for corrosion-resistant material - Google Patents

Abstract

A titanium alloy for corrosion-resistant material that while inhibiting a drop of corrosion resistance, can be produced at low cost. There is provided a titanium alloy for corrosion-resistant material characterized in that the titanium alloy is composed of, by mass%, 0.01 to 0.12% of the sum of at least one platinum group element, further at least one of Al, Cr, Zr, Nb, Si, Sn and Mn and the balance Ti and impurities, and that the total content of Al, Cr, Zr, Nb, Si, Sn and Mn therein is 5% or less by mass%.

Description

 Specification

 Titanium alloy for corrosion resistant materials

 Technical field

 [0001] The present invention relates to a titanium alloy for corrosion resistant materials.

 Background art

 [0002] Since an oxide film is formed on the surface of titanium, it is widely used in places where it is difficult to be corroded compared to general metals and where corrosion resistance is required. However, in such applications, a material having further excellent corrosion resistance is required, and conventionally, another element is added to titanium to improve the corrosion resistance.

 For example, Ti-Pd alloys are known as titanium with improved corrosion resistance, as specified in JIS 11, 12, and 13 types. These are alloys in which 0.12-0.25% by mass of Pd is contained in pure titanium. In addition to Sarakuko and Pd, Co and Ni are also included (see Patent Documents 1 and 2).

[0003] By the way, titanium has excellent properties compared to general metals, such as light weight and high strength, as well as strong strength with excellent corrosion resistance, and various alloys can be used for sports clubs such as golf clubs and bicycles. It is used for a variety of purposes, including food products. However, since titanium alloys are more expensive than ordinary metals, in recent years, not only sponge titanium produced by titanium ore power, but also commercialized and inexpensively regenerated titanium alloys that are no longer needed. The use of recycled titanium alloys is now being considered!

 However, in the case where the above-mentioned corrosion resistance is required, even if it is a trace amount, if other elements are mixed, there is a possibility that corrosion starts from that element. No recycled titanium alloy is used for the titanium alloy for foodstuffs. However, since white metal elements such as Pd are generally much more expensive than titanium, corrosion-resistant titanium alloys have been very expensive in the past.

 That is, the conventional titanium alloy for corrosion resistant materials has a problem that it is difficult to manufacture at low cost while suppressing a decrease in corrosion resistance.

Patent Document 1: Japanese Patent No. 2132925 Patent Document 2: Japanese Patent Publication No. 4-57735

 Disclosure of the invention

 Problems to be solved by the invention

[0004] In view of the above problems, an object of the present invention is to provide a titanium alloy for corrosion resistant material that can be manufactured at low cost while suppressing a decrease in corrosion resistance.

 Means for solving the problem

 [0005] As a result of earnest studies to solve the above problems, the present inventors have found that the titanium alloy contains one or more of Al, Cr, Zr, Nb, Si, Sn and Mn in a predetermined amount. In such a case, the present inventors have found that the decrease in corrosion resistance can be suppressed and have completed the present invention. That is, the present invention contains, in mass%, one or more of platinum group elements in a total of 0.01 to 0.12%, and further contains one or more of Al, Cr, Zr, Nb, Si, Sn, and Mn, Provided is a titanium alloy for corrosion resistant materials, wherein the balance is Ti and impurities, and the total content of Al, Cr, Zr, Nb, Si, Sn and Mn is 5% by mass or less.

[0006] The fact that a titanium alloy contains Al, Cr, Zr, Nb, Si, Sn, and Mn means that Al, Cr, Zr, Nb, Si are more than inevitable in the titanium alloy. , Sn and Mn are intended. The content of these elements can be measured by using a commonly used analytical instrument, and the content of these elements, which are usually present as inevitable levels in titanium alloys, is the largest. A1: 0. 007 mass _^0/0, Cr: 0. 007 mass _^0/0, Zr: 0. 001 mass _^0/0, Nb: 0. 001 mass _^0/0, Si: 0. 004 mass _^0/0, sn: 0.001 mass _^0/0, Mn: since it is 0.001% by mass, in the present specification, "titanium alloy, Al, Cr, Zr, Nb , Si, Sn and Mn are contained" Is intended to mean that these elements are present in titanium alloys in excess of these amounts!

 The invention's effect

[0007] According to the present invention, since the corrosion-resistant titanium alloy contains Al, Cr, Zr, Nb, Si, Sn and Mn, etc., one kind of Al, Cr, Zr, Nb, Si, Sn and Mn is used. Recycled titanium alloys from products containing the above-mentioned titanium alloys can be reused as corrosion resistant titanium alloys. Moreover, according to the present invention, the titanium alloy for corrosion-resistant materials has platinum group elements. One or more of the elements are contained in a total of 0.01-0.12%, and the total content of Al, Cr, Zr, Nb, Si, Sn, and Mn contained is 5% or less in total. Therefore, a decrease in corrosion resistance can be suppressed.

 That is, it is possible to provide a titanium alloy for corrosion resistant materials that can be manufactured at a low cost while suppressing a decrease in corrosion resistance.

 BEST MODE FOR CARRYING OUT THE INVENTION

 [0008] The titanium alloy for corrosion-resistant materials of this embodiment will be described below. First, the amount of each element contained in the titanium alloy for corrosion resistant materials and the reason for determining the amount will be described. The titanium alloy for corrosion resistant materials of this embodiment usually contains one or more of a white metal element, Co and Ni, Al, Cr, Zr, Nb, Si, Sn and Mn, The balance is Ti and impurity power.

 [0009] The white metal element is an essential component of the titanium alloy for corrosion-resistant material, and the content is 0.01% to 0.12% by mass. The content of the white metal element is set to 0.01 to 0.12% if the white metal element is less than 0.01% by mass and the corrosion resistance titanium alloy has sufficient corrosion resistance. This is because it may cause corrosion. On the other hand, even if the content exceeds 0.12%, the corrosion resistance cannot be expected to be further improved, and the cost of the titanium alloy for corrosion resistant material may be increased.

 As this white metal element, it is preferable to use a force Pd that can use Ru, Rh, Pd, Os, Ir, and Pt.

 [0010] Co and Ni are optional components, and the content is 0.05 to 2.00% by mass. These are replaced with Ti contained in the titanium alloy for corrosion-resistant materials as a residue of the above-mentioned white metal elements and essential components such as one or more of Al, Cr, Zr, Nb, Si, Sn and Mn described later. It can be contained in a titanium alloy for corrosion resistant materials. By containing 0.05 to 2.00% by mass of these, there is an effect of increasing the strength of the titanium alloy for corrosion resistant material while further improving the corrosion resistance. When the total amount of Co and Ni is less than 0.05%, it is difficult to obtain the effect of increasing the strength of the corrosion-resistant titanium alloy while further improving the corrosion resistance.

[0011] At least one of Al, Cr, Zr, Nb, Si, Sn, and Mn is an essential component for a corrosion-resistant titanium alloy, and the total content of Al, Cr, Zr, Nb, Si, Sn, and Mn is Less than 5% by mass It is. The content of these elements is within this range when the total content of Al, Cr, Zr, Nb, Si, Sn and Mn exceeds 5%. This is because the corrosion resistance of the titanium alloy is lowered and corrosion occurs. In this respect, the total content of these is preferably 3% or less, and more preferably 2% or less.

 [0012] Further, examples of impurities include unavoidable impurities such as C, 0, H, and Fe. The titanium alloy for corrosion-resistant materials of the present embodiment includes other elements within a range that does not impair the effects of the present invention. It is also possible to contain a trace amount of these elements. In particular, it is already known that V, Mo, and W have little effect on corrosion resistance, and these can be included in a titanium alloy for corrosion resistant materials as long as the total amount is about 5% or less by mass%. is there.

 [0013] Such titanium alloys for corrosion resistant materials are used in, for example, pipes and heat exchangers in nickel refineries used in environments exposed to concentrated sulfuric acid, nickel sulfate, salty nickel, etc. It is suitable for an electric field tank.

 Example

 [0014] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

[0015] (Sample preparation)

 (Examples 1-29, Comparative Example 1-: L 1)

 Samples for evaluation of corrosion resistance of each Example and Comparative Example were adjusted using pure titanium and each component so that the components shown in Tables 1 and 2 were contained in the titanium alloys in the amounts shown in Tables 1 and 2. Titanium alloy for food was produced. In Comparative Example 1, pure titanium was used.

 At this time, first, titanium alloys having respective compositions were melted to a size of 20 mm thickness × 70 mm width × 90 mm length by button arc melting.

Next, this melted product was rolled to a thickness of 3 mm by hot rolling, and then a 50 mm wide × 100 mm long test piece was cut out from the surface scale removed by pickling. Furthermore, one side of this test piece was polished with # 200 abrasive paper, and the side and back side were sealed with a sealant so that only this polished surface was exposed to the surface, and used as a sample for corrosion resistance evaluation. . In addition, as a conventional titanium alloy for corrosion-resistant materials that has been manufactured with strength such as sponge titanium,

Corrosion-resistant titanium alloys (conventional examples 1 to 4) containing the components shown in 3 were prepared and evaluated in the same manner as the corrosion-resistant titanium alloys of Examples and Comparative Examples.

 [¾1]

 ** Represents the total amount of Mn, Sn, Al, Cr, Zr, Nb and Si.

Table 2] Ingredient (%) * Mouth PT

 Pd Co Ni Mn Sn Al Cr Zr Nb Si **

 -0

 t 瞧 2 0.05 6 6

J; 赚 | J 3 0.05 0.35 6 6

 0.05 6 6

 t 瞧 5 0.05 3 3 6

1: 6 6 0.05 0.1 0.2 6 6 t 薩 7 0.05 6 7 13 t 薩 8 0.05 2 5 7

]; 薩 9 0.05 6 6

1: 瞧 1 0 0.05 5.5 5.5

J: 瞧 1 1 0.05 6 6

 * The values in the table indicate mass% 1 O

 ** Represents the total amount of Mn, Sn, A1, Cr, Zr, Nb and Si.

[0018] [Table 3]

 ** Represents the total amount of Mn, Sn, A1, Cr, Zr, Nb and Si.

[0019] (Nickel chloride resistance test)

 Samples for corrosion resistance evaluation of each example, comparative example, and conventional example were immersed in a 20% salt / nickel solution at 100 ° C for 100 hours, and the surface of the sample for corrosion resistance evaluation after immersion was observed with the naked eye and an optical microscope. Then, surface properties were evaluated. As a result, the surface state of the initial sample for corrosion resistance evaluation and the surface of the sample for corrosion resistance evaluation after immersion in a salt-nickel solution were judged as `` O '' and slightly increased unevenness. “△” was assigned to those with confirmed defects, and “X” was assigned to those with clearly confirmed increases in irregularities. The results are shown in Table 4.

 In addition, the weight of the sample for corrosion resistance evaluation was measured using an electronic balance capable of measuring up to 0.1 mg before and after immersion in the nickel chloride solution, and the difference was calculated as weight loss (ΔM). Also, reduce the amount of thinning by the following formula from the surface area (S) of the sample for corrosion resistance evaluation before immersion.

Thinning amount (gZm ² ) = Δ M (g) ZS (m ² )

The results are shown in Table 4. [0020] (Heat-resistant sulfuric acid test)

 Samples for evaluation of corrosion resistance of Examples, Comparative Examples, and Conventional Examples were immersed in a 5% sulfuric acid aqueous solution at 240 ° C for 1 hour, and the amount of thinning was obtained by calculation in the same manner as in the nickel chloride resistance test. The results are shown in Table 4.

 [0021] (Heat-resistant hydrochloric acid test)

 The samples for corrosion resistance evaluation of each Example, Comparative Example, and Conventional Example were immersed in a boiled 10% aqueous hydrochloric acid solution for 1 hour, and the thickness reduction was obtained by calculation in the same manner as the nickel chloride resistance test. The results are shown in Table 4.

 [0022] (Crevice corrosion resistance test)

 Samples for corrosion resistance evaluation of Examples, Comparative Examples, and Conventional Examples were overlapped with each other so that the surfaces were aligned, and immersed in a 20% NaCl solution at 90 ° C adjusted to pH 1 with hydrochloric acid for 100 hours. Thus, a crevice corrosion resistance test was conducted. In addition, the sample after the test was judged as “◯” if no change was confirmed on the surface of the sample as in the above-mentioned chloride resistance test, and “△” if a slight increase in irregularities was confirmed. The case where the increase in unevenness was clearly confirmed was judged as “X”. The results are shown in Table 4.

[0023] [Table 4]

Fine heat resistant salt resistant skimmer Resistant heat resistant salt resistant skimmer Nickel chloride resistant Nickel chloride resistant

 Acid acid acid corrosive acid 瞧 corrosive

 Surface Surface Surface Thinning amount Thinning amount Thinning amount Thinning amount Thinning amount Thinning amount Property Property Property Property Example Ί ○ <0.10 0.76 1.5 ○ 赚 Example 1 0.26 13.5 41.2

 Example 2 ○ Gu 0.10 0.61 1.8 ○} 2 △ 0.14 1.01 2.5 Δ

 Example 3 ○ <0.10 0.65 1.7 ○ Example 3 Δ 0.15 1.25 3.5 Δ

 Example 4 ○ 0.1 0.86 1.9 ○ Example 4 赚 0.13 1.13 3.7 Δ

 Example 5 ○ 0.10 0.35 1.1 ○ Example 5 厶 0.14 1.01 2.5 Δ

 Example 6 ○ 0.10 0.58 1.7 ○ Specific glue 6 Δ 0.15 1.21 3.4 厶

 Example 7 ○ So-called 0.58 1.6 ○ Specific shelf 7 厶 0.25 1.81 4.2 Δ

 Example 8 ο 0.10 0.36 1.2 〇 Comparative example 8 Δ 0.16 1.22 2.4 厶

 Example 9 ○ Gu 0.10 0.42 1.3 ○ Comparative Example 9 厶 0.15 1.1 2.2 Δ

 Example 10 ○ <0.10 0.46 1.4 ○ j: 赚 o △ 0.13 1.05 2.1 Δ

 Example 1 1 ο 0.10 0.57 1.4 〇 Comparison 1 1 厶 0.14 1.Π 2.2 Δ

 Example 12 ο 0.10 0.61 1.8 ο

 Example 13 ○ <0.10 0.62 1.7 ○ Subordinate 1 O <0.10 0.36 1.2 ○

 Example 14 ○ 0.10 0.54 1.3 ○ Conventional example 2 o 0.10 0.42 1.3 ○

 Example 1 5 ο <0.10 0.7 1.8 ο Conventional example 3 〇 0.10 0.46 1.4 O

 Example 16 〇 <0.10 0.51 1.5 〇 Conventional example 4 〇 Contract 0.57 1.4 〇

 Example 17 ο <0.10 0.58 1.3 〇

 Example 18 ο 0.10 0.6 1.4 〇

 Example 19 ο 0.10 0.63 1.4 ο

 Example 20 ○ <0.10 0.65 1.4 ○

 Example 21 ○ <0.10 0.7 1.5 ○

 Example 22 ○ <0.10 0.68 1.5 ○

 Example 23 ○ 0.10 0.63 1.3 ○

 Example 24 ○ 0.10 0.63 1.3 ○

 Example 25 ○ 0.10 0.65 1.3 ο

 Example 26 ○ 0.10 0.68 1.4 ○

 Example 27 〇 <0.10 0.68 1.4 〇

 Example 28 ○ 0.10 0.72 1.4 ○

 Example 29 ○ 0.10 0.72 1.4 ○

* The unit of “thinning amount is (g / m ² )” in “Business” c and “<0.10” indicates that the thinning amount is less than 0 g / m ² . Also from Table 4, one or more platinum group elements are contained in a total of 0.01 to 0.12% by mass, and one or more of Al, Cr, Zr, Nb, Si, Sn and Mn are further contained. The balance is Ti and impurities, and the total content of Al, Cr, Zr, Nb, Si, Sn and Mn is 5% or less by mass%, or a titanium alloy for corrosion resistance, or One or more platinum group elements are contained in a total of 0.01 to 0.12% by mass%, and one or both of Co and Ni are contained in a total of 0.05 to 2.00% in mass%, Al, Cr , Zr, Nb, Si, Sn, and Mn are further contained, the balance is Ti and impurity power, and the total content of Al, Cr, Zr, Nb, Si, Sn, and Mn is 5% by mass. Titanium alloys for corrosion resistant materials, which are characterized by the following, have superior corrosion resistance compared to the comparative examples, and are equivalent to titanium alloys for corrosion resistant materials using conventional sponge titanium. It can be seen that has a food habits. That is, the titanium alloy for corrosion-resistant materials of the present invention can suppress a decrease in corrosion resistance while using a recycled titanium alloy or the like, and can be manufactured at a low cost while suppressing a decrease in corrosion resistance. Talking.

Claims

The scope of the claims  [1] In mass%, one or more platinum group elements are contained in a total of 0.01 to 0-12%, and one or more of Al, Cr, Zr, Nb, Si, Sn and Mn are further contained, with the balance being Ti. And a titanium alloy for corrosion-resistant materials, characterized in that the total content of Al, Cr, Zr, Nb, Si, Sn and Mn is 5% or less by mass.  [2] One or more platinum group elements in a mass% are contained in a total of 0.01 to 0-12%, one or both of Co and Ni are contained in a mass in a total of 0.05 to 2.00%, Al , Cr, Zr, Nb, Si, Sn and Mn are further contained, the balance is Ti and impurities, and the total content of Al, Cr, Zr, Nb, Si, Sn and Mn is 5% by mass. % Titanium alloy for corrosion resistant materials, characterized by  [3] One or more platinum group elements in a mass percentage of 0.01 to 0.12% in total, A1: more than 0.001% and less than 5% in mass%, Cr: 0.007% More than 5% or less, Zr: More than 0.001% and less than 5%, Nb: More than 0.001% and less than 5%, Si: More than 0.004% and less than 5%, Sn: More than 0.001% 5 % Or less and Mn: more than 0.001% and less than 5%, at least one of the forces S is further included, and the total force of Al, Cr, Zr, Nb, Si, Sn and Mn is also included. 2. The titanium alloy for corrosion-resistant materials according to claim 1, wherein the mass percentage is 5% or less, and the balance is Ti and impurity power. [4] One or more of the platinum group elements are contained in a total of 0.01 to 0.12% by mass, and one or both of Co and Ni are contained in a total of 0.05 to 00.00% by mass. , 8% by mass%: more than 0.007% and less than 5%, Cr: more than 0.007% and less than 5%, Zr: more than 0.001% and less than 5%, Nb: more than 0.001% 5% or less, Si: more than 0.004% and less than 5%, Sn: more than 0.001% and less than 5% and Mn: more than 0.001% and less than 5%, at least one more and, moreover, Al, Cr, Zr, Nb, Si, the total content of Sn and Mn is not more than 5% by mass _^0/0, to claim 2, wherein the balance being Ti and impurities Titanium alloys for corrosion resistant materials as described.