JP3393012B2 - Manufacturing method of drawn tube with excellent corrosion resistance - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is to provide a method for producing inexpensive tube excellent in corrosion resistance of the inner and outer surfaces, the tube obtained in the present invention has corrosion resistance such as a piping tube of a heat exchanger It can be used for required products.

[0002]

2. Description of the Related Art Aluminum alloy tubes are used as piping materials for heat exchangers, and their internal and external corrosion resistance is one of the important characteristics. For a tube with improved internal and external corrosion resistance, use a tubular core material 60 as shown in Fig. 1.
Clad tubes having thin sacrificial metal layers 61, 62 respectively on the inner and outer surfaces thereof are often used. The method for producing the clad tube includes roll-forming the clad material produced by rolling into a tubular shape, and an electric resistance welding method for welding the butt end surfaces of the tubular shaped body, or the inner and outer surfaces of a cylindrical billet of aluminum alloy For example, there is a fitting billet method in which aluminum alloy cylinders serving as sacrificial layers are fitted into each and then extruded.

[0003]

However, in the electric resistance welding method, expensive rolling equipment is required to manufacture the clad material strip, and it is difficult to weld the ends of the thin strip, so that the thinning is limited. There is. Further, there is a problem that the corrosion resistance of the welded seam portion is low.

On the other hand, the fitting billet method, cylindrical core, skin, a billet as the sacrificial layer, becomes ingot directly or extrusion after cutting to extremely costly to produce, further sacrifice of the inner The clad ratio of the layer is likely to vary,
Further, if the cladding rate is specified to obtain stable corrosion resistance, there is a problem that the yield is significantly reduced. In addition, although a method of forming the skin material portion by casting has been proposed in the conventional examples, the productivity is extremely poor and it has not been put to practical use. The present invention has been made as a result of earnest research in view of such a situation, and its object is to:
It is an object of the present invention to provide a tube having excellent corrosion resistance on the inner and outer surfaces and a method for manufacturing the tube at low cost.

[0005]

The invention according to claim 1 is
Inner surface contains 40 wt% or less of zinc or Al and the balance cannot be Zn
Cylindrical core material alloy sprayed with zinc alloy consisting of evasive impurities
The outer surface of the minute billet is a sleeve made of leather alloy.
-Shaped covering material is divided into multiple split mold members that are parallel to the length direction.
Formed into a composite billet, and heat is applied to this composite billet.
With a method of manufacturing a drawn tube that performs inter-extrusion and drawing in order
The cylindrical billet contains 0.05 to 1.2 wt% Si and Fe.
0.05 to 2.0 wt% is contained, the balance is composed of an aluminum alloy consisting of Al and unavoidable impurities , the split mold material
A method for producing a drawn tube having excellent corrosion resistance, which comprises 0.3 to 10 wt% Zn and the balance being an aluminum alloy containing Al and inevitable impurities.

According to the second aspect of the invention, the inner surface is made of zinc or
Containing 40 wt% or less of Al and the balance Zn and unavoidable impurities
Cylindrical core material made of thermally sprayed zinc alloy
On the outer surface of the glove, use a sleeve-shaped covering material of skin alloy component
Formed by multiple split molds that are parallel to each other
As a billet, this composite billet is hot extruded and drawn
A method of manufacturing a drawn tube for sequentially applying
-Shaped billet contains 0.05 to 1.2 wt% Si, 0.05 to 2.0 wt% Fe, 1.2 wt% or less Cu, 2.0 wt% or less Mn, 2.0 wt% or less M
g, 2.0 wt% or less Ni, 0.3 wt% or less Cr, 0.3 wt% or less Z
r, 0.3 wt% or less of Ti, 0.3 wt% or less of Zn containing one or more, the balance is composed of an aluminum alloy consisting of Al and inevitable impurities , the split mold material is Zn
Of 0.3 to 10 wt% and the balance being aluminum alloy composed of Al and inevitable impurities, which is a method for producing a drawn tube having excellent corrosion resistance.

According to the third aspect of the invention, the inner surface is made of zinc or
Containing 40 wt% or less of Al and the balance Zn and unavoidable impurities
Cylindrical core material made of thermally sprayed zinc alloy
On the outer surface of the glove, use a sleeve-shaped covering material of skin alloy component
Formed by multiple split molds that are parallel to each other
As a billet, this composite billet is hot extruded and drawn
A method of manufacturing a drawn tube for sequentially applying
-Shaped billet contains Si 0.05 ~ 1.2 wt%, Fe 0.05 ~ 2.0 wt%, the balance is composed of an aluminum alloy consisting of Al and unavoidable impurities , the split mold material Zn 0.3 ~ 10 wt%
Excellent corrosion resistance, characterized by containing one or two of 2.0 wt% or less of Mg and 2.0 wt% or less of Mn, and the balance being an aluminum alloy composed of Al and inevitable impurities. It is a method of manufacturing a drawn tube.

According to the invention of claim 4, the inner surface is made of zinc or
Remainder containing Al or less 40 wt% is ne of Zn and not avoidable impurities
Cylindrical core material made of thermally sprayed zinc alloy
On the outer surface of the glove, use a sleeve-shaped covering material of skin alloy component
Formed by multiple split molds that are parallel to each other
As a billet, this composite billet is hot extruded and drawn
A method of manufacturing a drawn tube for sequentially applying
-Shaped billet contains 0.05 to 1.2 wt% Si, 0.05 to 2.0 wt% Fe, 1.2 wt% or less Cu, 2.0 wt% or less Mn, 2.0 wt% or less M
g, 2.0 wt% or less Ni, 0.3 wt% or less Cr, 0.3 wt% or less Z
r, 0.3 wt% or less of Ti, 0.3 wt% or less of Zn containing one or more, the balance is composed of an aluminum alloy consisting of Al and inevitable impurities , the split mold material is Zn
0.3 to 10 wt% of Mg, 2.0 wt% or less of Mg, 2.0 wt% or less
A method for producing a drawn tube having excellent corrosion resistance, which comprises one or two of Mn and the balance being an aluminum alloy containing Al and inevitable impurities.

According to the invention of claim 5, the inner surface is made of zinc or
300 ° C for cylindrical billet before extrusion which is sprayed with zinc alloy
Heat for 1 hour or more and 48 hours or less at a temperature of 500 ° C or higher
5. A process according to claim 1, wherein the process is performed.
The method for producing a drawn tube having excellent corrosion resistance as described in 1 .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION First, the alloy composition of the drawn tube according to the present invention will be described. The tubular core alloy of the drawn tube in the present invention contains Si in an amount of 0.05 to 1.2 wt% and Fe.
Aluminum alloy containing 0.05 to 2.0 wt% with the balance Al and unavoidable impurities, or 1.2 w
Cu less than t%, Mn less than 2.0 wt%, Mg less than 2.0 wt%, 2.0 wt%
It is an aluminum alloy containing one or more of the following Ni, 0.3 wt% or less Cr, 0.3 wt% or less Zr, 0.3 wt% or less Ti, and 0.3 wt% or less Zn.

The role of the alloy elements will be described below. Si contributes to the strength improvement. If Si is less than 0.05 wt%, its effect cannot be sufficiently obtained, and if it exceeds 1.2 wt%, the workability of the alloy is reduced, and in the one in which the zinc alloy like the present invention is sprayed, the fracture occurs during the drawing process. It will be easier. Therefore, Si
Is 0.05 wt% or more and 1.2 wt% or less, but considering extrudability, 0.8 wt% or less shows stable characteristics.

Fe has the function of making the crystal grains finer and increasing the strength. If the amount is 0.05 wt% or less, the effect cannot be sufficiently obtained, and if it exceeds 2.0 wt%, the workability is deteriorated and cracking occurs during drawing. Further, Fe and Si are often mixed as impurities, and from the viewpoint of providing an inexpensive tube which is an object of the present invention, it is preferable that Si of 0.06 wt% or more and Fe of 0.1 wt% or more are used as a low purity material. Gold can be used, which is desirable in terms of cost.

Cu of 1.2 wt% or less, Mn of 2.0 wt% or less, 2.0 wt%
The following Mg, 2.0 wt% or less Ni, 0.3 wt% or less Cr, 0.3 wt% or less Zr, 0.3 wt% or less Ti, 0.3 wt% or less Zn is added to adjust the strength and formability. It is an optional additive element. Mn,
If Ni, Cr, Zr, and Ti are added in excess of the upper limits, the formability will deteriorate and they will crack during drawing. If Cu, Mg, and Zn are added in excess of the upper limits, the corrosion resistance will decrease.

In addition to the above alloy components, B added for refining the ingot structure, V added for strength improvement, etc.
Elements other than the above may be contained as long as each is 0.05 wt% or less.

The skin material formed on the outer surface contains 0.3 to 10 wt% Zn.
An aluminum alloy containing Al and unavoidable impurities in the balance, or an aluminum alloy containing one or two of 2.0 wt% or less of Mg and 2.0 wt% or less of Mn is used.

In the aluminum alloy of the skin material, Zn
Makes the potential base and gives a sacrificial effect to the tubular core material. Here, if the Zn content is less than 0.3 wt%, the potential does not become sufficiently base. On the other hand, if it exceeds 10 wt%, the workability is deteriorated and the tube is broken during the drawing process.

Mg of 2.0 wt% or less and Mn of 2.0 wt% or less mainly contribute to the strength improvement. The strength of the tube material is strongly influenced by the strength of the outer skin material. Therefore, the improvement of the strength of the skin material significantly contributes to the improvement of the allowable strength of the tube in practical use. If Mg and Mn are added in excess of the upper limits, the workability deteriorates and they will crack during drawing. The above is the alloy component of the skin material formed on the outer surface, but the impurity elements such as Fe and Si are 0.
If it is 5 wt% or less, it may be contained. Here, the thickness of the skin material covering the outer surface depends on the thickness of the tubular core material portion of the tube, but is usually about 15 to 200 μm.

The tube used in the present invention is formed by thermally spraying a zinc alloy containing 40% by weight or less of zinc or Al and unavoidable impurities on the inner surface of a cylindrical billet serving as a tubular core material, and then extruding. It is characterized by having a sacrificial layer. The natural potential of the zinc alloy is better than that of the tubular core.
It is desirable that it be more than 200 mV base. The reason is that the sacrificial layer of zinc alloy has a smaller thickness as compared with the conventional case where an Al-Zn alloy cylinder is fitted, so that a stable sacrificial anticorrosion effect cannot be obtained unless the potential difference is large. This is because. In the present invention, the Al content of the zinc alloy is 40 wt.
The reason for defining below% is that when Al is contained in excess of 40 wt%, the potential does not become sufficiently base and sufficient corrosion resistance cannot be secured. It should be noted that Al may not be added to the zinc alloy. Although the alloy components of the sacrificial layer in the present invention have been described above, elements other than the above which are mixed as unavoidable impurities may be contained as long as each is 0.5 wt% or less.

Next, the inventions according to claims 1 to 4 are further described.
Will be explained in detail . The present invention is directed to a plurality of split mold members obtained by splitting a sleeve-shaped coating material of skin material alloy component in parallel with the outer surface of a cylindrical billet of tubular core material alloy component whose inner surface is sprayed with zinc or a zinc alloy. The composite billet is hot-extruded and then drawn. The cylindrical billet is produced by punching a cylindrical billet or cutting the inner surface of a hollow billet. It is desirable that the inner surface of the hollow billet is mechanically or chemically treated before thermal spraying of a Zn alloy or the like, because the Zn alloy or the like is likely to adhere thereto. The reason for spraying Zn or a Zn alloy before hot extrusion is that the thickness of the sprayed layer is not uniform, but it is uniformized by hot extrusion to improve drawability, and the resulting tube has a smooth sprayed surface. This is because the corrosion resistance is further improved. The thermal spraying may be performed by a normal thermal spraying method. It is desirable to heat and spray the aluminum alloy billet to improve the spray yield of Zn and the like. If the aluminum alloy billet is heated during homogenization treatment or sprayed during cooling after completion of homogenization treatment, productivity is not impaired and energy is saved.

Next, a method of forming the sleeve-shaped covering material by the split mold material will be described. The split mold members 30 shown in FIGS. 2 (a) to 2 (f) are formed such that the mating portions of the side faces of the adjacent split mold members are fitted in an uneven shape. The sleeve-shaped covering material 40 formed by using these split mold members 30,
In the mating portion of the side surfaces of the adjacent split mold materials 30, the convex portion 31 of one split mold material is guided to the recess 32 of the other split mold material, and the mating portions of the adjacent split mold materials 30 overlap each other within the wall thickness, and the radial direction There is no straight gap toward you. Therefore, when the composite billet 50 on which the sleeve-shaped covering material 40 is formed is extruded, the adjacent split mold members 30 are integrated and no seam is generated.

The split mold members shown in FIGS. 3 (g) to 3 (j) are hollow 33 having a predetermined cross-sectional shape extending over the side surfaces of the adjacent split mold members.
Alternatively, a groove 34 is formed, and the hollow 33 or the groove 34 is a joint mold member of the same material as the split mold member 30 with a sectional shape suitable for each.
It is a fitting of 35. These split mold members 30 are also shown in FIG.
Similar to that shown in (1), it is integrated after extrusion and no seam is formed. The split mold members can be kept in a sleeve shape as a whole by engaging the split mold members in a direction other than the longitudinal direction in a retaining manner or by connecting at least ends of the split mold members to each other by welding or the like. In each of the split mold members, the cross section (transverse cross section) perpendicular to the length direction is the same for each mold member, so that mass production can be easily performed by extrusion. Therefore, the manufacturing cost of the sleeve-shaped covering material becomes very low. The number of split mold materials used varies depending on the diameter of the sleeve-shaped covering material to be formed, the difficulty of combining the split mold materials, the material of the covering material, and the like. Generally, if the diameter of the sleeve-shaped covering material is large, a large number of split mold materials are required.

For the hot extrusion of the composite billet, a conventional indirect extrusion is applied. After hot extrusion, a tube having a predetermined shape is formed by a drawing method. The drawing process may be carried out in the usual manner, and there is no problem in inserting heat treatment such as intermediate annealing in the middle.

By the way, when a cylindrical billet whose inner surface is sprayed with zinc or a zinc alloy (sacrificial layer) is extruded and then drawn, the sacrificial layer may be peeled off. If the drawing process is continued with peeling, fracture may occur, and the corrosion resistance of the peeled portion is extremely reduced. Therefore, the present inventors conducted various investigations on the cause of the peeling. As a result, it was found that minute peeling occurs immediately after hot extrusion, and this minute peeling expands during drawing because the deformation behavior is significantly different between zinc or zinc alloy and aluminum alloy.
If the extrusion ratio is increased in order to make the extrusion size closer to the product size after the drawing process in order to reduce the manufacturing cost, the micro-peeling becomes more likely to occur. The fine peeling does not pose a problem when the extruded pipe is used as it is.

A fifth aspect of the present invention is the method for producing a drawn tube according to the first to fourth aspects, wherein peeling of the sacrificial layer on the inner surface of the cylindrical billet is suppressed. That is, after spraying zinc or a zinc alloy on the inner surface of a cylindrical billet, a heat treatment is applied to the cylindrical billet to form a diffusion layer at the interface between the sprayed layer and the billet, and this diffusion layer causes deformation during drawing. This is to reduce the difference in behavior. If the heat treatment is performed at less than 300 ° C. or less than 1 hour, the diffusion layer cannot be formed to have a sufficient thickness. If it exceeds 500 ℃, the sprayed metal will melt and flow. If it exceeds 48 hours, productivity will be poor and cost will be increased. If this heating is combined with heating for hot extrusion (usually about 30 minutes), productivity is not impaired and energy is saved. The drawn tube may be subjected to final annealing to be heat-treated into an O material or the like depending on required characteristics such as formability. Thus, the present invention
The tube manufactured in 1. has a sacrificial anticorrosion layer on the inner and outer surfaces and is excellent in corrosion resistance. Therefore, it is suitable for applications where corrosion resistance is required, especially for heat exchanger tubes.

[0025]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 First, a composite billet having a cross-sectional shape shown in FIG. 4 was produced. That is, the inner surface of the cylindrical billet 10 of aluminum alloy having the cylindrical core material composition shown in Table 1 was cut smoothly (outer diameter 3
68mm, inner diameter 90mm, length 990mm), this cylindrical billet 10
Spraying zinc or zinc alloy as the sacrificial layer 20 on the inner surface of the
Next, on the outer surface of the cylindrical billet 10, four split mold members 30 made of an aluminum alloy having a skin composition shown in Table 2 are provided as concave portions 31 and convex portions.
32 was engaged and set. Each of the split mold members 30 is in a retaining state in the radial direction, and in this condition, the adjacent split mold members are welded to each other and the sleeve-shaped covering member 40 is
As a result, a composite billet 50 was produced. Sleeve material 40
The overall dimensions are 374 mm inner diameter, 12 mm wall thickness and 990 mm length. The aluminum alloy having the skin composition shown in Table 2 contains Fe or Si as an impurity in an amount of 0.5 wt% or less. The split mold member 30 was selected from the shapes shown in FIGS.
The potential difference between the tubular core material alloy and the sprayed zinc or zinc alloy is more than 200 mV, and the tubular core material alloy is more noble, and zinc or the zinc alloy contains 0.5 wt% or less of the impurity element. Next, the composite billet was subjected to hot indirect extrusion and then drawn to obtain a drawn tube having an outer diameter of 35 mm and a wall thickness of 0.9 mm. Thickness from the combination of tubular core material, sacrificial layer, leather material and billet
The manufacturing process up to 0.9 mm tube is shown in Tables 3 and 4 . The obtained 0.9 mm drawn tube was heat-treated at 400 ° C. for 2 hours. When the cross section of the drawn tube was ground and observed, the outer skin and the tubular core material and the split mold members of the outer skin were integrally joined and no seam was observed. No peeling of the sacrificial material was observed.

(Conventional example) A cylindrical billet of aluminum alloy (outer diameter 368 mm, inner diameter
An aluminum alloy cylinder (outer diameter 88 mm, inner diameter 50 mm, length 990 mm) that is a sacrificial layer is fitted on the inner surface (90 mm, length 990 mm), and an aluminum alloy cylinder (inner diameter 374) that serves as a skin material on the outer surface.
mm, wall thickness 12 mm, length 990 mm) were fitted into the fitting billet, which was hot extruded and pulled out to produce a tube. Both the cylindrical billet and the two aluminum alloy cylinders were produced by cutting a cylindrical ingot.

The resulting tube (wall thickness 0.9 mm) is 50 mm long
Cut it into pieces, cut it open in the longitudinal direction and mold it into a plate,
An outer surface or an inner surface of this plate-shaped body was masked with a resin to prepare a sample. OY water (Cl ^- 195ppm, S
_{^{O 4 2- 60ppm, Cu 2+ 1ppm}} , immersed in Fe ³⁺ 30 ppm) in a 8 hour hold at 88 ° C., was carried out up to 5 months the cycle test to repeat the 16 hour hold at room temperature. The sample after the test was examined for the presence of through pitting corrosion. The results are shown in Table 5.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

[Table 4]

[0032]

[Table 5]

As is clear from Table 5, No. 1 of the present invention example
Each of Nos. 7 to 7 has no pitting corrosion in the immersion period of 5 months and has the same corrosion resistance as the conventional example of the high corrosion resistant tube. Further, the tube of the present invention is inexpensive because the skin material portion of the composite billet is formed by the split mold material and the sacrificial layer is formed by thermal spraying. On the other hand, in the conventional example, since the skin material portion and the sacrificial layer are formed by cutting the billet, it is very expensive.

[0034]

As described above, the drawn tube manufactured according to the present invention has excellent corrosion resistance on the inner and outer surfaces and can be manufactured at low cost. Therefore, it has a remarkable industrial effect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a tube having a three-layer structure.

FIG. 2 is a cross-sectional view of a split mold member for an outer cover used in the present invention.

FIG. 3 is a cross-sectional view of the split mold member for the outer cover used in the present invention.

FIG. 4 is a partial cross-sectional view showing an example of a composite billet used in the present invention.

[Explanation of symbols]

10 Cylindrical billet 20 Sacrificial layer of zinc or zinc alloy 30 Divided mold material 31 Recessed portion 32 Convex portion 33 Hollow 34 Groove 35 Joint shaped material 40 Sleeve-like covering material 50 Composite billet 60 Cylindrical core material 61,62 Sacrificial metal layer T Sleeve-like covering material Material thickness r ₁ Inner diameter of cylindrical billet r ₂ Outer diameter of cylindrical billet R ₁ Inner diameter of sleeve coating

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akio Niikura 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (56) Reference JP-A-53-133564 (JP, A) JP-A 4-15496 (JP, A) JP-A 8-35787 (JP, A) JP-A 5-320798 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C23C 4/00 -4/18 C22C 21/00 F28F 19/06

Claims (5)

(57) [Claims] 1. The inner surface contains 40 wt% or less of zinc or Al.
Thermal spraying zinc alloy with balance Zn and unavoidable impurities
On the outer surface of the cylindrical billet of the tubular core alloy component, the skin alloy
The sleeve-like coating material of the component is divided in parallel in the longitudinal direction.
The composite billet is made of several split mold materials.
A drawing chew that performs hot extrusion and drawing processing in order on a composite billet.
A method for manufacturing a tub, wherein the cylindrical billet contains Si of 0.05
~ 1.2wt%, containing 0.05 ~ 2.0wt% Fe, the balance is made of aluminum alloy consisting of Al and unavoidable impurities ,
A method for producing a drawn tube with excellent corrosion resistance, characterized in that the split mold material contains 0.3 to 10 wt% Zn and the balance is made of an aluminum alloy containing Al and inevitable impurities.
Law. 2. The inner surface contains 40 wt% or less of zinc or Al.
Thermal spraying zinc alloy with balance Zn and unavoidable impurities
On the outer surface of the cylindrical billet of the tubular core alloy component, the skin alloy
The sleeve-like coating material of the component is divided in parallel in the longitudinal direction.
The composite billet is made of several split mold materials.
A drawing chew that performs hot extrusion and drawing processing in order on a composite billet.
A method for manufacturing a tub, wherein the cylindrical billet contains Si of 0.05
~ 1.2wt%, containing 0.05 to 2.0wt% Fe, 1.2wt% or less of Cu,
2.0 wt% or less Mn, 2.0 wt% or less Mg, 2.0 wt% or less Ni, 0.
3wt% or less Cr, 0.3wt% or less Zr, 0.3wt% or less Ti, 0.3w
Contains 1 or 2 or more of t% or less Zn, and the balance
An aluminum alloy of configurations consisting of Al and unavoidable impurities
A method for producing a drawn tube having excellent corrosion resistance, characterized in that the split mold material is made of an aluminum alloy containing 0.3 to 10 wt% Zn and the balance being Al and inevitable impurities. . 3. The inner surface contains 40 wt% or less of zinc or Al.
Thermal spraying zinc alloy with balance Zn and unavoidable impurities
On the outer surface of the cylindrical billet of the tubular core alloy component, the skin alloy
The sleeve-like coating material of the component is divided in parallel in the longitudinal direction.
The composite billet is made of several split mold materials.
A drawing chew that performs hot extrusion and drawing processing in order on a composite billet.
A method for manufacturing a tub, wherein the cylindrical billet contains Si of 0.05
~ 1.2wt%, containing 0.05 ~ 2.0wt% Fe, the balance is made of aluminum alloy consisting of Al and unavoidable impurities ,
The split mold material contains Zn of 0.3 to 10 wt% and is 2.0 wt% or less.
A drawn tube excellent in corrosion resistance, characterized in that it contains one or two of Mg and Mn of 2.0 wt% or less and the balance is made of an aluminum alloy containing Al and inevitable impurities . Production method. 4. The inner surface contains 40 wt% or less of zinc or Al.
Thermal spraying zinc alloy with balance Zn and unavoidable impurities
On the outer surface of the cylindrical billet of the tubular core alloy component, the skin alloy
The sleeve-like coating material of the component is divided in parallel in the longitudinal direction.
The composite billet is made of several split mold materials.
A drawing chew that performs hot extrusion and drawing processing in order on a composite billet.
A method for manufacturing a tub, wherein the cylindrical billet contains Si of 0.05
~ 1.2wt%, containing 0.05 to 2.0wt% Fe, 1.2wt% or less of Cu,
2.0 wt% or less Mn, 2.0 wt% or less Mg, 2.0 wt% or less Ni, 0.
3wt% or less Cr, 0.3wt% or less Zr, 0.3wt% or less Ti, 0.3w
Contains 1 or 2 or more of t% or less Zn, and the balance
An aluminum alloy of configurations consisting of Al and unavoidable impurities
The split mold material contains 0.3 to 10 wt% Zn, 2.
A drawn tube with excellent corrosion resistance, characterized in that it contains one or two of Mg of 0 wt% or less and Mn of 2.0 wt% or less and the balance is made of an aluminum alloy containing Al and inevitable impurities . Production method. 5. A press having an inner surface sprayed with zinc or a zinc alloy.
A temperature of 300 ° C to 500 ° C for the cylindrical billet before delivery
Characterized by heat treatment for 1 hour to 48 hours
The method for producing a drawn tube having excellent corrosion resistance according to any one of claims 1 to 4 .