JPH062062A - Aluminum alloy for drawing - Google Patents

Abstract

PURPOSE:To provide the aluminum allay for drawing capable of simplifying the stage for reducing the drawing earing ratio of a worked product in the process of manufacturing the sheet stock for drawing. CONSTITUTION:This aluminum alloy for drawing has fundamental properties of contg., by weight, 0.5 to 2.0% Fe and 0.1 to l.0% Cr as well as in which <=0.4% Si and <=0.2% Cu are regulated, and the balance aluminum with inevitable impurities. Furthermore, the compsn. is preferably incorporate with <=0.1% Ti as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy for drawing for producing various aluminum alloy products by drawing, and more particularly to an aluminum alloy for drawing suitable for spontaneous color development by anodizing.

[0002]

2. Description of the Related Art Generally, an Al--Fe alloy is widely used as a container and other materials because it can obtain a milky white or gray or black gray tone by anodizing.

However, when such an Al--Fe alloy is drawn, it is drawn as shown in FIG.
The ear (1) is generated in the direction of large anisotropy, and the valley (2) is generated in the direction of small anisotropy, and the aperture ratio is about 15%, which is extremely high.
This causes a decrease in material yield.

Therefore, conventionally, in order to reduce the reduction ratio, the hot rolling condition, the cold reduction ratio, the final annealing condition (temperature, time, temperature rising speed, etc.) in the manufacturing process of the blank for drawing. ) And the like, and by adding an intermediate annealing step, the 45 ° factor (4
The anisotropy in the 5 ° direction is being reduced.

[0005]

However, in the method of reducing the ear cut rate as described above, it is very difficult to find an appropriate combination because the combination of the above conditions is very complicated. There is a problem that it is difficult. Moreover, since a slight variation in the set values of these various conditions results in an increase in the squeezing rate of the drawn product, it is difficult to say that this is an effective method for reducing the squeezing rate.
Furthermore, in addition to the need for additional steps such as intermediate annealing, productivity is reduced and manufacturing costs are increased.

In order to solve the above problems, the present invention simplifies a complicated process for reducing the earing ratio of a drawn product in the process of manufacturing a blank and improves productivity. In addition to the above, it is an object of the present invention to provide an aluminum alloy for drawing, which can reduce the manufacturing cost of a drawn product and reduce the ear reduction ratio.

[0007]

The aluminum alloy for drawing according to the present invention is basically composed of Fe; 0.5 to 2.0 wt%, Cr;
1 to 1.0 wt% is included, and Si is 0.4 wt
%, Cu: 0.2 wt% or less, the balance being aluminum and inevitable impurities.

In the above composition, 0.1 wt% is further added.
% Or less of Ti is preferably contained.

In the aluminum alloy for drawing, Fe is necessary to form an oxide film by anodizing treatment with sulfuric acid or the like to obtain a milky white or gray to black gray tone. If such Fe is less than 0.5 wt%, the effect of color development is poor, and if it exceeds 2.0 wt%, Al-Fe-based and Al-Fe-Si-based coarse-grained compounds are formed to cause plastic deformation. And deteriorates workability and moldability. The preferable Fe content range is 0.8 to 1.5 wt%, and particularly 1.0 to 1.5 wt%. Cr, when formed into a plate material, reduces the plate surface anisotropy and reduces the ear reduction ratio, but if it is less than 0.1 wt%, the effect of reducing the plate surface anisotropy is poor, and if it exceeds 1.0 wt%. Castability deteriorates, and Al-Cr system or Al-Fe-in the alloy structure.
Cr-based coarse-grained compounds are generated, which lowers corrosion resistance and inhibits plastic deformability, resulting in deterioration of moldability. The preferable Cr content range is 0.2 to 0.6 wt%, and particularly preferably 0.25 to 0.45 wt%.

In the aluminum alloy for drawing, when Si is contained, the crystal grains become large and the surface becomes rough, and the oxide film is blackened during the anodizing treatment, and when Cu is contained, Al-Cu metal is contained. There is a problem that an intermetallic compound is generated to deteriorate the moldability. Although it is practically impossible to completely remove these elements in the alloy manufacturing process, Si: 0.4 wt% or less, C
u: By restricting each to 0.2 wt% or less, these problems can be substantially solved.

Further, Ti as an optional additional element has the effect of refining the alloy structure and improving the formability. If such Ti exceeds 0.1 wt%, Al-Ti
A compound is produced, which rather deteriorates moldability.

[0012]

The aluminum alloy for drawing according to the present invention can improve the forming workability only by adjusting the alloy composition as described above, and lowers the drawing ear ratio of the drawn product due to the excellent forming workability. You can In addition, when manufacturing a blank for drawing, it is sufficient to carry out the usual ordinary method, and no special condition setting or additional process is required.

[0013]

EXAMPLES First, slabs of Examples 1 to 6 having alloy compositions shown in Table 1 and Conventional Examples 1 and 2 having alloy compositions outside the scope of the present invention were manufactured by a normal DC casting method.
Next, these slabs were hot-rolled at a preheating temperature of 500 ° C., then cold-rolled to a thickness of 1 mm, and finally annealed at 350 ° C. for 2 hours to obtain an aluminum alloy base plate. This aluminum alloy base plate is drawn to obtain cup-shaped processed products having a diameter of 35 mmφ and a depth of about 24 mmφ as shown in FIG. 1, and these processed products are anodized with normal sulfuric acid. An oxide film having a thickness of 15 μm was formed and spontaneously developed. In addition, in Examples 1, 2, 5, 6 and Conventional Example 1, the homogenizing treatment was performed at 600 ° C. for 10 hours before the hot rolling. Table 1 shows the squeezing rate and the color tone of the surface of these processed products.

[Table 1] As is clear from Table 1, in all of the examples of the present invention, the squeezing rate is 3% or less, and the squeezing rate is dramatically reduced as compared with 14 to 15% of the conventional example, and the moldability is improved. You can see that

It should be noted that, in the present embodiment, although the natural color was developed by the anodizing treatment after the drawing process, it goes without saying that the aluminum alloy of the present invention can be used as a drawing material which does not require the anodizing process.

[0015]

INDUSTRIAL APPLICABILITY The aluminum alloy for drawing according to the present invention can improve the formability by adjusting the alloy composition and achieve a reduction in the drawing ear rate of the drawn product. In this case, each process such as casting, rolling and annealing may be performed by an ordinary general method, and no special condition setting or additional process is required in each of these processes.
Therefore, it is possible to simplify the conventional manufacturing process of a complicated raw plate to improve the productivity of the drawn product, and to increase the material yield due to the reduction of the ear reduction ratio to reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a perspective view of a drawn product.

[Explanation of symbols]

 1 ... ear 2 ... valley

Claims (2)

[Claims] 1. Fe: 0.5 to 2.0 wt%, Cr: 0.
1 to 1.0 wt% is included, and Si is 0.4 wt
%, Cu; 0.2 wt% or less, the balance being aluminum and inevitable impurities, and an aluminum alloy for drawing. 2. Fe: 0.5 to 2.0 wt%, Cr: 0.
1 to 1.0 wt%, Ti; 0.1 wt% or less, and Si: 0.4 wt% or less, Cu: 0.2 wt% or less, the balance is aluminum and inevitable impurities Aluminum alloy for drawing.