JPS63238903A - Aluminum sheet and aluminum alloy sheet for deep drawing - Google Patents

Abstract

PURPOSE:To improve the critical drawing coefficient of Al sheets for deep drawing at deep drawing by rolling by rolls whose surface is roughened by specifying a max. roughness and the number of holes deeper than a specified depth in a specified measuring length. CONSTITUTION:Rolling is performed by a roughened surface rolling roll so that a surface of Al and Al alloy sheets has a max. roughness (R max) of 2-20 mu in a 25.4 mm measuring length L and >=25 holes whose depth H of >=1.27 mu in the 25.4 mm measuring length. Thus, the surface of rolled Al and Al alloy sheets A is roughened and the critical drawing coefficient at deep drawing work is improved and the deep drawability is increased.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an aluminum plate and an aluminum alloy plate for deep drawing. This invention relates to aluminum plates and aluminum alloy plates coated with fluororesin for deep drawing of kitchen utensils, automobile parts, household appliance parts, etc.

[Prior Art] Conventionally, aluminum plates and aluminum alloy plates for deep drawing have a so-called dull finish (DC).
C plates and BC plates with a bright finish (BC) are generally used.

The issues that have been pointed out in the past regarding deep-drawn products are: (i) Reducing the occurrence of flow marks and ears.

(ii) Increasing the limiting drawing ratio (LDR).

etc.

In particular, in order to improve the dimensional accuracy of deep-drawn products, the clearance between the punch and die is reduced, and high-strength materials are often used to reduce thickness and weight. In the current situation, it is becoming more and more difficult to improve the limit drawing ratio (LDR) because increasing the drawing ratio will cause more cracks to occur during processing.

In order to solve the problems that have been pointed out in the past (iXi;), we have traditionally tried to optimize the alloy composition and manufacturing method of the material,
Improvements in the deep drawing process (including improvements in lubricants) are being considered, but sufficient results have not been achieved.

Regarding the conventional problem (i), the present inventor has already discovered that when rolling aluminum plates and aluminum alloy plates, the surface of the plate is changed to that of a conventional DC plate or BC plate using a rolling roll with a roughened surface. By making it rougher than the board,
It was discovered that the occurrence of flow marks and ears in deep-drawn molded products could be suppressed, and the application was previously filed (Japanese Patent Application No. 193431-1982).

Then, as a result of further research into the relationship between plate surface roughness and deep drawability, the inventor found that by roughening the plate surface within a certain upper limit, flow He discovered that it was possible to suppress the occurrence of marks and ears, and also improve the limiting drawing ratio (LDR), and completed the application (Patent Application No. 60-0280).
No. 81).

[Problems to be Solved by the Invention] The present invention is based on the inventor's further research on the shape of the surface roughness of aluminum plates and aluminum alloy plates for deep drawing, which have been conventionally used for deep drawing, as explained above. We discovered that the limiting drawing ratio (LDR) could be improved by regularly arranging holes of approximately the same shape, rather than simply creating ridges randomly on the surface of aluminum plates and aluminum alloy plates. They developed aluminum plates and aluminum alloy plates.

[Means for Solving the Problems] The aluminum plate for deep drawing and the aluminum alloy plate according to the present invention have a maximum roughness within a measurement length of 25.4 μm (Rm
ax) A rolling roll with a roughened surface, characterized by having 25 or more holes with a diameter of 2 to 20 μm and a depth of 27 μm or more per hole within a measurement length of 25.4 μm. These are aluminum plates and aluminum alloy plates for deep drawing that are produced by rolling.
゛The aluminum plate for deep drawing and the aluminum alloy plate according to the present invention will be explained in detail below.

That is, at least in a direction parallel or perpendicular to the rolling direction,
25.4 The maximum roughness (Riax) within the measurement length of the dragon is 2 μm
Below and when the number of holes is 25 or less, the limit drawing ratio (L
D R) could not be improved, and 25.41
The maximum roughness within the measurement length of 1111 (R+ax) is 20 μm
If it exceeds , the critical drawing ratio (LDR) will be lower than that of a conventional roughened plate. Therefore, the maximum roughness (Rg+ax) within the measurement length of 25.4 flIm is set to 2 to 20 pm, and the number of holes within the measurement length of 25.4 mm is set to 25 or more.

FIG. 1 shows a schematic diagram of an aluminum plate for deep drawing and an aluminum alloy plate according to the present invention.

On the surface of the aluminum plate and aluminum alloy plate A,
At least 25 in the direction parallel or perpendicular to the rolling direction.
．． The maximum roughness RIIlax) within the measurement length l of 4+nm is 2-20 μm, and there are 25 or more holes W with a depth of 8.27mm or more within the measurement length l of 25.4mm. [Example] Examples of an aluminum plate for deep drawing and an aluminum alloy plate according to the present invention will be described.

Example 25. At least in the direction parallel or perpendicular to the rolling direction.
Various aluminum alloy plates with different maximum roughness (Rmax) and number of holes within the measurement length of 4+am were deep drawn using Daphne Mechanic Oil, and the limit drawing ratio (LDR) and productivity were determined. Table 1 shows the results of the quality inspection.

From Table 1, the following is clear.

The aluminum alloy plate for deep drawing according to the present invention (present invention material) has an improved critical drawing ratio (t, DR) compared to the comparative material.

Furthermore, when comparing various materials of the present invention, the maximum roughness (Rma
x) is within the range from the lower limit of 2 μl to around 10 μm for the present invention material, the limiting drawing ratio (LDR) improves as the maximum roughness (Rmax) increases, but the maximum roughness (Rmax)
When x) approaches the upper limit of 20 μm for the material of the present invention, the limiting drawing ratio (LDR) gradually decreases.゛Furthermore, even if the maximum roughness is 2 μm or more, the limit drawing ratio (LDR) decreases when the hole depth is 27 μI.

Note that if the number of holes is excessively large as in m material 2.3.4, productivity will decrease, so the number of holes should be 200, for example.
It is better to keep it to less than 1. The reason why productivity decreases due to an increase in the number of holes is due to the limit of the transfer ability of the roll and clogging. Note that the same applies not only to aluminum alloy plates but also to aluminum plates.

*:○...Good, Δ...Slightly bad, ×...Poor.

[Effect of the invention - As explained above, since the aluminum plate and aluminum alloy plate for deep drawing according to the present invention have the above configuration, the surfaces of the aluminum plate and aluminum alloy plate are roughened. , Limit drawing rate during deep drawing (
This is a problem that has the excellent effect of improving deep drawing workability because it can improve LDR).

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an aluminum plate for deep drawing and an aluminum alloy plate according to the present invention.

Claims (1)

[Claims] 25.4μ in the direction parallel or perpendicular to the rolling direction
Maximum roughness (Rmax) 2 to 20μ within the measurement length of m
m, and the depth within the measurement length of 25.4 μm is 1
．． An aluminum plate for deep drawing and an aluminum alloy plate manufactured by rolling with a rolling roll having a roughened surface, characterized in that the number of holes of 27 μm or more is 25 or more.