JPS6037186B2 - Manufacturing method of Al-Mn-Mg alloy hard plate with excellent deep drawing workability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a Yamaichi Mn-Mg alloy hard plate having excellent deep drawability, and in particular to a method for producing a so-called D1 (DeepDraw) hard plate.
The purpose of the present invention is to provide an appropriate method for manufacturing an N-Mn-Mg alloy hard plate having excellent properties as a can stock.

Aluminum alloy plates for so-called DI cans are ironed after deep drawing, so they are required to have high strength and have a low deep drawing selvage ratio (for example, 4% or less), as well as to prevent surface roughness during processing. In addition, there are demands for various properties that are suitable for deep drawing, such as ease of processing, and aluminum alloys with Mn: 1.0 to 1.0 are required to meet these demands.
5% by weight, Mg: 0.8-1. Round weight %, Feo. 2～
0.7% by weight, Si: 0.1 to 0.3% by weight,
Ti: 0.05% by weight or less, B: 0.05 as necessary
Aluminum alloys have been developed that contain one or more of Cu: 0.2% by weight or less, with the balance consisting of AI and unavoidable impurities.
It is utilized under the name 004 alloy.

The composition ranges of Mn, Mg, Fe, and Si in this alloy are determined from the viewpoints of strength, critical drawing ratio, reduction of selvage variation, prevention of rough skin and flow marks, etc., taking into account the interaction between each component. Ti and B are added as crystal refiners, and Cu is added to improve grain quality and deep drawability. By the way, even if this alloy has the above-mentioned properties, the product properties vary depending on the heat treatment conditions and processing conditions. For example, homogeneous treatment → hot rolling → cold rolling → intermediate cold rolling → final cold rolling →
In the conventional general method for manufacturing products, increasing the cold working rate in order to obtain appropriate product strength greatly increases the selvage in the 450 direction of rolling. If blunting is performed, the surface may become rough, and in particular, it is difficult to stably obtain a deep-drawn selvage ratio of 4% or less in practice. The present invention was devised after repeated studies in view of the above-mentioned circumstances, and includes an aluminum alloy having the above-mentioned alloy composition, which is subjected to, for example, homogenization treatment, hot rolling, cold rolling, and then a partial phosphorous annealing process. The product is then subjected to light cross-rolling and final annealing to produce a final cold-rolled product, and in this case, the product is deep-rolled by performing it under conditions that satisfy the following conditions. A hard aluminum alloy plate with excellent drawing workability can be stably obtained. That is, prior to hot rolling an aluminum alloy ingot having the composition as described above, it is homogenized by heating in one stage or in multiple stages at a temperature of 530 to 61,000 for 1 to 24 hours.

This homogenization treatment is effective for improving the strength, ballability, and deep drawing workability of the final board, as well as reducing variations in the deep drawing edge ratio, and is effective when the homogenization process is less than 530 minutes or less than 1 hour. Since sufficient homogenization cannot be obtained in any case, it becomes difficult to impart a large 00 to 9 azimuth radius during phosphor dulling before final cold rolling. If the homogenization process exceeds 61,000, the surface of the coin will swell, and no significant effect will be obtained even if the coin is heated for more than two hours. The ingot homogenized as described above is hot rolled to a thickness of 3 to 1 mm, preferably 5 to 7 mm.

Note that coin coins are usually manufactured by semi-continuous casting to have a cross-sectional thickness of about 300 to 60 meters, and regardless of the thickness of the coin coins, the hot rolled finish should be in the range of 3 to 1 inch as described above. If it is less than 3 ribs, rough skin tends to occur, and if it is more than 1 rib, 45o azimuth ears are likely to appear and winding and other handling during coiling becomes difficult. The hot-rolled sheet as described above is subsequently cold-rolled at a processing rate of 50 to 85% to impart appropriate processing strain.

In this case, if the working rate is 85% or more, the crystal structure that causes the 45o-oriented ears will grow significantly, which is undesirable, and if it is less than 50%, it is impossible to obtain an appropriate working strain due to cold rolling. As mentioned above, in the present invention, the rolled material obtained as described above is further subjected to partial sintering, mild cold rolling, and final solidification steps, and then subjected to normal cross-rolling to be manufactured into a product. , this part of Akatsuki Anchor is 230
It is carried out for about 10 minutes to 2 hours at a temperature of ~27,000℃,
In general, a refining effect called ``H, 24, and 2 Kowaki treatment'' is expressed, and the recrystallization rate is about 25 to 75%, and the 00 to 900 direction ears are sufficiently removed in the final round treatment. make sure you get it. In this case, the treatment effect is insufficient at temperatures below 230°C and below 1 minute;
If the treatment is for more than 0 pi or for more than 2 hours, recrystallization will be more than 75%, making it impossible to properly obtain 0-900 azimuth ears, and will also lead to coarsening of crystal grains, causing rough skin, both of which are undesirable. It happens. It is desirable that the mild cold rolling after the above-mentioned partial racing anchor be carried out in the range of 5 to 35%, and if it is less than 5% or more than 35%, after the final Akatsuma process, it will be 0 to 900 azimuth rolling. This means that you will not be able to obtain enough. The final annealing is performed at a temperature of 300 to 50 picoC for 30 minutes or more and about 5 hours.

In other words, the effects of each step as described above and this final mark are combined to produce a 1 to 5% oo to 90o orientation selvage in the next rolling.
% final cold rolling. As a result, even if the 450 selvage is produced, it is offset by the 00 to 900 azimuth selvage imparted in the previous process, and a board having the desired deep-drawn selvage ratio of 4% or less is obtained as a whole, and at the same time, the desired strength is obtained. A plate material with workability is obtained. Although it is possible to stably obtain a plate material with a deep-drawn selvage ratio of 4% or less by going through the above process, as a result of the inventors' studies regarding such a plate material, it is not necessarily preferable for rough skin conditions. As a result of repeated investigations into the cause of this problem, it was found that the rate of temperature rise to the competitive anchor temperature is an important factor in the final shogun process, and an appropriate I learned that if the conditions are not met, the product will cause skin irritation.

That is, it was confirmed that when homogenization treatment at 530 to 6100 C was performed, if the temperature increase rate in the final annealing step was not 35 qo/hr or more, coarsening of recrystallization would occur, resulting in rough skin. That is, this tendency is remarkable when a homogenization treatment of 530 to 57 psi is performed, and in this case, it is desirable to set the temperature increase rate to 100 qC/hr or more. Note that as a method for achieving this temperature increase rate of 3 mm/hr, a hot blast furnace, an electric heating furnace, a salt bath furnace, or a Rentsugi annealing furnace may be appropriately used. N- of the present invention as described above
A specific example of manufacturing a Mn-Mg alloy hard plate is as follows.

Example 1 Mn: 1.09% by weight, Mg: 1.2% by weight, Fe:
0.49 weight%, Si: 0.2 box weight%, Ti: 0.0
A DC coin coin with a thickness of 508 ribs made of aluminum alloy containing 4% by weight was heated at 550qC for 7. Immediate homogenization was carried out and hot rolled to 5.8 mm.

The hot rolling start temperature is 540°C, and the finishing temperature is 32°C.
It was perfect. This material was then cold-rolled at a processing rate of 75%, then partially phosphorous-annealed for 30 minutes at 5-level temperature conditions and mildly cold-rolled at 7-level temperature conditions, and further heated to 100% in a hot air oven.
Raise the temperature at a heating rate of qo/hr to 1 at 400 pm.
A final phosphor dulling process was carried out for an hour, and then a final cold rolling process was carried out at a processing rate of 68% to obtain a plate material with a skin thickness of 0.42. A deep drawing test was performed on the final phosphor-annealed plate material obtained as described above, and the results are shown in Table 1 below.

Table 1: Deep-drawn selvage ratio of final phosphorus-blunt treated material [Note] 00-900 azimuth selvage is indicated by a numeral 10, and 450 azimuth selvage is indicated by a - number.

The same applies to Table 2. Also, is the condition for measuring the deep drawing selvage rate a punch diameter of 50 ribs? , a drawing ratio of 52%, a die clearance of 19%, and a wrinkle presser load of 1000k9.

In other words, according to Table 1, 45o azimuth lugs are greatly desired for partially baked hokobemura (cold rolling processing rate 0%), whereas other types that have been partially cold rolled and then lightly cold rolled are Things are 0
It can be understood that a metal structure with 0 to 900 azimuth ears is formed, and in order to moderately develop this oo to 90 o azimuth ears, the cooling anchor temperature range is 220 to 270q.
It can be understood that it is preferable that the vertical cold rolling processing rate be in the range of 5 to 35%. Further, the deep drawing selvage ratio measurement results for the final cold rolled material are shown in Table 2 below. Table 2 Deep drawing selvage ratio of final cold-rolled material Note: Deep drawing was not possible with × marks.

According to Table 2 of the cover, the range in which an appropriate direction ear is developed is slightly narrower than that of Table 1, with a partial hammer temperature of 230 to 2.
70qo (light cold working rate is 5 to 35%), and it is clear that this makes it possible to develop the 00 to 900 azimuth selvage while at the same time reducing the appearance of the 450 azimuth selvage.

Example 2 A DC coin coin having the same composition and size as in Example 1 was homogenized and hot rolled under the conditions shown in Table 3 below to obtain a plate material with a side thickness of 5.8 mm.

3 This hot rolled plate was cold rolled at 260°C with a processing rate of 75%.
After partial annealing and mild cold rolling at a processing rate of 13%, the temperature increase rate was changed to 10 qo/hour, 25 qo/hour, 35°C,
The temperature was changed to 10,000 and 1,000 qC, then the final branding was performed by raising the temperature to 40,000 and holding it for 2 hours, followed by cold rolling at a processing rate of 67% to obtain a plate with a rib thickness of 0.42.

A deep drawing test was conducted on this plate in the same manner as in Example 1, and the degree of roughness of the surface was measured. The results are shown in Table 4 below. Table 4 Skin roughness measurement results [Note] ○...No rough skin, ×...Rough skin, ■
...Slightly rough skin, △...Slightly rough skin. In other words, as shown in Table 4, to prevent rough skin during deep drawing, it is desirable to increase the temperature at a rate of 35 qo/hr or more during final annealing. As a result, it is possible to keep the size of the crystals at the end of the final phosphorous dulling to about 30 to 100 r, and it is possible to prevent rough skin.

According to the present invention as explained above, it is possible to accurately obtain an appropriate AI-Mn-Mg alloy hard plate that has high strength that can withstand deep drawing processing, has a low deep drawing selvage rate, and does not cause roughness during processing. This invention is industrially highly effective.

Claims (1)

[Claims] 1 Mn: 1.0-1.5% by weight, Mg: 0.8-1.
3% by weight, Fe: 0.2-0.7% by weight, Si: 0.1
~0.3% by weight, optionally containing Ti: 0.05
By heating an aluminum alloy ingot containing one or more of B: 0.05% by weight or less, Cu: 0.2% by weight or less, and the remainder consisting of Al in one or multiple stages. After homogenization treatment at a temperature of 530°C to 610°C for 1 to 24 hours, hot rolling to a thickness of 3 to 10 mm, followed by cold rolling at a processing rate of 50 to 85% and 230 to 270 mm.
Partial annealing was performed at ℃ for 10 minutes to 2 hours, and then the processing rate was 5.
After performing a mild cold rolling of ~35%, the material was heated to a temperature of 300 to 500°C at a heating rate of 35°C/hr or more, and subjected to final annealing for 30 minutes or more, and further processed at a processing rate of 50 to 90.
A method for producing an Al-Mn-Ag alloy hard plate having excellent deep drawing workability, the method comprising subjecting the plate to a final cold rolling of %. 2. Al-Mn-Mg with excellent deep drawability according to claim 1, wherein the homogenization treatment is performed at 530 to 570°C and the temperature increase rate during final annealing is 100°C/hr or more.
Method for manufacturing hard alloy plates.