JPS6140299B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an aluminum alloy plate, such as an alloy plate for caps, which has excellent deep drawability, low selvage ratio, and appropriate strength, and a method for manufacturing the same. Conventionally, in order to obtain the properties of aluminum alloy sheets such as those for deep drawing described above, the following steps have been taken: ingot formation - sufficient homogenization treatment - hot rolling - (cold rolling) - intermediate annealing - cold rolling - intermediate annealing. By combining each step of cold rolling, homogenizing and intermediate annealing two or more times,
It is heated for a sufficiently long time. In this conventional method, the crystal grains of the alloy plate have a size of 50 to 100 μm due to the long intermediate annealing. When the crystal grains become large in this way, formability deteriorates, and in order to particularly improve the formability of thin plates with a thickness of 0.3 mm or less, it is necessary to further reduce the crystal grains. or,
It is preferable to carry out intermediate annealing once, rather than twice or more, from the viewpoint of process simplification and energy saving. That is, it is meaningful to carry out intermediate annealing once, and to refine the crystal grains in this single intermediate annealing so that the formability and selvage ratio are at least the same as those of conventional materials. The present invention was invented based on the above viewpoints, and the first invention includes Si0.1 to 0.7%, Mg0.01 to
2.0% (preferably 0.3-20%), any one or two of Fe0.3-1.0%, Mn0.3-1.5%, and Cu0.03-0.3% ( Preferably
0.04 to 0.25%), and the remainder consists of aluminum and impurities, which are aluminum alloys, and the crystal grain size is 25 μm when final cold rolling is performed from 20% to 60% to a plate thickness of 0.3 mm or less. This is an aluminum alloy plate with excellent formability, which is characterized by the following: Both Si and Mg provide strength and formability,
Both Fe and Mn have the effect of imparting strength and controlling the size of ears that occur during deep drawing. Cu has the effect of controlling strength, formability, and the size of ears that occur during deep drawing, but it also has the effect of reducing corrosion resistance. Considering these advantages and disadvantages, the content is set to 0.03% or more and 0.3% or less, preferably 0.04 to 0.25%. If there is too little, there will be no advantage, and if there is too much, the disadvantages will become apparent. Exceeding the upper limit of each component is undesirable because moldability deteriorates. Moreover, those having a lower limit have a smaller effect than the lower limit. Impurities such as Zn, Ti, Cr, etc. do not affect the present invention as long as they are each 0.05% or less, so there is no problem even if they are included. Products with such compositions have a concentration of 20% or more due to a prescribed process.
When final cold rolling is performed to a thickness of 0.3 mm or less by 60% or less final cold rolling, the crystal grain size can be reduced to 25 μm or less, resulting in excellent formability. Such an aluminum alloy plate with excellent formability is obtained according to the second invention. That is, the second invention has Si, 0.1 to 0.7%, Mg 0.01 to 2.0%.
(preferably 0.3 to 2.0%) or two
Seeds and either Fe0.3~1.0% or Mn0.3~1.5%
species or two species and Cu0.03 to 0.3% (preferably 0.04
~0.25%), and the remainder is Al and impurities, which are aluminum alloys, are homogenized and then 480~580%
Start hot rolling at ℃, finish hot rolling at 290℃ or higher and 350℃ or lower, then cold roll at 400~570℃
Excellent formability characterized by annealing for 5 minutes or less and final cold rolling of 20% or more and 60% or less, resulting in a grain size of 25μm or less when the plate thickness is 0.3mm or less. This is a method for manufacturing an aluminum alloy plate. First, homogenization treatment is one of the factors that changes the selvage ratio of the alloy plate, and is generally performed at as high a temperature as possible, just below the melting temperature, but for a sufficient period of time. Alloys containing 0.5% or more of Mn must be homogenized at 560°C or higher for 8 hours or more, but
For alloys mainly containing Si, lower temperatures and shorter times may be required. Furthermore, two-stage heating may be performed to control the selvage ratio. Hot rolling may be performed by cooling after homogenization treatment and reheating. In that case, changes in the structure of the ingot during cooling and reheating affect the selvage ratio, so the heating temperature may be different from that in the case of subsequent hot rolling after homogenization treatment. The material temperature at the end of hot rolling must be high enough to recrystallize the material. When hot-rolled from 500℃ under normal conditions to a 3mm thick plate,
The temperature will be 260-280℃. Therefore, we made improvements to the rolling start temperature, rolling reduction rate, number of passes rolling speed, lubricating oil temperature, etc., to increase the hot rolling end temperature to 290℃ or higher.
More preferably, the temperature is 310°C or higher. Furthermore, if the temperature exceeds 350°C, the surface of the plate will be severely oxidized, which may cause defects in appearance, which is not preferable. Therefore, the hot rolling finish temperature is 350℃
Make it as follows. This is the most important condition because it controls the selvedge ratio and at the same time, the precipitation of alloy components during rolling has the effect of improving the workability of the final plate. The final plate used for the purpose of the alloy plate of the present invention is 0.3 mmt or less and has a final cold rolling amount of 20 to 60 mm.
%, therefore, intermediate annealing is usually performed at a thickness of 1 mm or less, and cold rolling must be performed following the hot rolling process. Subsequent annealing is performed at high temperature for a short time to improve workability. Industrially, a coiled plate is unwound and passed through a high-temperature furnace for heat annealing. If the annealing temperature is less than 400°C, recrystallization will be difficult to proceed, requiring a long time for recrystallization, and the effect will be diminished. The maximum annealing temperature is the melting point of the material.
Furthermore, in order to avoid crystal grain growth when the temperature is high, the treatment time must be shortened, and must be 5 minutes or less. The optimum final cold rolling is 20% or more, especially 20% to 60%. If it is less than 20%, the strength will not be fully demonstrated,
Moreover, if it exceeds 60%, the workability may deteriorate depending on the material. Furthermore, since the material strength of alloy plates containing Mg may decrease when left at room temperature, stabilization heat treatment may be applied in advance at a temperature below the recrystallization temperature. By going through each of the above steps, in the second invention, the crystal grain size can be reduced to 25 μm or less, and workability is improved. Moreover, since intermediate annealing only needs to be performed once, the energy cost required for heat treatment can be reduced, and it is also possible to reduce in-process costs by shortening the manufacturing process. Next, examples and comparative examples will be explained. Example 1 An ingot of the alloy shown in Example 1 in Table 1 (alloy composition) was faceted, homogenized at 580°C for 10 hours, cooled to 540°C, and immediately hot rolled to a thickness of 2.8 mm. At this time, the material temperature at the end of rolling was 320°C. This was cold worked to a thickness of 0.33mm, heat treated at 540℃ for 5 seconds, and finally cold worked to a thickness of 30% to a thickness of 0.23mm.
It was set as t. The properties of the obtained 0.23 mmt plate are shown in Table 2, and the formability is improved despite the fact that less heat energy is applied during the manufacturing process. Comparative Example 1 The alloy ingot in Example 1 was homogenized at 580°C for 10 hours, cooled, faced, reheated to 520°C, hot-rolled to 5 mmt at a finishing temperature of 312°C, and heated at 400°C for 1 hour. After intermediate annealing, cold rolling to 0.33mmt
Then, intermediate annealing was again performed at 400℃ for 1 hour, and 30℃
% final cold rolling to produce a 0.23 mmt plate. The properties of this plate are shown in Table 2. Example 2 An ingot of the alloy shown in Example 2 in Table 1 was face-milled,
After heating at 590°C for 5 hours, the temperature was lowered and homogenized at 540°C for 5 hours, followed by immediately hot rolling to a thickness of 2.4 mm, at which time the material temperature at the end of rolling was 310°C. This was cold worked to 0.29mmt at 450°C.
A heat treatment was applied for 20 seconds, followed by a final cold working of 30% to produce a 0.20 mmt plate. The properties of the obtained 0.20 mmt plate are shown in Table 2, and the formability is improved by finer grains, but the strength and selvage ratio are the same as those of Comparative Example 2, which will be described later. Comparative Example 2 The alloy ingot in Example 2 was homogenized at 580°C for 10 hours, cooled, faced, reheated to 480°C, hot rolled at a finishing temperature of 300°C to a thickness of 6 mm, and further cold worked. After that, it was intermediately annealed at 360°C for 1 hour, cold worked to 0.29mmt, and then intermediately annealed at 360°C for 1 hour, and then 30%
The final cold working process was carried out to produce a 0.20mmt plate. The properties of this plate are shown in Table 2. Example 3 An ingot of the alloy shown in Example 3 in Table 1 was heated at 595°C for 10
After time homogenization, cool to 560℃ and hot-roll 2.2
mmt. At this time, the material temperature at the end of rolling is
It was 332℃. This was cold worked to a thickness of 0.31 mm, subjected to high-speed short-time annealing at 500° C. for 10 seconds, and then final cold worked to a thickness of 25% to obtain a 0.23 mm thick plate. The properties of the obtained 0.23 mmt plate are shown in Table 2, and the crystal grains are fine and the drawing workability is improved. Comparative Example 3 The alloy ingot in Example 3 was homogenized at 580°C for 10 hours, cooled, faced, reheated to 540°C, hot rolled to 30mmt at a finishing temperature of 297°C, and further cold worked. After that, it was intermediately annealed at 360 to 380℃ for 1 hour and cold worked to 0.31mm.
Intermediate annealing was again performed at 360 to 380°C for 1 hour, and a final cold working of 25% was performed to obtain a 0.23 mmt plate. The properties of this plate are shown in Table 2. Example 4 An ingot of the alloy shown in Example 4 in Table 1 was heated at 550°C for 10
After time homogenization, it was hot rolled at 500°C to a thickness of 2.0 mm. At this time, the material temperature at the end of rolling was 298°C. This was cold worked to 0.6mmt and heated to 500°C.
After high-speed short-time annealing for 60 seconds, final cold working of 58% was performed to obtain a 0.25 mmt plate. The properties of the obtained 0.25 mmt plate are shown in Table 2, and in Comparative Example 4 described below, it was not possible to reduce the 45°-4 direction selvage ratio that develops with the final cold rolling amount. In the second embodiment, the selvage ratio is reduced and the moldability is improved at the same time. Comparative Example 4 The alloy ingot in Example 4 was heated at 550℃ after facing.
After homogenizing for 10 hours, cool to 500℃ and finish at 290℃
The plate was hot rolled to 3.0mmt, further cold worked to 0.6mmt, intermediate annealed at 360°C for 1 hour, and final cold worked to 58% to form a 0.25mmt plate. The properties of this plate are shown in Table 2. Example 5 An ingot of the alloy shown in Example 5 in Table 1 was treated in the same manner as in Example 1, except that the end temperature of hot rolling was 310°C, to obtain a plate of 0.23 mmt. The properties of the obtained plate were as shown in Table 2. Comparative Example 5 The alloy ingot in Example 5 was heated at 580°C after facing.
After homogenizing for 10 hours, hot rolling at 520℃ to finish temperature
5mmt at 315℃, intermediate annealing at 400℃ for 1 hour, cold working to 0.33mmt, annealing again at 400℃ for 1 hour, final cold working by 30% to 0.23mm.
mmt plate. The properties of this plate are shown in Table 2. Example 6 An ingot of the alloy shown in Example 6 in Table 1 was treated in the same manner as in Example 5, except that the end temperature of hot rolling was 302°C, to obtain a plate of 0.23 mmt. The properties of the obtained plate were as shown in Table 2. Comparative Example 6 The alloy ingot in Example 6 was processed into a plate under the same conditions as in Comparative Example 5, except that the end temperature of hot rolling was 310°C. The properties of this plate are shown in Table 2. Example 7 An ingot of the alloy shown in Example 7 in Table 1 was treated in the same manner as in Example 5, except that the finishing temperature of hot rolling was 315°C to obtain a plate of 0.23 mmt. The properties of the board were as shown in Table 2. Comparative Example 7 The alloy ingot in Example 7 was processed into a plate under the same conditions as in Comparative Example 5, except that the end temperature of hot rolling was 310°C. The properties of this plate are shown in Table 2. Example 8 An ingot of the alloy shown in Example 8 in Table 1 was heated at 550°C for 10
After time homogenization, it was hot rolled at 500°C to a thickness of 2.0 mm. At this time, the material temperature at the end of rolling was 300°C. This was cold worked to 0.6mmt and heated to 500°C.
After high-speed short-time annealing for 60 seconds, final cold working of 58% was performed to obtain a 0.25 mmt plate. The properties of the obtained plate were as shown in Table 2. Comparative Example 8 The alloy ingot in Example 8 was processed into a plate under the same conditions as Comparative Example 4, except that the hot rolling end temperature was 310°C. The properties of this plate are shown in Table 2. Example 9 An ingot of the alloy shown in Example 9 in Table 1 was treated in the same manner as in Example 2, except that the end temperature of hot rolling was 307°C to obtain a plate of 0.20 mmt. The properties of the obtained plate were as shown in Table 2. Comparative Example 9 The alloy ingot of Example 9 was processed into a plate under the same conditions as Comparative Example 2, except that the end temperature of hot rolling was 305°C. The properties of this plate are shown in Table 2. Example 10 An ingot of the alloy shown in Example 10 in Table 1 was treated in the same manner as in Example 2, except that the end temperature of hot rolling was 312°C, to obtain a plate of 0.20 mmt. The properties of the obtained plate were as shown in Table 2. Comparative Example 10 The alloy ingot of Example 10 was treated under the same conditions as Comparative Example 9 to form a plate. The properties of this plate are shown in Table 2. Example 11 An ingot of the alloy shown in Example 10 in Table 1 was treated in the same manner as in Example 2, except that the end temperature of hot rolling was 295°C to obtain a plate of 0.20 mmt. The properties of the obtained plate were as shown in Table 2. Comparative Example 11 The alloy ingot of Example 11 was processed into a plate under the same conditions as Comparative Example 2, except that the end temperature of hot rolling was 310°C. The properties of this plate are shown in Table 2.

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Claims (1)

[Claims] 1 Any 1 of 0.1 to 0.7% Si or 0.01 to 2.0% Mg
From an aluminum alloy containing one or two species, one or two of Fe0.3-1.0%, Mn0.3-1.5%, and Cu0.03-1.3%, with the remainder being Al and impurities. The grain size is 25 when the plate thickness is 0.3 mm or less by final cold rolling of 20% or more and 60% or less.
An aluminum alloy plate with excellent formability characterized by a particle size of less than μm. 2 Any 1 of Si0.1~0.7%, Mg0.01~2.0%
Homogeneous aluminum alloy containing one or two types, Fe0.3~1.0%, Mn0.3~1.5%, Cu0.03~0.3%, and the remainder being Al and impurities. After the chemical treatment, start hot rolling at 480-580℃, finish hot rolling at 290-350℃, cold-roll, and then perform annealing at 400-570℃ for 5 minutes or less. A method for producing an aluminum alloy sheet with excellent formability, characterized in that final cold rolling is carried out by 20% or more and 60% or less, and the crystal grain size is 25 μm or less when the sheet thickness is 0.3 mm or less.