JPS58224142A - Aluminum alloy plate with superior formability and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a fine-grained Al alloy plate with superior formability by single process annealing by subjecting an Al alloy having a specified composition after homogenizing to final cold rolling to a specified thickness at a specified draft. CONSTITUTION:An Al alloy contg. two or more among 0.1-0.7% Si, 0.3-1.0% Fe, 0.3-1.5% Mn and 0.01-2.0% Mg is homogenized. The alloy is cold rolled at about 480-580 deg.C starting temp. and >= about 290 deg.C finishing temp., optionally cold rolled, and annealed at about 400-570 deg.C for <=5min. It is then subjected to final cold rolling to <=0.3mm. thickness at >=20% draft. The grain size can be made as fine as <=25mum, so the workability can be improved. Since process annealing is required only once, energy necessary for the heat treatment and the cost are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aluminum alloy plate, such as an alloy plate for camping, which has excellent deep drawability, a low selvage ratio, and appropriate strength, and a method for manufacturing the same.

Conventionally, in order to obtain various objects in aluminum alloy sheets such as those for deep drawing, the following steps have been carried out: ingot formation, sufficient homogenization treatment, hot rolling, (cold rolling), intermediate annealing, cold rolling, and intermediate rolling. Each step of annealing and cold rolling is combined, and heating is applied for a sufficiently long time by homogenization and two or more intermediate annealing steps.

In this conventional method, the crystal grains of the alloy plate have a size of 50 to 100 μm due to the addition of a long intermediate annealing. When the crystal grains become large as described above, the formability deteriorates, and in order to particularly improve the formability of thin plates with a thickness of 0.3 tm or less, it is necessary to further reduce the crystal grains. Further, 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 is Sj O81-0.7%, Fe 0.3
~1.0%, Mn 0.3-1.5%, Mg 0.0
Made of an aluminum alloy containing two or more of the following: This is an aluminum alloy plate with excellent formability.

Si and Mg provide strength and formability, and FeXMn provides strength and has the effect of controlling the size of ears that occur during deep drawing. Exceeding the upper limits of each component and '□ is not preferable because it reduces moldability.

Moreover, if the amount has a lower limit, the effect will be small if the amount is less than the lower limit.

When such a composition is subjected to a final cold rolling of 20% or more in a predetermined process to have a thickness of 0.3111111 or less, the crystal grain size can be reduced to 25 μm or less, and it has excellent formability.

Such an aluminum alloy plate with excellent formability is obtained by the second invention. Susuwachi, the second invention is Si
0.1-0.7%, F'e O, 3-1.0%, Mn
0.3-1.5%, Mg0.01-2. 2 out of 0%
After homogenizing an aluminum alloy containing more than one species,
After starting hot rolling at 480 to 580°C, finishing hot rolling at 290°C or higher, and performing cold rolling as necessary, 4
Annealing treatment at oo~570℃ for 5 minutes or less, 20%
This is a method for producing an aluminum alloy sheet with excellent formability, which is characterized in that the final cold rolling described above is carried out to reduce the crystal grain size to 25 μm or less.

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 Fe and alloys containing 0.3% or more of Fe are 560
Although it is necessary to homogenize at a temperature of 8° C. or higher for 8 hours or more, an alloy containing mainly ceramic and Si may require a lower temperature and a shorter time.

Further, two-stage heating may be performed to control the selvage ratio.

Hot rolling may be performed by cooling after homogenization treatment and then 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 into a 3-piece thick plate, the temperature is 260-28℃.
It becomes 0℃. Therefore, rolling start temperature, reduction rate, number of baths,
The rolling speed, lubricating oil temperature, etc. are adjusted so that the hot rolling end temperature is 290°C or higher, more preferably 310°C or higher.

This is the most important condition because it controls the selvedge ratio and at the same time, the precipitation of alloy components that progresses after rolling has the effect of improving the workability of the final plate.

Most of the final sheets used for the intended use of the alloy sheet of the present invention have a final cold rolling amount of 0.4 tar or less and a final cold rolling amount of 2.
Since the thickness is 0 to 60 inches, intermediate annealing is usually performed at a thickness of 1 mt or less, and a cold rolling process is required following the hot rolling process. However, if the final plate thickness is 0.4 mm, the cold rolling process is not necessary. Therefore, the cold rolling process is performed as necessary.

The 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. Annealing temperature is 400℃
If it is less than <<, recrystallization progresses and recrystallization takes a long time, resulting in a weakened effect. The maximum annealing temperature is the melting point of the material. Furthermore, in order to avoid the growth of crystal grains 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 6°. If it is less than 20%, the strength will not be sufficiently exhibited, and if the
% or more, workability may deteriorate depending on the material.

Furthermore, since the material strength of an alloy plate containing Arashi may decrease when left at room temperature, it may be subjected to stabilizing heat treatment at a temperature below the recrystallization temperature in advance.

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 Si0.65%, Fe0.82%, CuO,04%,
Mn 0.01%, Mg 0.01%, Zn 0.01%
, Ti, a 0.0”・At””! J l a&!
a#jJl[FIJ L・Homogenized at 580°C for 10 hours, cooled to 540°C, and immediately hot rolled to 2.8 w
m t. At this time, the material temperature at the end of rolling was 32
It is 0°C. This was cold worked to 0.33 IOIt, heat treated at 540°C for 5 seconds, and finally cold worked to 30 inches to 0.23IOIt.

The properties of the obtained 0.23 mmt plate are as shown in the table, 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, solidified, reheated to 520°C, hot rolled to 5 mt, and intermediately annealed at 400°C for 1 hour. Cold rolled to 0.33 wqt, intermediate annealed again at 400°C for 1 hour, and final cold rolled to 30% to 0.33 wqt.
A 23 mmtO plate was used. The characteristics of this board are shown in the table.

Example 2 SiO, 15%, FeO, 54%, CuO, 12%
, Mn 0.4891=, Mg 0.80%, Cr 0
．． An ingot of an alloy consisting of 01% Ti, 102% Ti, and the remainder At was solidified and heated at 590°C for 5 hours, then lowered to 500°C.
Homogenized at 40℃ for 5 hours and immediately hot rolled to 2.4M
It was set as t. The material temperature at the end of rolling at this time is 310℃
Met. This was cold worked to 0.29mt, and 4
Heat treatment was applied at 50°C for 20 seconds, and final cold working of 30 inches was performed to form a 0.20wnt plate.

The properties of the obtained 0, 20 + emt roots are as shown in the table, and the formability is improved due to 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, solidified, reheated to 480°C, hot rolled to 6mmt, and further cold worked to 2.5mm. tta
nt, intermediate annealing at 360°C for 1 hour, cold working to 0.29mmt, intermediate annealing again at 360°C for 1 hour, and final cold working of 30 inches. .20mmt plate. The characteristics of this board are shown in the table.

Example 3 SiO, 30%, F”e O, 61%, Cu O, 16
%, Mn 1.2%, Mg O,o 1%, At remainder
After homogenizing the ingot at 595°C for 10 hours, the ingot was heated to 560°C.
It was cooled to 2.2 wry+t and hot rolled. At this time, the grain temperature at the end of rolling was 332°C.

This was cold-worked to 0.31 mmt, subjected to high-speed short-time annealing at 500°C for 10 seconds, and then final cold-worked to 25 inches to form a 0.23W+ plate.

The properties of the obtained 0.23 mt plate are as shown in the table, 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, solidified, reheated to 540°C, and hot rolled. Otan t and further cold worked to 1.5
mt, intermediate annealing at 360-380°C for 1 hour, cold working to 0.31TfnRt, and then 360-380°C again.
An intermediate annealing was performed at 380° C. for 1 hour, and a final cold working of 25% was performed to obtain a 0.23w1t plate. The characteristics of this board are shown in the table.

Example 4 Si0.14%, Fe 0.35%, CuO, 06%
, Mn 0.35%, Mg 1.55%, CrO,02
%, Zn001%, TiO,04%, At balance was homogenized at 550°C for 10 hours, and then hot rolled at 500°C. Orrant and Toshida. At this time, the material temperature at the end of rolling was 298°C. This was cold-worked to 0.6 mm t, high-speed short-time annealing at 500°C for 60 seconds, and then final cold-worked to 58% to 0.
．． Toshida 25mmt plate.

The properties of the obtained 0.25mmt plate are as shown in the table.
In Comparative Example 4 described later, it was not possible to reduce the 45-4 direction ear ratio that develops with the final cold rolling amount, but
In this example, the selvage ratio is reduced and at the same time the moldability is improved.

Comparative Example 4 The alloy ingot in Example 4 was solidified, homogenized at 550°C for 10 hours, cooled to 500°C, hot rolled to 3.0mmt, and further cold worked to 0.6mmt.
After that, intermediate annealing was performed at 360°C for 1 hour, and 5
The final cold working of Section 8 was made into a 0.25 mmt plate. The characteristics of this board are shown in the table.

Claims (1)

[Claims] (1) Si 0.1-0.7%, FeO, 3-1
．． 0%, Mn0.3-1.5, Mg0.01-2.
Made of an aluminum alloy containing two or more of the following:
An aluminum alloy plate with excellent formability, characterized in that the crystal grain size is 25 μm or less when the value is 25 μm or less. (21SiO, 1-0.7%, FeO, 3-1.0%
After homogenizing an aluminum alloy containing two or more of the following: 0.3% to 1.5% Mg and 0.01% to 2.0% Mg, hot rolling was started at 480°C to 580°C and then rolled to 290°C. After completing hot rolling and performing cold rolling as necessary, annealing treatment is performed at 400 to 570°C for 5 minutes or less, and
A method for producing an aluminum alloy sheet with excellent formability, which comprises performing a final cold rolling of 0 mm or more to have a crystal grain size of 25 μm or less.