JPH06172945A - Production of aluminum plate for building excellent in suitability to baking finish at high temperature - Google Patents

Abstract

PURPOSE:To produce an Al plate which very hardly undergoes the lowering of the material strength even by baking finish at a high temp. CONSTITUTION:An Al alloy ingot consisting of 0.8-1.5% Mn, 0.05-0.20% Cu and the balance Al with inevitable impurities is soaked, hot-rolled, cold-rolled and finish-annealed at 250-350 deg.C to obtain the objective Al plate which does not undergo or very hardly undergoes the lowering of the strength even by baking finish at a high temp. and ensures necessary strength (120-175N/mm<2>).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an aluminum plate used for an exterior panel of a building such as a building.

[0002]

2. Description of the Related Art A1100 material has been conventionally used as an aluminum plate used for exterior panels of buildings and the like. As this general manufacturing process, ingot-making → soaking treatment → hot rolling →
Building plate materials (plate thickness: 1 to 5 mm) are manufactured by the cold rolling process, and the plate materials are subjected to surface treatment such as painting or alumite at a curtain wall maker.

Regarding the aluminum plate for this kind of use,
Recently, high temperature baking coating such as fluororesin coating has been increasing from the viewpoint of corrosion resistance, weather resistance and stain resistance. However, with the conventional A1100 material, this high temperature baking treatment (usually 240
(-280 ° C.), the material strength is significantly reduced, and there is a problem that workability is significantly impaired in subsequent processing and handling.

It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a method for manufacturing an aluminum plate material in which the material strength is extremely reduced even by high temperature baking coating.

[0005]

Means for Solving the Problems The present inventor has completed the present invention as a result of comprehensively examining the component composition and manufacturing conditions of an Al plate in order to solve the above problems.

That is, Mn: 0.8 to 1.5%, Cu:
An Al alloy ingot containing 0.05 to 0.20% and the balance Al and unavoidable impurities is subjected to soaking treatment, followed by hot rolling and cold rolling, and finish annealing at 250 to 350 ° C. The gist is a method for manufacturing an aluminum plate for construction excellent in high temperature baking paintability, which is characterized by carrying out.

The present invention will be described in more detail below.

[Action]

In summary, the present invention has a composition in which Mn: 0.5 to 1.5% is added as compared with the conventional A1100 material, and finish annealing is performed at a temperature of 250 to 350 ° C. after cold rolling. The most characteristic is to do.

First, the reasons for limiting the composition of the Al alloy will be described.

Mn: Mn is added in order to increase the strength and prevent the strength from being deteriorated even by finish annealing and subsequent high temperature baking treatment. If it is less than 0.8%, the strength is greatly decreased, and If it exceeds 1.5%, the above-mentioned improvement effect will not be further improved, and the aluminum rolling process will be adversely affected.
(Eg, reduction of rolling speed, reduction of reduction amount per pass). Therefore, the amount of Mn added is set in the range of 0.8 to 1.5%.

Cu: Cu is basically the same as the specified range (0.05 to 0.20%) of the A1100 material, and has the function of maintaining the material strength. However, if it is less than 0.05%, there is no effect, and if it exceeds 0.20%, there is a problem that the corrosion resistance decreases. Therefore, the amount of addition of Cu is set in the range of 0.05 to 0.20%.

It is desirable that the inevitable impurities are as small as possible. The allowable limit is S according to the regulation of A1100 material.
i + Fe ≦ 0.95% and Zn ≦ 0.10%.

Next, the manufacturing process and conditions of the present invention will be described.

First, the Al alloy ingot having the above composition is subjected to soaking treatment. This heat treatment is performed for homogenizing the non-uniformity of the structure and components in the ingot and for the heat treatment for hot rolling, and is 500 to 600 ° C x 2 to 24
Time conditions are desirable. If the soaking temperature is lower than 500 ° C, the effect cannot be obtained, and if it exceeds 600 ° C, burning or the like occurs, which is not desirable. Although the soaking time depends on the soaking temperature, 2 to 24 hours are suitable.

After the soaking treatment, hot rolling and cold rolling (including intermediate annealing if necessary) are performed. These conditions are not particularly limited either, but the thickness is 5 to 10 mm by hot rolling,
A plate thickness of 1 to 5 mm as a building plate material is obtained by cold finish rolling. If the sheet thickness after hot rolling is less than 5 mm, the product sheet thickness
Cold rolling ratio (usually 1 to 5 mm) is insufficient, material strength is insufficient, and bending workability is deteriorated due to coarsening of crystal grains. Is difficult, and the amount of cold rolling increases, resulting in a decrease in productivity, which is not desirable.

After cold finish rolling, finish annealing (temperature 250 to
350 ° C.). Since the aluminum plate itself is in a heat-treated state by the execution of this finish annealing, such as high temperature baking coating (usually 230 to 300 ° C.),
The material strength basically does not change even by the subsequent heat treatment. That is, it is possible to prevent the strength change due to the baking temperature by previously performing a heat treatment (finish annealing) at a temperature equal to or higher than the baking temperature. Annealing temperature is 2
If the temperature is lower than 50 ° C, the strength will be largely decreased, and if the temperature exceeds 350 ° C, the material strength itself will be low, which is not preferable.

In the conventional A1100 material, the material strength itself becomes too low by the above-mentioned finish annealing (temperature of 250 to 350 ° C.), but in the present invention, the addition of Mn: 0.8 to 1.5%. It is possible to obtain a predetermined material strength also by finish annealing.

In view of the purpose of finish annealing in the present invention, the finish annealing temperature in the above temperature range (250 to 350 ° C.) is determined in consideration of the selected temperature for baking coating (usually 230 to 300 ° C.). It is preferable to select a temperature equal to or higher than the actual baking coating temperature.

Next, examples of the present invention will be described.

[0020]

【Example】

An aluminum material having the composition shown in Table 1 was used as a test material, and the ingot was subjected to a soaking treatment (585 ° C. ×
9 hours) → hot rolling (6 mmt) → cold rolling (4 mmt) → finish annealing. The finish annealing was performed under the conditions shown in Table 1, but the finish annealing was not performed for some of the comparative materials. The material strength of the obtained aluminum plate is also shown in Table 1.

As is clear from Table 1, all the materials of the present invention show the required strength (120 to 175 N / mm ² ) with almost no decrease in strength even by high temperature baking coating. On the other hand, the comparative material not subjected to finish annealing has a large decrease in strength due to high temperature baking coating, and the comparative material subjected to finish annealing does not have the required strength.

[0023]

[Table 1]

[0024]

As described in detail above, according to the present invention,
Even if the high temperature baking is applied, the aluminum plate for construction can be obtained without the deterioration of the material strength or the deterioration of the strength is very small.

Claims (3)

[Claims] 1. Mn: 0.8% by weight (hereinafter the same)
1.5%, Cu: 0.05 to 0.20%, balance A
250 to 350 after hot-rolling and cold-rolling after soaking the Al alloy ingot consisting of 1 and unavoidable impurities.
A method for producing an aluminum plate for construction which is excellent in high temperature baking paintability, characterized by performing finish annealing at ℃. 2. The soaking treatment condition is 500 to 600 ° C. × 2.
The method according to claim 1, which is -24 hours. 3. The method according to claim 1, wherein the thickness is 5 to 10 mm by hot rolling.