JPS605660B2 - Aluminum alloy plate material for forming processing and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aluminum alloy plate material for forming that has excellent strength and corrosion resistance, and a method for manufacturing the same.

Conventionally, 6061 is a medium-strength corrosion-resistant aluminum alloy.
Alloy and 5052 alloy are known as representative alloys.

The 6061 alloy is a heat-treated alloy that obtains appropriate strength by quenching and tempering to precipitate a fine 8' phase.

5052 alloy is an alloy that increases its strength through cold work hardening.

The present invention relates to a formed aluminum alloy sheet material having a strength higher than that of the work-hardened 5052 alloy or 6061 alloy T6 material and corrosion resistance at the same level as the 6061 alloy, and the gist thereof is "Si2.3 to 3. 5%, Mg0.4
~1.0%, Zno. 05-0.5%, Mno. 4-0
．． 9%, Sno. 01-0.06% of Tio. 1% or less, BO. This is an aluminum alloy plate material for forming processing, characterized in that it contains 0.05% or less and consists of residual peaks and impurities.
Si coexists with Mg and contributes to improving the strength; below the lower limit, this effect is insufficient, and above the upper limit, rolling workability deteriorates.

As mentioned above, Mg coexists with Si and contributes to improving strength, as well as improving hot and cold rolling workability.

When the lower limit is reached, this effect is insufficient, and when the upper limit is exceeded, rolling workability and weldability deteriorate. Zn coexists with Mg and contributes to improving strength; below the lower limit, this effect is insufficient, and above the upper limit, corrosion resistance decreases.

Mn makes crystal grains finer and contributes to improving strength.

If it is less than the lower limit, this effect will be insufficient, and if it exceeds the upper limit, giant intermetallic compounds will precipitate or competitiveness will decrease. Sn
This feature promotes high-temperature aging and finely precipitates the intermediate phase 3', which is effective in improving strength and preventing strength loss after paint quenching treatment, and also improves corrosion resistance.

This effect is insufficient at the lower limit, and castability deteriorates when the upper limit is exceeded. Ti and B make the coin lump structure finer,
Tj may be up to 0.1% and B may be included up to 0.05%.

When the respective upper limits are exceeded, t-giant intermetallic compounds crystallize. Also, ``Fe as an impurity reduces corrosion resistance, so
．． 50% or less. Cu also reduces corrosion resistance, so 0
．． The content should be 30% or less, preferably 0.15% or less.

Since Cr forms a giant intermetallic compound that reduces the permeability, it should be kept at 0.20% or less, preferably 0.10% or less.

The present invention also relates to a method for producing the above-mentioned alloy plate material, ``The gist of which is to produce an alloy having the above composition in an amount of 400 to 56,000.
For forming processing, which is characterized by subjecting it to homogenization treatment at 1 to 2 degrees Celsius, hot rolling at 400 to 540°C, followed by solution treatment at 480 to 56,000°C after rolling at least 50% or more. This is a method for manufacturing aluminum alloy plates.

The purpose of homogenization treatment is to promote the infiltration of Mg, Zn, Sj, etc. and the fine precipitation of Mn-based compounds.If the temperature exceeds 400°C, this effect will be insufficient and it will be difficult to obtain a sufficient strength level. do not have.

If it exceeds 560o0, the coin will melt, which is not preferable.

Hot rolling is carried out at a temperature of 400 to 54,000 ℃; however, at temperatures other than this, edge cracking at the end of the plate during rolling is severe and the rolling loss is greatly reduced.

It is desirable that the degree of rolling is at least 90%. If it is less than 90%, the cast structure will not be sufficiently destroyed, resulting in a decrease in strength and elongation after heat treatment. Cold rolling should be at least 50% or more. If it is less than 50%, the hot-rolled structure is not sufficiently destroyed, resulting in a decrease in strength after heat treatment.

Solution treatment is carried out at 480 to 560 oo.
If it is less than 00, solution treatment is insufficient and sufficient strength cannot be obtained.

If it exceeds 56,000, eutectic melting occurs, resulting in a significant decrease in elongation.

Next, examples and comparative examples will be described.

Example 1 and Comparative Example 1 Tests were conducted on alloys having the compositions shown in Table 1 below.

Alloy No. 1 to 7 are alloys according to the present invention, and NO. 8
-12 are comparative alloys. No. 1 among comparative alloys. 11 is 6
061 alloy, No. 12 is a 5052 alloy. Table I
Each of the alloys shown in Table 1 was hot-rolled for 500 pm after being rolled at 520 qo x 100 pm to form a thickness of 3 ribs.

This material was heat-softened at 400 qo×lhr and then cold-rolled to a thickness of 1 skin. After solution treatment at 535° C. for 30 minutes, this cold-rolled material was subjected to water leech treatment and aged at 175° C. for 7 hours. Table 2 shows the strength and corrosion resistance test results for each alloy. Table 2 *Amount of weight loss after 100 plates of ASTM old 117 salt water mist test (3y0, 5% salt water mist) were applied to a 50 square plate with a thickness of 1 side.

As a result, only the alloy of the present invention has higher strength than the 6061 alloy and the same level of corrosion resistance.

Example 2 and Comparative Example 2 No. 2 shown in Table 1 above. 1-1
The alloy of No. 1 was hot-rolled to a thickness of 3 ribs in exactly the same manner as in Example 1, and softened by heating at 400 qo x lhr.

This material was cold rolled to a thickness of 0.6 mm and 550 qo x 20
After solution treatment for seconds, air was introduced at an average cooling rate of 18° C. seconds. Thereafter, it was cold rolled by 75% to give a sail thickness of 0.15. No. For alloy No. 12, alloy No. 1~
400℃×lhr after cold rolling to 0.6yanagi t in the same way as No. 11
It was softened and then extended from 0.6 to 0.15 leg t. (No. 12 is a 5052 alloy and was subjected to this process because it was a non-heat treated material.) Table 3 shows the strength of each alloy.

Table 13 As is clear from Table 3 above, the alloy of the present invention has higher strength than the 6061 alloy or the 5052 alloy even after cold rolling, and the decrease in strength after the baking treatment is also small.

Claims (1)

[Claims] 1 Si2.3-3.5%, Mg0.4-1.0%, Z
n0.05-0.5%, Mn0.4-0.9%, Sn0
．． 01~0.06%, Ti0.1% or less, B0.05%
An aluminum alloy plate material for forming processing characterized by comprising the following: remaining Al and impurities. 2 Si2.3-3.5%, Mg0.4-1.0%, Z
n0.05-0.5%, Mn0.4-0.9%, Sn0
．． 01~0.06%, Ti0.1% or less, B0.05%
400 to 5 alloy consisting of remaining Al and impurities including:
Homogenization treatment at 60°C for 1 to 24 hours to obtain 400 to 540
1. A method for producing an aluminum alloy plate material for forming, which comprises hot rolling at 50° C., followed by cold rolling to at least 50% and then solution treatment at 480 to 560° C.