| 摘要 |
PROBLEM TO BE SOLVED: To provide an Al alloy plate which has superior hem formability, has little bending anisotropy, has high strength after having been painted and baked, causes little aging at room temperature, and is suitable for an automotive body sheet. SOLUTION: The aluminum alloy plate is made of an Al-Mg-Si-based Al alloy or an Al-Mg-Si-Cu-based Al alloy; satisfies the expressions of (C<SB>1/10</SB>+C<SB>1/4</SB>)/2>C<SB>1/2</SB>and 20<(C<SB>1/10</SB>+C<SB>1/4</SB>)<500, when C<SB>1/10</SB>, C<SB>1/4</SB>and C<SB>1/2</SB>are defined as cube orientation density at respective positions of 1/10, 1/4 and 1/2 deep from the sheet surface in a sheet thickness direction; has ä011}<100> orientation density at a position of 1/2 deep in a sheet thickness direction in a range of 2 to 50 times that of a random crystal orientation sample, at a half position of the plate thickness; and has 0 degree and 90 degrees earing rates of 5% or higher. The manufacturing method comprises the steps of: homogenizing the ingot at 490°C or higher; cooling it at 2°C/min or more; starting hot rolling at 300 to 450°C; finishing the hot rolling at 100 to 350°C; skipping cold rolling; solution-heat-treating it at 480°C or higher; cooling it to 50 to lower than 150°C, at 100°C/min or more; and stabilization-treating it in that temperature range for one hour or longer. COPYRIGHT: (C)2007,JPO&INPIT
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