| 摘要 |
PROBLEM TO BE SOLVED: To provide a 6,000 series aluminum alloy sheet hard to be broken in pess forming, also generating little wrinkle, having a wide formabile range and suitable for an automobile body and to provide its production method. SOLUTION: This aluminum alloy sheet having excellent formability has a composition containing, by mass, 0.4 to 1.6% Si, 0.15 to 1% Mg, >=1% Mg+Si and 0.3 to 1.2% Cu, and the balance Al with inevitable impurities. Its 0.2% proof stress YS is <=150MPa, the difference with TS (TS-YS) is >=130MPa. Further, in Lankford values at 7.5% in each direction of 0 deg., 45 deg. and 90 deg. to the rolling direction, the minimum value rmin is >=0.6. Preferably, the tensile strength TS is >=220MPa, and, the average value rave of the Lankford values at 7.5% in each direction of 0 deg., 45 deg. and 90 deg. to the rolling direction is >=0.65. In its production method, process annealing is performed in the process of cold rolling. Further, after solution treatment, stabilization heat treatment at a low temperature about 100 deg.C or slow cooling from the same temperature is performed.
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