| 摘要 |
PROBLEM TO BE SOLVED: To manufacture an Al-Mg alloy sheet excellent in a formability and a shape-fixability without applying a stabilizing treatment. SOLUTION: In a method for manufacturing the aluminum alloy sheet for automobile, which is excellent in a press-formability, surface roughness resistance and the shape-fixability, molten metal comprising 3.0-3.5 mass% Mn, 0.05-0.3 mass% Fe, 0.05-0.15 mass% Si and further, Mn to be regulated to <0.1 mass% and the balance Al with inevitable impurities, is cast to a thin sheet having thickness of 5-15 mm with a twin-roll type caster so that the cooling speed at 1/4 thickness become 20-200°C/sec, and after winding into a coil, a cold-rolling is applied at 60-98% cold-rolling ratio with the roll having 0.2-0.7μm Ra of roll roughness, and after applying the finish-annealing at 400-520°C holding temperature by CAL (a continuous annealing line) or 300-400°C holding temperature with a butch-type annealing furnace, this stress correction is performed with a leveller. COPYRIGHT: (C)2008,JPO&INPIT
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