| 摘要 |
PURPOSE:To manufacture the titled Al alloy sheet having high strength, superior formability and corrosion resistance by successively subjecting and Al alloy ingot having a specified compsn. to soaking, hot rolling, process annealing and cold rolling under specified conditions. CONSTITUTION:An Al alloy ingot consisting of, by weight, 0.4-2.8% Mg, 0.4-1.5% Mn (Mn/Mg >=2.0), 0.05-1.00% Cu, <=0.25% Fe and the balance Al with inevitable impurities or further contg. 0.05-0.35% Cr is soaked at 480-about 590 deg.C, hot rolled and cold rolled. The resulting sheet is heated to 400-600 deg.C at >=100 deg.C/min heating rate, held for <=10min and cooled at >=100 deg.C/min cooling rate to carry out process annealing. The heated sheet may be immediately cooled. By the process annealing, the average crystal grain size in the thickness direction is regulated to <=80mum and Mg and Cr are forced to enter into solid soln. The sheet is further cold rolled at >=30% final draft to manufacture a baking hardening Al alloy sheet which hardens by baking finish. |
