ALUMINUM ALLOY SHEET WITH EXCELLENT FORMABILITY AND PAINT BAKE HARDENABILITY AND METHOD FOR PRODUCTION THEREOF

摘要

A rolled sheet of a 6000 type aluminum alloy containing Si and Mg as main alloy components and having excellent formability sufficient to allow flat h em working, excellent resistance to denting, and good hardenability during baki ng a coating, which exhibits an anisotropy of Lankford values of more than 0.4 or the strength ratio for cube orientations of the texture thereof of 20 or mor e, and exhibits a critical bend radius of 0.5 mm or less at 180 ~ bending even when the offset yield strength thereof exceeds 140 MPa through aging at room temperature; and a method for producing the rolled sheet of the aluminum alloy, which comprises subjecting an ingot to a homogenization treatment, cooling to a temperature lower than 350 ~ C at a cooling rate of 100 ~ C / h r or more, optionally to room temperature, heating again to a temperature of 3 00 to 500~C and subjecting it to hot rolling, cold rolling the hot rolled product, and subjecting the cold rolled sheet to a solution treatment at a temperature of 400 ~ C or highr, followed by quenching.