ALUMINUM ALLOY FORGING MATERIAL FOR STRUCTURE HAVING EXCELLENT CORROSION RESISTANCE AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an aluminum alloy forging material for structure which is excellent in a balance of strength, toughness and corrosion resistance, and to provide a method for producing the same.;SOLUTION: The aluminum alloy forging material comprises 0.40 to 0.8% Si, 0.8 to 1.2% Mg, ≤0.40% Cu, 0.08 to 0.15% Mn and 0.10 to 0.35% Cr, and the balance Al with impurities. In the vertical cross-section of the forging material, the surface layer part has a recrystallized structure, and in the part other than the surface layer part, a Hypo-crystal structure with a mean crystal grain size of ≤10 μm occupying the region of 50 to 95% in the vertical cross-section is present. The aluminum alloy has the composition within the componential standards of a JIS 6061 alloy, thus is also excellent in productivity and recycling properties, and can expand the applying range to automobile structural members.;COPYRIGHT: (C)2004,JPO