HIGH STRENGTH ALUMINUM ALLOY FOR WELDING EXCELLENT IN STRESS CORROSION-CRACKING RESISTANCE

摘要

PURPOSE:To improve the stress corrosion-cracking resistance, strength, and weldability of an aluminum alloy by regulating the amounts and ratio of Fe and Si, and adding specified amounts Mn and B thereto. CONSTITUTION:The compsn. of a high strength Al alloy for welding is formed of, by weight, 5 to 8% Zn, 1.2 to 4.0% Mg, 1.5 to 4.0% Cu, 0.01 to 1.5% Mn, 0.005 to 0.2% Ti, 0.0001 to 0.08% B, and 0.2 to 15% Fe+Si as well as 2 Fe/Si as essential components and the balance Al with inevitable impurities. Furthermore, one or more kinds among 0.01 to 0.6% Cr, 0.01 to 0.25% Zr and 0.03 to 0.5% Mo are incorporated therein. Mn improves its stress corrosion-cracking resistance and strength, and Ti and B refine its structure and improve its weldability. This alloy has high strength as the material for welded structures and excellent in formability in extruding, rolling, forging or the like.