Is superior in resistance stress corrosion crack Characteristic the high strength aluminum alloy null for the welding structural material

摘要

PURPOSE:To improve the stress corrosion cracking resistance, strength, and weldability of an aluminum alloy by adding trace amounts of rare earth elements or misch metal to an Al-Zn-Mg-Cu series alloy. 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, 1.6 to 4.0% Cu, 0.03 to 5.0% rare earth elements or misch metal, 0.01 to 1.0% Fe, 0.005 to 0.2% Ti, 0.0001 to 0.08% B, 0.01 to 0.2% V, and the balance Al with ineviatable impurities. Furthermore, at least one or more kinds among 0.01 to 1.5 Mn, 0.01 to 0.6% Cr, 0.01 to 0.25% Zr, and 0.03 to 0.5% Mo are incorporated therein. Rare earth elements or misch metal improve its stress corrosion cracking resistance and weld cracking resistance. This alloy has high strength as the material for welded structures and excellent in formability in extruding, rolling, forging or the like.