METHOD FOR WELDING ALUMINUM ALLOY MATERIAL AND FILLER METAL FOR WELDING ALUMINUM ALLOY MATERIAL

摘要

PROBLEM TO BE SOLVED: To improve tensile strength, hardness and fatigue strength of weld metal, to suppress microcrack on base metal to be welded and to improve joint strength by executing welding using filler metal consisting of a specified rate of Si and Mg and the balance Al with inevitable impurities. ;SOLUTION: The filler metal to be used consists of 3-7 wt.% Si, 0.4-1.0 wt.% Mg and the balance Al with inevitable impurities. It is preferable to apply this filler metal to welding of aluminum alloy having the alloy composition of JIS 6000 series and fillet welding. As the effect of 3-7 wt.% Si, stress concentration in a toe part of weld is suppressed, fatigue strength is improved, Mg₂Si is precipitated in the weld metal, the tensile strength and hardness of the weld metal is elevated, and the joint strength is improved. As the effect of 0.4-1.0 wt.% Mg, the fusing pointof molten metal is lowered and microcrack on the base metal of welding is suppressed. In the sample of joint shape, 5, 6, 8 and 9 are metal plates, 11 and 12 are tubing and 7, 10 and 13 are weld metal.;COPYRIGHT: (C)1998,JPO