| 摘要 |
PURPOSE:To improve welding quality so as to contrive energy saving by greatly extending life of electrode and achieving normal nugget shape in the resistance spot welding of Al and Al alloy having different sheet thickness and heat conductivity. CONSTITUTION:Two sheets of Al or Al alloy sheets 5, 6 having a thickness of T1, T2 are spot welded. A ratio between an oxide film thickness t1 of contacting side with a platy electrode having a thickness of T1 and an oxide film thickness t2 contacting with a platy electrode having a thickness of T2 is in conformance with in the case of (1) T1>=T2, (1.5XT1/T2-0.5)<-1=t1/t2<=T1/ T2, in the case of (2) T1<=T2, T1/T2<=t1/t2<=1.5XT1/T2-0.5 and the oxide film thicknesses t1, t2 are regulated in a range of 2.5-7.0nm, under these condition resistance spot welding executed. What is regulated is the oxide film thickness of the sides in contact with electrode only, an oxide film thickness of joining boundary is not specifically regulated. Also, a chemical method such as alkaly cleaver, acid, etc., is recommended for control of oxide film thickness. |
