LAP RESISTANCE WELDING METHOD AND LAP WELDED JOINT

摘要

PPROBLEM TO BE SOLVED: To provide a lap resistance welding method and a lap welded joint which are low in nugget-crack susceptibility and difficult to generate fracture inside the nugget. PSOLUTION: After overlapping high strength steel sheets 1a, 1b which are 340 MPa in tensile strength and have the thickness of 0.5 to 10 mm and arranging an iron insert material which has composition controlled to, by weight, 0.1% C, 1.4% Si, 2.0% Mn, 0.15% P, 0.03% S and 0.1% Al and the thickness tSB1/SBof which is 1/50 and 1/5 of the thickness tSBmin/SBof a thinner high strength steel sheet 1a between the high strength steel sheets 1a, 1b, welding is performed. PCOPYRIGHT: (C)2008,JPO&INPIT