Lap joint welding arrangement and a related welding method for forming the same

摘要

A first member and a second member have end portions overlapped and welded by irradiating a laser beam on an outer surface of a lap portion. A front end surface of a fused portion slants at an obtuse angle larger than 90° with respect to a naked outer surface of the second member. A dilution rate S=B/(A+B) is equal to or less than 45%, where "A" represents a cross-sectional area of the fused portion merging into the first member and "B" represents a cross-sectional area of the fused portion merging into the second member.