| 摘要 |
The purpose of the present invention is to provide a resistance spot welding joint in which nugget segregation is reduced with sheet groupings of two or more, separation fractures are suppressed by making occurrences of cracking difficult, and which has high strength without softening. When d is the diameter of a nugget formed of steel sheets in a resistance spot welding joint for thin steel sheets, the resistance spot welding joint is characterized by the proportion of the surface area in which the P concentration m (mass%) exceeds twice the P concentration M (mass%) of the base composition being 5% or less with a surface analysis of the distribution state of the amount of P present in the region within the nugget surrounded by a closed curve at a distance of d/100 and a closed curve at a distance of d/5 performed on a horizontal plane of the nugget surrounded by a corona bond in a direction toward the inside of the nugget from the end part of the melt part. |
