OVERLAP-WELDED MEMBER, AUTOMOBILE PART, METHOD OF WELDING OVERLAPPED PORTION, AND METHOD OF MANUFACTURING OVERLAP-WELDED MEMBER

摘要

The present invention provides an overlap-welded member in which an overlapped portion including plural steel sheet members is joined at a spot-welded portion, in which at least one of the plural steel sheet members contains martensite, and the spot-welded portion includes: a nugget formed through spot welding; a heat-affected zone formed in the vicinity of the nugget; the softest zone having the lowest Vickers hardness in the heat-affected zone; and a tempered area formed between a central portion of the nugget and the softest zone and made out of tempered martensite having Vickers hardness of not more than 120% in the case where Vickers hardness of the softest zone is 100%.