| 摘要 |
PROBLEM TO BE SOLVED: To prevent a formed part of a high strength steel sheet with a tensile strength of 1,180 MPa or more, even when subjected to welding, from being fractured upon collision due to a low strain at the most softened zone in a HAZ (Heat-Affected Zone) of a spot weld zone.SOLUTION: A lap weld member 1 comprises: a first constituent member 2 that is a steel sheet with a tensile strength of at least 1,180 MPa or a formed part thereof; and a second structural member 3 that is other steel sheet or a formed part thereof and welded by being lapped on the first constituent member 2. The lap weld member 1 has one or more nuggets 6 formed by, for example, spot weld and a softened zone 7 generated on the side of the first constituent member 2 so as to surround a part or the whole of the nuggets 6, where the softened zone 7 is formed in a range which includes a range where the most softened zone in a HAZ formed when spot-welded, excludes an edge face 2b of the high strength steel sheet 2. |
