| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent solidification cracking in overlap laser welding. <P>SOLUTION: In the laser welding method where a plurality of steel materials in which at least one is made of high tensile strength steel are overlapped, as laser light is emitted to the vicinities of the edge parts of the overlapped sheet materials from the overlapped direction in such a manner that melting is caused to the back face of the sheet material on the lower side to be overlapped, the laser light is moved along the edge parts, so as to form a weld zone in which the content of carbon in the weld metal satisfies 0.05≤C≤0.08%; thus the overlapped sheet materials are welded each other, the width of the overlapped parts in the sheet materials is controlled to≤8 mm, and also, the weld zone is formed at a position far by≥3.5 mm from the edges of the sheet materials. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
