| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a laser welding method capable of fully securing fatigue strength of a joined body in butt welding of metallic plates different in thickness. <P>SOLUTION: In this laser welding method, in the manner that beam spots S1, S2 are in contact with each other on an abutted part of metallic plates 1, 2 and arranged in a planned welding line R direction, a laser beam is divided into a first and a second laser beam L1, L2. As a result, heat input time to the metallic plates 1, 2 is extended, with the heat input increased in the direction orthogonal to the planned welding line R, so that the width of a weld zone 21 is expanded. Also, metallic vapor from a filler wire 16 is likely to be diffused in the direction orthogonal to the planned welding line R, with the expansion of the width of the weld zone 21 encouraged. Consequently, the angleθ<SB>1</SB>of the inclined portion 22 of the weld zone 21 is reduced, with stress concentration at the weld zone 21 relaxed, so that fatigue strength is fully secured for the joined body of the metallic plates 1, 2. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
