| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method of laser welding for overlapped zinc steel plates using at least two laser beams excellent in quality and its forming of consequent beads in order to reduce scattering of melted metal and defects in the welding parts caused by generation of zinc gas in welding overlapped zinc steel plates. SOLUTION: After heating and evaporating plated zinc in the sphere of intended connection by a first laser beam 25, a second laser beam 26 welds the sphere of the connection. In this process, the diameter of the first laser beam (D1), the diameter of the second laser beam (D2), and the distance between the centers of these two laser beams (L) satisfy the expressions 0.56×(D1+D2)< L<1.8×(D1+D2). At the same time, the average energy density of the first laser beam (E1) and the average energy density of the second laser beam (E2) are so adjusted as to satisfy the expressions 0.8×t1/(t1+t2)<E1/E2<1.6×t1/(t1+ t2).</p> |
