LASER WELDING METHOD

摘要

The method of lap-welding of metal plates using a laser beam, wherein at least one of the metal plates is surface-treated, includes putting a metal plate on the other metal plate and forming a gap between the metal plates so that gas generated at the treated surface at the time weld can be dissipated therethrough.  A surface-treated first work (12) and a surface-treated second work (14) are placed one on the other and clamped by means of a clamp (16) with an opening (16d) of the clamp centered at the location (18a) on the first work (12) to be welded. Then a laser beam is directed to the location (18a) to form a weld (19). The beam is then directed near the inner periphery of the opening (16d) to form a heated portion (20a) so that the heated portion deflects to form a gap (G1) through which the gas (22) generated at the treated surface (12b,14a) dissipates thereby reducing gas pressure.