METHOD OF LASER WELDING METAL PLATED PLATE

PROBLEM TO BE SOLVED: To provide a method of the laser welding a galvanized plate, which surely attains excellent welding without any melting defect such as blowholes. SOLUTION: A laser beam 18 is applied in a moving manner along a straight path K from a starting point P1 to a terminating point P2 at an end of a superposed portion of a lower plate 11 and an upper plate 12. The laser beam 18 has the high energy density so as to form a through-hole 20 penetrating both the lower plate 11 and the upper plate 12. Zinc vapor generated by applying the laser beam 18 is allowed to escape outside via two paths. One deaeration path goes outside through a space of superposed surfaces of the lower plate 11 and the upper plate 12 at an end of a superposed section of the lower plate 11 and the upper plate 12. The other deaeration path goes outside through the through-hole 20. COPYRIGHT: (C)2010,JPO&INPIT