Patent ID: 8610026
Filing Date: 2013-12-17
Classification: B23K

Abstract:
1. A laser beam welding method for welding, with laser beams, first and second workpieces stacked one on the other, which comprise metal sheets including superposed surfaces, at least one of the superposed surfaces being surface-treated, comprising: the first step of clamping a portion of the first workpiece around a welding spot with a clamping jig having an opening; the second step of, after the first step, applying one of the laser beams to the welding spot to form a melted region; the third step of, after the second step, applying the one of the laser beams to a portion of the first workpiece around the melted region to form a heated region, thereby forming a gap between the superposed surfaces of the first workpiece and the second workpiece; and the fourth step of, after the third step, applying the other of the laser beams to the welding spot to weld the first workpiece and the second workpiece to each other, and diffusing, into the gap, a gas which is produced from surface-treated layers during a period in which the first workpiece and the second workpiece are welded to each other.