| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a laser beam overlap welding method which minimizes welding defects and furnishes weld zones excellent in appearance, without sacrificing productivity and rustproof capability in the overlap welding of metal plates including galvanized steel plates, and metal plates suitable for laser beam overlap welding. <P>SOLUTION: The invention relates to the laser beam welding method in which the metal plates including at least a galvanized steel plate are subjected to overlap welding, and relates to metal plates and a welding structure used for the welding. The cross section perpendicular to the weld line of at least one of the metal plates is of a crank shape which has a depression on its interface side. The following conditions are satisfied: Xa≥Z/(4800×Ya), Xb≤0.35×Yb where Xa is the minimum depth (mm) of the depression on the weld line, Xb is the maximum depth (mm) of the depression on the weld line, Ya is the thickness (mm) of a thinner metal plate, Yb is the thickness (mm) of the metal plate on the irradiated face side, and Z is the total deposited zinc amount (g/m<SP>2</SP>) on the interface. Further, flections of the metal plate near the crank shape have a convex angle toward the interface side. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
