METHOD FOR LASER WELDING OF MATERIALS WITH DIFFERENT THICKNESSES AND WELDED MEMBER HAVING DIFFERENT THICKNESSES PRODUCED BY SAID METHOD

摘要

Provided is a method for laser welding of materials having different thicknesses whereby excellent welding strength can be achieved regardless of the thickness of a thick plate. Also provided is a welded member having different thicknesses. That is the present invention is a method for laser welding of materials having different thicknesses wherein two plate materials (10 12) of different thicknesses are butted together so as to be flush with each other at one surface and then welded together by focusing a laser beam (14) on the butt surfaces. The method for laser welding of materials having different thicknesses is characterized in that the laser beam (14) obliquely falls incident toward the butt end face (12a) of the thick plate (12) from the flush surface side of the thin plate (10) with an aiming position (P) of the laser beam (14) being set so as to be on the butt end face (12a) of the thick plate (12) and an aiming position depth (D) from the plate surface on the laser beam (14) incident side being set within the range defined by expression (1) given below. t/3=D=t (1) (where t represents the thickness of the thin plate (10) in the direction of the plane of the butt end face (10a) and D and t are both in millimeters)