| 摘要 |
PURPOSE:To eliminate the need for annealing process of conventional methods and make possible efficient welding by welding the butt close contact part of dissimilar metals through high-density energy radiation then reradiating the portion of a higher welding hardness at the annealing temperature. CONSTITUTION:For example, in welding a protection cover 6 of mild steel to a pressure plate 2 of a load cell using corrosion-resistant SNCM-5, the butt close contact part thereof is radiated with a laser beam 9 and is thereby welded, after which the laser beam 9 is radiated to the weld metal part 12 of the pressure plate 2 of a higher welding hardness of the weld metal part. At the time, it is heated so as to become the annealing temperature of SNCM5, i.e., a range from about 550-650 deg.C, by which the good weld zone of low hardness is obtained. Unlike with conventional methods, the adverse influence upon electrical parts, etc. owing to the temperature rise at the welding is eliminated, no skill is required and the welding may be done efficiently through saving of the annealing process after the welding. |
