Reasonable design, free adjustment. According to different metal materials, different stall discharge frequency can be used to achieve the best repair effect. The heat affected area is small. There is no heat input during the instant of stacking, so there is no deformation, undercut and residual stress. No local annealing occurs, and no reheating is required after the repair. Welding shock is minimal. The welding machine overcomes the phenomenon of ordinary argon arc welding on the periphery of the workpiece during welding repair.