Method of build up welding to thin-walled portion

摘要

A recess formed in close contact with a thin-walled portion 3a of a workpiece to store molten metal at a surfaced portion, a jig 4 manufactured from a material with a higher heat-resisting temperature than that of the molten metal and a satisfactorily large heat capacity, a step (A) wherein the jig is installed on the workpiece, a preheating step (B) in which the workpiece and the jig are preheated to a predetermined temperature under the condition that jig 4 is installed, a build up welding step (C) for build up welding the thin-walled portion of the workpiece and forming weld beads at surfaced portion, and a jig-removing step (D) for removing the jig after weld beads solidify completely.