METHOD FOR WELDING NICKEL BASE SUPERALLOY

PROBLEM TO BE SOLVED: To provide a new welding method to solve such problems that a nickel base superalloy containing a high content of γ' phase develops cracks very easily when it is welded or when it is heat-treated after welding and also characteristics of the basic material may be substantially deteriorated by the application of the conventional welding method. SOLUTION: This method is a welding method for welding superalloy members (10) and (12), and comprises (a) the step wherein a groove for welding (14) is formed at the contact surface between the members, (b) the step wherein the members are weld by using filler metal (16) at ambient temperature, (c) the step wherein a brazing paste (18) is applied between the filler metal and the members on the adjoining surfaces and (d) the step of heat-treatment of the members including a stress relieving cycle and a brazing cycle. The same method can be applied to repair cracks in a member made of the nickel base superalloy. COPYRIGHT: (C)2008,JPO&INPIT