Defect repair method of high-temperature alloy casting

Abstract

The invention discloses a defect repair method of a high-temperature alloy casting, and belongs to the technical field of precision casting of metallurgical casting. A defect communicated with the surface of the casting is changed into a closed defect by using electron beam surface blocking, and then hot isostatic pressing is performed on the closed defect, so that the qualification rate of the casting is improved. The electron beam surface blocking process comprises the following steps and control technical parameters: detecting through visual contact, fluorescence and X-ray to determine a loose region and level; machining a square or circular groove with an area of being greater than that of the defect and depth of 3-5 mm on the surface with the defect of the casting if a defect beyond tolerance communicated with the surface exists; machining a matchable cover plate with thickness equal to that of the groove and gap of 0.1-0.5, placing the cover plate on the groove and spot-welding at 3-4 positions by using argon arc welding for fixation; sealing and welding the cover plate at the groove of the casting by using an electron beam under the condition that the vacuum degree is 10<-4> to 10<-1> Pa. The method has the advantages that the electron beam surface defect blocking and hot isostatic pressing defect closing are combined, the effectiveness for repair of the casting through the hot isostatic pressing is improved, and the method can be used for producing high-temperature alloy composite members.

Description

technical field

[0001] The invention belongs to the technical field of precision casting of metallurgical casting. In particular, it provides a method for repairing defects of superalloy castings, which is suitable for repairing defects such as excessive shrinkage cavities and porosity of superalloy complex components. Background technique

[0002] Cast superalloys have a high degree of alloying, a wide range of liquid-solid phase temperatures, and are prone to form coarse dendrites, reducing melt fluidity and feeding effects. With the development of aviation and aerospace technology, the structure of high-temperature alloy castings is becoming more and more complex, and the wall thickness varies greatly, which affects the filling and shrinkage of castings, and is prone to shrinkage cavities and loose defects, and the qualified rate of castings is low. Hot isostatic pressing technology uses high temperature and high pressure to make castings undergo micro-creep, thereby clo...