Failure analysis of cracked side bolts of gas conduit mounting for a certain type of engine
In order to solve the problem of cracking and failure of bolts on the installation side of gas ducts of an engine,this paper analyzes the reasons for the unqualified fluorescence display of bolts from the perspectives of bolt macro,microscopic morphology,fracture,material and assembly.The results show that the metallographic structure and hardness of the bolt meet the requirements.There are two types of defects in the fluorescence of the bolts on the side of the gas pipeline,one is the fold[1]defect and the other is the crack[2]defect.Folding defects arise during thread rolling and are typical part original man-ufacturing defects.The crack defect is multi-sourced,which is related to the folding defect,and the crack is induced by repeated disassembly and assembly.All cracks did not develop fatigue[3]during commissioning.It is recommended to optimize the bolt thread rolling forming process[4-5],which can ef-fectively reduce the occurrence of bolt folding.When the engine gas pipe is disassembled,the bolt is disposed of as a new part for rehabilitation.The failure did not recur and the bolt failure problem was effectively resolved.
万方数据
维普
