理化检验-物理分册
理化檢驗-物理分冊
이화검험-물리분책
Physical Testing and Chemical Analysis Part A:Physical Testing
2015年
11期
820-823
,共4页
排气门%径向开裂%堆焊%应力
排氣門%徑嚮開裂%堆銲%應力
배기문%경향개렬%퇴한%응력
exhaust valve%cracking in radial direction%weld overlaying%stress
某发动机排气门在耐久试验中于头部发生径向开裂，通过化学成分分析、宏观检验及金相检验，对排气门开裂原因及过程进行了分析。结果表明：由于气门锥面堆焊工艺不合理且未进行及时充分的去应力处理，导致堆焊层内残余应力较高，在机械应力及热应力的共同作用下，在堆焊层内靠近气门锥面处形成裂纹源并沿径向扩展。
某髮動機排氣門在耐久試驗中于頭部髮生徑嚮開裂，通過化學成分分析、宏觀檢驗及金相檢驗，對排氣門開裂原因及過程進行瞭分析。結果錶明：由于氣門錐麵堆銲工藝不閤理且未進行及時充分的去應力處理，導緻堆銲層內殘餘應力較高，在機械應力及熱應力的共同作用下，在堆銲層內靠近氣門錐麵處形成裂紋源併沿徑嚮擴展。
모발동궤배기문재내구시험중우두부발생경향개렬，통과화학성분분석、굉관검험급금상검험，대배기문개렬원인급과정진행료분석。결과표명：유우기문추면퇴한공예불합리차미진행급시충분적거응력처리，도치퇴한층내잔여응력교고，재궤계응력급열응력적공동작용하，재퇴한층내고근기문추면처형성렬문원병연경향확전。
The head of engine exhaust valve cracked in radial direction during the durability test.The cracking causes of exhaust valve were analyzed by chemical compositions analysis,macroscopic inspection and metallographic inspection.The results show that the weld overlaying technology of cone area of exhaust valve was not optimum, and the stress relief treatment was not in-time and complete.As a result of that,high residual stress remained in weld overlaying cladding.Under the combined action of mechanical stress and thermal stress,cracks were formed in weld overlaying cladding near the cone area and then propagated on radial direction.
