摩托车发动机曲轴断裂原因分析  

Failure Analysis on Crankshaft in a Motorcycle Engine

作　　者：谭莹[1] 曹标[1] 陈明[1] 莫明珍[1] 

机构地区：[1]广东出入境检验检疫局技术中心,广州510623

出　　处：《失效分析与预防》2009年第1期35-38,共4页Failure Analysis and Prevention

摘　　要：摩托车发动机曲轴在运行6350km后断裂。通过断口宏微观观察、表面痕迹分析、成分分析、金相组织检查及硬度检测等方法对断裂曲轴进行了分析。结果表明,曲轴定位槽底部存在电灼伤,灼伤造成应力集中,在内外载荷的共同作用下首先在应力集中的灼伤部位产生裂纹,最终发生疲劳断裂。灼伤是在精磨后安装定位销之前电极接触所致。The crankshaft in a motorcycle engine fractured after the service of 6 350 km. The fracture cause of the crankshaft was analyzed by facture surface observation, surface mark analysis, chemical composition analysis, metallographic examination and hardness testing. The results show that there existed electrical burn at the bottom of the crankshaft locating slot, which was caused by electrode contact before fixing the locating pin. There was stress concentration at the electrically burned zone. As a result, cracks initiated from the electrically burned zone under the effect of service load, and finally, the crankshaft fractured.

关 键 词：曲轴 疲劳断裂 电极灼伤 

分 类 号：TK413.31[动力工程及工程热物理—动力机械及工程]