摘要
用化学分析、力学性能试验、扫描电镜等方法分析了某大型柴油机曲轴早期断裂的原因。结果表明:宏观断口上有明显的疲劳源区和宏观疲劳条纹,曲轴属于疲劳断裂。疲劳裂纹萌生在曲轴油孔内表面的缺陷处(缺陷尺寸为767μm×500μm),该缺陷是机械加工油孔时刃具刀尖崩裂造成的,在工作交变扭转应力作用下缺陷萌生疲劳裂纹并扩展,导致曲轴发生早期疲劳断裂。
The reason of failure and break had been investigated for heavy diesel engine crankshaft which broke by fatigue on the basis of the physical test and chemical analysis, macrograph and microfracturegraphy （SEM. EDS） of the broke crankshaft. The results show that the initial fatigue crack appears near the surface detect of the oil hole of the crankshaft inner. The defect is lager （about 767μm×500μm） and caused by cutting tool tip break apart during machining. The fatigue crack propagates with a repeated-turning stress and finally the crankshaft broke at early stage.
出处
《机械工程材料》
CAS
CSCD
北大核心
2007年第9期76-78,共3页
Materials For Mechanical Engineering
关键词
疲劳断裂
大型柴油机
曲轴
失效分析
fatigue fracture
heavy diesel engine
crankshaft
failure analysis
