摘要
对疲劳断裂钩舌的化学成份、金相组织、夹杂物、力学性能、断口特征及钩舌结构和工作条件进行分析.结果表明:钩舌下牵引台尺寸小,根部过渡圆角小,运用中应力集中大,是钩舌疲劳裂纹在该部位萌生并扩展,造成早期断裂失效的主要原因.铝含量偏高,在铸造晶界形成大量AlN夹杂物,导致沿晶断裂,使疲劳裂纹扩展及断裂过程加速,但不是钩舌失效的主要原因.
Chemical composition,microstructure,non-metallic inclusion,mechanical properties,fracture characteristics,design structure and operating conditions of a fatigue failure coupler knuckle of type F51AE were studied.The results show that the coupler knuckle failed before its expected life is mainly attributed to its smaller size and poor round transition at root corner of lower pulling lug where fatigue crack is initiated and propagated due to high stress concentration.Another reason for the failure of the coupler knuckle is ascribed to the promotion of fatigue crack propagation and rupture process caused by intergranular fracture due to large amounts of AlN particles formed along grain boundaries during crystallization from a melt enriched aluminum.
出处
《大连交通大学学报》
CAS
2011年第4期43-47,共5页
Journal of Dalian Jiaotong University
关键词
F51AE钩舌
疲劳断裂
下牵引台
应力集中
晶界AlN颗粒
F51AE coupler knuckle； fatigue fracture； lower pulling lugs； stress concentration； AlN particles on grain boundary
