转向架轴箱弹簧断裂失效分析

Fracture failure analysis of bogie axle box spring

为分析某车转向架轴箱弹簧服役过程中出现的断裂失效,应用扫描电子显微镜、光学显微镜、直读光谱分析仪等,对断裂件的组织形貌进行宏观和微观检查,并对硬度、化学成分等进行分析。结果表明:由于弹簧表面严重脱碳,局部存在挤压和磨损,以及有不连续的表面缺陷,产生疲劳裂纹,造成了局部应力集中;在交变载荷作用下局部应力集中处成为疲劳源,产生疲劳裂纹并不断扩展直至最终失稳疲劳断裂。

In order to analyze the car bogie axle box spring occurred fracture failure in service,the structure pattern of broken part was macro and microstructure inspected by adopting Scanning Electron Microscope,Optical Microscope,Direct Reading Spectrometer and so on,the hardness and chemical composition was analyzed.Results show that spring exist serious surface decarburization,local exist extrusion and wear,discontinuous surface defects occur fatigue crack,cause the local stress concentration.Local stress concentration become the fatigue source under the action of alternating load,then cause fatigue crack,it expanding until finally the fatigue fracture of instability.