【摘要】 500GF-3RJ型燃气发电机组的连杆,仅仅运行了60 h后突然发生断裂,进行了化学成分、金相组织及扫描电镜断口分析,并对连杆进行了应力分析。结果表明,连杆螺栓连接加工表面转角的过渡圆角处存在粗糙的加工刀痕,在连杆转角部位产生了很大的应力集中,是导致连杆发生疲劳断裂的主要原因,而失效连杆的金相组织中存在铁素体和魏氏组织引起硬度及强度的降低,对连杆疲劳裂纹的萌生和扩展起到了加速作用。更多还原

【Abstract】 One connecting rod of 500GF-3RJ gas generator set suddenly broke only 60 hours after operation. The chemical composition,microstructure,fracture morphology and stress of the fractured connecting rod are analyzed. Results show that serious rough machining tool marks is found at the knuckle of corner of the connecting rod bolt jointing to surface where have a great stress concentration when the gas generator set runs,which is the main reason of fatigue fracture of the connecting rod. Meanwhile,a certain amount of ferrite and widmanstatten in microstructure of the failure connecting rod,as the microstructure defects,make it decrease hardness and strength,to play an acceleration action for fatigue crack initiation and propagation of the failure connecting rod.更多还原