某企业乙二醇回收气往复式压缩机连杆大头盖及其紧固螺栓发生了断裂事故。对该连杆大头盖和紧固螺栓进行了断口宏观形貌、材料化学成分、扫描电镜、显微组织等的检验分析。结果表明:造成此次压缩机事故的主要原因是压缩机连杆螺栓预紧力不足导致连杆两瓦之间存在间隙，造成该部位螺栓表面产生微动磨损诱发裂纹源，产生疲劳断裂，进而导致连杆大头盖断裂、连杆发生弯曲变形。

An accident occurred in an enterprise in which the connecting rod cap and its fastening bolts of a glycol gas recycling reciprocating compressor fractured. A series of study on the fractured connecting rod cap and fastening bolts were carried out by visual inspection, material chemical composition analysis, SEM observation and metallographic examination. The results show that the main reason of the compressor accident could be described as following: a gap between two connecting rods generated because the compressor connecting rod bolts were not fully tightened; then the crack source was induced by fretting wear at the surface of bolts, and then the crack grew to contribute to fatigue fracture; at last the connecting rod cap fractured and led to the deformation of the connecting rod.