摘要
通过对已断裂的迷宫压缩机组合活塞裙的服役情况调查和宏观裂纹观察分析,发现活塞裙与活塞盖发生了相对周向和轴向运动,形成了多源裂纹;通过扫描电镜进行裂纹断口微观分析,同时进行了化学成分分析、金相分析和机械性能分析,能够判断该活塞裙属于多源疲劳断裂,是交变的扭转力及轴向冲击力的共同作用导致,因运行条件突变或使用不当等原因造成活塞套内壁局部区域偏心磨损且产生磨削裂纹,为疲劳失效的萌生提供了必要条件。
Through the investigation and observation of the broken combined piston skirt of labyrinth compressor,relative rotational motion and axial movement between the piston skirt and piston cover which caused the multiple source crack was found. The fracture microscopic analysis was carried out by scanning electron microscope,and also the chemical composition analysis, metallographic analysis and mechanical property analysis had been done, the analysis displayed that the piston skirt was multiple source fatigue fracture which was caused by alternating torsion and axial force. Because of operating condition mutation or improper use, the piston skirt inner wall was local eccentric wear and developed the grinding crack which promote the fatigue failure of the skirt.
引文
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