压缩机中体链接螺杆断裂失效原因分析

Failure cause analysis of compressor body link screw

某公司压缩机4号缸中体链接螺杆在使用过程中发生断裂,螺杆接触介质为润滑油。通过力学性能检验、化学成分分析、金相检验、断口形貌分析等方法,对比同设备断裂螺杆与完好螺杆性能,综合分析了螺杆断裂失效原因。结果表明,螺牙顶部存在的原始裂纹缺陷是引起螺杆断裂的根本原因,缺陷部位易产生应力集中,螺杆在使用过程中受到轴向应力、弯曲应力、扭转载荷及外界脉冲冲击等力的共同作用,裂纹不断扩展,发生疲劳断裂。

A company The connecting screw of the compressor's No.4 cylinder was broken in use,The screw contact medium is lubricating oil.In this paper,mechanical properties test,chemical composition analysis,metallographic test,fracture morphology analysis and other methods are used.And,The performance of broken screw is compared with that of intact screw.The failure reason of screw is analyzed.The result show that,The primary crack defect at the top of screw teeth is the root cause of screw fracture,Stress concentration is easy to occur at the defective site,Screw in the process of use by axial stress,bending stress,torsion load and external impulse impact forces,The crack continues to expand and fatigue fracture occurs.