十字轴失效分析

Failure Analysis on Cross Axle

经渗碳、淬硬处理的20CrMnTi钢十字轴运行12 000 h即因表面出现较深的压痕、点蚀和剥落等缺陷而失效。对失效十字轴进行了化学成分分析、金相检验和硬度试验,并与进口十字轴作了比较,结果发现,十字轴的过早失效主要与选材不当有关,应采用比20CrMnTi钢更高级的合金渗碳钢。

Carburized and hardened cross axle made of 20CrMnTi steel failed after operating for 12 000 h owing to the occurrence of deeper indentation,pitting,spalling and other defects at the surface.For the failed cross axle,chemical composition analysis,metallographic examination and hardness test were performed and the test results were compared with that of the cross axle from abroad to clarify the failure cause.The results indicate that earlier failure of the cross axle is caused by its improper material,and therefore deep-hardening carburiz ing steel rather than 20CrMnTi steel should be adopted.