42CrMo钢支撑轴断裂原因分析

Analysis on Cause for 42CrMo Steel Support Shaft Fracturing

两件42CrMo钢支撑轴在使用中过早断裂。为揭示其断裂的原因,检测了支撑轴的化学成分、显微组织和硬度。结果表明:支撑轴的圆角部位有刀痕、腐蚀坑和二次淬硬层,导致其在循环应力的作用下产生疲劳断裂。

Two 42CrMo steel support shafts fractured prematurely in service.The chemical composition,microstructure and hardness of the fractured support shaft were detected to reveal the cause of their fracturing.The results showed that the support shaft displayed incisions,etching pits and secondary hardened layer in its fillet,thus resulting their fatigue fracturing by the action of circulating stress.