40Cr链轮齿部断裂失效分析

Failure Analysis of 40Cr Sprocket at the Teeth Area

对某厂生产的40Cr链轮齿根断裂件进行了金相显微组织、显微硬度、表面应力分析等方面的检测分析。链轮裂纹均在齿根部出现,齿部混晶严重,组织与基体之间无明显过渡区,可认为是高频加热水淬工序时,高频功率过高,时间过长,淬火时在淬火应力及组织应力的作用下沿齿根开裂。

This paper analyzed the failure causes of the 40Cr Sprocket. Through the analysis of surface stress, microstructure and microhardness testing. The cracks appears at the teeth root. There was severely mixed grain at the teeth area and there wasn＇t signifi- cantly transitional area between the teeth area and the matrix. Overmatched power and long time in high-frequency quenching processing caused the cracks at the teeth root on the effect of thermal stress and structural stress.