某型发动机38CrMoAlA离合器齿轮缺陷分析

某型发动机38CrMoAlA离合器齿轮在工厂试车后,对其进行荧光磁粉探伤时发现,齿轮端面上有3条磁痕缺陷显示。通过对磁痕缺陷进行外观检查、电镜观察、金相检查、化学成分分析和断口观察,并抽取1件新品齿轮进行故障模拟再现,确定了磁痕缺陷的性质及产生原因。结果表明,离合器齿轮在机械加工磨削过程中,存在较大的残余热应力,在试车工作应力的诱发下,导致了延迟裂纹的产生。

Defects Analysis of a Type of Engine 38CrMoAlA Clutch Gear

A certain type of engine38CrMoAlA clutch gear in the factory after commissioning,fluorescent magnetic particle inspection found three magnetic gear contrate mark defect display.Through the magnetic mark defect of gear on the appearance inspection,electron microscope,metallographic examination,chemical composition analysis,and fracture surface observation,and extract a new gear fault simulation reappearance,identified the magnetic nature and causes of the defective.Results show that because the clutch gear in the machining process of grinding larger residual thermal stress,under the commissioning work stress induced delay led to cracks.