某45钢减速器轴在使用过程中发生断裂。通过对断裂件进行宏观分析、化学成分分析、力学性能试验、金相检验以及断口微观分析, 分析了该减速器轴断裂属性及原因。结果表明: 减速器轴断裂属性为多源疲劳断裂, 断裂主要是由轴未进行调质处理致使材料力学性能偏低、轴表面存在加工缺陷以及轴变径处存在严重的应力集中所引起。

A 45 steel reducer shaft fractured during use. The fracture properties and causes were analyzed by means of macro analysis, chemical composition analysis, mechanical property test, metallographic examination and fracture micro analysis. The results show that the fracture property of the reducer shaft was multi-source fatigue fracture, and the fracture were mainly caused by the lower mechanical properties because of improper heat treatment (no quenching and tempering treatment), the machining defects on the shaft surface and the serious stress concentration at the shaft diameter changing position.