某材料为42CrMo的石料圆锥破碎机主轴在使用半年后发生早期断裂，采用宏观分析、化学成分分析、非金属夹杂物评定、低倍试验、拉伸试验、冲击试验、硬度试验、平均晶粒度评定、金相检验、微观分析和能谱分析等方法对断裂轴进行失效分析。结果表明：在破碎机运行过程中，主轴和锥体芯之间发生磨损，主轴外圆周表面产生微裂纹，最终主轴在循环载荷作用下发生疲劳断裂。

The main shaft of a stone cone crusher with 42CrMo material fractured after half a year of service. The failure analysis of the fractured shaft was carried out by means of macroscopic analysis, chemical composition analysis, non-metallic inclusion assessment, macroscopic test, tensile test, impact test, hardness test, average grain size assessment, metallographic examination, microscopic analysis and energy spectrum analysis. The results show that during the operation of the crusher, wear occured between the spindle and the cone core, micro-cracks occured on the outer circumferential surface of the spindle, fatigue fracture of final spindle under cyclic loading.