高炉上料车车轴在使用过程中发生断裂。采用断口宏观形貌观察、化学成分分析和金相检验等方法对车轴进行了综合分析。结果表明:材料内部存在的大量非金属夹杂物成为裂纹源,为裂纹的产生提供了条件;另外机加工不当造成的应力集中加速了裂纹的扩展,以至在正常载荷条件下工作的车轴产生了断裂。

A axle of blast furnace charging wagon broke in use. The fracture reason was analyzed by means of macro-morphology inspection,chemical composition analysis and microstructure examination. The results showed that much inclusions existed in the material,which was the source of crack. Moreover,the illogical machining controls accelerated crack growth, that led to the axle broke under normal loading condition.