通过宏观检验、化学成分分析、力学性能测试、金相检验、断口分析等, 研究了电机轴快速断裂的原因。结果表明: 电机轴断裂的直接原因是轴边部大颗粒硅酸盐夹杂物在电机运转过程中造成应力集中, 形成裂纹源; 间接原因是由于内部非金属夹杂物较多, 皮下气泡严重, 已形成表面裂纹, 材料整体呈脆性及冲击功偏低。

The fracture reason of motor shaft was analyzed by means of macro examination, chemical composition analysis, mechanical property testing, metallographic examination, fracture analysis and so on. The results showed that the immediate cause of fracture was stress concentration from silicate inclusions on shaft side, which resulted in original crack initiation; its remote cause was high concentration of nonmetallic inclusions, undersurface pinhole, surface crack, brittle material and low impact energy of the material.