LZ50钢列车车轴表面开裂机理研究

采用光学金相、X射线能谱仪、扫描电子显微镜等手段对出现开裂的LZ50钢列车车轴整体及裂纹部位进行系统分析,发现轴表面裂纹源处存在许多腐蚀坑,坑内腐蚀产物含有Cl和O元素,坑底存在较多沿轴周向分布的微裂纹。结果表明,较强的腐蚀性物质使轴颈卸荷槽部位轴表面形成较深腐蚀坑,使该区域极易产生应力集中,从而引起车轴表面开裂。

Study on surface-cracking principle for LZ50 steel train axle

The surface cracking behaviors for the failure LZ50 steel train axle are investigated by the use of optical metallography, X-rays energy spectrum, scanning electric microscope etc. Many corrosion pits in which the corrosion products contain the elements chlorine and oxygen are found on the crack source zone, and there are more circumferential micro-cracks along the axis at the bottom of the pits. The results show that the formation of deep corrosion pits is promoted by the very corrosive substance on the ax...