目的 深入研究铁路继电器触点的失效机理。方法 在直流条件下进行铁路继电器电寿命试验，自动识别静触点表面与动触点的接触区域。利用三维形貌扫描仪和扫描电镜扫描触点，选定平面基准面，计算触点表面粗糙度参数，分析触点表面形貌变化。对触点烧蚀后的表面进行元素分析，研究触点表面的微观组织结构和失效机理。结果 Sa/Sq的值小于 0.8 表示随机性较强的表面， Sa/Sq（静）=0.246

The work aims to study the failure mechanism of railway relay contacts. The electric relay electric life test was carried out under the direct current condition to automatically recognize the contact area between the static contact surface and the moving contact. 3D topography scanner and SEM were used to scan the contacts, the plane reference surface was selected, the contact surface roughness parameters were calculated, and the surface topography changes of the contact surfaces were analyzed. Elemental analysis was performed on the ablated surface of the contact to investigate the microstructure and failure mechanism of the contact surface. The Sa/Sq value less than 0.8 indicated a random surface. For Sa/Sq (static) =0.246