详细介绍了在机务段小辅修中机车关键零部件磁粉探伤过程、磁痕分析方法及其评定,并举例说明磁粉探伤对铁路行车安全的重要性。针对现场探伤中存在的不足,提出机务段小辅修磁粉探伤中应该重点注意的事项及建议,以便提高检测质量。 This paper introduces in detail the magnetic particle inspection process, the magnetic mark analysis method and the evaluation of the key parts of locomotives in the minor auxiliary repair of the locomotive depot and illustrates the importance of magnetic particle inspection on the safety of railway traffic. In view of the flaws existing in field flaw detection, this paper puts forward some issues and suggestions that should be paid attention to in the small auxiliary flaw detection of locomotive depot in order to improve the test quality.