为分析某燃煤电厂汽轮机动叶片断裂的原因，防止同类事故再次发生，对该叶片进行了宏观形貌检查、化学成分分析、金相检验、扫描电镜、能谱分析、硬度检测和常温力学性能试验。由该发电机组最近一次水质分析数据可知，锅炉用水中S^2-、Cl^-离子含量过高，该马氏体不锈钢叶片长期工作在腐蚀介质中，最终在应力集中最大的点蚀小坑处发生应力腐蚀开裂。根据电厂的实际生产情况，主要从腐蚀介质和消除应力集中这两方面提出了预防叶片发生应力腐蚀开裂的措施。

In order to analyze the fracture causes of a turbine blade in a coal-fired power plant and prevent similar accidents from happening again, the blade was examined by macroscopic morphological examination, chemical composition analysis, metallographic examination, scanning eletron microscopy (SEM), energy spectrum analysis, hardness test and normal temperature mechanical property test. According to the latest water quality analysis data of the generating set, the concentrations of S^2- and Cl^- ions in the boiler water were too high. The martensitic stainless steel blade had been working in such corrosive medium for a long time, finally leading to stress corrosion cracking occurring in a small pit where maximum stress concentrated. According to the actual production of the power plant, some measures to prevent the stress corrosion cracking of the blade were put forward from two aspects of corrosive medium and eliminating stress concentration.