通过宏观、微观分析及金相检验等方法,系统分析了加氢裂化压缩机机械密封定位销失效的原因。结果表明:定位销的热处理工艺存在不足,工作条件下的振动与磨损以及受到含S介质腐蚀的联合作用,使定位销最终在磨损最严重的部位发生了脆性断裂。 By macroscopical, microscopic analysis and metallographic examination, the causes of failure of the mechanical seal locating pins of hydrocracking compressors are systematically analyzed. The results show that there is a lack of heat treatment technology for the dowel pins, vibration and wear under working conditions, and joint corrosion caused by the medium containing S, so that the dowel pin finally becomes brittle fracture in the most worn parts.