某煤化工企业空分装置的一蒸汽换热器管束发生了泄漏失效。为防止此类事故再次发生，对失效管束进行了宏微观形貌观察、扫描电镜分析及能谱分析，结合化工工艺分析确定其失效原因。结果表明，该换热器管束泄漏失效是由于碱腐蚀作用引起的点蚀穿孔。最后，针对换热管的是失效原因给出了合理的改进建议。

A leakage failure happened in the steam heat exchanger tube bundle in an air separation unit of a coal chemical plant. In order to prevent such accident, observation of macro and micro morphology, analysis by scanning electron microscopy and energy dispersive spectroscopy combined with chemical process analysis were conducted to find out the failure causes. The results show that the leakage failure of the steam heat exchanger tube bundle was due to pitting perforation caused by alkali corrosion. The reasonable improvement suggestions were given according to the failure reasons of the heat exchanger tubes.