采用宏观形貌观察、化学成分分析、腐蚀产物能谱及X衍射分析、显微组织检查等，对某厂运行约半年即泄漏的10号钢U型换热管进行了失效原因分析。结果表明：U型管外壁结垢严重，发生了垢下腐蚀；同时，Cl^-在垢下闭塞区中富集并引发“自催化酸化”效应，加速了垢下腐蚀的进程，导致换热管半年内就发生泄漏。

Macroscopic morphology observation, chemical composition analysis, corrosion product energy spectrum and X-ray diffraction analysis and microstructure inspection were used to analyze the failure reasons of a 10^# steel U-shaped heat exchange tube run in a plant for about half a year. The results show that the fouling on the outer wall of the U-tube was serious and the corrosion under the scale occurred. At the same time, the enrichment of Cl^- in the occlusion zone under the scale and the “autocatalytic acidification” effect accelerated the progress of corrosion under the scale, resulting in leakage of the heat exchange tube within half a year.