某管板式换热器运行不到2个月，换热管进口端即发生开裂。通过宏观分析、化学成分分析、水质分析、金相分析、断口以及能谱分析等方法，对换热管开裂属性及原因进行了分析。结果表明：该换热管开裂为应力腐蚀开裂；循环冷却水中较高含量的氯离子以及换热管进口端处于应力腐蚀敏感温度区导致了应力腐蚀的快速发展。最后，给出了进行焊后热处理和加强循环冷却水处理的建议。

After a tube-in-sheet heat exchanger being put into use for less than 2 months, cracking happened at the inlet end of the heat exchange tubes. By means of macro analysis, chemical composition analysis, water quality analysis, metallographic analysis, fracture analysis, energy spectrum analysis and so on, the cracking property and reasons of the heat exchange tubes were analyzed. The results show the cracking of the heat exchange tubes was stress corrosion cracking which caused by the combined action of high content of chloride ion in the circulating cooling water and stress corrosion sensitive temperature of the inlet end of the heat exchange tubes. Finally, measures of adopting post weld heat treatment and strengthening circulating cooling water treatment were proposed.