某航海船舶用辅冷凝器的传热管为B30铜镍合金管材，服役20 d就发生了腐蚀泄漏。采用宏观检验、显微组织分析，化学成分分析，及透射电镜晶界分析等方法分析了铜镍合金管材的穿孔泄漏原因。结果表明:铜镍合金管材内壁含有碳氧附着物，降低了钝化膜的致密性和完整性，在内壁上形成点蚀，点蚀处的合金基体在弱碱性海水中发生脱镍，同时Cl^-的侵入，致使金属基体与钝化膜形成电偶腐蚀，最终导致铜镍合金管材穿孔泄漏。

The heat transfer tube of an auxiliary condenser for a marine vessel was a B30 copper-nickel alloy tube, and corrosion and leakage occurred after 20 days of service. The causes of perforation and leakage of the copper-nickel alloy pipe were analyzed by means of macro inspection, microstructure analysis, chemical composition analysis, and TEM grain boundary analysis. The results showed that the inner wall of the copper-nickel alloy pipe contained carbon and oxygen attachments, which reduced the compactness and integrity of the passivation film and formed pitting on the inner wall. The alloy matrix at the pitting was de-nickeled in weak alkaline seawater, and the intrusion of Cl^- caused the metal matrix and the passivation film to form galvanic corrosion, which eventually led to the perforation and leakage of the copper-nickel alloy pipe.