某船用空冷器交付使用3个月发现其换热管泄漏。采用宏观检验、化学成分分析、金相检验、扫描电镜和能谱分析等方法对换热管的泄漏原因进行了分析。结果表明:泄漏原因为点腐蚀所致,由于冷却系统内的腐蚀产物以及海洋生物随同海水进入空冷器芯的换热管内,附着于换热管内壁形成沉积物,该沉积物分布不均匀,使换热管不同部位存在供氧差异和介质浓度差异,从而形成微电池效应,产生点腐蚀导致泄漏。

The air cooler of a ship has been found that the heat exchange tube was leaked three months after delivered,a systematic research was made to analysis the reason of the leakage of heat exchange tube, including macro examination, chemical component analysis, metallographic examination, SEM and energy spectrum analysis. The results showed that the reason of leakage was pitting corrosion, because the corrosion products of cooling system and marine organism along with the sea water into the heat exchange tube of air cooler core, attached to the inner wall of heat exchange tube and formed sediments, the distribution of sediments was uneven, the different parts of it had oxygen differences and medium concentration difference, thereby forming a micro cell effect, and the pitting corrosion resulted in leakage.