材料期刊网

某型舰船淡化海水管路材质为镀锌管,使用一段时间后,镀锌管内部锈蚀严重,管内水质变差.通过腐蚀形貌观察、点蚀深度测量等手段,进行了宏观腐蚀形貌观察;采用荧光光谱、红外光谱和X射线衍射(XRD)等微观分析手段,分析了镀锌管的腐蚀产物成分.结果表明:镀锌管腐蚀类型为局部腐蚀,点蚀严重.镀锌管腐蚀严重的主要原因是淡化海水腐蚀性较强,水质呈弱酸性;管路锈层主要成分为不稳定的γ-FeOOH和Fe3O4,且锈层疏松,不能对底层基体提供保护.建议后期对淡化海水管路的维修更换和设计选材时选用耐蚀性更强的316L不锈钢,且需对淡化海水进行矿化调质.

Galvanized steel pipes were used for desalination seawater pipe in a certain type of ship.Galvanized steel pipe internal corrosion was serious and the water quality became bad after a period of time at sea.Through the corrosion morphology observasion and pitting depth measurement,the macroscopic corrosion morphology was observed;using the microscopic analysis methods such as fluorescence,IR and XRD,the corrosion products of galvanized pipe were analyzed.The results show that the galvanized pipe corrosion type is localized corrosion and pitting corrosion is serious.The main reasons for the galvanized pipe corrosion were as follows:firstly,corrosion of the seawater was rather strong and the water quality was in weak acid,secondly,unstable γ-FeOOH and Fe3 O4 were main ingredients in the pipe,and rust layer was loose,which provide protection to the underlying substrate.It is suggested that for seawater pipeline replacement and maintenance in the late design,316L stainless steel with stronger corrosion resistance should be chosen,and mineralization process should be carried out in desalination.