针对湛江海洋环境冶金设施紧固件防腐蚀需要,设计并研究了粉末渗锌和锌铝膜复合涂层防腐蚀体系.采用浸涂烘干焙烧方法制备锌铝膜涂层,利用电化学方法测试粉末渗锌和锌铝膜复合涂层的性能.结果表明,采用主要成分为鳞片锌粉285 g/L、鳞片铝粉65 g/L和钼酸钠30 g/L等组成的涂液体系进行浸涂并经70～80 ℃干燥及300 ℃焙烧可制备性能较好的锌铝膜,锌铝膜和渗锌层与钢基体相比同属于阳极,其自腐蚀电位和自腐蚀电流密度明显低于40Cr钢基体;3.5% NaCl中锌铝膜在约-0.80 V～-0.30 V(Ag/AgCl)电位区间存在钝化现象.

An anti-corrosion system of sherardizing and zinc-aluminum film composite coatings was designed and investigated in order to meet the needs of the corrosion protection of the metallurgical equipment in Zhanjiang.The Zn-Al film was prepared using a process of dip coating,drying and roasting.The corrosion performance of the Zn-Al film was tested by electrochemical methods.The results showed that a Zn-Al film with relatively good performance could be obtained when the Zn-Al film was prepared by dip coating in the coating solution composed of 285 g/L flake zinc,65 g/L flake aluminum,30 g/L sodium molybdate and so on,followed by drying at 70～80 ℃ and roasting at 300 ℃.Relative to the base metal 40Cr steel,both the Zn-Al film and zinc impregnation layer were anodic,the self-corrosion potential and self-current density of Zn-Al film and zinc impregnation layer were lower than those of 40Cr steel.The Zn-Al film showed a passivation region in the electrode potential range from -0.8 V～-0.3 V (Ag/AgCl) in 3.5% NaCl.