热镀锌层磷化膜硝酸铈封闭后处理的研究  

Post-Sealing of Phosphated Hot-Dipped Galvanised Steel by Cerium Nitrate

作　　者：孔纲[1] 林碧兰[1] 刘军[1] 卢锦堂[1] 

机构地区：[1]华南理工大学材料科学与工程学院,广东广州510640

出　　处：《材料保护》2008年第2期8-10,共3页Materials Protection

基　　金：华南理工大学自然科学青年基金项目(E5050310)

摘　　要：为进一步增强磷化膜的耐蚀性,将磷化热镀锌钢板用硝酸铈溶液进行封闭后处理,并采用扫描电镜(SEM)和X射线能谱(EDAX)对所得复合膜层的组织形貌和化学成分进行了分析。结果表明,经硝酸铈溶液封闭处理后,磷化膜的孔隙被封闭,在锌层表面形成了由磷化膜和铈盐转化膜构成的连续完整的复合膜。其耐蚀性显著优于单磷化膜,其中热镀锌钢磷化300s再在硝酸铈溶液中封闭处理300s后所获得的复合膜耐蚀性最佳,并优于常规铬酸盐钝化膜。Phosphated hot dipped galvanized(HDG)steel was post-sealed with cerium nitrate solution so as to improve the corrosion resistance of the phosphating coatings.The surface morphology and chemical composition of the resulting composite coatings were investigated by means of scanning electron microscopy(SEM)and energy dispersive spectrometry(EDS),while the corrosion resistance of the composite coating was also evaluated.Results showed that the pores in the phosphating coating were sealed after post-sealing the phosphating HDG steel with cerium nitrate solution,accompanied by the formation of a continuous and complete composite coating composed of phosphate coating and cerium salt conversion film on the surface of the HDG steel.The composite coating on the HDG steel had much better corrosion resistance than single phosphating coating.In particularly,the composite coating prepared by 300 s of phosphating plus 300 s of post-sealing showed the best corrosion resistance and was superior to chromate coatings.

关 键 词：热镀锌层 磷化膜 稀土盐 耐蚀性 

分 类 号：TG174[金属学及工艺—金属表面处理]