热镀锌钢板钼酸盐钝化膜的耐蚀性研究  

Corrosion Resistance of Molybdate Passive Film on Hot Dipped Galvanized Steel

作　　者：刘艳荣[1] 周婉秋[1] 施耀萍[2] 武士威[1] 刘佳旭[1] 

机构地区：[1]沈阳师范大学化学与生命科学学院,辽宁沈阳110034 [2]天津市轻工装备研究所,天津300193

出　　处：《电镀与环保》2011年第2期26-29,共4页Electroplating & Pollution Control

基　　金：沈阳师范大学博士启动基金(BS200816);沈阳师范大学实验室主任基金(SY200706)资助项目

摘　　要：对热镀锌钢板钼酸盐钝化膜进行了研究,探索了一种新的镀锌层无铬钝化工艺,制备出均匀、致密的黑色钝化膜。钝化液的主要成分为钼酸盐,并添加了适量的促进剂和添加剂。采用电化学方法在中性NaCl溶液中研究了钝化膜的耐蚀性能。极化曲线测试结果表明:钝化膜阳极极化曲线呈现钝化特征,相对于热镀锌钢板基体而言,钝化膜的腐蚀电位正移,腐蚀电流密度减小。EIS研究显示:阻抗弧曲率半径明显增大,表明该钝化膜在质量分数为3.5%的NaCl溶液中可有效阻止腐蚀介质的浸蚀。SEM观察表明:钼酸盐钝化膜在热镀锌钢板表面覆盖的较为均匀、致密,无裂纹出现。EDX分析表明:钝化膜主要由Mo,P,O,Zn,Fe和Al等元素组成。Molybdate passivation film was investigated for hot dip galvanized steel sheet.A new chrome-free passivation process was studied,and a uniform and dense black passivation film was prepared.The main ingredient of the bath is molybdate,to which appropriate amount of accelerator and additive is also added.The corrosion resistance of the passive film was studied in neutral NaCl solution with electrochemical methods.The polarization curve tests showed that the anodic branch of the curve presented passivation characteristics.Compared with that of hot dip galvanized steel,the corrosion potential of the film shifted positively and the corrosion current density decreased.Electrochemical impedance spectroscopy（EIS） measurement illustrated that the radius of capacitive impedance arc was increased significantly which validated that the film could prevent corrosion effectively in corrosive medium of 3.5 % NaCl.SEM observation indicated that the molybdate passivation film were uniform and compact with no visible cracks.EDX analysis results indicated that the film was composed of Mo,P,O,Zn,Fe and Al.

关 键 词：热镀锌钢板 钼酸盐钝化膜 耐蚀性 SEM 

分 类 号：TG174[金属学及工艺—金属表面处理]