Zn-Al合金热镀层在干湿交替条件的腐蚀  

CORROSION OF HOT-DIP Zn-Al ALLOY COATING UNDER ALTERNATING WET AND DRY CONDITIONS

作　　者：阎永贵 

机构地区：[1]七二五所青岛分部,青岛266071

出　　处：《腐蚀科学与防护技术》2001年第z1期481-483,共3页Corrosion Science and Protection Technology

摘　　要：在干湿交替和逐渐增加氯离子浓度的条件下 ,对 4种热浸镀Zn基合金层进行了电化学测试评价 .电极电位和腐蚀速率的试验结果表明 4种热镀层防护性能的顺序为ZnAlMg镀层 ,ZnAlSi镀层 ,ZnAl镀层 ,Zn镀层 .电极电位的测试可以较好的观察和评价镀层的完整性 ,镀Zn层、镀ZnAl层、镀ZnAlSi、镀ZnAlMg层分别在第 9、13、2 1周期出现红锈 ,而ZnAlMg镀层 4 8周期仍未出现红锈 .随着氯离子浓度和试验周期的增加 ,各种涂层的腐蚀速率呈周期性变化 ,其中ZnAlMg镀层的腐蚀速率最小 .交流阻抗谱较线性极化测试结果的主要区别在于得到腐蚀速率相对较少 。Four kinds of hot-dip Zn-alloy coatings were tested by electrochemical measurements under alternating wet and dry conditions with increasing Cl - concentrations.The results indicate that ZnAlMg coating is superior to Zn,ZnAl and ZnAlSi coatings.The measurement of Ecorr can used to predict the integrity of coatings.With increasing Cl - concentration and test cycles,the variation of the corrosion rate (CR)of every coating may be differentiated and among them the CR of ZnAlMg coating is the lowest.The main discrepancy between the EIS and linear polarization is that the CR deduced from EIS is lower,but the tendency of the CRS obtained from the two is the same.

关 键 词：加速试验方法 干湿交替 热镀层 

分 类 号：TG172.9[金属学及工艺—金属表面处理]