无铬封闭对冷轧汽车板锌系磷化膜耐蚀性能的影响  

Influence of Chromium-Free Sealing Treatment on Corrosion Resistance of Zinc Phosphating Film on Cold-Rolled Automo-tive Sheet

作　　者：沈璟虹[1] 万茂松[2] SHEN Jinghong;WAN Maosong(College of Intelligent Manufacturing,Wuxi Vocational College of Science and Technology,Wuxi 214028,China;College of Automobile and Traffic Engineering,Nanjing Forestry University,Nan-jing 210037,China)

机构地区：[1]无锡科技职业学院智能制造学院,江苏无锡214028 [2]南京林业大学汽车与交通工程学院,江苏南京210037

出　　处：《电镀与精饰》2020年第9期6-10,共5页Plating & Finishing

基　　金：江苏省高等学校自然科学研究面上项目(18KJB460019)。

摘　　要：为了提高冷轧汽车板锌系磷化膜的耐腐蚀性能,使用硅酸钠溶液对磷化膜进行封闭处理。以硅酸钠浓度、溶液温度和封闭时间作为影响因素,以变色时间作为评判磷化膜耐腐蚀性能的指标,通过正交试验设计与分析得到最佳封闭工艺条件为:硅酸钠浓度10 g/L、溶液温度80℃、封闭时间16 min。在最佳封闭工艺条件下封闭后磷化膜的致密度较高,主要成分为Zn、P、O、Na和Si元素,其耐腐蚀性能明显优于封闭前磷化膜。硅酸钠填充了晶粒间的缝隙,使磷化膜的致密度提高,阻挡了腐蚀介质向磷化膜内部渗透,从而提高磷化膜的耐腐蚀性能。In order to improve the corrosion resistance of zinc phosphating film on cold-rolled automotive sheet,the phosphating film was sealed with sodium silicate solution.The corrosion resistance of phosphating film was evaluated using the concentration of sodium silicate,solution temperature and sealing time as the influencing factors and the color-changing time as the index.The optimal sealing process conditions obtained through orthogonal test design and analysis were as follows:concentration of sodium silicate 10 g/L,solution temperature 80℃,sealing time 16 min.The phosphating film sealed under the optimal sealing process conditions has a compact structure,and is mainly composed of Zn,P,O,Na and Si elements.The corrosion resistance of the phosphating film after sealed is obviously better than that of the phosphating film before sealed.The density of phosphating film is improved because of sodium silicate filled the gap between the grains,which prevents the corrosive medium from permeating into phosphating film,so as to improve the corrosion resistance of phosphating film.

关 键 词：锌系磷化膜 冷轧汽车板 无铬封闭 硅酸钠溶液 耐腐蚀性能 

分 类 号：TB43[一般工业技术]