(1. 华南理工大学 化学科学学院，广州 510640；
2. 广州二轻工业科学技术研究所，广州 510170)
摘 要: 采用电化学方法、扫描电镜和X射线光电子能谱研究了锌酸盐镀锌层的三价铬钝化膜的电化学性能、表面结构与成膜机理。结果表明：锌酸盐镀锌层的三价铬钝化膜表面结构致密、无明显裂纹，具有较好的耐腐蚀性能；这种钝化膜表层与里层的组成不同，表层的组成为Cr2O3-Cr(OH)3-ZnO共混物；里层(离表层10~30 nm处)的主要组成为Cr2O3-ZnO-Zn共混物；钝化膜的成膜过程可能包括镀锌层的溶解、碱性薄层的形成、胶状膜的形成和胶状膜转化成钝化膜4个步骤。
关键字: 镀锌；三价铬；钝化膜
（1.College of Chemistry, South China University of Technology, Guangzhou 510640, China;
2.Guangzhou Etsing Plating Research Institute, Guangzhou 510633, China）
Abstract:The electrochemistry behavior, surface microstructure and forming process of trivalent chromium passivation film were studied by electrochemical methods, scanning electron microscopy and X-ray photoelectron spectroscopy. The trivalent chromium passivation film based on zincate plating obtained has compact structure with no obvious crack, and excellent anticorrosion performance. Different compositions are detected from the surface to inner film, the surface mainly contains Cr2O3-Cr(OH)3-ZnO compound, the inner (10−30 nm to surface) composes of Cr2O3-ZnO-Zn.The forming process of passivation film possibly consists of four steps which are zinc dissolution, basic area appearance, gelatiniform film forming and converting to passivation film.
Key words: zincate plating; trivalent chromium; passivation film
