电镀锌三价铬彩色钝化膜封闭剂的制备-表面技术.PDF

第 46 卷 第 2 期 表面技术 2017 年 2 月 SURFACE TECHNOLOGY ·199 · 电镀锌三价铬彩色钝化膜封闭剂的制备 禚昌岩 （徐州高新区淮海科技创新研究院，江苏 徐州 221116） 摘 要：目的 制备性能良好的封闭剂，以提高电镀锌三价铬彩色钝化膜的耐蚀性。方法 以氟化钠、硅酸 钠、OP 为主要原料制备封闭剂。采用 5%醋酸铅点滴法测定封闭处理后的电镀锌三价铬彩色钝化膜的耐蚀 性能，探讨了封闭剂的配方，分析了封闭时间、烘干温度、烘干时间等工艺条件对耐蚀性的影响，并通过 正交试验对封闭工艺进行了优化，确定了以氟化钠和硅酸钠为主盐的封闭剂的钝化处理工艺规范。结果 试 验得到的封闭剂组成为：氟化钠0.2 mol/L ，硅酸钠0.05 mol/L ，OP 1 mL/L。采用该封闭剂，在浸渍时间20 min 、烘干温度80 ℃的条件下，醋酸铅点滴实验最高达到近900 s。结论 封闭后膜层呈彩虹色，色泽明亮， 钝化膜耐蚀性提高。 关键词：封闭剂；三价铬钝化；电镀锌；氟化钠；硅酸钠 中图分类号：TQ153.1 文献标识码：A 文章编号：1001-3660(2017)02-0199-05 DOI ：10.16490/j.cnki.issn.1001-3660.2017.02.033 Preparation of Cr III-based Iridescent Passivation Flim Sealant on Zinc Coatings ZHUO Chang-yan (Xuzhou High-tech-Huaihai Science Technology Innovation Institute, Xuzhou 221116, China) ABSTRACT: The work aims to improve corrosion resistance of Cr III-based iridescent passivation film on zinc coatings by preparing a fine sealant. Principal raw materials of sealing agent were as follows: NaF, Na SiO and OP. The corrosion resis- 2 3 tance of Cr III-based iridescent passivation film subject to sealing treatment was studied by 5% lead acetate drop method. For- mulation of the sealant was discussed; effects of such process conditions as sealing time, process conditions baking temperature and baking time on corrosion resistance were analyzed; the sealing process was optimized by performing an orthogonal test, so as to determine passivation process specification for sealants with NaF and Na SiO