钝化封闭二合一三价铬高耐蚀蓝白钝化液的研究

The Blue-White Passivation Fluid for Passivation and Shielding of Galvanized Workpiece by Trivalent Chromate Conversion Coating

为获得一种用于镀锌工件的钝化封闭二合一的三价铬高耐蚀蓝白钝化液,先将SiO23-在特定条件下与NaF反应生成含有SiF62-(能促进成膜)与H4SiO4(能封闭钝化膜)的溶液,再加入硫酸铬、硫酸镍、硝酸钴、硝酸钠、镧系金属盐、苯胺类缓蚀剂和醚类表面活性剂等配成钝化液。通过改变SiO32-的量,研究了不同配方所获得的钝化膜的外观、耐蚀性和耐热性等。结果表明,当SiO23-的量为7.20g/L时配制的钝化液所获镀锌钝化膜层的外观颜色均匀蓝白光亮,耐蚀性和耐热性最好。

The reaction of SiO32-and NaF was carried out under certain conditions to generate a solution containing SiF62-capable of promoting film-formation and H4SiO4 capable of shielding passivation coating. After introducing chromium sulfate, nickel sulfate, cobalt nitrate, sodium nitrate, lanthanide salts, aniline type corrosion inhibitor, and surfactants into the above-mentioned solution, a blue-white trivalent chromate passsivation fluid for the passivation and shielding of galvanized workpieces was formulated. The appearance, corrosion resistance, and heat resistance of the passivation coatings prepared from the solutions containing different doses of SiO32- were investigated. Results indicated that the trivalent chromium passivation coating prepared from the solution containing 7. 20 g/L SiO32- was evenly blue and bright and had excellent corrosion resistance and heat resistance.