镀锌层无铬彩色钝化剂的研究

Study on chromium-free colored passivator for electroplated zinc coatings

通过单因素试验和正交试验研究了一种无铬彩色钝化剂中不同组分(包括硫酸亚铈、柠檬酸钠和硝酸钴)用量对钝化膜外观与耐蚀性的影响,得到较优的钝化剂配方为:硫酸亚铈50 g/L,柠檬酸钠15 g/L,硝酸钴20 g/L。采用最优配方在pH 1.5和温度20~30℃的条件下对镀锌层处理15 s,所得钝化膜平整、均匀,呈光亮的彩虹色。该钝化膜可通过24 h的中性盐雾腐蚀试验。

A chromium-free colored passivator was introduced. The effects of the dosages of the bath components including cerium（Ⅲ） sulfate, sodium citrate and cobalt nitrate were studied by single factor experiment and orthogonal test. The optimal bath composition was obtained as follows： cerium（Ⅲ） sulfate 50 g/L, sodium citrate 15 g/L, and cobalt nitrate 20 g/L The passivation film obtained on zinc coating from the optimal passivation solution at pH 1.5 and temperature 20-30 ℃ for 15 s is level, uniform and brightly colored and can pass a 24-h neutral salt sprav test.