中文摘要：

在三价铬钝化液中添加稀土钕，以提高三价铬蓝白钝化膜的耐蚀性。研究了钝化温度、pH、时间以及钝化液中稀土钕含量对钝化膜耐蚀性的影响，得到镀锌层三价铬蓝白钝化的最优工艺条件为：Cr2（SO4）3 18．9g／L，Nd（NO3）3·6H2O 4g／L，NaNO3 2．2g/L，C6H8O7·H2O 0．7g／L，CoSO4·7H2O 7g/m，NaH2PO2·H2O 3．4g／L，NH4HF2 0．2g／L，温度30℃，pH1．9，时间30s。钝化液中添加稀土钕可有效提高钝化膜的耐蚀性。在最佳工艺条件下，钝化膜在3．5％NaCl溶液中的腐蚀电位、腐蚀电流密度和交流阻抗分别为-1．231V、0．568μA／cm^2和1937Ω·cm^2，中性盐雾试验出现白锈的时间为93h。

英文摘要：

Neodymium, a rare earth, was added to a blue-white trivalent chromium passivation solution to improve the corrosion resistance ofpassivation film obtained therefrom. The effects of passivation temperature, pH, time, and neodymium content in passivation solution on the corrosion resistance of passivation film were studied. The optimal process conditions of blue-white trivalent chromium passivation for zinc coatings were obtained as follows： Cr2（SO4）3 18.9 g/L, Nd（NO3）3·6H2O 4 g/L, NaNO3 2.2 g/L, C6H8O7·H2O 0.7 g/L, CoSO4·7H2O 7 g/L, NaH2PO2·H2O 3.4 g/L, NH4HF2 0.2 g/L, temperature 30 ℃, pH 1.9, and time 30 s. The addition of neodymium to passivation solution can improve the corrosion resistance of passivation film effectively. The passivation film obtained under the optimal process conditions has the following properties： corrosion potential -1.23 V, corrosion current density 0.568μA/cm^2, and alternating current impedance 1 937 Ω·cm^2 in 3.5% NaCl solution, and formation time of white rust in neutral salt spray test 93 h.