锌镀层稀土钝化处理及其在氯化钠溶液中的溶解

Rare earth passivating of zinc deposit and its resolution in sodium chloride solutions

研究了锌镀层经铈盐、镧盐和镨盐溶液钝化处理，及其在中型０－５ ｍｏｌ／Ｌ ＮａＣｌ溶液中的电化学行为，并与重铬酸盐、钼酸盐钝化进行比较。铈盐钝化处理效果接近重铬酸盐钝化，镧盐、镨盐钝化优于钼酸盐钝化。锌镀层稀土钝化的机理在于生成稀土氯化物、氢氧化物沉淀，由此降低镀层中锌的溶解速率，提高了镀层耐蚀性能。

Cerium, lanthanum, praseodymiun salt passivation of zinc deposit, comparing with chromating molybdenum salt passivating, and their electrochemical behavior in 0 5 mol/L neutral sodium chloride solutions. Performance of cerium salt passivating film was similar with that of chromating film. And lanthanum, praseodymium salt passivating was superior than molybdenum salt. Passivating mechanism of the three rare earth types is due to formation of rare earth oxide, hydroxide precipitation, therefore, resolution rate of zinc deposit was reduced, and corrosion resistance was improved.