采用稀土化学活化处理的锌粉制备渗锌层及其耐蚀性

Preparation and corrosion resistance of sherardized coating using zinc powder chemically activated by rare earth salt

为了改进粉末渗锌工艺和提高渗锌层的耐蚀性,预先对锌粉进行稀土化学活化处理,活化配方为:锌粉144g,LaCl_3 4g,浓盐酸5mL,去离子水50mL。对比研究了分别采用普通锌粉、活化锌粉和普通锌粉+稀土镧组成的渗锌剂配方所得渗锌层的外观、表面形貌、厚度和耐蚀性。结果表明,采用稀土化学活化处理的锌粉渗锌时,不存在锌粉粘结现象,所得渗锌层均匀、致密。虽然渗锌层的厚度较另外两种小,但其耐蚀性更优。

To improve the sherardizing process and corrosion resistance of sherardized coating, the zinc powder were chemically pre-activated in a solution composed of 144 g zinc powder, 4 g LaCl3, 5 mL concentrated hydrochloric acid and 50 mL deionized water. The appearance, surface morphology, thickness and corrosion resistance of the sherardized coatings obtained from sherardizing solutions containing common zinc powder, activated zinc powder and common zinc powder plus rare earth lanthanum respectively were comparatively studied. The results showed that no caking occurs to zinc powder during the sherardizing process when using the zinc powder chemically activated with rare earth, and the sherardized coating obtained is uniform and compact, and its corrosion resistance is better though it＇s thinner than that of the other two coatings.