Preparation and Corrosion Resistance of Silicate Passiva-tion Film Formed on Galvanized Zn Coatings
In this paper, one kind of silicate passivation technics was reported and by which method silicate passivation film on galvanized Zn coatings with satisfactory property was got. Zn coatings were prepared by conventional plating technics. The solution composition and operating conditions of passivation are: sodium silicate 10-30 g/L, H2SO4 5 mL/L, HNO3 5 mL/L, H2O2 5-20 mL/L, pH 1.5-2.5, passivation time 5-30 s, temperature 25 °C. The corrosion resistance of galvanized Zn coatings with different passivated technics were investigated by NSS corrosion test and compared with Zn coatings treated by Cr(VI) and Cr(III). The silicate passivation film can keep no rust for 72 h and obviously shows the best property. Surface morphologies of galvanized Zn coatings with different passivated method were got by metallurgical microscopy, and the silicate passivation film shows the most uniform surface, and has the least micro-hole. All the results show that silicate passivation technics can provide galvanized Zn coatings superior anti-corrosion performance and simultaneously avoid the pollution of chromium, so this technology has a wide application in future.
galvanized Zn coating silicate conversion film corrosion resistance
Fan Yunying Jiang Yehua Li Zulai
Kunming University of Science and Technology, Kunming 650093, China
国际会议
西安
英文
211-214
2011-05-11（万方平台首次上网日期，不代表论文的发表时间）