Composition and Performance of the Composite Coatings Obtained by Phosphating and Cerium Nitrate Post-Sealing on Galvanized Steel
来源期刊：Journal of Rare Earths2007年第S1期
论文作者：林碧兰 卢锦堂 孔纲 刘军
文章页码：461 - 464
摘 要：To improve the corrosion resistance of phosphate coatings, the phosphated hot-dip galvanized （HDG） steel was post-sealed with cerium nitrate solution. The morphology, composition, corrosion resistance of the coatings was investigated by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS） and neutral salt spray （NSS） tests. The results show that after post-sealing the phosphated HDG samples with cerium nitrate solution, the pores among the zinc phosphate crystals are sealed by the compounds containing phosphorus, oxygen and cerium; the zinc phosphate crystals are covered by the flocculent cerium compounds; and the continuous composite coatings are formed on HDG steel. The corrosion resistance of the composite coatings, which increases with the increase in phosphating time and cerium nitrate post-sealing time, is far higher than that of the single phosphate coatings. The composite coatings with the optimal corrosion resistance are obtained for phosphating 300 s and post-sealing 300 s; and the corrosion resistance is more outstanding than that of the chromate coatings.
林碧兰，卢锦堂，孔纲，刘军
摘 要：To improve the corrosion resistance of phosphate coatings, the phosphated hot-dip galvanized （HDG） steel was post-sealed with cerium nitrate solution. The morphology, composition, corrosion resistance of the coatings was investigated by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS） and neutral salt spray （NSS） tests. The results show that after post-sealing the phosphated HDG samples with cerium nitrate solution, the pores among the zinc phosphate crystals are sealed by the compounds containing phosphorus, oxygen and cerium; the zinc phosphate crystals are covered by the flocculent cerium compounds; and the continuous composite coatings are formed on HDG steel. The corrosion resistance of the composite coatings, which increases with the increase in phosphating time and cerium nitrate post-sealing time, is far higher than that of the single phosphate coatings. The composite coatings with the optimal corrosion resistance are obtained for phosphating 300 s and post-sealing 300 s; and the corrosion resistance is more outstanding than that of the chromate coatings.
关键词：
