文章编号：1004 – 227X (2019) 03 – 0104 – 05
Effect of phosphating on corrosion resistance of electrophoretic coating on hot-dip galvanized steel sheet after stone chipping // LI Min*, HAO Yu-lin, ZHAO Xiao-fei, MIAO Yu-fang
Abstract: The effect of the quality of phosphating film on hot-dip galvanized steel sheet on the resistance of subsequent electrophoretic coating to stone chipping and corrosion was studied. On the premise of the qualification of pretreatment, the decrease in grain size and micropore resistance of phosphating film results in the increase of electrophoretic coating thickness and the enhancement of the adhesion between electrophoretic coating and phosphating film. The result of cyclic corrosion test after stone chipping results showed that the quality of phosphating film on hot-dip galvanized steel sheet is the key factor affecting the corrosion resistance of the electrophoretic coating suffered from chipping. The smaller the grain size of phosphating film is, the stronger the chipping corrosion resistance of electrophoretic coating is.
Keywords: hot-dip galvanized steel sheet; phosphating film; grain size; electrophoretic coating; stone chipping; cyclic corrosion; adhesion
First-author’s address: Research Institute of Technology of Shougang Group Co., Ltd., Beijing 100041, China