Al-Zn-Si-RE coating with high Al content was deposited on mild steel by arc spraying. The electrochemical behavior of Al-Zn-Si-RE coating in 3.5%NaCl solution was systematically studied by potentiodynamic polarization...Al-Zn-Si-RE coating with high Al content was deposited on mild steel by arc spraying. The electrochemical behavior of Al-Zn-Si-RE coating in 3.5%NaCl solution was systematically studied by potentiodynamic polarization, corrosion potential (φcor ) and electrochemical impedance spectroscopy techniques (EIS). The impedance data were fitted to appropriate equivalent circuits to explain the different electrochemical processes occurring at the electrode-electrolyte interface. The results indicate that Al-Zn-Si-RE coating reveals the similar polarization behavior as Zn-15Al coating. The coating has no passive region in the anodic polarization, but far lower corrosion current and much higher corrosion potential. Al-Zn-Si-RE coating provides effective sacrificial protection for steel substrate and the sacrificial anodic protection plays dominant role during the immersion process. In addition, theφcor evolution and EIS plots indicate that the corrosion process can be divided into five stages: pitting-dissolution-redeposition, activation corrosion, cathodic protection, physical barriers and the coating failure.展开更多
The spangle size of the 55% Al-Zn-Si steel is affected by the composition of the zinc pot, the cooling capacity after plating, and the substrate. According to previous studies, the size of spangles can be reduced by i...The spangle size of the 55% Al-Zn-Si steel is affected by the composition of the zinc pot, the cooling capacity after plating, and the substrate. According to previous studies, the size of spangles can be reduced by increasing the cooling ability after plating, and by adding Ti in the zinc pot. However, these two methods cannot reduce the spangle size smaller than 1. 5 mm. Therefore, in this study, we have focused on the influence of substrates on the formation of spangles of 55% Al-Zn-Si steel by comparing and analyzing substrates with different surface roughness, composition, morphology, crystal orientation, and alloy layers.展开更多
基金Project(CXLX12_0149)supported by Funding of Jiangsu Innovation Program for Graduate Education,ChinaProject(BA2011029)supported by Special Fund of Transformation of Sci-tech Achievements of Jiangsu Province,China+1 种基金Project(BY2011101)supported by the Creative Fund of Combination of Industry,Academia and Research of Jiangsu Province,China-Prospective Joint Research ProjectProject(kfjj120217)supported by Open Funds of NUAA Innovation Base(Laboratory)for Graduate Students
文摘Al-Zn-Si-RE coating with high Al content was deposited on mild steel by arc spraying. The electrochemical behavior of Al-Zn-Si-RE coating in 3.5%NaCl solution was systematically studied by potentiodynamic polarization, corrosion potential (φcor ) and electrochemical impedance spectroscopy techniques (EIS). The impedance data were fitted to appropriate equivalent circuits to explain the different electrochemical processes occurring at the electrode-electrolyte interface. The results indicate that Al-Zn-Si-RE coating reveals the similar polarization behavior as Zn-15Al coating. The coating has no passive region in the anodic polarization, but far lower corrosion current and much higher corrosion potential. Al-Zn-Si-RE coating provides effective sacrificial protection for steel substrate and the sacrificial anodic protection plays dominant role during the immersion process. In addition, theφcor evolution and EIS plots indicate that the corrosion process can be divided into five stages: pitting-dissolution-redeposition, activation corrosion, cathodic protection, physical barriers and the coating failure.
基金supported by the Research Institute,Testing Center,Cold Rolling Mill and Manufacturing Department of Baosteel
文摘The spangle size of the 55% Al-Zn-Si steel is affected by the composition of the zinc pot, the cooling capacity after plating, and the substrate. According to previous studies, the size of spangles can be reduced by increasing the cooling ability after plating, and by adding Ti in the zinc pot. However, these two methods cannot reduce the spangle size smaller than 1. 5 mm. Therefore, in this study, we have focused on the influence of substrates on the formation of spangles of 55% Al-Zn-Si steel by comparing and analyzing substrates with different surface roughness, composition, morphology, crystal orientation, and alloy layers.
