Authors : Y. Hamlaoui , F. Pedraza-Diaz and L. Tifouti
Abstract: In this research, corrosion monitoring of Zn-based coatings is investigated through potentiodynamic, immersion and Electrochemical Impedance Spectroscopy (EIS) methods. This study is devoted to the study focuses on the corrosion resistance of a laboratory-made electrolytic coating. For such purpose, the corrosion behaviour is studied in different media (NaCl, NaOH and rain water), at different concentrations and varying pH and oxygen concentration. The results show that EIS allows to establish the interfacial reactions and the dissolution mechanisms occurring in three corrosive media, hence to foresee the protection conferred by these coatings. The kinetic model describing the Zn dissolution in aereted NaCl and Na2SO4 solutions, proposed in the literature, applies partially in the case of galvanised steel. Finally, each Zn/medium interface is characterised by a specific equivalent circuit giving a similar impedance response. It is concluded that EIS appears as a quick and reliable technique to evaluate the corrosion resistance of industrial coatings depending on the medium considered.
Y. Hamlaoui , F. Pedraza-Diaz and L. Tifouti , 2007. Comparative Study by EIS on the Corrosion Resistance of Electroplated Zn Coating in Different Corrosive Media . Journal of Engineering and Applied Sciences, 2: 706-713.