Effect of Current Density of Electrodeposition on Microstructure and Corrosion Behavior of Mn-Co-CeO2 Coating on AISI 430 Steel

AISI 430 ferritic stainless steel is used as interconnects in solid oxide fuel cells. In order to improve the corrosion resistance of this steel under operation conditions of solid oxide fuel cells, a protective and conductive coating layer on the interconnects can be used. In this research, AISI 430 ferritic stainless steel was coated with electrolytic with manganese, cobalt and cerium oxide under different density densities (400, 500, 600 and 700 mA/cm2). The coated specimens were studied by scanning electron microscopy (SEM) with X-ray diffraction spectroscopy (EDX). In order to investigate the corrosion behavior of the coatings, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests was used in aqueous NaCl solution of 3.5%. The results showed that with increasing the current density, the coating became even more uniform. The results of electrochemical polarization showed that the coating produced at a current density of 600 mA/cm2 has a better corrosion resistance (0.186 μA.cm2) than the coatings produced at current density of 400 (2.06 μA.cm-2), 500 (1.767 μA.cm-2) and 700 (1.02 μA.cm-2). Also the results of electrochemical impedance spectroscopy showed that the capacity of coating produced at current density of 600 mA/cm2 (1.47E-4 Ω-1cm-2Sn) is lower in comparison with the coatings produced at current density of 400 mA/cm2 (2.5E-4 Ω-1cm-2Sn), 500 mA/cm2 (1.6E-4 Ω-1cm-2Sn) and 700 mA/cm2 (2.1E-4 Ω-1cm-2Sn) which indicating better corrosion resistance of produced coating at current density of 600 mA/cm2.

Effect of Current Density of Electrodeposition on Microstructure and Corrosion Behavior of Mn-Co-CeO2 Coating on AISI 430 Steel Keywords:

Microstructure , Potantiodynamic polarization , Electrochemical impedance spectroscopy , Current density , AISI 430 ferritic stainless steel , Mn-Co-CeO2 coating , میکروساختار , پلاریزاسیون پتانسیودینامیک , امپدانس الکتروشیمیایی , دانسیته جریان , فولاد زنگ نزن فریتی AISI 430 , پوشش Mn-Co-CeO2.