Comparison of pure and white cast iron dissolution kinetics in highly alkaline electrolyte

Abstract

Electrochemical impedance spectroscopy was used to compare the anodic dissolution kinetic of pure and white cast iron in 14 M NaOH. It was found that iron carbide in the anode material causes an apparent decrease in the surface oxide layer resistivity and consequently in the protective properties. Also the potential of the anodic end of the passivity region is moved towards more cathodic potential. The changes of the impedance spectra with electrode potential and electrolyte temperature are reported.