Electrodissolution kinetics of an Fe?Ni alloy in acidic chloride media of 1.0 M ionic strength

Anodic dissolution of an Fe−5Ni alloy in deoxygenated acidic chloride solutions of 1.0 M ionic strength has been studied. Steady state partial current densities of the iron and nickel components were obtained by atomic absorption spectrophotometry analysis of the solutions. Alloy and component electrodissolution rates show two anodic Tafel regions indicating simultaneous parallel reactions as reported previously for pure iron. Anodic Tafel slopes of 0.075 and 0.04V dec−1 were obtained in the lower (A) and higher (B) polarization regions, respectively. The kinetic results for the alloy are consistent with the Cl− accelerated mechanism in Region (A) and the Bockris or OH− accelerated mechanism in Region (B) for both iron and nickel components as proposed previously for pure iron.