Influence of Dissolved Zinc Ions on The Anodic Dissolution of Iron

Abstract

The influence of dissolved zinc ion on the anodic dissolution of iron was investigated by potentiodynamic measurement and channel flow electrodes. In the polarization curves of iron, the anodic current around the immersion potential decreased with increase of zinc ion concentration in acidic solution, but increased in neutral solution. It is considered that the anodic dissolution of iron in acidic solution containing zinc ion was inhibited by the adsorption species onto the iron surface. In neutral solution containing zinc ion, the anodic dissolution of iron was accelerated by decrease in pH near the electrode caused by hydrolysis reaction of dissolved zinc ion. In the case of bare iron on which air formed oxide film was removed, the anodic dissolution of iron is inhibited by the presence of zinc ion in both acidic and neutral solution.