Metal Dissolution under Cathodic Current

Abstract

It has been comfirmed that the metal dissolution occurs at the cathode where enormous hydrogen gas bubbles are evolving in sulfuric acid, hydrochloric acid and electropolishing solutions. The rates of dissolution are much higher at the cathode than at the anode, and comoparable to those at the active corrosion potentials. The oxidizing ions such as HCrO₄^- and NO₃^- considerably increase the dissolution rates by the depolarizing effect at the cathode. It has been proposed that the dissolution occurs at the localized anode where is shielded by hydrogen gas bubbles due to the cathodic reaction.