Electrochemical corrosion behavior of hot-rolled steel under oxide scale in chloride solution

In this work, electrochemical corrosion behavior of a hot-rolled steel with oxide scale was investigated in chloride solution through electrochemical measurements and surface characterization. Results demonstrated that the presence of a layer of compact oxide scale would protect the underlying steel from corrosion attack. Upon immersion in chloride solution, oxide scale on the steel surface is reduced, resulting in increase of electrode activity and corrosion rate of the steel. With the further immersion, the insolvable corrosion product and/or new oxide form to accumulate on the electrode surface, enhancing the electrode resistance and decreasing the corrosion of the steel. The amount of dissolved oxygen affects the corrosion of steel. With the increasing concentration of oxygen, there is more compact corrosion product and/or new oxide generating on electrode surface.