The influence of ultraviolet light irradiation on corrosion behavior of carbon steel

Corrosion of carbon steel in sodium chloride solution has been studied under ultraviolet illumination using weight loss, polarization, electrochemical impedance spectroscopy (EIS) and current transient tests. In polarization test an increasing in corrosion current density observed under UV illumination. Impedance spectroscopy indicate that the charge transfer resistance of system decreased by irradiation of UV light on carbon steel electrode. The weight loss of carbon steel in solution increased under UV light which confirms the results which obtained from electrochemical measurements. It was proposed that the essential effect of UV irradiation is on the oxide film, iron oxide, which forms on the surface and a little modification on the properties of solution. Therefore in presence of UV, the conductivity of oxide film might be increased and lead to higher metal dissolution and corrosion rate.