Effect of UV Illumination on the Corrosion Behavior of Under a Thin NaCl Electrolyte Layer

The corrosion behavior of 304 stainless steel (SS)under a liquid NaCl thin film was investigated by analyzing the corrosion morphologies, polarization curves, Mott-Schottky (M-S) measurements and transient photocurrent experiments. The results revealed that ultraviolet (UV) illumination promoted pitting nucleation and growth. An extremely rapid oxygen supply caused shallow pitting areas on the UV-irradiated specimen surface. Light-responsive passive films appeared on the surface of the pre-passivated stainless steel. In addition, the corrosion process of 304 SS under thin NaCl electrolyte layer with UV irradiation was influenced by the photovoltaic effect of semiconductor corrosion products.