Effect of ultraviolet illumination on corrosion resistance of 304 austenitic stainless steel in molybdate-containing solution

This study investigates the effect of ultraviolet (UV) illumination on the corrosion resistance of 304 stainless steel in molybdate-containing solution. The UV illumination was found to reduce the passivation and pitting resistance of the passive films. In addition, the passive film exhibited n-type semiconductor characteristics. Under UV illumination, the content of Cr2O3 within the passive film decreased. Moreover, the formation of a built-in electric field inhibited the absorption of MoO4 2- on the substrate surface, thereby weakening the corrosion inhibition of Na2MoO4. This leads to a reduction in the corrosion resistance of the passive film.