Effect of chloride ions on 316L stainless steel in cyclic cooling water

摘要

The effect of Cl- on the 316L stainless steel in simulated cooling water has been studied using polarization curves,electrochemical impedance spectroscopy (EIS),MottSchottky plot and scanning electron microscopy (SEM) techniques.Cl- concentrations vary from 200 to 900 mg/L.Results reveal that the corrosion resistance increases with the decrease of Cl-concentration in simulated cooling water.The increase of Cl- concentration leads to the shift of the corrosion potential towards the positive direction.Mott-Schottky curves show that in the passive film,Cr2O3 and FeO at the inner layer exhibit P-type but Fe2O3 and CrO3 (CrO42-) N-type semiconductive properties.The SEM/EDX data demonstrate that elements such as Fe,O,C,Si and Cl as well as the presence of calcium and aluminum are presented on the surface of the metal.