Inhibition of chloride localized corrosion of mild steel by PO3y, 4 CrO2y, MoO2y, and NOy anions

The effect of phosphate PO43y., chromate CrO42y., molybedate MoO42y.and nitrite NOy2 . ions on the pitting corrosion of steel in 0.1 M NaCl solution has been studied using potentiodynamic polarization and SEM techniques. The addition of increasing concentrations of PO43y, CrO42y, MoO42yand NOy2 anions causes a shift of the pitting potential Epit. in the positive direction, indicating the inhibitive effect of the added anions on the pitting attack. The adsorption characteristics of these anions on the steel surface play a significant role in the inhibition processes. The PO43yanion has a strong inhibitive effect of chloride pitting corrosion. The effect of different inorganic anions on the pitting corrosion of steel samples I and II with different composition.was also studied in 0.1 M NaCl solution. q2000 Elsevier Science B.V. All rights reserved.