The corrosion resistance performance of mild steel in simulated concrete pore solution (pH >12) containing a) 0.5 M sodium Nitrite b) 0.2 M sodium citrate c) 0.4 M sodium benzoate inhibitors in 0.5 M NaCl solution contamination were evaluated by electrochemical studies. The observed inhibition efficiencies were compared with gravimetric method after 30 days of immersion, for inhibited and uninhibited system. The maximum inhibition efficiency of 0.5 M sodium nitrite +0.2 M sodium citrate +0.4 M sodium benzoate mixed inhibitor system was found to be 75%. The inhibition efficiencies for the mixed inhibitor system were compared with control and single inhibitor system. From these study it was found that the role of nitrite ion present in the mixed inhibitor system repassivated the mild steel that drastically reduce the corrosion rate even in presence of high chloride concentration.
Inhibitor, Inhibition efficiency, Chloride, Mild steel, Corrosion rate