Sodium nitrite as corrosion inhibitor for mild steel in simulated concrete pore solution

M. Pandiarajan, S. RajendranJ.

Abstract

The corrosion inhibition effect of mild steel in si mulated concrete pore solution (SCPS) by Sodium N itrite and Zn 2+ has been investigated using weight loss method and cyclic voltammetry. The results show that 93% of i nhibition efficiency is achieved with binary system consistin g of 100 ppm of sodium nitrite – 50 ppm of Zn 2+ . Surface evaluation technique like FTIR is used to determi ne the nature of the protective film formed on the metal surface. The protective film consists of Fe 2+ - SN complex, Zn 2+ - SN complex and Zn(OH) 2 . Cyclic voltammetry study reveals that the protective film is more compact and stable even in 3.5% NaCl environment.