Abstract

The inhibition efficiency (IE) of various concentrations of a TSC- Zn2+ system in controlling corrosion of mild steel immersed in well water was evaluated by a weight-loss study. The formulation consisting of 50 ppm of TSC and 25 ppm of Zn2+ showed 70% inhibition efficiency. A synergistic effect was noticed between trisodium citrate - Zn2+ system. In the presence of Zn2+ TSC has excellent inhibition efficiency. Polarization studies reveal that TSC - Zn2+ function as a mixed inhibitor. AC impedance spectra suggest that a protective film is formed on the metal surface. FTIR spectra reveal that the protective film consists of Fe2+ - TSC complex and Zn(OH)2. SEM micrographs and AFM reveals that a protective film is formed on the metal surface

Key words: Corrosion inhibition, Carbon steel; Trisodium citrate; Synergistic effect