Inhibition of corrosion of carbon steel by heptane sulphonic acid – Zn2+ system

Corrosion inhibition of carbon steel in dam water by sodium heptane sulphonate (SHS) and zinc ion system was investigated using weight loss and potentiodynamic polarization methods. Results of weight loss method indicated that inhibition efficiency (IE) increased as the inhibitor concentration increased. A synergistic effect existed between SHS and Zn2+. The influence of sodium potassium tartrate (SPT) on the IE of the SHS-Zn2+ system was evaluated. As the immersion period increased, the IE decreased. Polarization study revealed that SHS-Zn2+ system functioned as a cathodic inhibitor. AC impedance spectra revealed that a protective film was formed on the metal surface. The nature of the metal surface was analyzed by FTIR spectra, SEM and AFM analyses.