Corrosion protection of non-alloyed AIAI 316L concrete steel metal grade in aqueous H2SO4: Electroanalytical and surface analyses with Metiamide

The inhibitive ability of an imidazoline-derived compound, Metiamide (N-methyl-N′-(2-{[(4-methyl-1H-imidazol-5-yl)methyl]thio}ethyl)thiourea) – MTA – on non-alloyed AIAI 316L concrete steel metal grade (MS) corrosion in 0.5 M H2SO4 solution has been evaluated in this study using Electrochemical impedance spectroscopy, Potentiodynamic polarization and Linear polarization resistance methods. The inhibitor protected MS by inhibiting its corrosion rate in the acidic medium and the inhibition efficiency (I%) increased with the concentration of the inhibitor. The adsorption behaviour of MTA inhibitor has been explained with respect to impedance data. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) characterizations for surface morphological studies complemented the electrochemical studies. This work is designed to study the protection of non-alloyed concrete iron steel used in acid service environment with an organic corrosion inhibitor.