Imidazole and Al3+nano material as corrosion inhibitor for mild steel in hydrochloric acid solutions

Abstract The corrosion inhibition efficiency of Imidazole in controlling the corrosion of mild steel immersed in 0.2 N HCl for 60 min in the presence and absence of Al3+ has been studied by weight loss method. The formulation consisting of 550 ppm of Imidazole and 60 ppm Al3+ offers 94% inhibition efficiency. The synergistic effect exists between Imidazole and Al3+ system. Polarization study shows that the best formulation system controls anodic reaction predominantly. The FTIR spectra study reveals that the protective film consists of Fe2+ - C = O group and N–H stretch on metal surface.The mechanism of corrosion inhibition is proposed based on the results obtained from weight loss study and polarization study. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to investigate the nature of protective film formed on the mild steel surface.