Inhibition of mild steel corrosion in hydrochloric acid solution by Fe and Cr Schiff base complexes

A comparative study of Fe and Cr complexes with a Schiff base ligand (1-[(2-hydroxyethyl)amino]-2-(5-methoxysalicylideneamino)ethane) as inhibitors for mild steel corrosion in 0.5 M HCl solution at 25°C was carried out. Electrochemical techniques were applied to study the metal corrosion behavior of these inhibitors. EDX, SEM and ATR-FTIR studies of the electrode surface confirmed existence of a protective adsorbed film of the inhibitors on the electrode surface. The inhibition efficiency was increased with the inhibitor concentration. The mechanism of adsorption is concluded that the adsorbed chloride ions on the metal surface could be stabilized in their anionic form like a crab-claw.