Corrosion Inhibition of Mild Steel in 0.5 M HCl Using a Hydrazide Derivative as Inhibitor

The inhibition behaviour of N'-(4- (dimethylamino) benzylidene)-4-hydroxybenzo hydrazide (DABBH) on the corrosion of mild steel in 0.5 M hydrochloric acid was studied by Tafel polarization technique and electrochemical impedance spectroscopy technique. The inhibition efficiency of DABBH increased with the increase in its concentration and increase in temperature. Polarization study showed that DABBH acts as a mixed type inhibitor and its adsorption on mild steel surface was found to follow Langmuir's adsorption isotherm. The formation of protective film was confirmed by scanning electron microscopy study.