Abstract
The inhibition effect of some Schiff base compounds toward the corrosion of 1018 carbon steel in hydrochloric acid solution was studied using weight loss, galvanostatic polarization, and electrochemical impedance spectroscopy measurements. The percentage inhibition efficiency increased with increasing inhibitor concentration and with decreasing temperature. The polarization measurements indicated that the inhibitors are of mixed type and inhibit corrosion by adsorption on the steel surface. The adsorption process is described by the Freundlich adsorption isotherm. The activation energy and some activation thermodynamic parameters were calculated and explained. From the impedance data it is found that the corrosion of carbon steel is controlled by the charge transfer process at all concentrations of inhibitors.