Electrochemical Evaluation of Linseed Oil as Environmentfriendly Inhibitor for Corrosion of Steel in HCl Solution

The effect of linseed oil (LO) on the corrosion of carbon steel in 1 M HCl solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) technique and weight loss measurements. The inhibiting action increases with the concentration of the tested inhibitor. The highest efficiency (98.2%) is obtained at 3g/L of LO. The influence of temperature on the corrosion behavior of carbon steel in 1 M HCl, with the addition of LO was also studied. The obtained data from EIS measurements were analyzed to model the corrosion inhibition process through an appropriate equivalent circuit model; a constant phase element (CPE) has been used. Polarization measurements show also that LO acts as a good mixed inhibitor. The inhibition process is attributed to the formation of an adsorbed film of the inhibitor on the metal surface which protects the metal against corrosion. LO is adsorbed on the steel surface according to a Langmuir isotherm adsorption model. The results obtained showed that the linseed oil could serve as an effective green inhibitor of the corrosion of carbon steel in hydrochloric acid medium.