An investigation of carbon steel corrosion inhibition in 1 M HCl by Lepidium sativum oil as green inhibitor

The extracted lipid of lepidium sativum l was examined for fatty acid composition. oleic (22.03 g/100 g) and linolenic (29.22 g/100 g) acids were the predominant unsaturated fatty acids, while palmitic acid (8.03 g/100 g) was found as the major saturated acid. the inhibition of the corrosion of carbon steel in hydrochloric acid medium by lepidium sativum l oil has been studied using weight loss, electrochemical impedance spectroscopy (eis) and tafel polarisation methods. inhibition was found to increase with increasing concentration of the oil but decreases with temperature. polarization curves showed that lepidium sativum l oil behaves as a mixed-type inhibitor. the adsorption of the oil on the carbon steel surface obeyed the langmuir adsorption isotherm. the thermodynamic parameters for activation processes were calculated and discussed. values of inhibition efficiency calculated from weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy are in good agreement.