Comparative Study of Corrosion Inhibition on Mild Steel in HCl Medium by Three Green Compounds: Argania spinosa Press Cake, Kernels and Hulls Extracts

Argania spinosa press cake, kernels and hulls extracts are excellent corrosion inhibitors for steel. In this work electrochemical methods are used to study the inhibition of corrosion on steel in 1 M HCl. It has shown that Argan press cake, kernels and hulls extracts suppress both the anodic and cathodic process and they behave as mixed-type inhibitors. The inhibition efficiency was found to increase with inhibitors content. Data obtained from EIS measurements, were analyzed to model the corrosion inhibition process through appropriate equivalent circuit model; a constant phase element has been used. The values of the inhibition efficiency calculated from these techniques are in reasonably good agreement. The adsorption isotherm of natural compounds on the steel surface was found to obey Langmuir’s adsorption isotherm.