Use of as Green Corrosion Inhibitor for Carbon Steel in Sulfuric Acid

A study on the use of Cynara scolymus ( C. scolymus ) as a green corrosion inhibitor for 1018 carbon steel in 0.5 M sulfuric acid has been carried out by using weight loss tests, potentiodynamic polarization curves and electrochemical impedance spectroscopy measurements. It was found that C. scolymus is a good corrosion inhibitor with its efficiency increasing with the inhibitor concentration but it decreases with an increase in the temperature. C. scolymus is a mixed type of inhibitor, which is physically adsorbed on to the metal surface by following a Temkin adsorption isotherm. It forms a protective film by the contained compounds such as fatty acids, phenolics as quinic acid and sterols such as stigmasterol and γ-sitosterol.