Study of Garlic Extract as a Green Corrosion Inhibitor for Mild Steel in Acidic Media

Abstract

This paper studies extract as corrosion inhibitors extracted from garlic. The IR spectrum analysis of the extract shows that the main ingredient of extract is amino acids, and the better extracting condition is that 30°C50mL 10%H2SO4and 20g peeled garlic react for 120.0h, and composite amino acids content in the extract is 19.0mg/L. The result of corrosion inhibition performance using static weight loss shows that the dosage of the extract, temperature and concentration of acidic mediums have effect on corrosion inhibition remarkably. The corrosion inhibitive efficiency for A3 steel is 93.26% in 5% Hydrochloric acid and 79.2% in5% mud acid when the dosage of the garlic extract is 4.0%(V/V) and 6.0%(V/V),respectively. The investigated results of electrochemistry performance of the extract indicates that corrosion potential of A3 steel shift in negative direction both in Hydrochloric acid and in mud acid, which indicates that the extract are inhibitors of inhibiting cathodic corrosion, and circular-arc radius of alternating-current impedance spectroscopy increase notably in acidic medium, and corrosion inhibition effect is remarkable. Therefore, it is feasible to extract inhibitors from garlic.