Aqueous Extract of Salvadora Persica as a Novel Green Corrosion Inhibitor for Low-Alloy Steel in Acidic Media - Part I

摘要

The corrosion inhibition characteristics of aqueous extract of Salvadora Persica (AESP) on lowchromium-molybdenum steel (ASTM A213) grade T2 (0.5Cr- 0.5Mo) in 1M hydrochloric acidsolutions has been studied chemically and electrochemically at different temperatures. The protectionefficiency in absence and presence of AESP was investigated by using mass loss method, InductivelyCoupled Plasma Optical Emission Spectrophotometer (ICP-OES), as will as potentiodynamicpolarization, electrochemical impedance spectroscopy (EIS), and electrochemical frequencymodulation (EFM) techniques. The protection efficiency was found to increase with a correspondingincrease in the AESP concentration and decrease with temperature. Amongst the different adsorptionisotherms, the studied compound more closely followed the Temkin isotherm. The values of standardfree energy of adsorption (G o ads ) revealed that AESP is adsorbed on the low-alloy steel surface viaphysisorption mechanism.