Adsorption Behaviour of Thioglycolic Acid on Pre-corroded A3 Steel

In order to confirm the inhibition effect of corrosion product film of A3 steel,the adsorption behaviour of TGA(thioglycolic acid) on FeCO3 surface and its inhibition mechanism in sodium bicarbonate solution were studied by polarization curves,EIS and theoretical analysis.The results indicated that TGA formed a multi-layer film on the surface of FeCO3 and acted as negative catalytic inhibitor,its inhibition effect reached the maximum at the concentration of 1000 mg/L.The adsorption of TGA is spontaneous and the corresponding Gibbs free energy is -25.766 kJ/mol.