Abstrato

Effect of Zn ions on corrosion inhibition of aminotris (methylenephosphonic) acid for carbon steel in acidic solution

Najoua Labjar, Souad ElHajjaji, H.Saufi, M.MekkaouiAlaoui, MounimLebrini, Fouad Bentiss, Charafeddine Jama

The synergistic effect of zinc ions on the corrosion inhibition of carbon steel in 1MHCl solutions by aminotris-tris (methylene phosphonic) acid (ATMP)hasbeenstudiedusingelectrochemical impedance spectroscopy (EIS), Tafel polarisationmethod, gravimetric measurement and inductively coupled plasma (ICP).The results revealed significant synergistic effect betweenATMP and Zn+2 which depend on themolar ratio, temperature and immersion time. The presence of Zn2+/ATMPinduces a decrease in anodic and cathodic currents. They act as a mixed–type inhibitor. The addition of zinc ions in acidic solution containingATMPinduces theformationofstablecomplexes and stabilizes the adsorption ofATMPon the steel surface. The synergistic effectwas observed betweenZn2+ andATMPwith an optimummolar ratio ofZn+2/ATMP = 5/5.