Inhibition Behavior of Lauroyl Corrosion Inhibitor on Q235 Carbon Steel in Citric Acid Medium

The corrosion behavior of sodium lauroamphoacetate corrosion inhibitor on Q235 carbon steel in 4.0% citric acid solution was studied by weight-loss experiment, electrochemical impedance spectroscopy (EIS), Tafel polarization curve and quantum chemistry calculation. Results show that the corrosion inhibitor has good effect on the corrosion of carbon steel, when the inhibitor mass fraction was 0.8%, its inhibition efficiency reached 78.44%. Electrochemical experiments show that the corrosion inhibitor is a kind of anodic type corrosion inhibitor, mainly as a form of adsorption on the metal surface to form a cladding. The LUMO and HOMO orbit energy were calculated by quantum chemistry calculation, the results show that corrosion inhibitor carboxyl O atom was adsorbed on the membrane of the active site.