Inhibition Perfromance of APPB for A3 Steel in Hydrochloric Acid

The inhibition perfromance of 1-(1-anilino-3-phenyl-2-propenyl)-2,3-dihydro-benzimi-dazol (APPB) on A3 steel in HCl solution was investigated by weight-loss test,potentiodynamic polarization and electrochemical impedance spectroscopy.The results showed that the inhibition efficiency increased with increasing the concentration of APPB and concentration of hydrochloric acid,and decreased with increasing temperature.Active energy of corrosion reaction with APPB was larger than that without APPB.APPB was adsorbed on A3 steel surface spontaneously,and the adsorption of APPB followed Langmuir isotherm.The relationship between the molecular structure of APPB and the inhibition efficiency was investigated by quantum chemical calculations.