LAUSR

Abstract Study of the corrosion inhibition effect of the combined admixture of l-leucine and 5-bromovanilin on the corrosion of P4 low carbon mold steel in 1.5 M H2SO4 and HCl solution was performed with weight loss measurement, potentiodynamic polarization and optical microscopy analysis. Data obtained showed the compound performed effectively from mid to highest concentration in H2SO4 solution and at all concentrations in HCl. In both acids the inhibition efficiency was well above 80%. Anodic corrosion inhibition mechanism was determined for the compound in H2SO4 according to Freundlich and Frumkin adsorption isotherms while cathodic inhibition mechanism was the inhibition mode in HCl according to Langmuir adsorption isotherm. Optical images of inhibited and non-inhibited steel surfaces significantly contrast each other.