The Electrochemical measurements were performed to investigate the inhibitive effect of C6H12N4 (IEO) on corrosion of mild steel in 0.1mol.L-1 H2SO4 at room temperature with different concentration(0.001~0.05 mol). Impedance spectroscopy measurement (EIS) showed that the polarization resistance (Rp) increased and double layer capacitance (Cdl) decreased with the increase in the inhibitor concentrations, and the results of potentiodynamic polarization showed that the inhibitors suppressed cathodic kinetics of steel corrosion without change in the mechanism. The Nyquist plots of impedance expressed mainly as a depressed capacitive loop with different compounds and concentrations. The results of optical microscopy analysis showed that the metal was protected from corrosion by the addition of C6H12N4 inhibitor. The adsorption of C6H12N4 in 0.1mol.L-1 H2SO4 solution obeys Langmuir’s isotherm equation.

Corrosion inhibition, Mild steel, Electrochemical measurement, Inhibition corrosion efficiencies (ICE)