Corrosion Inhibition of Thiourea on Cold Rolled Steel in Low Concentration Acetic Acid Solution at Normal Temperature

The inhibition effects of thiourea(TU) on the corrosion of a cold rolled steel(CRS) in 0.05 mol/L HAc were investigated by polarization curves and electrochemical impedance spectroscopy(EIS). The results show that TU is a good inhibitor in low concentration acetic acid solution at normal temperature, and the inhibition efficiency increases with the increase of the concentration of TU, but when the concentration of TU is higher than 30 mg/L, the inhibition efficiency would be decreased with the increase of the concentration of TU. Polarization curves show that TU acts as a mixed-type inhibitor in acetic acid.