The inhibition of mild steel corrosion in acidic medium by 1-methyl-3-pyridin-2-yl-thiourea

The effect of 1-methyl-3-pyridin-2-yl-thiourea on the corrosion resistance of mild steel in H2SO4 solution was investigated by different techniques. The results show that the inhibition efficiency increases with the increase of inhibitor concentration. This compound affects both the anodic dissolution of steel and the hydrogen evolution reaction in 0.5 M H2SO4. The adsorption of this inhibitor is also found to obey the Langmuir adsorption isotherm. From the adsorption isotherm, value of the ΔGads for the adsorption process was calculated. From the corrosion rate obtained at 25–45 ± 1 °C Ea, ΔHa and possible mechanism have been proposed.