Investigating the inhibiting action of thiourea derivative on mild steel corrosion in acid medium

The corrosion is a natural phenomenon which affects the productivity and safety of men and machines. Since the mild steel has wide application in almost all industries, and is more prone to corrosion, particularly in acid medium, the present work aims to study the corrosive behavior of mild steel in 0.1N H₂SO₄ medium at different concentrations of N -benzyl - N¹ - phenyl thiourea (BPTU) and temperatures using Tafel extrapolation and linear polarization methods. The results obtained reveal that BPTU is functioning as an excellent anodic inhibitor for mild steel in 0.1N H₂SO₄ medium. The study shows that BPTU adsorbed on the steel surface follows Temkin’s adsorption isotherm and the inhibition is governed by physisorption mechanism followed by chemical adsorption. The study also shows that there is a direct correlation between the inhibition efficiency and the temperature studied. The thermodynamic parameters deduced indicated that there is a good interaction between the inhibitor molecules and mild steel surface. The investigation shows that the results obtained from the Tafel extrapolation technique and the linear polarization method are in good agreement. It is evident from the investigation that the compound BPTU can be efficiently used as corrosion inhibitor for mild steel in sulfuric acid solution at the elevated temperatures.