Experimental analysis of mild steel corrosion in aqueous medium

Corrosion is one of the major problems in almost all the industries. The loss due to corrosion is about 3 - 4 % of GNP in the developed countries and it is even more in the developing countries. Mild steel is a commonly material which is widely used in almost all the manufacturing sectors and is very prone to the corrosion, especially in acidic environment. Therefore, it is essential to control the corrosion of mild steel in acid medium to reduce the unexpected economic loss due to corrosion. The inhibition is one of the simplest mechanisms used for extenuating the corrosion of metallic components, predominantly in aqueous medium. The present study, tries to evaluate the influence of N-benzyl-N’-phenyl thiourea (BPTU) on the corrosion behavior of mild steel in 0.1M HCl medium using the Tafel extrapolation method and the results are cross checked with linear polarization technique. It is evident from the study that the Tafel extrapolation and the linear polarization results are closely matches with each other. The investigation reveals that BPTU works as an efficient anodic inhibitor for mild steel corrosion in HCl solution and the protective efficiency (PE) of more than 97 % is noticed even at very low concentration of BPTU. The investigation also reveals that BPTU is chemically adsorbed on the steel surface, following Temkin’s adsorption isotherm. The presence of BPTU significantly reduces the anodic dissolution of the mild steel and the PE of the compound deduced is linearly varies with the concentrations of the inhibitor.