Electrochemical behaviour of carbon steel in sodium chloride solution by using thiophenol derivative inhibitor

Abstract

The corrosion inhibition performance of thiophenol has been evaluated for carbon steel immersed in sodium chloride solution by weight loss method. As a results of weight loss method, it gives the corrosion rate and inhibition efficiency. The increase of corrosion inhibition efficiency with increase in concentration of thiophenol derivative inhibitor. When increase in concentration of inhibitor, the corrosion rate decreases. It is because of the higher concentration of inhibitor solution which arrest the active site of a carbon steel by the way of forming protective layer on the surface of carbon steel. The mechanistic aspects of corrosion inhibition has been assessed by electrochemical studies such as potentio dynamic polarisation studies and AC impedance spectra. The decrease of corrosion current and double layer capacitance value, increase in linear polarisation resistance values and impedance values obtained from electrochemical studies suggest that the formation of protective layer on the carbon steel surface. Surface analysis of polished, corroded and inhibitor carbon steel surface has been evaluated by SEM.