Experimental investigation on corrosion control of 13CR L80 steel in hydrochloric acid solution using thiophene methanol

Abstract

The influence of different eco-friendly inhibitors on the corrosion behavior of 13Cr L80 steel in 15% HCl solution was experimentally investigated. In the preliminary study, corrosion tests were performed with various oil well steels like13Cr L80, L80, N80 and P110 steels in order to evaluate the comparative corrosion resistance of these metals when exposed to 15% aqueous hydrochloric acid solutions without inhibitors. In this paper the inhibitive action of a selected inhibitor, thiophene methanol (TML) on the corrosion behaviour of 13Cr L80 steel in 15% HCl solution at different levels of concentrations (0-100 mM) was investigated using weight-loss, electrochemical polarization and AC impedance spectroscopic methods and their results were compared. The inhibition efficiency of TML increased almost linearly with its concentration and was found to be maximum (86.79%) at 75 mM and the increase in temperature resulted in the decrease of the inhibitor efficiency (?) and degree of surface coverage (?). Surface morphology of the corroded sample was analyzed by SEM. FT-IR spectral study and TGA were carried out to characterize the surface products. The result shows that TML is a good inhibitor for 13Cr L80 steel in HCl acid medium. The adsorption of the TML on the 13Cr L80 steel surface obeyed the Langmuir adsorption isotherm. Thermodynamic and activation parameters are discussed.