Keywords: Green corrosion inhibitor; mild steel; Murraya koenigii; potentiodynamic polarization; SEM

Abstract

Green corrosion inhibitor is one of the recent emerging remedy to prevent oil and gas pipeline corrosion. In this study, the leaf extract of Murraya koenigii (curry leaf tree) has been tested as a corrosion inhibitor for mild steel corrosion in CO2-saturated 3.5% NaCl medium. Standard corrosion evaluation techniques viz., weight loss method and electrochemical technique (potentiodynamic polarization) were employed to study the corrosion inhibition properties. The changes of surface morphology on mild steel specimens before and after corrosion studies were screened through scanning electron microscopy (SEM) combined with energy dispersive X-Ray analyzer (EDX). In addition, Fourier Transform Infrared (FTIR) Spectroscopy was used to characterize the leaf extract and the corrosion protective film formed over the mild steel surfaces. Results showed that Murraya koenigii leaf extract successfully reduced the corrosion rate through adsorption process, which followed the Langmuir adsorption isotherm.