Environmentally friendly inhibitor of the corrosion of mild steel: Commercial oil of Eucalyptus

Abstract

A study assessing plant extracts as green corrosion inhibitors is important because of the potential cost effective and environmental benefits.This study employed a strategy to evaluate the effectiveness these molecules against corrosion of mild steel in acid media.Many plant extracts have been used as corrosion inhibitors of iron or steel in acidic media.This research aims to examine the effects of commercial oil of Eucalyptus on inhibition of corrosion with mild steel in hydrochloric acid by means of gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopic measurements.The results of the polarization curves show that the corrosion current density decreases from 3618 A/cm 2 to 87 A/cm 2 with the addition of the Eucalyptus inhibitor.The charge transfer resistance increases from 17 Ohm•cm 2 to 185 Ohm•cm 2 in the electrochemical impedance spectrum after the addition of the oil Eucalyptus inhibitor in the more concentrated solutions It is found that the adsorption of our green inhibitor on steel surface obeys the Langmuir adsorption isotherm equation.The inhibition efficiency was found to be increased with increasing immersion time of samples in the solution.The polarization plots indicate that the studied Eucalyptus inhibitor affects both the anodic metal dissolution, and the catholic hydrogen evolution acting as a mixed type inhibitor.