Department of chemistry, Qaemshahr Branch, Islamic Azad University, Qaemshahr, Iran
The aim of this study was to investigate the effect of inhibition of Marrubium astranicum
leaves extract on the corrosion of carbon steel in hydrochloric acid solution by using weight
loss and tafel polarization methods. Inhibition was found to increase with increasing
concentration of the leaves extract. The inhibition efficiency of this extract at an optimum
concentration of 100 mg L-1 was 99.9 %. The effect of inhibitor concentration, immersion
time and temperature on the corrosion behavior of carbon steel in 1 M HCl was also studied.
The inhibition was assumed to occur via adsorption of the inhibitor molecules on the metal
surface. The adsorption of the extract on the carbon steel surface obeys the Langmuir
adsorption isotherm. The results obtained show that the leave extract of plant could serve as
an effective green inhibitor of the corrosion of carbon steel in hydrochloric acid.