14 research outputs found
Synergistic Combination Effect of Salvia officinalis and Lavandula officinalis on the Corrosion Inhibition of Low-Carbon Steel in the Presence of SO42−- and Cl−-Containing Aqueous Environment
The corrosion inhibition of low-carbon steel in 1 M H2SO4 and HCl solutions by
the admixture of Salvia officinalis and Lavandula officinalis essential oil
extracts was studied through potentiodynamic polarization analysis, coupon
measurement and optical microscopy. The carbon steel undergoes severe
surface deterioration in H2SO4, while the morphology of the steel from HCl
showed selective deterioration with numerous corrosion pits in the absence of
the oil extracts. The extracts performed effectively in the acid media with
optimal inhibition efficiency of 86.92 and 96.90% in H2SO4, and 84.68 and
97.59% in HCl from potentiodynamic polarization and coupon analysis. The oil
extract displayed anodic inhibition properties in H2SO4 due to surface coverage
of the steel and cathodic inhibition in HCl due to selective precipitation of
extract molecules. Thermodynamic calculations show the extracts adsorbed
onto the steel surface, effectively suppressing the corrosion reactions through
chemisorption mechanism according to the Langmuir, Frumkin and Freundlich
adsorption isotherms