"Effect of Plectranthus amboinicus (Indian borage) on the corrosion of carbon steel in well water"


P. Thirupathi & B. R. Venkatraman (Associate Professor)
Periyar E.V.R. College (Autonomous), Tiruchirappalli-620 023, Tamilnadu, South India. Affiliated to Bharathidasan University.


Corrosion inhibition effect of plectranthus amboinicus on carbon steel in well water. The inhibition effect of plectranthus Amboinicus leaves extract on the corrosion of carbon steel was studied by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy and a surface study like scanning electron microscope (SEM). The potentiodynamic polarization studies reveal that the extract behaves as a mixed type inhibitor. The effect of temperature on the inhibition of corrosion was also studied. Activation energy (Ea), enthalpy (ΔH) and heat of adsorption (Qads) were calculated thermodynamically.