DILL EXTRACT AS GREEN INHIBITOR FOR THE CORROSION OF CARBON STEEL IN H3PO4 SOLUTION

The inhibiting effect of dill extract (DE) on the corrosion of C-steel in 1 N H3PO4 was studied by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS). The results showed that the inhibition efficiency increases with increasing the inhibitor concentration, while it decreases with increasing the temperature. The adsorption of dill extract on the C-steel surface obeys Langmuir adsorption isotherm. Some thermodynamic parameters were calculated and discussed. The values of free energy of adsorption for investigated inhibitors were calculated. Polarization curves show that dill extract is mixed-type inhibitors. The results obtained from chemical and electrochemical techniques are in good agreement.