Corrosion Inhibition of Steel (St 44-2) by Pomegranate Shells in Acidic Medium


Pomegranate shells were investigated as green inhibitors for steel 44-2 in 0.1M HCl at various temperatures (30, 40, 50, and 60) °C using electrochemical technique. Five concentrations of inhibitor were added 4, 8, 12, and 16 ppm. Corrosion tests were performed by Potentiostat at 5 mV.sec-1 scan rate and the data measured by Tafel extrapolation method such as Tafel slopes, corrosion current density and corrosion potential. Inhibition efficiencies were calculated and indicated that 8 ppm was the best concentration for inhibition especially at 60oC, where was 96.47%. Pomegranate Shells behaves as anodic inhibitor type and obeys Langmuir adsorption isotherm. The equilibrium constant of the adsorption-desorption process and the apparent free energy of adsorption confirm the physicsorption of Pomegranate shells. FTIR spectroscopy was used to test film formed on steel surface compared with FTIR spectrum of Pomegranate Shells. These spectra confirm the formation of Fe2+Pomegranate shells complex.