Electrochemical Evaluation of Chrysin Flavonoid as Corrosion Inhibitor for Mild Steel in Sulphuric Acid Solution

Recently research is focused on natural organic compounds as metallic corrosion inhibitors demonstrating good corrosion protection and efficiencies. Steel corrosion behavior in acid media was evaluated in the presence of a pure natural flavonoid metabolite named Chrysin present in different plants. The evaluation of corrosion protection was studied using polarization curves, electrochemical impedance spectroscopy (EIS) and electrochemical current density under potentiostatic conditions. Polarization curves present active dissolution and at high overpotentials two passivation regions were found. Slight corrosion protection was obtained from EIS measurements and potentiostatic curves at three different anodic potentials: -370, +216 and +600 mV, revealed a more stable passive film in the presence of Chrysin at both passive regions. High corrosion protection was obtained on the film formed at +600 mV during the first 4 hours of immersion.