Inhibitory effect of Ricinus communis (Castor-oil plant) leaf extract on corrosion of mild steel in low chloride medium

Plant extract Ricinus communis was tested for its inhibitory effects towards mild steel in 100 ppm sodium chloride. The corrosion behaviour of plant extract (Ricinus communis) was studied by means of electrochemical polarization and impedance measurements. It was found from weight loss measurements that the inhibition efficiency was about 84% in 300 ppm of the plant extract. Polarization measurements indicated that the plant extracts generally act as cathodic inhibitors on the fourth day. Electrochemical impedance results also showed that the natural plant extract increases the corrosion resistance of mild steel. Results of our study from polarization and electrochemical impedance measurements indicated that Ricinus communis might alleviate the corrosion process in mild steel.