Environment friendly acid corrosion inhibition of mild steel by Ricinus communis Leaves
By R.Saratha, N.Kasthuri, P.Thilagavathy
Large extent of mild steel corrosion occurs during acid pickling and surface cleaning. Various synthetic chemicals have been studied as corrosion inhibitors and reported. But pure synthetic chemicals are costly. Some of them are toxic and their disposal creates pollution problems. In the present study the acid extract of Ricinus Communis leaves have been investigated as a cheap and eco-friendly corrosion inhibitor for mild steel in 1M HCl medium by weight loss and polarization techniques. Using various concentrations of inhibitor, studies were carried out for ½ h, 1 h, 3 h, 7 h and 24 h immersion times and at different temperatures. The results indicate Ricinus communis leaves to be a good corrosion inhibitor for mild steel. The inhibition efficiency was found to increase with inhibitor concentration. Inhibition efficiency of 97.19% at 2.5%v/v inhibitor concentration was obtained. The potentiodynamic polarization results reveal that the extract behave like mixed type inhibitor.
Keywords : Acid corrosion, corrosion inhibitors, mild steel, polarization methods