CORROSION INHIBITION OF HEAT TREATED MILD STEEL WITH NEEM LEAVE EXTRACT IN A CHLORIDE MEDIUM

Tolumoye J. Tuaweri, Ezenwa A. Ogbonnaya, Okechukwu O. Onyemaobi

Abstract: Influence of Neem leave extract on the corrosion inhibition of mild steel in a chloride medium was investigated. It was carried out by immersing as-received and heat treated mild steel coupons in salt water with various concentrations of Neem leave extract ranging from 0-20%. Method of investigation was gravimetric, based on weight loss of coupons in the different solutions. The results show that mild steel samples immersed in salt water without Neem leave extract exhibited a much higher weight loss as compared to those with Neem leave extract. A unique trend observed in these investigations was that weight loss was higher for the as-received than the heat treated samples prior to addition of Neem leave extract into the corrosive medium. On addition of the Neem leave extract, a reversed trend was observed where weight loss of the heat treated became higher than the as-received coupons. Change in corrosion rate was insignificant for the control samples for both as-received and heat treated samples. On the contrary, an evident decreasing trend was observed for the heat treated samples while those of as-received were insignificant with time. However. 5% inhibitor showed best corrosion inhibition with the least corrosion rates. The overall results indicate that Neem leave extract effectively inhibits mild steel corrosion in a chloride medium

Keywords: Corrosion, mild steel, salt water, inhibitor, Neem leave, heat treatment

DOI: https://doi.org/10.15623/ijret.2015.0406069