Corrosion Inhibition of Austenitic Stainless Steel Type 316 In Sulphuric Acid Solution Using Eco-Friendly Waste Product
Pitting corrosion of stainless steels causes tremendous damage in industries. The use of inhibitors for corrosion control of metals in aggressive medium is an accepted practice. Different organic compounds were studied and are being studied to investigate their corrosion inhibition efficiency. All these studies show that organic compounds especially those with N, S and O showed significant inhibition efficiency. Unfortunately most of these compounds are expensive and toxic. In view of this, there is need for the use of cheap, safe inhibitors for corrosion. In the present study, the inhibition of the pitting corrosion of stainless steel Type 316 by methanol extract of egg shell powder in 0.5M H2SO4 solution at ambient temperature was studied using gravimetric and potentiodynamic polarization measurements. The results showed that egg shell in H2SO4-stainless steel environment decreased the corrosion rate at all the concentrations studied. The effective performance of the egg shell gives values of 71.93% - 91.95% inhibition efficiency, at 2 and 10 gram inhibitor concentration from gravimetric analysis. It has been found that the percentage inhibition efficiency increases with an increase in the inhibitor concentration. The two methods employed for the corrosion assessment were in good agreement and the inhibition process was explained due to the adsorption of these compounds at the 316 SS surface.
Keywords - Stainless Steel, Pitting Corrosion, Corrosion Inhibitor, Inhibition, Sulphuric Acid