CORROSION INHIBITION OF CARBON STEEL IN SALINE SOLUTIONS BY GLUCONATE, ZINC SULPHATE AND CLAY ELUATE

The effect of gluconate, zinc sulphate and green clay eluate on the corrosion inhibition of carbon steel (EN S235 JRG) in 0,5 % and 3,5 % sodium chloride solution has been evaluated in this work using Tafel polarization technique. Substantial general corrosion inhibition using sodium gluconate solely can be obtained with moderate concentrations. In this case, corrosion inhibition is predominately obtained by anodic mechanism and is limited to general corrosion, whereas carbon steel becomes liable to localised pitting corrosion. However, when sodium gluconate is combined with zinc sulphate and/or green clay eluate in adequate concentrations both general and localized corrosion are diminished which indicates good synergy between applied inhibitors.