ENVIRONMENTALLY FRIENDLY INHIBITORS OF CARBON STEEL CORROSION IN CHLORIDE ENVIRONMENTS

In this research the effect of cerium (III) chloride heptahydrate (CC) and sodium gluconate (SG) on the corrosion inhibition of carbon steels C45 (1531) and DIN RSt 37-2 (0361) in chloride environments has been evaluated using Tafel polarization technique, EIS method and weight loss measurements. Experiments were performed in seawater and 3.5 % NaCl solution. The concentration of CC varied from 0.04 to 10 mmol/L and SG from 1 to 4.5 mmol/L. In order to compare accomplished efficiencies experiments with commercial inhibitors were also performed. The results show that substantial corrosion inhibition using CC and SG in chloride environments can be obtained in synergistic manner. SG acts predominately as anodic inhibitor whereas CC acts as mixed type inhibitor. Thus, using both inhibitors overall inhibition is anodic inhibition.