Corrosion and Corrosion Inhibition of Mild Steel in Red Sea Water byEDTA

The corrosion of mild steel (MS) was studied in Red Sea water. The effect of disodium ethylenediaminetetraacetic acid salt (Na-EDTA) as an inhibitor in this medium was also studied. Weight loss, and Open Circuit Potential (OCP) were used as the tools of the study, where the Fe-surfaces before and after corrosion were examined using Scanning Electron Microscopy (SEM). We notice that, the corrosion reaction was reduced when Na-EDTA was added to the medium. As the concentration of Na-EDTA was increased, the corrosion rate decreases. It seems that, certain barrier of Na-EDTA adsorbed on Fe-surface which isolate the corroded medium from Fe-surface. The adsorption phenomenon was studied by different adsorption isotherms and found to fit well with Langmuir and Temkin. Thermodynamic parameters were determined from Arrhenius and Eyring equations. SEM shows the decrease of the roughness of MS after adding Na-EDTA.