Corrosion of Iron in 0.5M NaCl - A Rotating Disk Electrode Study

Abstract : The corrosion of iron was studied in 0.5 Molar sodium chloride solution by the rotating disk technique. Limiting diffusion currents were measured in nitrogen-saturated, air-saturated, and oxygen-saturated solutions at rotational speeds of 0, 100, 400, 900, 1600 and 2500 rpm. Corrosion potentials and corrosion rates at the corrosion potential were also determined. The observed limiting diffusion currents potential were also determined. The observed limiting diffusion currents showed good agreement with limiting diffusion currents calculated from the Levich theory for the rotating disk electrode. Measured corrosion rates (currents) were found to be lower than the limiting diffusion current, which is explained on the basis of a corrosion product film on the surface of the electrode.