Development of Aluminium Base Anode for Cathodic Protection of Steel

Aluminum-iron activated with ore tailing alloy was developed as an anode for the protection of steel in a seawater environment using an impressed current cathodic protection mechanism. The materials used in this research were aluminum, iron ore tailings and low-carbon steel. The anode was produced via the sand-casting method by the addition of varying weight fractions of iron ore tailings (5–25%). The resulting anodes were characterized; the microstructure of the anodes was observed by scanning electron microscopy/energy dispersive spectroscopy, and X-ray diffraction was used to identify the phases present. The corrosion behavior of the anodes was determined in seawater with a salinity of 2.1% using a potentiostat. The micrograph results showed that some anodes had large grains, small grains and a mixture of unevenly distributed grains throughout the material. The energy dispersive spectroscopy spectrogram showed aluminum, oxygen and zinc to be the most prominent elements in the anodes. In addition, inclusions and several intermetallics were observed. Sample D (85 Al% + 15 IOT%) has a corrosion potential of -405.197 mV (silver/silver chloride) compared to steel, which has a corrosion potential of -637.653 mV (silver/silver chloride). Sample D has more positive potentials than steel, which means that sample D is the most suitable anode for protecting steel via impressed current system cathodic protection.