Cathodic protection of underground mild steel pipes by impressed current using solar cells as rectifier

Abstract

The need for constant supply of electricity to protect steel structures brings about the use of solar cells. This research work involves the cathodic  protection of underground mild steel pipes by impressed current using solar cells as rectifier. The pipes were buried at two separate sites; X and Y. Site X  for the control experiment and Y for the main experiment. The Impressed Current cathodic Protection (ICCP) was applied to the pipes on site Y and the  pipes on site X buried without any protection for a period of 40 days. The Pipe to Soil Potentials (PSP) was measured for the pipes on the two sites using  multimeter. The pipe to soil potentials measured for the pipes on site Y were within the range recommended for protection (<-850mV) and that of the  pipes on site X were above the range. Protection efficiencies using the results obtained from the PSP tests were obtained with maximum protection  efficiencies of 82%. Physical examination and microstructures of the pipes also indicated visible proof of corrosion on the buried pipes without protection  and this was not seen on the buried pipes under ICCP using solar cell.