CATHODIC PROTECTION OF MILD-STEEL AND COPPER IN DEEP WATERS OF THE ARABIAN SEA AND BAY OF BENGAL

Performance of cathodic protection system to mild steel and copper in deep (> 1000 m) oceanic waters of the Arabian Sea and Bay of Bengal has been assessed using aluminium and mild steel sacrificial anodes. The corrosion rates of unprotected metals as well as their percentage protection increased with increasing depth. The ranges of protection achieved have been found to be 74-91% and 92-97% at depths of 1000 and 3000 m respectively. The difference in corrosion rates and the degree of protection of the metals at different depths have been attributed to the concentration of dissolved oxygen at those depths.