Application of impressed current cathodic protection on chain structure: An experimental study combined with COMSOL simulation

Corrosion protection of mooring chain is difficult but of great significance to guarantee the security of deep-sea operation. In consideration of the advantages and limitation of impressed current cathodic protection (ICCP), the feasibility of ICCP application on chain structure was studied through physical experiments combining with COMSOL simulation. The influence of electrical continuity on the protection potential distribution was investigated by potential measurement and numerical simulation. It was demonstrated that the conductivity was the key factor restricting the successful application of ICCP on the chain structure. With improved electrical continuity, the surface potential distribution of the chain structure under ICCP was uniform with a difference less than 12 mV, and the 90 -day corrosion rate significantly reduced by 94.8% compared with that without ICCP. Furthermore, the quantitative formula of the relationship between the critical conductivity required for ICCP and the chain diameter was determined to be sigma c = 0.015d2 + 0.65d + 10.49. The effect of corrosion time and auxiliary anode distance on the potential distribution was also investigated. This work might provide new idea for the corrosion protection of mooring chain and provide reference for the design of mooring chain with improved possibility in corrosion protection.