Advanced conductive coatings for cathodic protection of pipeline systems

This study introduces a conductive smart coating (SC) system that serves as both an external corrosion barrier and a conductive pathway for impressed-current distribution to mitigate corrosion under insulation (CUI). The SC was evaluated using a laboratory CUI cell based on ASTM G189-07 and benchmarked against conventional industrial coatings (IC) under controlled corrosive conditions. An impressive current of 2.0 mA at 1.5 was applied to ensure cathodic polarization of the SC samples during the test period. Visual inspection and creepage tests revealed that scribed and inscribed SC samples maintained intact external surfaces without corrosion, while IC samples developed localized defects. The Mass loss analysis confirmed significantly lower corrosion rates for SC samples at 0.038 mmpy at 25°C and 0.065 mmpy at 70°C compared with IC samples, which exhibited 0.15 mmpy and 0.344 mmpy, respectively. Statistical testing (t-test, p < 0.001) verified the superiority of SC performance, while its conductive matrix further enabled real-time in-situ monitoring of corrosion activity. These results highlight the potential of ICCP-enhanced smart coatings as a durable and cost-effective solution for pipeline systems, particularly in harsh marine and offshore environments where CUI management and space for anode installation are major challenges.