Experimental Simulation of Sweet TLC for Aged Internally Coated Pipelines

Abstract Top of the Line Corrosion (TLC) in a sweet environment continues to present challenges to pipeline integrity. A fundamental aspect of understanding TLC involves clarifying the development of condensation on uncoated steel in comparison to aged coated steel, within an atmosphere containing CO2. This investigation addressed this issue by analyzing the interaction between droplets and surfaces through the measurement of the contact angle between the droplet and the metal surface, as well as through continuous observation of droplet formation and spreading throughout the testing process. Complementary short-term electrochemical experiments, conducted over a period of 14 hours at temperatures of 35 °C, monitored the progression of corrosion rates under these conditions. It is anticipated that droplet behaviour exhibits differences between uncoated steel and aged coatings retrieved from field service, thereby linking wetting dynamics to initial corrosion process and offering essential insights for advancing TLC prediction.