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Carbon Dioxide-induced Stress Corrosion Cracking (CO2-SCC) is an environmentally assisted corrosion cracking phenomenon that has recently been identified as a new failure mode in flexible pipe armor wires. The phenomenon has been observed to take place notably in severe CO2 environments and is a cause of great concern to the flexible pipe industry. Since its detection, a diverse and extensive testing program has been established to develop an understanding of the phenomenon and define safe application limits for carbon steel wires to prevent the initiation of CO2-SCC. Several different testing methodologies have been explored and small-scale laboratory testing has played an instrumental role to this overall effort. This paper focuses on the results from three different small scale testing methodologies and the impact of different parameters such as CO2 fugacity, temperature and confinement that play a crucial role in the initiation of CO2-SCC. Furthermore, careful prominence has been given to the test set-up and methodology that has been rigorously developed over the last few years. With this developed protocol in place, CO2-SCC has been effectively reproduced on all wire grades in a small-scale testing environment. Results have also shown that for a CO2 fugacity greater than 15 bar and applied stress at 100% of the actual yield strength (AYS), all existing wire grades are susceptible to CO2-SCC thus creating significant limitations to flexible pipe design with respect to this new failure phenomenon.

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