Corrosion Behaviour Comparison of Solution Annealed and Cold Work Super Duplex Stainless Steel in a CCS Environment: A Study of Material Performance over Time

Abstract Carbon Capture and Storage (CCS) is a promising technology in the net-zero goal for global CO2 emissions. The success of CCS operations can depend on corrosion control, material selection, and integrity management, among other things. Despite extended experience with material performance in natural CO2 injection, challenges persist in safely and effectively injecting anthropogenic CO2 including impurities. Indeed, industrial impurities complicate corrosion and limit existing knowledge’s applicability. Since captured CO2 often comes from multiple industrial emitters, each CCS project need to establish CO2 specifications to ensure safe operations, given the lack of standardized guidelines. These specifications delineate upper limits for critical impurities. In a CO2 stream containing H2S, oxygen (O2) as an impurity can affect the corrosion resistance of UNS S32760 material in solution annealed and cold worked conditions, 80ksi and 125ksi grades, respectively. If the bottom-hole exhibits elevated temperatures, a high chloride content, and a low pH, O2 may trigger localized corrosion and stress corrosion cracking. Therefore, a fit-for-purpose testing program was undertaken to assess the main corrosion risks associated with the CCS project. The influence of microstructure and testing duration on corrosion behavior is discussed. The findings from this testing program are critical in determining the applicability of the material for CCS infrastructure and the development of corrosion control testing.