Abstract:
The susceptibility of high-strength carbon steel wires to CO2-stress corrosion cracking (CO2-SCC) was evaluated through electrochemical monitoring, alternating load tests, EBSD, SEM, and Raman spectroscopy under identical service-simulated conditions (10.6 bar CO₂, 40 ◦C, 80 % yield stress). Only the eutectoid Steel A exhibited SCC, associated with spheroidized cementite at grain boundaries, high dislocation density, and a high fraction of highangle grain boundaries. Hypoeutectoid Steels B and C, with higher ferrite fractions and lamellar pearlite, showed only generalized corrosion. Pseudo-passivation times and FeCO₃ film properties correlated with cementite morphology and ferrite content, while EBSD revealed that grain boundary character and local misorientation controlled crack initiation, propagation, and arrest. These findings demonstrate that SCC-CO₂ susceptibility arises from the interplay of microstructure, film stability, and localized plasticity, highlighting the importance of microstructural design, such as favoring lamellar pearlite and reduced defect density, to improve the durability of flexible pipes in aggressive CO₂ environments.
Referência:
PIMENTEL, Tarcisio H.C.; SILVA, Carlos Alberto da; MASOUMI, Mohammad; ABREU, Hamilton Ferreira Gomes de; VENTURELLI, Bianka Nani; SANTOS, Fabrício Pinheiro dos; PALMIERI, Ilson Baptista; SOUZA, Jose Adailson; PANOSSIANI, Zehbour. Microstructural determination of CO2 stress corrosion cracking in high-strength carbono steel wires for flexible pipes. Corrosion Sicence, 258, 113379, 15p., 2026.
Acesso ao artigo no site do Periódico:
https://www.sciencedirect.com/science/article/abs/pii/S0010938X25007073