Further study on crack growth model of buried pipelines exposed to concentrated carbonate-bicarbonate solution

This paper develops and validates a physical crack growth model for stress corrosion cracking and corrosion fatigue for pipelines exposed to concentrated carbonate-bicarbonate solution, assuming that the crack growth is dominated by repeated rupture of passive film at the crack tip. A further analysis indicates that the crack growth in gas line is controlled by the stress corrosion cracking mechanism but the crack growth of liquid line is governed by the corrosion fatigue mechanism. Both cyclic-loading-enhanced stress corrosion cracking and mechanical fatigue may affect the crack growth. Finally, the procedure for field application is outlined.