Stress Corrosion Cracking (SCC) can occur on the soil side of buried natural gas pipelines when the coating breaks down and ground water comes in contact with the pipe surface. A dilute, near-neutral electrolyte and a transgranular crack morphology have been identified with recent field cracks in Canada. A series of experiments have been conducted on fatigue pre-cracked specimens using a range of loading conditions, all of which involved a cyclic component of load. Crack growth was measured using post-mortem fractographic examination. Maximum average crack growth rates were obtained by dividing the maximum observed crack growth by the total duration of the test. These crack growth results have been interpreted based on a superposition model for SCC (time dependent crack growth) and fatigue (cycle dependent crack growth). The use of this data in the modeling of SCC in pipelines for the prediction of remaining life is discussed.
Stress Corrosion Cracking of pipelinesteels in dilute, near-neutral solutions
Spannungskorrosionsrißbildung von Rohrleitungsstählen in schwachen, fast neutralen Lösungen
1996
6 Seiten, 6 Bilder, 20 Quellen
Conference paper
English