This is the final report of a research project, PR-230-9413, funded by PRCl on the environmental effects on the propagation of transgranular stress corrosion cracks (TGSCC) of linepipe steels in soil environments of near-neutral pH. Supervision by the Ad Hoc Group on this project, chaired initially by Matt Cetiner of TransCanada PipeLines and then by Paul Wong of NOVA Gas Transmission Ltd., set the objectives and the scope of the work and was an integral component in the completion of this research. Three full-size ERW pipes, 508 mm (20 inches) diameter, hot-rolled Grade 359 (X-52), and a gravel-type...
This is the final report of a research project, PR-230-9413, funded by PRCl on the environmental effects on the propagation of transgranular stress corrosion cracks (TGSCC) of linepipe steels in soil environments of near-neutral pH. Supervision by the Ad Hoc Group on this project, chaired initially by Matt Cetiner of TransCanada PipeLines and then by Paul Wong of NOVA Gas Transmission Ltd., set the objectives and the scope of the work and was an integral component in the completion of this research. Three full-size ERW pipes, 508 mm (20 inches) diameter, hot-rolled Grade 359 (X-52), and a gravel-type soil were used. The pipe had been manufactured in the late 1950s and had been in service in a natural gas transmission pipeline for about 38 years. Crack growth was measured as a function of environmental variables and of loading severity, at the free corrosion potential (F. C. P.), at potentials anodic to F.C.P. and at cathodic potentials. At the free corrosion potential, the crack growth rate was found to be influenced by carbon dioxide. Growth rates of cracks with direct carbon dioxide admission tended to be higher than growth rates of other cracks.