Tomography of Inclined SCC Cracks in Australian Gas Pipelines

Abstract

Stress Corrosion Cracking (SCC) in pipeline steel occurs when an aggressive environment and tensile stresses act on a susceptible microstructure. Typically, SCC in gas pipelines tends to travel perpendicular to the hoop stresses in the through wall direction. Studies conducted on the TransCanada pipeline where a rupture had occurred revealed the incidence of SCC cracks whose crack path deviated at an angle from the normal. These inclined cracks have also been found in a pipeline in Australia which has lead to an increased need to better understand inclined SCC. This paper, based on the Australian pipeline, investigates the incidence rate, morphology, and observed interactions of inclined SCC in the Australian pipe.