Assessing the Susceptibility of Existing Pipelines to Hydrogen Embrittlement

With fossil fuels being phased out and growing global interest in a hydrogen economy, there is demand for re-purposing existing pipelines transportation of gas. However, embrittlement (HE) can limit pipeline steel’s performance. In this study, the effect on mechanical properties an X60 base metal (polygonal ferrite/pearlite) its girth weld (acicular was measured with novel slow strain rate tensile (SSRT) test which hollow pipe-like specimens were internally pressurised nitrogen gas from 0 to 100 bars. Results showed that exposure H2 at bars reduced ductility by up 40% 14%. Reduction cross-sectional area (%RA) 28% 11% metal. Fracture surface analysis micro-void coalescence as well quasi-cleavage fracture characteristic HE. Susceptibility HE also observed form secondary longitudinal internal transverse cracks.