Evaluation of HydrogenEmbrittlement Susceptibility in Pipeline Steel Welds with Simultaneous Quantification of HydrogenContent and Permeability - CANCELLED (RIP2026-00001)
Slow strain rate, fatigue crack growth rate, and fracture toughness (respectively SSRT, FCGR, and FT) tests in high pressure gaseous hydrogen are used in evaluating hydrogen embrittlement (HE) susceptibility of pipelines steels welds. SSRT demonstrates effects of HE at loading above UTS. FCGR and FT tests quantify resistance to propagation of existing cracks but cannot characterize susceptibility to HE crack nucleation. Furthermore, these tests do not quantify the effect of hydrogen concentration and hydrogen permeation kinetics on the HE susceptibility. We developed a HE susceptibility test that simultaneously quantifies hydrogen diffusion and hydrogen concentration leading to failures in test specimens of pipeline steel welds (OSU Invention Disclosure IDF-064901 2024). The test is based on AMPP TM21453-2023 and utilizes hollow test specimens subjected to constant tensile loads below or close above the YS. The specimen’s OD surface is subjected to electrolytic charging with hydrogen. The hydrogen permeating through the specimen wall is transported by a carrier gas and measured using thermal conductivity detector of a gas chromatograph. Test results of HE susceptibility in pipeline steel welds and simulated HAZ microstructures are presented, together with related hydrogen diffusion coefficients and critical hydrogen concentrations leading to HE failures.
