Can dents and gouges compromise the structural integrity of hydrogen transport pipelines?
2026-05-29 • Computational Engineering, Finance, and Science
Computational Engineering, Finance, and Science
AI summaryⓘ
The authors studied how natural gas pipelines might be safely reused for hydrogen by checking how dents and scratches affect their strength when exposed to hydrogen. They created a new model that combines how hydrogen moves through steel, how the steel bends and stretches, and how it gets damaged. They tested this model with real experiments on pipeline steel and then used it to look at dents made before and during hydrogen exposure. They found that hydrogen usually doesn't make these dents much worse unless the dent traps hydrogen inside and the pipeline is pressurized from inside. This helps understand when pipeline defects could be risky for hydrogen transport.
hydrogen embrittlementpipeline steelplastic strainhydrogen transporttriaxialitydamage lawpipe indentationhydrogen permeationnatural gas pipelineshydrogen exposure
Authors
R. Das, B. Bezensek, E. Martínez-Pañeda
Abstract
Repurposing natural gas pipelines for hydrogen transport requires understanding how external defects, like dents and gouges, affect structural integrity under H$_2$ exposure. To address this, we combine experiments with a new hydrogen embrittlement model aimed at large plastic straining scenarios, which integrates: (i) multi-trap hydrogen transport, (ii) finite-strain plasticity, and (iii) a hydrogen- and triaxiality-dependent damage law. Each constituent of the model is validated with experiments on X65 pipeline steel: (i) hydrogen permeation, (ii) full-scale pipe-indentation, and (iii) mechanical testing at different hydrogen and triaxiality levels. The validated model is used to study \textit{passive} (indent before H$_2$ exposure) and \textit{active} (indent with H$_2$) dents and gouges. Results reveal that hydrogen does not significantly increase the damage severity of those defects, unless hydrogen egress is completely precluded at the outer surface of a pipeline that is being pressurised internally and contains a pre-existing \textit{passive} dent with a gouge.