Understanding the role of oxygen in preventing hydrogen embrittlement in pipeline steels
Published in International Journal of Hydrogen Energy, 2026
Keywords: Hydrogen embrittlement (HE); Pipeline steels; Gaseous hydrogen charging; Oxygen inhibition; Oxide layer
Abstract
Transporting hydrogen via pipelines requires understanding steel interactions. This study develops a gaseous charging methodology approximating operating conditions in pure H2. These parameters are applied to investigate the inhibiting effect of oxygen in H2 gas mixtures with varying oxygen levels (100, 250, and 1000 vppm) on hydrogen uptake. Long-term tests evaluate the effectiveness of oxygen inhibition, while ex-situ quasi-static tensile tests on notched round bars examine macroscopic hydrogen embrittlement and fracture surface characteristics. Hydrogen absorption trends remained consistent across the pipeline steels, regardless of the charging parameters used, with elevated temperatures affecting hydrogen distribution. At a concentration of 1000 vppm, oxygen effectively suppressed absorption. Extended exposure increased the hydrogen concentration in the formed oxide layer, trapping it unless disturbed by external stresses or physical damage. Only the material with the highest hydrogen uptake showed embrittlement and fracture in pure H2, while oxygen preserved ductility, confirming its role as an inhibitor.
Recommended citation: Jubica, L. Claeys, A. Laureys, L. De Pue, W. De Waele, J. Schweicher, K. Verbeken, T. Depover, "Understanding the role of oxygen in preventing hydrogen embrittlement in pipeline steels," International Journal of Hydrogen Energy 252 (2026) 156142. doi:10.1016/j.ijhydene.2026.156142
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