COMPARISON OF LINEAR-ELASTIC FRACTURE AND ELASTIC-PLASTIC FRACTURE OF FERRITIC STEELS IN GASEOUS HYDROGEN

There is a common misperception that exposure to gaseous hydrogen makes construction steels brittle. Reality, however, is more nuanced. Whereas very high-strength steels can display characteristics of brittle fracture, low- to medium-strength steels remain ductile in gaseous hydrogen. Typical pressure vessel steels (e.g., quench and tempered Cr-Mo and Ni-Cr-Mo steels) and line-pipe steels (e.g., low-carbon steels) remain sufficiently ductile that fracture measurements do not satisfy the requirements of standardized linear elastic fracture mechanics. Generally, for steels with tensile strength 1,000 bar. This presentation reviews the requirements of linear elastic and elastic plastic fracture testing in the context of fracture tests in gaseous hydrogen that have been reported in the literature.
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