Compatibility of metallic materials with high pressure gaseous hydrogen: applicable standards and non-standard tests|Compatibilità dei materiali metallici in contatto con idrogeno gassoso ad alta pressione: normative vigenti e prove non standardizzate

The blending of hydrogen gas within the natural gas (NG) transportation and distribution network will be a reality soon, inside the wider picture of the ecological transition to renewable sources. The compatibility of materials that will be employed for the transport of high pressures gaseous hydrogen needs to be thoroughly evaluated. Numerous existing standards and documents currently address this issue and will be discussed briefly and critically in this article, highlighting their strengths but also any shortcomings. Next, the issue of non-standardized characterization tests to evaluate the susceptibility of steels to HE (hydrogen embrittlement), such as hydrogen pre-charge, tests under cathodic polarization, and hollow specimen, will be addressed. Again, the advantages and limitations of non-standardized characterization tests will be critically discussed.