Mechanical testing methods for assessing hydrogen embrittlement in pipeline steels: a review

As the transport of gaseous hydrogen and its use as a low carbon-footprint energy vector become increasingly likely scenarios, both the scientific literature and technical standards addressing the compatibility of pipeline steels with high-pressure hydrogen environments are rapidly expanding. This work presents a detailed review of the most relevant hydrogen embrittlement testing methodologies proposed in standards and the academic literature. The focus is placed on testing approaches that support design-oriented assessments, rather than simple alloy qualification for hydrogen service. Particular attention is given to tensile tests (conducted on smooth and notched specimens), as well as to J-integral and fatigue tests performed following the fracture mechanics’ approach. The influences of hydrogen partial pressure and deformation rate are critically examined, as these parameters are essential for ensuring meaningful comparisons across different studies.