Tensile testing in high pressure gaseous hydrogen using conventional and tubular specimens: Austenitic stainless steels

Hydrogen Embrittlement as a Conspicuous Material Challenge─Comprehensive Review and Future Directions

“…A significant loss of ductility due to H was also observed in pipeline steel, austenitic steel and nickel alloy . Similar observations were obtained in in situ experiments. ,, …”

“…13 Similar observations were obtained in in situ experiments. 235,501,748 While H causes a reduction of ductility in general, the exact degree of reduction depends on a combination of material, geometric constraint, and H concentration. For pipeline steels, there is a consensus that the susceptibility to ductility loss increases with the strength of the material.…”

“…819,820 The comparison with conventional tensile specimens can be hindered by the inner surface roughness 821 and by the different necking mechanisms during ductile failure. 748,822 The small punch test (SPT), which is commonly used as a screening tool for nuclear materials, requires a simple procedure to test miniature specimens, 10 × 10 × 0.5 mm 3 approximately, and it has been recently standardized (ASTM E3205-20 or BS EN 10371:2021) for metallic materials. The application of SPT to the study of HE has been considered for pre-charged specimens, 823 electrochemical in situ testing, 824,825 or even with gaseous in situ setups.…”

“…For example, to circumvent the need of an autoclave containing a high volume of gaseous H 2 at high pressure, hollow specimens have been proposed as a safer and simpler alternative. This procedure is based on a tubular specimen exposed to high-pressure H in the inner machined hole; it was firstly proposed by Chandler and Walter and has been also adopted by other authors. , The comparison with conventional tensile specimens can be hindered by the inner surface roughness and by the different necking mechanisms during ductile failure. , …”