This paper presents the first experimental characterisation of combined hydrogen–temperature effects in 316plus (EN 1.4420), a new austenitic stainless steel for liquid hydrogen (LH 2 ) storage. Uniaxial tensile tests were conducted at room temperature (RT), 77 K and 20 K on uncharged and hydrogen-precharged specimens, complemented by fractography and EBSD-based quantification of strain-induced martensite (SIM). 316plus exhibited cryogenic strengthening at 77 K and 20 K by enhanced SIM formation. Hydrogen did not influence strength at RT or 77 K and caused a modest decrease ( ≈ 10%) at 20 K, keeping 316plus at the upper bound of cryogenic strength for 316L. The presence of hydrogen resulted in significant reductions in ductility at all temperatures, being most severe at 77 and 20 K ( ≈ 40%–50%). Hydrogen suppressed SIM at 20 K, but SIM fraction did not correlate with ductility reduction. Despite the combined effect of temperature and hydrogen, 316plus retained notable ductility (reduction in area ≈ 30%). • First study of hydrogen–temperature effects in 316plus for LH 2 storage is presented. • Cryogenic strengthening of 316plus at 77–20 K is driven by enhanced SIM formation. • Hydrogen has little effect on strength except ∼ 10% reduction at 20 K. • Severe ductility loss is observed under hydrogen at 77–20 K ( ∼ 40%–50%). • 316plus retains ∼ 30% reduction in area despite hydrogen and cryogenic loading.
Li et al. (Sat,) studied this question.