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A novel metastable austenitic stainless steel denoted as 13Cr12Mn is obtained by adding 12 wt% Mn to 13Cr–5Ni–2Mo super‐martensitic stainless steel. The designed 13Cr12Mn exhibits a yield strength of 899 MPa, a tensile strength of 1068 MPa, and an elongation of 21.2%. The in situ hydrogen‐charging incremental step loading technique experiments are conducted to evaluate hydrogen embrittlement. The hydrogen‐induced cracking threshold stress of 13Cr12Mn is determined to be 961 MPa, which exceeds that of tempered S13Cr with a similar yield strength by 400 MPa. In addition, 13Cr12Mn also shows good resistance to general corrosion and pitting corrosion in alkaline solutions. [ABSTRACT FROM AUTHOR]

The effect of cryogenic plastic pre-strain (15 %, 30 %, and 45 % true strain) on the hydrogen embrittlement (HE) of an equimolar FeNiCoCrMn high-entropy alloy was studied through slow strain rate tension (SSRT) at 1 × 10−5 s−1. As the pre-strain increased, ductility loss under harsh electrochemical hydrogen charging showed a downward trend accompanied by the promotion of hydrogen adsorption. This work provided an effective strategy for achieving the synergy of high strength and improved HE resistance. The raw/processed data required to reproduce these findings cannot be shared at this time as the data is related to an ongoing study. [Display omitted] • Cryogenic pre-straining makes effective strengthening. • Hydrogen embrittlement is greatly alleviated in highly pre-strained FeNiCoCrMn. • The deformation twins act as stronger hydrogen traps than the dislocations. [ABSTRACT FROM AUTHOR]

A 13Cr austenitic stainless steel with a good combination of high yield strength, ductility and hydrogen embrittlement resistance was designed by combining hetero-deformation induced strengthening and martensitic transformation induced plasticity effects. Room temperature metastable austenite is promoted by adding 8 wt% Mn to a 13Cr–5Ni–2Mo supermartensitic stainless steel. A heterostructure consisting of remaining martensite grains located between lath austenite grains and micrometer-sized austenite grains embedded inside ultrafine grains, was fabricated by cold rolling (44% reduction) and annealing at 973 K through a shear reversion process. The novel 13Cr austenitic stainless steel exhibits a yield strength of 923 MPa, tensile strength of 1085 MPa and total elongation of 33.2%. The hydrogen embrittlement resistance of the novel steel was determined by incremental step loading technique testing and was increased 40% compared with that of the 13Cr–5Ni–2Mo supermartensitic stainless steel. This study provides an approach for the design and industrial fabrication of high strength (125 ksi grade level), high ductility and hydrogen embrittlement resistant stainless steels that can be used in harsh service environments containing hydrogen. [ABSTRACT FROM AUTHOR]

The effect of deformation twins on the hydrogen embrittlement (HE) of a twinning-induced plasticity (TWIP) steel with various pre-strain levels, coupled with subsequent annealing treatment was systematically investigated by a slow strain rate tension test after cathodic hydrogen charging. The results revealed that specimens with high twin volume fraction had relatively better HE resistance. The high-density twin boundary not only plays an important role in hindering hydrogen diffusion, but also can refine the grains and inhibit the accumulation of hydrogen, so as to relieve stress concentration and avoid premature fracture of the specimen. [Display omitted] • The larger the pre-strain, the higher the strength, and the better the HE resistance. • Sample annealing after high pre-strain still maintains good HE resistance. • Twins have an advantage over dislocations in hindering hydrogen diffusion. • High density of twin boundaries can disperse hydrogen to prevent strain localization. [ABSTRACT FROM AUTHOR]