Abstract: This high-strength austenitic stainless steel having excellent hydrogen embrittlement resistance characteristics includes, by mass %, C: 0.2% or less, Si: 0.3% to 1.5%, Mn: 7.0% to 11.0%, P: 0.06% or less, S: 0.008% or less, Ni: 5.0% to 10.0%, Cr: 14.0% to 20.0%, Cu: 1.0% to 5.0%, N: 0.01% to 0.4%, and 0: 0.015% or less, with the balance being Fe and unavoidable impurities, wherein an average size of Cr-based carbonitrides is 100 nm or less, and an amount of the Cr-based carbonitrides is 0.001% to 0.5% in terms of % by mass.

Abstract: This high-strength austenitic stainless steel having excellent hydrogen embrittlement resistance characteristics includes, by mass %, C: 0.2% or less, Si: 0.3% to 1.5%, Mn: 7.0% to 11.0%, P: 0.06% or less, S: 0.008% or less, Ni: 5.0% to 10.0%, Cr: 14.0% to 20.0%, Cu: 1.0% to 5.0%, N: 0.01% to 0.4%, and 0: 0.015% or less, with the balance being Fe and unavoidable impurities, wherein an average size of Cr-based carbonitrides is 100 nm or less, and an amount of the Cr-based carbonitrides is 0.001% to 0.5% in terms of % by mass.

Abstract: This high-strength austenitic stainless steel having excellent hydrogen embrittlement resistance characteristics includes, by mass %, C: 0.2% or less, Si: 0.3% to 1.5%, Mn: 7.0% to 11.0%, P: 0.06% or less, S: 0.008% or less, Ni: 5.0% to 10.0%, Cr: 14.0% to 20.0%, Cu: 1.0% to 5.0%, N: 0.01% to 0.4%, and 0: 0.015% or less, with the balance being Fe and unavoidable impurities, wherein an average size of Cr-based carbonitrides is 100 nm or less, and an amount of the Cr-based carbonitrides is 0.001% to 0.5% in terms of % by mass.

Abstract: Inexpensive stainless steel and inexpensive and high strength stainless steel which has excellent hydrogen environment embrittlement resistance even if used in a hydrogen resistant environment in over 40 MPa high pressure hydrogen gas or a hydrogen resistant environment in liquid hydrogen, characterized by containing, by mass %, C: 0.1% or less, Si: 0.4 to 1.5%, Mn: 8 to 11%, Cr: 15 to 17%, Ni: 5 to 8%, Cu: 1 to 4%, and N: 0.01 to less than 0.15% and having a balance of Fe and unavoidable impurities, having a volume rate of ?-ferrite of 10% or less, and having a long axis of ?-ferrite before annealing of 0.04 to 0.1 mm.

Abstract: Inexpensive stainless steel and inexpensive and high strength stainless steel which has excellent hydrogen environment embrittlement resistance even if used in a hydrogen resistant environment in over 40 MPa high pressure hydrogen gas or a hydrogen resistant environment in liquid hydrogen, characterized by containing, by mass %, C: 0.1% or less, Si: 0.4 to 1.5%, Mn: 8 to 11%, Cr: 15 to 17%, Ni: 5 to 8%, Cu: 1 to 4%, and N: 0.01 to less than 0.15% and having a balance of Fe and unavoidable impurities, having a volume rate of ?-ferrite of 10% or less, and having a long axis of ?-ferrite before annealing of 0.04 to 0.1 mm.