High-strength austenitic stainless steel for high-pressure hydrogen gas

摘要

An austenitic stainless steel for high-pressure hydrogen gas, characterized by containing, in terms of mass%, up to 0.10% C, up to 1.0% Si, 3-7%, excluding 7%, Mn, 15-30% Cr, 10-17%, excluding 17%, Ni, up to 0.10% Al, 0.10-0.50% N, and 0.01-1.0% V and/or 0.01-0.50% Nb, with the remainder comprising Fe and impurities, the impurities including up to 0.050% P and up to 0.050% S. The stainless steel is further characterized by having a tensile strength of 800 MPa or greater, having a crystal grain size number (ASTM E 112) of 8 or larger, and containing alloy carbonitirde grains having a maximum diameter of 50-1,000 nm, the number of the grains being 0.4 or greater per µm