Patent ID: 7531129
Filing Date: 2009-05-12
Classification: C22C,Y10T

Abstract:
1. A stainless steel having an austenitic microstructure for high-pressure hydrogen gas characterized in that: (a) The steel consists of, by mass %, C: not more than 0.02%, Si: not more than 1.0%, Mn: 9.23 to 30%, Cr: more than 22% but not more than 30%, Ni: 17 to 30%, V: 0.001 to 1.0%, N: 0.10 to 0.50% and Al: not more than 0.10%, and optionally at least one element selected from at least one of the first, second and third groups of elements specified below, and the balance Fe and impurities, (b) among the impurities, P is not more than 0.030%, S is not more than 0.005%, and Ti, Zr and Hf are not more than 0.01% respectively, and (c) The contents of Cr, Mn and N satisfy the following relationship [1]:  wherein the symbols of the elements represent the contents, % by mass, of the respective elements; the first group of elements; the second group of elements; the third group of elements;