Patent ID: 8696835
Filing Date: 2014-04-15
Classification: C22C

Abstract:
1. In a method of storing hydrogen gas at a pressure of 70 MPa or more, wherein the hydrogen gas is in contact with one or more materials when stored, the improvement comprising improving the resistance to hydrogen embrittlement of at least one material in contact with the hydrogen gas during the storing step by making the at least one material from an austenitic stainless steel having a chemical composition containing, in mass percent, C: at most 0.10%, Si: at most 0.47%, Mn: 0.89-30%, P: at most 0.040%, S: at most 0.01%, Cr: 15-30%, Ni: 5.0-30%, sol. Al: at most 0.10%, N: 0.001-0.30%, and a remainder of Fe and impurities, and by having a structure such that the x-ray integrated intensity I(111) of a cross section in a direction perpendicular to the direction of working is at most 5 times that of a random direction and such that the x-ray integrated intensity ratio I(220)/I(111) of a cross section in the direction of working is at most 10 to indicate a low anisotropy for the structure, the steel having a tensile strength of 800 MPa or higher, an elongation of 30% or more, and a susceptibility to hydrogen embrittlement indicated by elongation (hydrogen)/elongation (air) is more than 0.75.