Abstract: A spring steel with high fatigue resistance in air and in corrosive conditions and with high resistance to cyclic sag, having the composition in weight percent: C=0.45-0.70% Si=1.65-2.50% Mn=0.20-0.75% Cr=0.60-2% Ni=0.15-1% Mo=traces-1% V=0.003-0.8% Cu=0.10-1% Ti=0.020-0.2% Nb=traces-0.2% AI=0.002-0.050% P=traces-0.015% S=traces-0.015% O=traces-0.0020% N=0.0020-0.0110% the balance being iron, and impurities resulting from the steel making process, where the carbon equivalent Ceq content calculated according to the formula: Ceq %=[C %]+0.12 [Si %]+0.17 [Mn %]?0.1 [Ni %]+0.13 [Cr %]?0.24 [V %] is between 0.80 and 1.00%, and whose hardness, after quenching and tempering, is greater than or equal to 55 HRC.

Abstract: Disclosed herein is a hydrogen permeable member composed of a metal porous body and a hydrogen permeable membrane placed thereon, with a diffusion preventing layer interposed between them, wherein the metal porous body has those parts on which the diffusion preventing layer is absent and such parts are filled with metal oxide particles and/or porous metal oxide. This structure prevents direct contact between the metal porous body and the hydrogen permeable membrane, thereby relieving the latter from deterioration by diffusion of metal from the former.