Hydrogen-resistant high strength material and method for producing the same

Abstract

A hydrogen-resistant high strength material made of a Ni-based alloy or an Fe—Ni-based alloy includes an aged portion and a hydrogen embrittlement suppressing layer that is to be exposed to hydrogen. The hydrogen embrittlement suppressing layer has a hydrogen embrittlement index of not less than 0.9, wherein the hydrogen embrittlement index is defined as a ratio of an elongation after hydrogen charging in relation to an elongation before hydrogen charging. The aged portion has a tensile strength exceeding 1000 MPa.

1 . A hydrogen-resistant high strength material made of a Ni-based alloy or an Fe—Ni-based alloy, comprising:
 an aging-treated portion; and   a hydrogen embrittlement suppressing layer that is to be exposed to hydrogen,   wherein the hydrogen embrittlement suppressing layer has a hydrogen embrittlement index of not less than 0.9, the hydrogen embrittlement index being defined as a ratio of an elongation after hydrogen charging in relation to an elongation before hydrogen charging, and   wherein the aged portion has a tensile strength exceeding 1000 MPa.   
     
     
         2 . The hydrogen-resistant high strength material according to  claim 1 , wherein the Ni-based alloy or the Fe—Ni-based alloy has a face-centered cubic lattice structure. 
     
     
         3 . The hydrogen-resistant high strength material according to  claim 1 , wherein a thickness of the hydrogen embrittlement suppressing layer is from 5 to 30% of a total thickness of the aged portion and the hydrogen embrittlement suppressing layer. 
     
     
         4 . A hydrogen embrittlement resistant piping, comprising the hydrogen-resistant high strength material according to  claim 1 . 
     
     
         5 . A reactor, comprising the hydrogen-resistant high strength material according to  claim 1 . 
     
     
         6 . A high-pressure container, comprising the hydrogen-resistant high strength material according to  claim 1 . 
     
     
         7 . A compressor, comprising the hydrogen-resistant high strength material according to  claim 1 . 
     
     
         8 . An accumulator, comprising the hydrogen-resistant high strength material according to  claim 1 . 
     
     
         9 . A hydrogen dispenser, comprising the hydrogen-resistant high strength material according to  claim 1 . 
     
     
         10 . A high-pressure hydrogen flowmeter, comprising the hydrogen-resistant high strength material according to  claim 1 . 
     
     
         11 . A hydrogen vehicle, comprising the hydrogen-resistant high strength material according to  claim 1 . 
     
     
         12 . A method for producing a hydrogen-resistant high strength material, comprising the steps of:
 applying an aging heat treatment to an entirety of a material made of a Ni-based alloy or an Fe—Ni-based alloy to form an aged portion; and,   applying a solution treatment locally to the aging-heat-treated material to form a hydrogen embrittlement suppressing layer.   
     
     
         13 . The method according to  claim 12 , wherein a thickness of the hydrogen embrittlement suppressing layer is from 5 to 30% of a total thickness of the aged portion and the hydrogen embrittlement suppressing layer. 
     
     
         14 . A method for producing a hydrogen-resistant high strength material, comprising the steps of:
 applying a solution treatment to an entirety of a material made of a Ni-based alloy or an Fe—Ni-based alloy; and,   after the solution treatment step, while keeping a portion where a hydrogen embrittlement suppressing layer is to be formed cooled, applying an aging heat treatment to other portion to form an aged portion.   
     
     
         15 . The method according to  claim 14 , wherein a thickness of the hydrogen embrittlement suppressing layer is from 5 to 30% of a total thickness of the aged portion and the hydrogen embrittlement suppressing layer.