Metal powder bonded body having excellent hydrogen embrittlement resistance

Abstract

Provided is a metal powder bonded body having excellent hydrogen embrittlement resistance, wherein the metal powder bonded body is a metallic material having excellent hydrogen embrittlement resistance, the metallic material is a metal powder bonded body manufactured by bonding metal powder, and the metal powder bonded body has characteristics of ductile fracture in an area of 80% or more of a total area of a fracture section when fractured in a hydrogen atmosphere.

What is claimed is: 
     
         1 . A metal powder bonded body having excellent hydrogen embrittlement resistance, wherein the metal powder bonded body is a metallic material having excellent hydrogen embrittlement resistance,
 the metallic material is a metal powder bonded body manufactured by bonding metal powder, and   the metal powder bonded body has characteristics of ductile fracture in an area of 80% or more of a total area of a fracture section when fractured in a hydrogen atmosphere.   
     
     
         2 . A metal powder bonded body having excellent hydrogen embrittlement resistance, wherein the metal powder bonded body is a metallic material having excellent hydrogen embrittlement resistance,
 the metallic material is a metal powder bonded body manufactured by bonding metal powder, and   in the metal powder bonded body, a ratio of tensile strength TS2 after being exposed to hydrogen to tensile strength TS1 before being exposed to hydrogen satisfies Equation (1):
   0.7<TS2/TS1<1.1.  Equation (1):
 
   
     
     
         3 . A metal powder bonded body having excellent hydrogen embrittlement resistance, wherein the metal powder bonded body is a metallic material having excellent hydrogen embrittlement resistance,
 the metallic material is a metal powder bonded body manufactured by bonding metal powder, and   in the metal powder bonded body, a ratio of elongation E2 after being exposed to hydrogen to elongation E1 before being exposed to hydrogen satisfies Equation (2):
   0.7< E 2/ E 1<1.1.  Equation (2):
 
   
     
     
         4 . A metal powder bonded body having excellent hydrogen embrittlement resistance, wherein the metal powder bonded body is a metallic material having excellent hydrogen embrittlement resistance,
 the metallic material is a metal powder bonded body manufactured by bonding metal powder, and   in the metal powder bonded body, a ratio of reduction of area RA2 after being exposed to hydrogen to reduction of area RA1 before being exposed to hydrogen satisfies Equation (3):
   0.7<RA2/RA1<1.1.  Equation (3):
 
   
     
     
         5 . A metal powder bonded body having excellent hydrogen embrittlement resistance, wherein the metal powder bonded body is a metallic material having excellent hydrogen embrittlement resistance,
 the metallic material is a metal powder bonded body manufactured by bonding metal powder, and   in the metal powder bonded body, a difference between a fraction Mf of a martensite phase after completion of a tensile test in a state of being exposed to hydrogen and a fraction Mb of a martensite phase before being exposed to hydrogen satisfies Equation (4):
   | Mf−Mb|≦ 10.  Equation (4):
 
   
     
     
         6 . The metal powder bonded body having excellent hydrogen embrittlement resistance of  claim 1 , wherein, in the characteristics of ductile fracture in the area of 80% or more of the total area of the fracture section, a fracture mode including dimples without a cleavage plane is shown in the area of 80% or more of the total fracture section during observation of the fracture section. 
     
     
         7 . The metal powder bonded body having excellent hydrogen embrittlement resistance of  claim 1 , wherein the metal powder comprises at least one of an iron alloy (including pure iron), steel, Ni-based alloy powder (including pure nickel (Ni)), Zr-based alloy powder (including pure zirconium (Zr)), W-based alloy powder (including pure tungsten (W)), rare earth metal powder, and transition metal powder. 
     
     
         8 . The metal powder bonded body having excellent hydrogen embrittlement resistance of  claim 1 , wherein the metal powder bonded body is manufactured from the metal powder by at least one processing method of sintering, forging, compression, extrusion, rolling, slip casting, and spray forming. 
     
     
         9 . The metal powder bonded body having excellent hydrogen embrittlement resistance of  claim 1 , wherein the metal powder is powder of 304L stainless steel, and
 the metal powder bonded body is manufactured by a hot isostatic press (HIP) method.   
     
     
         10 . The metal powder bonded body having excellent hydrogen embrittlement resistance of  claim 1 , wherein the metal powder bonded body comprises one in which single metal powder or heterogeneous metal powder is bonded. 
     
     
         11 . The metal powder bonded body having excellent hydrogen embrittlement resistance of  claim 1 , wherein the metal powder bonded body comprises one in which metal powder and ceramic powder are bonded. 
     
     
         12 . The metal powder bonded body having excellent hydrogen embrittlement resistance of  claim 1 , wherein the metal powder bonded body comprises one in which at least one of metal oxide, metal nitride, and metal carbide is present in a dispersed form in a metal matrix.