Oxidation resistant alloy coating film, method of producing an oxidation resistant alloy coating film, and heat resistant metal member

Abstract

A metal substrate is embedded in a diffusion and penetration processing agent containing metal oxide, active metal and catalytic compound and heat treatment is carried out, so that an oxidation resistant alloy coating film containing the metal constituting the metal oxide and the active metal is produced. Al 2 0 3 , Cr 2 O 3 , SiO 2 or the like are used as the metal oxide, Hf, Zr, Y, Ti, La, Ce, Mg, Ca or the like are used as the active metal, and NH-14Cl, NH4F, HCl, NaCl, NaF or the like are used as the catalytic compound. The metal substrate is Ni, Ni-based alloy, Fe-based alloy, and Co-based alloy. Heat treatment is carried out, for example, at a temperature of 700˜1340° C. for 1 minute˜25 hours in an atmosphere of inert gas or hydrogen gas.

1 . A method of producing an oxidation resistant alloy coating film on the surface of a metal substrate,
 wherein said oxidation resistant alloy coating film is produced by embedding said metal substrate in a diffusion and penetration processing agent containing powder of at least one kind of active metal selected from the group consisting of Hf, Zr, Y, Ti, La, Ce and Ca and powder of at least one kind of catalytic compound selected from the group consisting of NH 4 Cl, NH 4 F, HCl, NaCl and NaF, the rest being powder of metal oxide containing at least one kind of metal selected from the group consisting of Al, Cr and Si, and carrying out heat treatment at a temperature higher than the thermal decomposition temperature or sublimation temperature of said catalytic compound and lower than the melting point of said metal substrate.   
     
     
         2 . The method of producing an oxidation resistant alloy coating film according to  claim 1  wherein said metal oxide contains at least one kind of oxide selected from the group consisting of Al 2 O 3 , Cr 2 O 3  and SiO 2 . 
     
     
         3 . The method of producing an oxidation resistant alloy coating film according to  claim 1  wherein said heat treatment is carried out at a temperature of 600-1340° C. for 1 minute-25 hours in an atmosphere of inert gas or hydrogen gas. 
     
     
         4 . The method of producing an oxidation resistant alloy coating film according to  claim 1  wherein said diffusion and penetration processing agent contains at least one kind of active metal selected from the group consisting of Hf, Zr, Y and Ti by less than 89 weight % and NH 4 Cl by 1-10 weight % and the rest is Al 2 O 3 . 
     
     
         5 . The method of producing an oxidation resistant alloy coating film according to  claim 4  wherein said oxidation resistant alloy coating film comprises at least one phase selected from the group consisting of γ-Ni phase, γ′-Ni 3 Al phase, β-NiAl phase and δ-Ni 2 Al 3  phase, said γ-Ni phase contains 0.005 atomic %<(Hf+Zr+Y+Ti)<1 atomic % and 5 atomic %<Al<15 atomic %, said γ′-Ni 3 Al phase contains 0.005 atomic %<(Hf+Zr+Y+Ti)<10 atomic % and 16 atomic %<Al<27 atomic %, said β-NiAl phase contains 0.005 atomic %<(Hf+Zr+Y+Ti)<30 atomic % and 30 atomic %<Al<58 atomic %, and said δ-Ni 2 Al 3  phase contains 0.005 atomic %<(Hf+Zr+Y+Ti)<3 atomic % and 59 atomic %<Al<62 atomic %. 
     
     
         6 . The method of producing an oxidation resistant alloy coating film according to  claim 5  wherein said γ-Ni phase further contains 0.1-45 atomic % Cr, said γ′-Ni 3 Al phase further contains 0.1-7 atomic % Cr, said β-NiAl phase further contains 0.1-10 atomic % Cr and said δ-Ni 2 Al 3  phase further contains 0.1-5 atomic % Cr. 
     
     
         7 . The method of producing an oxidation resistant alloy coating film according to  claim 5  wherein said γ-Ni phase, said γ′-Ni 3 Al phase, said β-NiAl phase and said δ-Ni 2 Al 3  phase further contain at least one element selected from the group consisting of V, Nb, W, Mo, Ta, Pt, Ir, Ru, Co, Fe, Mn and Si by transport from said metal substrate and environment by 0.01-15 atomic %.