Metal powder for powder metallurgy, compound, granulated powder, and sintered body

Abstract

A metal powder for powder metallurgy contains Fe as a principal component, Cr in a proportion of 15% by mass or more and 26% by mass or less, Ni in a proportion of 7% by mass or more and 22% by mass or less, Si in a proportion of 0.3% by mass or more and 1.2% by mass or less, C in a proportion of 0.005% by mass or more and 0.3% by mass or less, Zr in a proportion of 0.01% by mass or more and 0.5% by mass or less, and Nb in a proportion of 0.01% by mass or more and 0.5% by mass or less. Further, the metal powder for powder metallurgy preferably has an austenite crystal structure.

What is claimed is: 
     
         1 . A metal powder for powder metallurgy, comprising:
 Fe as a principal component;   Cr in a proportion of 15% by mass or more and 26% by mass or less;   Ni in a proportion of 7% by mass or more and 22% by mass or less;   Si in a proportion of 0.3% by mass or more and 1.2% by mass or less;   C in a proportion of 0.005% by mass or more and 0.3% by mass or less;   Zr in a proportion of 0.01% by mass or more and 0.5% by mass or less; and   Nb in a proportion of 0.01% by mass or more and 0.5% by mass or less.   
     
     
         2 . The metal powder for powder metallurgy according to  claim 1 , wherein the metal powder has an austenite crystal structure. 
     
     
         3 . The metal powder for powder metallurgy according to  claim 1 , wherein the ratio of the content of Zr to the content of Nb (Zr/Nb) is 0.3 or more and 3 or less. 
     
     
         4 . The metal powder for powder metallurgy according to  claim 1 , wherein the sum of the content of Zr and the content of Nb is 0.05% by mass or more and 0.6% by mass or less. 
     
     
         5 . The metal powder for powder metallurgy according to  claim 1 , further comprising Mo in a proportion of 1% by mass or more and 5% by mass or less. 
     
     
         6 . The metal powder for powder metallurgy according to  claim 1 , wherein the metal powder has an average particle diameter of 0.5 μm or more and 30 μm or less. 
     
     
         7 . A compound, comprising the metal powder for powder metallurgy according to  claim 1  and a binder which binds the particles of the metal powder for powder metallurgy to one another. 
     
     
         8 . A compound, comprising the metal powder for powder metallurgy according to  claim 2  and a binder which binds the particles of the metal powder for powder metallurgy to one another. 
     
     
         9 . A compound, comprising the metal powder for powder metallurgy according to  claim 3  and a binder which binds the particles of the metal powder for powder metallurgy to one another. 
     
     
         10 . A compound, comprising the metal powder for powder metallurgy according to  claim 4  and a binder which binds the particles of the metal powder for powder metallurgy to one another. 
     
     
         11 . A compound, comprising the metal powder for powder metallurgy according to  claim 5  and a binder which binds the particles of the metal powder for powder metallurgy to one another. 
     
     
         12 . A compound, comprising the metal powder for powder metallurgy according to  claim 6  and a binder which binds the particles of the metal powder for powder metallurgy to one another. 
     
     
         13 . A granulated powder, wherein the granulated powder is obtained by granulating the metal powder for powder metallurgy according to  claim 1 . 
     
     
         14 . A granulated powder, wherein the granulated powder is obtained by granulating the metal powder for powder metallurgy according to  claim 2 . 
     
     
         15 . A granulated powder, wherein the granulated powder is obtained by granulating the metal powder for powder metallurgy according to  claim 3 . 
     
     
         16 . A granulated powder, wherein the granulated powder is obtained by granulating the metal powder for powder metallurgy according to  claim 4 . 
     
     
         17 . A granulated powder, wherein the granulated powder is obtained by granulating the metal powder for powder metallurgy according to  claim 5 . 
     
     
         18 . A granulated powder, wherein the granulated powder is obtained by granulating the metal powder for powder metallurgy according to  claim 6 . 
     
     
         19 . A sintered body, wherein the sintered body is produced by sintering a metal powder for powder metallurgy containing:
 Fe as a principal component;   Cr in a proportion of 15% by mass or more and 26% by mass or less;   Ni in a proportion of 7% by mass or more and 22% by mass or less;   Si in a proportion of 0.3% by mass or more and 1.2% by mass or less;   C in a proportion of 0.005% by mass or more and 0.3% by mass or less;   Zr in a proportion of 0.01% by mass or more and 0.5% by mass or less; and   Nb in a proportion of 0.01% by mass or more and 0.5% by mass or less.   
     
     
         20 . The sintered body according to  claim 19 , wherein the sintered body includes a first region which is in the form of a particle and has a relatively high silicon oxide content and a second region which has a relatively lower silicon oxide content than the first region.