Iron-based sintered body and method of manufacturing the same

Abstract

Provided is an iron-based sintered body having excellent mechanical properties. In the sintered body, the area fraction of pores is 15% or less and the area-based median size D50 of the pores is 20 82 m or less.

1 .- 9 . (canceled) 
     
     
         10 . An iron-based sintered body, comprising an area fraction of pores in the iron-based sintered body of 15% or less, and an area-based median size D50 of the pores of 20 μm or less. 
     
     
         11 . The iron-based sintered body according to  claim 10 , comprising Mo, Cu, and C. 
     
     
         12 . The iron-based sintered body according to  claim 11 , comprising Mo in an amount of 0.2 mass % to 1.5 mass %, Cu in an amount of 0.5 mass % to 4.0 mass %, and C in an amount of 0.1 mass % to 1.0 mass %. 
     
     
         13 . The iron-based sintered body according to  claim 10 , wherein the iron-based sintered body has been carburized, quenched, and tempered. 
     
     
         14 . The iron-based sintered body according to  claim 11 , wherein the iron-based sintered body has been carburized, quenched, and tempered. 
     
     
         15 . The iron-based sintered body according to  claim 12 , wherein the iron-based sintered body has been carburized, quenched, and tempered. 
     
     
         16 . A method of manufacturing an iron-based sintered body, the method comprising:
 compacting (i) partially diffusion alloyed steel powder in which Mo is adhered to the surface of particles of iron-based powder by diffusion bonding with (ii) mixed powder for powder metallurgy obtained by mixing at least Cu powder and graphite powder at a pressure of 400 MPa or more to obtain a compact; and   then sintering the obtained compact at 1000° C. or higher for 10 min or more.   
     
     
         17 . The method of manufacturing a high strength according to  claim 16 , the method further comprising carburizing, quenching, and tempering after sintering the obtained compact. 
     
     
         18 . The method of manufacturing an iron-based sintered body, according to  claim 16 , wherein the mixed powder for powder metallurgy contains Mo in an amount of 0.2 mass % to 1.5 mass % and the balance consisting of Fe and incidental impurities. 
     
     
         19 . The method of manufacturing an iron-based sintered body, according to  claim 17 , wherein the mixed powder for powder metallurgy contains Mo in an amount of 0.2 mass % to 1.5 mass % and the balance consisting of Fe and incidental impurities. 
     
     
         20 . The method of manufacturing an iron-based sintered body, according to  claim 16 , wherein the partially diffusion alloyed steel powder has a mean particle diameter of 30 μm to 120 μm and a specific surface area of less than 0.10 m 2 /g, and a circularity of particles of the partially diffusion alloyed steel powder that have a diameter in a range of 50 μm to 100 μm is 0.65 or less. 
     
     
         21 . The method of manufacturing an iron-based sintered body, according to  claim 17 , wherein the partially diffusion alloyed steel powder has a mean particle diameter of 30 μm to 120 μm and a specific surface area of less than 0.10 m 2 /g, and a circularity of particles of the partially diffusion alloyed steel powder that have a diameter in a range of 50 μm to 100 μm is 0.65 or less. 
     
     
         22 . The method of manufacturing an iron-based sintered body, according to  claim 18 , wherein the partially diffusion alloyed steel powder has a mean particle diameter of 30 μm to 120 μm and a specific surface area of less than 0.10 m 2 /g, and a circularity of particles of the partially diffusion alloyed steel powder that have a diameter in a range of 50 μm to 100 μm is 0.65 or less. 
     
     
         23 . The method of manufacturing an iron-based sintered body, according to  claim 19 , wherein the partially diffusion alloyed steel powder has a mean particle diameter of 30 μm to 120 μm and a specific surface area of less than 0.10 m 2 /g, and a circularity of particles of the partially diffusion alloyed steel powder that have a diameter in a range of 50 μm to 100 μm is 0.65 or less. 
     
     
         24 . The method of manufacturing an iron-based sintered body, according to  claim 16 , wherein the amount of the Cu powder mixed is 0.5 mass % to 4.0 mass % of the mixed powder for powder metallurgy. 
     
     
         25 . The method of manufacturing an iron-based sintered body, according to  claim 17 , wherein the amount of the Cu powder mixed is 0.5 mass % to 4.0 mass % of the mixed powder for powder metallurgy. 
     
     
         26 . The method of manufacturing an iron-based sintered body, according to  claim 18 , wherein the amount of the Cu powder mixed is 0.5 mass % to 4.0 mass % of the mixed powder for powder metallurgy. 
     
     
         27 . The method of manufacturing an iron-based sintered body, according to  claim 19 , wherein the amount of the Cu powder mixed is 0.5 mass % to 4.0 mass % of the mixed powder for powder metallurgy. 
     
     
         28 . The method of manufacturing an iron-based sintered body, according to  claim 20 , wherein the amount of the Cu powder mixed is 0.5 mass % to 4.0 mass % of the mixed powder for powder metallurgy. 
     
     
         29 . The method of manufacturing an iron-based sintered body, according to  claim 21 , wherein the amount of the Cu powder mixed is 0.5 mass % to 4.0 mass % of the mixed powder for powder metallurgy.