Iron-based sintered body and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-2018178291-A1
Application number	US-201615738223-A
Country	US
Kind code	A1
Filing date	Sep 16, 2016
Priority date	Sep 18, 2015
Publication date	Jun 28, 2018
Grant date	—

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.

First claim

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.

Assignees

• Jfe Steel Corp

Inventors

• Takashita Takuya
• Kobayashi Akio
• Nakamura Naomichi
• Sato Itsuya

Classifications

• C22C38/00

  Ferrous alloys, e.g. steel alloys (cast-iron alloys C22C37/00) · CPC title

• B22F3/16

  in successive or repeated steps · CPC title

• B22F5/00 Primary

  Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product · CPC title

• B22F2301/35

  Iron · CPC title

• C22C33/0264

  the maximum content of each alloying element not exceeding 5% · CPC title