Manufacturing method of wear-resistant iron-based sintered alloy and wear-resistant iron-based sintered alloy

Patent metadata

Field	Value
Publication number	US-10619229-B2
Application number	US-201715703387-A
Country	US
Kind code	B2
Filing date	Sep 13, 2017
Priority date	Sep 16, 2016
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

An iron alloy powder consists of, when the entirety thereof is assumed to be 100 mass %, Cr: 2.5 mass % to 3.5 mass %, Mo: 0.4 mass % to 0.6 mass %, and Fe and inevitable impurities as the balance, a mixed powder consisting of 15 mass % to 40 mass % of the iron alloy powder, 1.2 mass % to 1.8 mass % of a copper powder, 0.5 mass % to 1.0 mass % of a graphite powder, and a pure iron powder as the balance when the entire mixed powder is assumed to be 100 mass % is compacted into a compact, and the compact is sintered while transforming a structure derived from the pure iron powder into a structure in which a ferritic structure and a pearlitic structure are mixed and transforming a structure derived from the iron alloy powder into a martensitic structure.

First claim

What is claimed is:

1. A manufacturing method of a wear-resistant iron-based sintered alloy comprising:
a forming step of compacting a mixed powder containing a pure iron powder, an iron alloy powder, a copper powder, and a graphite powder into a compact; and
a sintering step of sintering the compact, wherein
the iron alloy powder consists of, with the entire iron alloy powder being 100 mass %, Cr: 2.5 mass % to 3.5 mass %, Mo: 0.4 mass % to 0.6 mass %, and Fe and inevitable impurities as a balance,
the entire mixed powder being 100 mass %, in the mixed powder, a proportion of the iron alloy powder is 15 mass % to 40 mass %, and a proportion of the copper powder is 1.2 mass % to 1.8 mass %, a proportion of the graphite powder is 0.5 mass % to 1.0 mass %, the balance is the pure iron powder, and
in the sintering step, a mixed ferritic structure and pearlitic structure is produced from the pure iron powder, and a martensitic structure is produced from the iron alloy powder.

2. The manufacturing method according to claim 1 , wherein, in the sintering step, the compact is heated under a condition that a heating temperature is set to 1050° C. to 1200° C. and a heating time is set to 10 minutes to 60 minutes, and the compact heated under the condition is cooled at a cooling rate of 20° C./min to 300° C./min.

3. The manufacturing method according to claim 1 , wherein the wear-resistant iron-based sintered alloy comprises:
C: 0.5 mass % to 1.0 mass %;
Cr: 0.45 mass % to 1.20 mass %;
Mo: 0.075 mass % to 0.200 mass %;
Cu: 1.2 mass % to 1.8 mass %; and
Fe and inevitable impurities as a balance, wherein
in the wear-resistant iron-based sintered alloy, hard particles with a martensitic structure is dispersed in an iron base with a structure in which a ferritic structure and a pearlitic structure are mixed,
C and Cu are contained in the iron base and the hard particles,
Cr and Mo are contained at least in the hard particles, and
the entire wear-resistant iron-based sintered alloy contains 15.3 mass % to 40.9 mass % of the hard particles based on 100% mass.

Assignees

• Toyota Motor Co Ltd
• Fine Sinter Co Ltd

Inventors

• Shinohara Nobuyuki
• Kamo Yuki
• Ueda Yoshihisa
• Yoneda Takanori
• Yoshida Yusaku
• Sugimoto Masaru

Classifications

• F01L2303/00

  Manufacturing of components used in valve arrangements · CPC title

• F01L2301/00

  Using particular materials · CPC title

• C22C33/0207 Primary

  Using a mixture of pre-alloyed powders or a master alloy · CPC title

• C22C38/22 Primary

  with molybdenum or tungsten · CPC title

• F01L3/00

  Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof · CPC title