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JP-2026076006-A - Iron-based sintered body and method for manufacturing an iron-based sintered body

JP2026076006AJP 2026076006 AJP2026076006 AJP 2026076006AJP-2026076006-A

Abstract

[Problem] The present disclosure aims to provide an iron-based sintered body that has strength and elongation equivalent to existing iron-based sintered bodies (Fe-Cu-C system, sintering temperature 1120°C) while reducing energy consumption during sintering and other processes. [Solution] An iron-based sintered body according to one aspect of the present disclosure contains, as elements, Cu: 3.5% by mass or more and 6.5% by mass or less, P: 0.25% by mass or more and 0.56% by mass or less, and C: 0.3% by mass or more and 1.2% by mass or less, and the area ratio of undiffused Cu in the cross-section of the sintered body is 0.5% or more and 2.5% or less. [Selection Diagram] Figure 2

Inventors

  • 山口 修平
  • 難波 茂信
  • 池田 知弘
  • 谷口 祐司

Assignees

  • 株式会社神戸製鋼所

Dates

Publication Date
20260511
Application Date
20241023

Claims (4)

  1. Iron-based sintered body, As an element, Cu: 3.5% by mass or more and 6.5% by mass or less, P: 0.25% by mass or more and 0.56% by mass or less, C: Contains 0.3% by mass or more and 1.2% by mass or less, An iron-based sintered body in which the area ratio of undiffused Cu in the cross-section of the sintered body is 0.5% or more and 2.5% or less.
  2. The iron-based sintered body according to claim 1, wherein the content of P is 7.0 parts by mass or more and 9.0 parts by mass or less per 100 parts by mass of the total content of Cu and P.
  3. A process of pressure molding an iron-based raw material powder containing phosphorus-containing copper alloy powder, The process comprises a step of sintering the molded body formed in the above pressure molding step in an inert gas atmosphere or a reducing gas atmosphere, The above iron-based raw material powder contains, as elements, Cu: 3.5% by mass or more and 6.5% by mass or less, P: 0.25% by mass or more and 0.56% by mass or less, C: Contains 0.3% by mass or more and 1.2% by mass or less, A method for manufacturing an iron-based sintered body, wherein the sintering temperature in the above sintering step is 850°C or higher and 1050°C or lower.
  4. The method for producing an iron-based sintered body according to claim 3, wherein the phosphorus content in the phosphorus-containing copper alloy powder is 7.0% by mass or more and 9.0% by mass or less.

Description

This disclosure relates to an iron-based sintered body and a method for manufacturing an iron-based sintered body. Today, achieving carbon neutrality is highly desirable. From this perspective, reducing energy consumption is required in the manufacturing process of sintered bodies. At the same time, sintered bodies are also required to possess excellent mechanical properties such as strength and elongation. In the manufacturing process of sintered bodies, the sintering stage accounts for the largest portion of energy consumption, approximately 40% of the total. Therefore, there is a need for technology that can reduce energy consumption during sintering while producing sintered bodies with superior strength and elongation. Japanese Patent Publication No. 2019-31738 "On the dimensional changes and some mechanical properties of iron-copper-carbon and iron-copper-phosphorus-carbon sintered alloys during sintering," "Powder and Powder Metallurgy," Vol. 31, No. 6, August 1984, pp. 7-13.ACTIVATED LOW TEMPERATURE SINTERING OF IRON POWDER STRUCTURES, PROGRESS IN POWDER METALLURGY VOLUME 37, 1981 National Powder Metallurgy Conference Proceedings Figure 1 is a flowchart showing a method for manufacturing an iron-based sintered body according to one embodiment of the present disclosure.Figure 2 is a graph showing the relationship between sintering temperature and compression ring strength for each sample in the examples.Figure 3 is a graph showing the relationship between the surface hardness and compression ring strength of each sample sintered at a sintering temperature of 1050°C in the examples.Figure 4 is a graph showing the relationship between compression ring strength and fracture strain for each sample sintered at a sintering temperature of 1050°C in the examples. [Description of Embodiments in this Disclosure] First, the embodiments of this disclosure will be listed and described. (1) An iron-based sintered body according to one aspect of this disclosure contains, as elements, Cu: 3.5% by mass or more and 6.5% by mass or less, P: 0.25% by mass or more and 0.56% by mass or less, and C: 0.3% by mass or more and 1.2% by mass or less, and the area ratio of undiffused Cu in the cross-section of the sintered body is 0.5% or more and 2.5% or less. The iron-based sintered body can achieve high strength by containing P and C within the above ranges. Furthermore, since the area ratio of undiffused Cu in the cross-section of the iron-based sintered body is 0.5% to 2.5%, it is considered to have good elongation. Moreover, because the area ratio of undiffused Cu in the cross-section of the iron-based sintered body is 0.5% to 2.5%, the sintering temperature can be lowered while maintaining elongation. Therefore, the iron-based sintered body can have strength and elongation equivalent to or better than the current iron-based sintered body (Fe-Cu-C system, sintering temperature 1120°C) while reducing energy consumption during sintering. Furthermore, since the iron-based sintered body does not require the use of Cu3P powder as described in Non-Patent Document 2, energy consumption during raw material powder production can be reduced. (2) In (1) above, it is preferable that the content of P relative to 100 parts by mass of the total content of Cu and P be 7.0 parts by mass or more and 9.0 parts by mass or less. According to the inventors' findings, by using phosphorus-containing copper alloy powder with a phosphorus content of 7.0% by mass or more and 9.0% by mass or less, controlling the content of Cu and P within the above range, and controlling the area ratio of undiffused Cu in the cross-section of the iron-based sintered body to 0.5% or more and 2.5% or less, both the strength and elongation of the iron-based sintered body can be increased. Therefore, the desired quality can be easily obtained in the iron-based sintered body if the content of P relative to 100 parts by mass of the total content of Cu and P is 7.0 parts by mass or more and 9.0 parts by mass or less. Furthermore, according to this embodiment, energy consumption during sintering can be easily and reliably reduced, and energy consumption during raw material powder production can be reduced more easily. (3) A method for manufacturing an iron-based sintered body according to another aspect of the present disclosure comprises the steps of: pressure molding an iron-based raw material powder containing phosphorus-containing copper alloy powder; and sintering the molded body formed in the pressure molding step in an inert gas atmosphere or a reducing gas atmosphere, wherein the iron-based raw material powder contains, as elements, Cu: 3.5% to 6.5% by mass, P: 0.25% to 0.56% by mass, and C: 0.3% to 1.2% by mass, and the sintering temperature in the sintering step is 850°C to 1050°C. Furthermore, the method for manufacturing an iron-based sintered body may further include a step of mixing each raw material powder. The method for manufacturing the iron-based sintered