Jfe Steel Corporation

Other

Kawasaki Steel Corporation

Unisia Jecs Corporation

Hyundai Motor Company

Kia Motors Corporation

Kawasaki Steel Corporaton

Hitachi, Ltd.

Masashi Fujinaga

Satoshi Uenosono

Shigeru Unami

Naomichi Nakamura

Takashi Yoshimura

Mitsumasa Iijima

Yasuo Hatai

Hiroyuki Amma

Takayuki Matsumoto

Shin Koizumi

Hiroyuki Anma

Takashi Kawano

Hak Soo Kim

Akio Kobayashi

Yukiko Ozaki

Tomoshige Ono

Toshio Maetani

Kohsuke Ashizuka

Hirofumi Enokido

Hisashi Sudo

The present disclosure relates to an iron-based prealloy powder having excellent strength and processability, and an iron-based alloy powder for powder metallurgy and a sinter-forged member using the same. The iron-based prealloy powder for powder metallurgy according to an embodiment of the present disclosure includes 0.5 to 5.0 wt % of Cu, 0.1 to 0.5 wt % of Mo, and a balance of Fe and other inevitable impurities. A Cu content (Cu %) and a Mo content (Mo %) satisfy the following Relational Equation (1):0.3&#xd7;Cu %+3&#xd7;Mo %&#x2264;2.7&#x2003;&#x2003;(1).

Iron-based prealloy powder, iron-based diffusion-bonded powder, and iron-based alloy powder for powder metallurgy using the same

A seed-covering agent, which covers a seed surface and contains an iron powder and a binder, is specified such that, in the above-described iron powder, the mass ratio of an iron powder having a particle size of 63 &#x3bc;m or less to a total mass of the iron powder is 0% or more and 75% or less, the mass ratio of an iron powder having a particle size of more than 63 &#x3bc;m and 150 &#x3bc;m or less to the total mass of the iron powder is 25% or more and 100% or less, and the mass ratio of an iron powder having a particle size of more than 150 &#x3bc;m to a total mass of the iron powder is 0% or more and 50% or less, and the average particle size of the above-described binder is 1 to 150 &#x3bc;m.

Seed-covering agent and seed covered with seed-covering agent

In a preliminary molding step, a metallic powder mixtureobtained by blending an iron-based metal powderwith graphitesuch that the graphite is present in an amount of preferably not less than 0.1% by weight, more preferably not less than 0.3% by weight, is compacted into a preformhaving a density of not less than 7.3 g/cm. In a provisional sintering step, the preformis provisionally sintered at a predetermined temperature to form a metallic powder-molded bodyhaving a structure in which the graphite remains along a grain boundary of the metal powder. In a re-compaction step, the metallic powder-molded bodyis re-compacted into a re-compacted body. In a re-sintering step, the re-compacted bodyis re-sintered to obtain a sintered body. In a heat treatment step, the sintered bodyis heat-treated to obtain a heat-treated sintered body Accordingly, in accordance with the present invention, there are provided a re-compacted body produced from a metallic powder-molded body having an excellent deformability which is suitably applied to the production of machine parts exhibiting high mechanical properties due to the use of sintered metal, and a sintered body produced from the re-compacted body as well as a process for the production thereof.

Metallic powder-molded body, re-compacted body of the molded body, sintered body produced from the re-compacted body, and processes for production thereof

A Mo source powder is added to and mixed with an iron-based powder containing 1.0% by mass or less of prealloyed Mn to yield a powder mixture containing 0.2 to 10.0% by mass of Mo, the resulting powder mixture is subjected to heat treatment in a reducing atmosphere to thereby yield an alloyed steel powder containing Mo as a powder partially diffused and bonded to a surface of the iron-based powder particles. The prepared alloyed steel powder for powder metallurgy has satisfactory compactability. The use of this alloyed steel powder can produce a sintered powder metal body (an intermediate material after compaction and preliminary sintering in re-compaction of sintered powder materials process) for highly strong sintered member.

Alloyed steel powder for powder metallurgy

A sintered iron-based powder metal body with lower re-compacting load and having a high density and a method of manufacturing an iron-based sintered component with fewer pores of a sharp shape and having high strength and high density.

Iron-based sintered powder metal body, manufacturing method thereof and manufacturing method of iron-based sintered component with high strength and high density

Metallic powder molding material and its re-compression molded body and sintered body obtained from the re-compression molded body and production methods thereof

Sintered powder metal bodies and process for producing the same

Growing community of inventors

Chiba, Japan

Masashi Fujinaga