公开(公告)号：US20180193908A1

公开(公告)日：2018-07-12

申请号：US15739839

申请日：2016-09-16

Applicant: JFE STEEL CORPORATION

Inventor： Takuya TAKASHITA ,  Akio KOBAYASHI ,  Naomichi NAKAMURA ,  Itsuya SATO

IPC: B22F1/00 ,  B22F3/16 ,  C22C33/02 ,  C22C38/16 ,  C22C38/12

Abstract: Provided is a mixed powder for powder metallurgy having a chemical system not using Ni which causes non-uniform metallic microstructure in a sintered body. A mixed powder for powder metallurgy comprises: a partially diffusion alloyed steel powder in which Mo diffusionally adheres to a particle surface of an iron-based powder; a Cu powder; and a graphite powder, wherein the mixed powder for powder metallurgy has a chemical composition containing Mo: 0.2 mass % to 1.5 mass %, Cu: 0.5 mass % to 4.0 mass %, and C: 0.1 mass % to 1.0 mass %, with the balance consisting of Fe and inevitable impurities, and the partially diffusion alloyed steel powder has: a mean particle diameter of 30 μm to 120 μm; a specific surface area of less than 0.10 m2/g; and a circularity of particles with a diameter in a range from 50 μm to 100 μm of 0.65 or less.

公开(公告)号：US20180178291A1

公开(公告)日：2018-06-28

申请号：US15738223

申请日：2016-09-16

Applicant: JFE STEEL CORPORATION

Inventor： Takuya TAKASHITA ,  Akio KOBAYASHI ,  Naomichi NAKAMURA ,  Itsuya SATO

IPC: B22F3/24 ,  C22C38/16 ,  C22C38/12 ,  C22C33/02 ,  B22F3/16

CPC classification number: B22F3/24 ,  B22F1/0059 ,  B22F3/16 ,  B22F2003/248 ,  B22F2301/35 ,  B22F2998/10 ,  C21D1/18 ,  C22C33/02 ,  C22C33/0257 ,  C22C38/00 ,  C22C38/12 ,  C22C38/16 ,  B22F3/02 ,  B22F3/10 ,  B22F2201/30

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.

公开(公告)号：US20220161321A1

公开(公告)日：2022-05-26

申请号：US17594163

申请日：2020-02-10

Applicant: JFE STEEL CORPORATION

Inventor： Takuya TAKASHITA ,  Nao NASU ,  Akio KOBAYASHI

IPC: B22F1/00 ,  B22F1/10 ,  B22F1/12 ,  C22C38/12 ,  B22F3/16 ,  B22F3/24

Abstract: Provided is a steel strip joining method that can appropriately evaluate risk of a fracture in a joined part and prevent a fracture more reliably. An iron-based mixed powder for powder metallurgy comprises: an iron-based alloy powder; and an alloying powder, wherein the iron-based alloy powder contains Mo: 0.2 mass % or more and 1.5 mass % or less, the alloying powder contains a graphite powder and a copper powder, a ratio of a mass of the graphite powder to a total mass of the iron-based alloy powder and the alloying powder is 0.10 mass % to 1.0 mass %, a ratio of a mass of the copper powder to the total mass of the iron-based alloy powder and the alloying powder is 0.5 mass % to 3.0 mass %, and the copper powder has an average particle size of 25 μm or less, and a specific surface area of 0.30 m2/g or more.

公开(公告)号：US20200001369A1

公开(公告)日：2020-01-02

申请号：US16480780

申请日：2018-01-25

Applicant: JFE STEEL CORPORATION

Inventor： Makoto NAKASEKO ,  Naomichi NAKAMURA ,  Mineo MURAKI ,  Takuya TAKASHITA

IPC: B22F9/08 ,  C22C45/02 ,  H01F1/153

Abstract: Provided is a method for manufacturing soft magnetic iron powder.A method for manufacturing soft magnetic iron powder, the method including ejecting high-pressure water to collide with a molten metal stream falling vertically downward, breaking up the molten metal stream into metal powder, and cooling the metal powder, in which, when a falling rate of the molten metal stream per unit time is defined as Qm (kg/min) and an ejection rate of high-pressure water per unit time is defined as Qaq (kg/min), a mass ratio (Qaq/Qm) is 50 or more, and a total content of ferrous constituents (Fe, Ni, and Co) is 76 at % or more.

公开(公告)号：US20180236537A1

公开(公告)日：2018-08-23

申请号：US15548850

申请日：2016-02-08

Applicant: JFE STEEL CORPORATION

Inventor： Takuya TAKASHITA ,  Akio KOBAYASHI ,  Naomichi NAKAMURA

IPC: B22F1/02 ,  B22F3/00 ,  C22C38/02 ,  H01F1/20 ,  B22F1/00 ,  H01F3/08

CPC classification number: B22F1/02 ,  B22F1/0059 ,  B22F1/0088 ,  B22F3/006 ,  B22F2999/00 ,  C22C38/00 ,  C22C38/02 ,  C23C10/08 ,  C23C16/26 ,  C23C16/4417 ,  H01F1/14708 ,  H01F1/20 ,  H01F3/08 ,  C22C2202/02 ,  C22C2200/02

Abstract: Soft magnetic powder for dust cores that yields dust cores having low eddy current loss is provided. Raw material powder for soft magnetic powder comprises Fe: 60 mass % or more, a γ-phase stabilizing element, and an electric resistance-increasing element: 1.0 mass % or more.

公开(公告)号：US20220331860A1

公开(公告)日：2022-10-20

申请号：US17754021

申请日：2020-06-16

Applicant: JFE STEEL CORPORATION

Inventor： Kohsuke ASHIZUKA ,  Nao NASU ,  Takuya TAKASHITA ,  Shigeru UNAMI

IPC: B22F1/00 ,  C22C38/16 ,  C22C38/12

Abstract: Provided is an alloyed steel powder for powder metallurgy which has excellent compressibility and can be used to produce a sintered body that obtains improved strength simply by sintering. The alloyed steel powder for powder metallurgy contains Cu: 1.0 mass % or more and 8.0 mass % or less, Mo: more than 0.50 mass % and 2.00 mass % or less, and at least one selected from the group consisting of V: 0.05 mass % or more and 0.50 mass % or less, Nb: 0.02 mass % or more and 0.40 mass % or less, and Ti: 0.02 mass % or more and 0.40 mass % or less, with the balance consisting of Fe and inevitable impurities.

公开(公告)号：US20220219229A1

公开(公告)日：2022-07-14

申请号：US17595648

申请日：2020-04-10

Applicant: JFE STEEL CORPORATION

Inventor： Nao NASU ,  Takuya TAKASHITA ,  Akio KOBAYASHI

IPC: B22F1/00 ,  B22F1/05 ,  C22C38/18 ,  C22C38/04 ,  C22C38/00 ,  B22F3/16

Abstract: Provided is an iron-based alloy sintered body having a tensile strength of 800 MPa or more, excellent machinability, a microstructure with an average Vickers hardness of 300 Hv or more and 900 Hv or less and a standard deviation of Vickers hardness of 200 Hv or less, and an average pore circularity of 0.30 or more.

公开(公告)号：US20210138547A1

公开(公告)日：2021-05-13

申请号：US16768692

申请日：2018-11-30

Applicant: JFE STEEL CORPORATION

Inventor： Takuya TAKASHITA ,  Akio KOBAYASHI ,  Naomichi NAKAMURA

IPC: B22F9/00 ,  C22C33/02 ,  C22C38/04 ,  C22C38/12 ,  C22C38/16

Abstract: Disclosed is a partially diffusion-alloyed steel powder having excellent fluidity, formability, and compressibility without containing Ni, Cr, and Si. A partially diffusion-alloyed steel powder having excellent fluidity, formability, and compressibility that includes an iron-based powder and Mo diffusionally adhered to a surface of the iron-based powder, in which Mo content is 0.2 mass % to 2.0 mass %, a weight-based median diameter D50 is 40 μm or more, and among particles contained in the partially diffusion-alloyed steel powder, those particles having an equivalent circular diameter of 50 μm to 200 μm have a number average of solidity of 0.70 to 0.86, the solidity being defined as (particle cross-sectional area/envelope-inside area).

公开(公告)号：US20180361474A9

公开(公告)日：2018-12-20

申请号：US15737429

申请日：2016-07-28

Applicant: JFE STEEL CORPORATION ,  JFE PRECISION CORPORATION ,  TOKIN CORPORATION ,  National Institute of Advanced Industrial Science and Technology

Inventor： Naomichi NAKAMURA ,  Makoto NAKASEKO ,  Takuya TAKASHITA ,  Mineo MURAKI ,  Hoshiaki TERAO ,  Raita WADA ,  Akiri URATA ,  Yu KANAMORI ,  Makoto YAMAKI ,  Koichi OKAMOTO ,  Toshinori TSUDA ,  Shoichi SATO ,  Kimihiro OZAKI

IPC: B22F3/14 ,  C22C45/02 ,  C22C38/16 ,  C22C38/02 ,  C22C38/00 ,  B22F1/02 ,  H01F1/153 ,  H01F41/02

Abstract: Provided is a soft magnetic dust core having high density and favorable properties. A method of manufacturing a soft magnetic dust core includes: preparing coated powder including amorphous powder made of an Fe—B—Si—P—C—Cu-based alloy, an Fe—B—P—C—Cu-based alloy, an Fe—B—Si—P—Cu-based alloy, or an Fe—B—P—Cu-based alloy, with a first initial crystallization temperature Tx1 and a second initial crystallization temperature Tx2; and a coating formed on a surface of particles of the amorphous powder; applying a compacting pressure to the coated powder or a mixture of the coated powder and the amorphous powder at a temperature equal to or lower than Tx1−100 K; and heating to a maximum end-point temperature equal to or higher than Tx1−50 K and lower than Tx2 with the compacting pressure being applied.

公开(公告)号：US20180169759A1

公开(公告)日：2018-06-21

申请号：US15737429

申请日：2016-07-28

Applicant: JFE STEEL CORPORATION ,  JFE PRECISION CORPORATION ,  TOKIN CORPORATION ,  National Institute of Advanced Industrial Science and Technology

Inventor： Naomichi NAKAMURA ,  Makoto NAKASEKO ,  Takuya TAKASHITA ,  Mineo MURAKI ,  Hoshiaki TERAO ,  Raita WADA ,  Akiri URATA ,  Yu KANAMORI ,  Makoto YAMAKI ,  Koichi OKAMOTO ,  Toshinori TSUDA ,  Shoichi SATO ,  Kimihiro OZAKI

IPC: B22F3/14 ,  C22C45/02 ,  C22C38/16 ,  C22C38/02 ,  C22C38/00 ,  B22F1/02 ,  H01F1/153 ,  H01F41/02

CPC classification number: B22F3/14 ,  B22F1/00 ,  B22F1/02 ,  B22F3/00 ,  B22F3/02 ,  B22F3/03 ,  B22F2301/35 ,  B22F2304/10 ,  C22C33/02 ,  C22C38/00 ,  C22C38/002 ,  C22C38/02 ,  C22C38/16 ,  C22C45/02 ,  C22C2200/02 ,  C22C2200/04 ,  C22C2202/02 ,  H01F1/15308 ,  H01F1/15325 ,  H01F1/15333 ,  H01F1/15375 ,  H01F3/08 ,  H01F27/255 ,  H01F41/0246

Abstract: Provided is a soft magnetic dust core having high density and favorable properties. A method of manufacturing a soft magnetic dust core includes: preparing coated powder including amorphous powder made of an Fe—B—Si—P—C—Cu-based alloy, an Fe—B—P—C—Cu-based alloy, an Fe—B—Si—P—Cu-based alloy, or an Fe—B—P—Cu-based alloy, with a first initial crystallization temperature Tx1 and a second initial crystallization temperature Tx2; and a coating formed on a surface of particles of the amorphous powder; applying a compacting pressure to the coated powder or a mixture of the coated powder and the amorphous powder at a temperature equal to or lower than Tx1−100 K; and heating to a maximum end-point temperature equal to or higher than Tx1−50 K and lower than Tx2 with the compacting pressure being applied.