公开(公告)号：US20240321492A1

公开(公告)日：2024-09-26

申请号：US18580493

申请日：2022-06-08

Applicant: JFE STEEL CORPORATION

Inventor： Hirotaka INOUE ,  Takeshi OMURA ,  Kunihiro SENDA

IPC: H01F1/147 ,  C21D1/30 ,  C21D6/00 ,  C21D10/00 ,  H01F27/245

CPC classification number: H01F1/14783 ,  C21D1/30 ,  C21D6/00 ,  C21D10/00 ,  H01F27/245 ,  C21D2201/05

Abstract: A wound core with low transformer iron loss and good magnetic characteristics without using two or more types of materials with different magnetic characteristics. The wound core includes a grain-oriented electrical steel sheet as a material and has a flat surface portion, a corner portion adjacent to the flat surface portion, a lap portion in the flat surface portion, and a bent portion in the corner portion, and the ratio of the length of the outer circumference to the length of the inner circumference (the length of the outer circumference/the length of the inner circumference) is 1.70 or less when viewed from the side, and the grain-oriented electrical steel sheet has a magnetic flux density B8 in the range of 1.92 T to 1.98 T at a magnetic field strength H of 800 A/m and has a specified iron loss deterioration rate of 1.30 or less under harmonic superposition.

公开(公告)号：US20230042199A1

公开(公告)日：2023-02-09

申请号：US17757776

申请日：2020-12-23

Applicant: JFE STEEL CORPORATION

Inventor： Yoshihisa ICHIHARA ,  Takeshi OMURA ,  Kunihiro SENDA

IPC: C21D9/46 ,  C21D6/00 ,  C21D1/34 ,  H01F1/16 ,  H01F41/02

Abstract: Provided is a grain-oriented electrical steel sheet having both low iron loss and good magnetostrictive properties, with which a transformer having excellent properties can be manufactured. The grain-oriented electrical steel sheet of the present disclosure has a linear strain region extending linearly in a direction intersecting the rolling direction, where the linear strain region has a region having compressive stress in the rolling direction, and a region adjacent in a rolling direction to the region having compressive stress has a region having tensile stress in the rolling direction.

公开(公告)号：US20220020514A1

公开(公告)日：2022-01-20

申请号：US17298672

申请日：2019-11-21

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi OMURA ,  Yoshihisa ICHIHARA ,  Kunihiro SENDA ,  Takahiro KOSHIHARA

IPC: H01F1/147 ,  C21D9/46 ,  C21D6/00 ,  C21D1/34 ,  C22C38/34 ,  C22C38/60 ,  C22C38/22 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00

Abstract: Disclosed is a grain-oriented electrical steel sheet with extremely low iron loss by means of a magnetic domain refining technique. In a grain-oriented electrical steel sheet having a plurality of magnetic domains refined via a local strain introduction portion, when a direct-current external magnetic field is applied to the steel sheet in a rolling direction, for a magnetic flux leaked from the local strain introduction portion at a position 1.0 mm away from a surface of the steel sheet at a side of the local strain introduction portion, a value obtained by dividing an intensity level of a total leakage magnetic flux by an intensity level of a magnetic flux leaked due to causes other than strain is more than 1.2.

公开(公告)号：US20210027939A1

公开(公告)日：2021-01-28

申请号：US17042182

申请日：2019-03-29

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi OMURA ,  Hirotaka INOUE ,  Seiji OKABE

IPC: H01F41/02 ,  H01F1/16 ,  H01F27/245

Abstract: Vibration of an iron core is reduced to reduce transformer noise. An iron core for a transformer comprises a plurality of grain-oriented electrical steel sheets stacked together, wherein at least one of the plurality of grain-oriented electrical steel sheets: (1) has a region in which closure domains are formed in a direction crossing a rolling direction and a region in which no closure domains are formed; and (2) has an area ratio R of 0.10% to 30%, the area ratio R being an area ratio, to the whole grain-oriented electrical steel sheet, of a region in which a shrinkage amount at a maximum displacement point when excited in the rolling direction at a maximum magnetic flux density of 1.7 T and a frequency of 50 Hz is at least 2×10−7 less than a shrinkage amount in the region in which no closure domains are formed.

公开(公告)号：US20200051731A1

公开(公告)日：2020-02-13

申请号：US16486505

申请日：2018-03-29

Applicant: JFE STEEL CORPORATION

Inventor： Seiji OKABE ,  Takeshi OMURA ,  Hirotaka INOUE

IPC: H01F27/245

Abstract: Iron core vibration and transformer noise can be reduced by using, as a transformer iron core, an iron core formed by a stack of at least two types of grain-oriented electrical steel sheets that differ in magnetostriction by 2×10−7 or more when excited from 0 T to 1.7 T.

公开(公告)号：US20190189318A1

公开(公告)日：2019-06-20

申请号：US16065352

申请日：2016-12-14

Applicant: JFE STEEL CORPORATION

Inventor： Masanori UESAKA ,  Kunihiro SENDA ,  Takeshi OMURA

IPC: H01F1/16 ,  C21D8/12 ,  C21D1/76 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  H01F1/147

CPC classification number: H01F1/16 ,  C21D1/76 ,  C21D8/1222 ,  C21D8/1233 ,  C21D8/1261 ,  C21D8/1266 ,  C21D8/1272 ,  C21D9/46 ,  C22C38/00 ,  C22C38/004 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C22C38/60 ,  H01F1/147 ,  H01F1/14775

Abstract: A non-oriented electrical steel sheet has low iron loss even under inverter excitation and can be suitably used as the iron core of a motor. The non-oriented electrical steel sheet has a specific chemical composition and an average grain size r of 40 μm to 120 μm. An area ratio R of a total area of grains having a grain size of ⅙ or less of the thickness of the steel sheet to a cross-sectional area of the steel sheet is 2% or greater, and the average grain size r (μm) and the area ratio R (%) satisfy a condition represented by Expression (1), R>−2.4×r+200 (1).

公开(公告)号：US20190013126A1

公开(公告)日：2019-01-10

申请号：US16068121

申请日：2017-01-24

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi OMURA ,  Shigehiro TAKAJO ,  Hirotaka INOUE

IPC: H01F1/18 ,  C21D9/46 ,  C21D8/12 ,  H01F41/22

Abstract: An excellent low noise property and excellent low iron loss property are obtained. A grain-oriented electrical steel sheet includes refined magnetic domains formed by electron beam irradiation. When the maximum magnetic flux density is 1.7 T, the grain-oriented electrical steel sheet has a residual magnetic flux density of 0.1 to 0.7 times the residual magnetic flux density before the electron beam irradiation and a maximum magnetizing force of 1.1 to 2.0 times the maximum magnetizing force before the electron beam irradiation.

公开(公告)号：US20250154618A1

公开(公告)日：2025-05-15

申请号：US19020031

申请日：2025-01-14

Applicant: JFE STEEL CORPORATION

Inventor： Hirotaka INOUE ,  Takeshi OMURA ,  Yoshihisa ICHIHARA ,  Shigehiro TAKAJO ,  Kunihiro SENDA

IPC: C21D9/46 ,  C21D6/00 ,  C21D8/12 ,  H01F1/16

Abstract: A method of manufacturing a grain-oriented electrical steel sheet includes sequentially subjecting a slab for grain-oriented electrical steel sheet to hot rolling, cold rolling, decarburization annealing, final annealing after applying an annealing separator to a surface of the steel sheet, and flattening annealing. After the cold rolling and before the applying of an annealing separator, resist ink is applied to one side of the steel sheet. A laser is repeatedly scanned across a rolling direction of the steel sheet on the applied surface to remove resist ink. Electrolytic etching is applied on the removed areas to form grooves that extend linearly across the rolling direction and are lined up at intervals in the rolling direction. The scanning of the laser is performed with an irradiation energy of the laser being less than 30 J/m and a temperature of the steel sheet being 40° C. to 200° C.

公开(公告)号：US20240209483A1

公开(公告)日：2024-06-27

申请号：US18562530

申请日：2022-05-24

Applicant: JFE STEEL CORPORATION

Inventor： Yoshihisa ICHIHARA ,  Takeshi OMURA ,  Kunihiro SENDA

IPC: C22C38/02 ,  C21D8/12 ,  C22C38/04

CPC classification number: C22C38/02 ,  C21D8/1294 ,  C22C38/04 ,  C21D2201/05

Abstract: Disclosed is a grain-oriented electrical steel sheet that exhibits excellent transformer characteristics and that has low iron loss and low magnetostriction properties. The grain-oriented electrical steel sheet has a magnetic flux density B-magnetostriction waveform λ, referred to as a butterfly curve, when excited to 1.5 T or more, such that an amount of steel sheet elongation (Δλ) with a magnetic flux density B ranging from 1.0 T to 1.5 T is 0.010×10−6 or more and 0.240×10−6 or less, and a length of a closure domain in the rolling direction, referred to as a closure domain width, is 20 μm or more and 240 μm or less.

公开(公告)号：US20240011111A1

公开(公告)日：2024-01-11

申请号：US18253922

申请日：2021-09-29

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi OMURA ,  Yoshihisa ICHIHARA ,  Kunihiro SENDA

IPC: C21D8/12 ,  C22C38/02 ,  C22C38/04 ,  C21D10/00

CPC classification number: C21D8/1222 ,  C22C38/02 ,  C22C38/04 ,  C21D8/1233 ,  C21D8/1255 ,  C21D10/005 ,  C21D2201/05

Abstract: Provided is a grain-oriented electrical steel sheet comprising a magnetic flux density B8 of 1.92 T or more, wherein a ratio Wa/Wb of a film thickness Wa of a forsterite film on a strain-introduced surface to a film thickness Wb of a forsterite film on a non-strain-introduced surface is 0.5 or more, an average width of a magnetic domain discontinuous portion on the non-strain-introduced surface is 1.00 time or more of an average width of a magnetic domain discontinuous portion on the strain-introduced surface, the average width of the magnetic domain discontinuous portion on the non-strain-introduced surface is 400 μm or less, and compressive stress exists in a rolling direction in a range from a surface of the steel sheet that is the strain-introduced surface to at least 2 μm in a sheet thickness direction.