公开(公告)号：US20210020349A1

公开(公告)日：2021-01-21

申请号：US17041442

申请日：2019-03-29

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi OMURA ,  Hirotaka INOUE ,  Seiji OKABE

IPC: H01F27/245 ,  H01F1/16 ,  C21D8/12 ,  C21D6/00

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; (2) has an area ratio R0 of 0.10% to 3.0%, the area ratio R0 being defined as a ratio of S0 to S; and (3) has an area ratio R1a of 50% or more, the area ratio R1a being defined as a ratio of S1a to S1.

公开(公告)号：US20200373046A1

公开(公告)日：2020-11-26

申请号：US16966268

申请日：2019-01-31

Applicant: JFE STEEL CORPORATION

Inventor： Hirotaka INOUE ,  Seiji OKABE ,  Takeshi OMURA

IPC: H01F1/16 ,  H01F27/245 ,  H01F41/02 ,  C22C38/44 ,  C22C38/42 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00

Abstract: A grain-oriented electrical steel sheet for a stacked transformer core. The steel sheet having a sheet thickness t, where t and an iron loss deterioration ratio obtained by subjecting the steel sheet under elliptic magnetization satisfy the following relations: (i) when t 0.20 mm, the iron loss deterioration ratio is 85% or less; (ii) when 0.20 mm

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：US20190017139A1

公开(公告)日：2019-01-17

申请号：US16081121

申请日：2017-03-08

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi OMURA ,  Hirotaka INOUE ,  Shigehiro TAKAJO ,  Seiji OKABE

IPC: C21D8/12 ,  H01F1/147

Abstract: To reduce variations in iron loss among materials subjected to magnetic domain refining by electron beam irradiation and to stably obtain good iron loss properties, disclosed is a method of producing a grain-oriented electrical steel sheet including performing magnetic domain refining treatment by irradiating with an electron beam, in a pressure reduced area, a surface of a grain-oriented electrical steel sheet after subjection to final annealing, the method further including: before the irradiating with the electron beam, delivering the grain-oriented electrical steel sheet wound in a coil shape and heating the delivered grain-oriented electrical steel sheet to 50° C. or higher; and then cooling the grain-oriented electrical steel sheet such that the grain-oriented electrical steel sheet has a temperature of lower than 50° C. at the time of entering the pressure reduced area.

公开(公告)号：US20180221941A1

公开(公告)日：2018-08-09

申请号：US15750133

申请日：2016-07-20

Applicant: JFE STEEL CORPORATION

Inventor： Seiji OKABE ,  Takeshi IMAMURA ,  Shigehiro TAKAJO

IPC: B22D11/06

Abstract: A single roll type apparatus manufactures a metal thin strip by injecting a molten metal onto a cooling roll outer peripheral face solidifying it to manufacture the strip. An airflow blocking device for blocking the airflow along the cooling roll surface is at a molten metal injection nozzle upstream side for injecting the molten metal in the cooling roll rotation direction, and a carbon dioxide gas injection nozzle for forming a carbon dioxide flow on the cooling roll outer peripheral surface between the airflow blocking device and molten metal injection nozzle or forming a carbon dioxide atmosphere on the cooling roll surface between the airflow blocking device and the molten metal injection nozzle is disposed, and a foreign material removal device for removing foreign material attached to the cooling roll surface is disposed at an upstream side of the airflow blocking device in the rotation direction of the cooling roll.

公开(公告)号：US20160133368A1

公开(公告)日：2016-05-12

申请号：US14894697

申请日：2014-05-27

Applicant: JFE STEEL CORPORATION

Inventor： Seiji OKABE ,  Hirotaka INOUE ,  Shigehiro TAKAJO

IPC: H01F3/02 ,  C22C38/08 ,  C21D8/12 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C22C38/60 ,  C22C38/06

CPC classification number: H01F3/02 ,  C21D8/125 ,  C21D8/1277 ,  C21D8/1288 ,  C22C38/00 ,  C22C38/001 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/18 ,  C22C38/60 ,  H01F1/16 ,  H01F27/245

Abstract: A grain-oriented electrical steel sheet subjected to magnetic domain refining by linearly introducing strains in a direction intersecting a rolling direction of the steel sheet repeatedly with intervals in the rolling direction, wherein if a repeating interval of the strains in the rolling direction is d (mm) and, when the steel sheet is placed on a flat surface, a mean value of difference between a height from the flat surface in linear strain-introduced areas of a steel sheet surface and a height from the flat surface in intermediate points between adjacent linear strain-introduced areas is h (mm), then the ratio h/d of the h to the d is 0.0025 or more and 0.015 or less.

Abstract translation: 通过以与轧制方向间隔反复地沿与钢板的轧制方向交叉的方向线性地引入应变而进行磁畴精制的晶粒取向电工钢板，其中如果轧制方向上的应变的重复间隔为d（ mm），并且当钢板被放置在平坦表面上时，在相邻的中间点之间的钢板表面的线性应变导入区域中的平坦表面的高度与来自平坦表面的高度之间的差的平均值 线性应变导入面积为h（mm），则h与d的比率h / d为0.0025以上且0.015以下。

公开(公告)号：US20200283863A1

公开(公告)日：2020-09-10

申请号：US16648663

申请日：2018-09-25

Applicant: JFE STEEL CORPORATION

Inventor： Kunihiro SENDA ,  Makoto WATANABE ,  Seiji OKABE ,  Souichiro YOSHIZAKI

IPC: C21D8/12 ,  C21D9/46 ,  C21D6/00 ,  C22C38/60 ,  C22C38/16 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  H01F1/16

Abstract: Further lower iron loss can be achieved in a grain-oriented electrical steel sheet including: a predetermined film mainly composed of forsterite on a front and back surfaces thereof; and a plurality of grooves on the front surface thereof, in which the plurality of grooves have an average depth of 6% or more of a thickness of the steel sheet and are spaced a distance of 1 mm to 15 mm from respective adjacent grooves, the steel sheet has a specific magnetic permeability μr15/50 of 35000 or more when subjected to alternating current magnetization at a frequency of 50 Hz and a maximum magnetic flux density of 1.5 T, and the steel sheet includes isolated parts having a presence frequency of 0.3/μm or less, the isolated parts being separated from a continuous part of the film in an interface between the steel sheet and the film in a cross section orthogonal to the rolling direction of the steel sheet.

公开(公告)号：US20180119244A1

公开(公告)日：2018-05-03

申请号：US15547677

申请日：2016-02-05

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi OMURA ,  Hirotaka INOUE ,  Seiji OKABE

IPC: C21D9/46 ,  C22C38/60 ,  C22C38/44 ,  C22C38/42 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/12 ,  C21D8/00 ,  C21D6/00 ,  C21D3/04 ,  C23C22/08 ,  G01R33/18 ,  G01H9/00 ,  H01F10/08 ,  H01F27/33

Abstract: Provided is a grain-oriented electrical steel sheet having an excellent noise property in an actual transformer. Magnetostrictive properties of the grain-oriented electrical steel sheet are set such that the number of acceleration/deceleration points that are present in the magnetostriction velocity level dλ/dt in one period of magnetostrictive vibration is 4 and the magnitude of velocity level change between adjacent velocity change points in an acceleration zone or deceleration zone of magnetostrictive vibration is 3.0×10−4 sec−1 or less.

公开(公告)号：US20180037965A1

公开(公告)日：2018-02-08

申请号：US15552297

申请日：2016-02-12

Applicant: JFE STEEL CORPORATION

Inventor： Shigehiro TAKAJO ,  Takeshi OMURA ,  Seiji OKABE

IPC: C21D8/12 ,  H01F1/16 ,  H01F27/245

CPC classification number: C21D8/1294 ,  C21D8/12 ,  C21D8/1288 ,  C21D9/46 ,  C21D2201/05 ,  H01F1/16 ,  H01F27/245

Abstract: Disclosed are a grain-oriented electrical steel sheet having strain regions extending in a direction transverse to a rolling direction at periodic interval s (mm) in the rolling direction. Each strain region has a closure domain region whose width in the rolling direction varies periodically on a steel sheet surface. Each closure domain region satisfies: Wmax/Wmin=1.2 or more and less than 2.5, where Wmax and Wmin respectively denote a maximum width and a minimum width on the steel sheet surface as measured in the rolling direction; Wave being 80 μm or more, where Wave denotes an average width on the steel sheet surface as measured in the rolling direction; D being 32 μm or more, where D denotes a maximum depth as measured in the sheet thickness direction; and (Wave*D)/s being 0.0007 mm or more and 0.0016 mm or less.