公开(公告)号：US20210310096A1

公开(公告)日：2021-10-07

申请号：US17349912

申请日：2021-06-17

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi OMURA ,  Hirotaka INOUE ,  Seiji OKABE

IPC: C21D9/46 ,  C22C38/60 ,  C21D8/12 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  G01R33/18 ,  C23C22/38 ,  H01F1/18 ,  C23C22/74 ,  C21D3/04 ,  C21D6/00 ,  C21D8/00 ,  C23C22/08 ,  G01H9/00 ,  H01F10/08

Abstract: Provided is a method for manufacturing a grain-oriented electrical steel sheet. The method comprises: hot rolling a slab to obtain a hot rolled sheet; subjecting the hot rolled sheet to hot band annealing as necessary; subjecting the hot rolled sheet to cold rolling; subjecting the cold rolled sheet to decarburization annealing; applying an annealing separator having MgO as a main component onto a surface of the decarburization annealed sheet and subjecting the decarburization annealed sheet to final annealing to form the forsterite film; and applying an insulating coating treatment liquid onto the final annealed sheet and subjecting the final annealed sheet to flattening annealing to form a tension-applying insulating coating. A difference in total tensions between one and opposite surfaces of the sheet is less than 0.5 MPa. A difference in tensions between the forsterite films in one and opposite surfaces of the sheet is 0.5 MPa or more.

公开(公告)号：US20210043358A1

公开(公告)日：2021-02-11

申请号：US16966256

申请日：2019-01-31

Applicant: JFE STEEL CORPORATION

Inventor： Hirotaka INOUE ,  Seiji OKABE ,  Takeshi OMURA

IPC: H01F27/245 ,  H01F41/02 ,  H01F1/147

Abstract: A grain-oriented electrical steel sheet for a wound 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 60% or less; (ii) when 0.20 mm

公开(公告)号：US20200087746A1

公开(公告)日：2020-03-19

申请号：US16468087

申请日：2017-12-14

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi OMURA ,  Hirotaka INOUE ,  Kunihiro SENDA ,  Seiji OKABE

IPC: C21D9/46 ,  C22C38/60 ,  C22C38/44 ,  C22C38/34 ,  C22C38/04 ,  C22C38/00 ,  C21D8/12 ,  C21D8/00 ,  C21D6/00 ,  C21D3/04 ,  H01F1/147 ,  H01F27/245 ,  H01F41/02

Abstract: Provided is a grain-oriented electrical steel sheet having better transformer iron loss property than conventional grain-oriented electrical steel sheets. A grain-oriented electrical steel sheet comprises: a steel substrate; a forsterite film on a surface of the steel substrate; and a Cr-depleted layer at a boundary between the steel substrate and the forsterite film, the Cr-depleted layer having a Cr concentration that is 0.70 times to 0.90 times a Cr concentration of the steel substrate.

公开(公告)号：US20230178276A1

公开(公告)日：2023-06-08

申请号：US17998356

申请日：2021-03-04

Applicant: JFE STEEL CORPORATION

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

IPC: H01F1/16

CPC classification number: H01F1/16 ,  C22C2202/02 ,  C22C38/60

Abstract: Provided is a linear groove formation pattern with which both an effect of reducing the building factor and a high magnetic flux density can be obtained. In a grain-oriented electrical steel sheet having a plurality of linear grooves extending in a direction crossing a rolling direction of the steel sheet on a surface of the steel sheet, a surface of the steel sheet between the linear grooves has a recessed defect that is recessed from the surface, a volume fraction of the recessed defect in the steel sheet is 0.0025 vol % or more and 0.01 vol % or less of a steel sheet without the recessed defect, and discontinuous portions that disrupt the extension of the linear grooves are provided at a frequency of 30 or more and 200 or less per square meter of the steel sheet.

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：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：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：US20230212706A1

公开(公告)日：2023-07-06

申请号：US17998926

申请日：2021-03-26

Applicant: JFE STEEL CORPORATION

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

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

CPC classification number: C21D9/46 ,  C21D8/1255 ,  C21D8/1283 ,  C21D8/1222 ,  C21D8/1233 ,  C21D6/008 ,  C21D8/1294 ,  C21D8/1272 ,  H01F1/16

Abstract: Provided is a grain-oriented electrical steel sheet which has been subjected to heat-resistant magnetic domain refining treatment and can effectively suppress carburizing and nitriding during stress relief annealing. The grain-oriented electrical steel sheet has a plurality of grooves on one side that extend linearly across the rolling direction and are lined up at intervals in the rolling direction, and has at least a forsterite film on a surface of the steel sheet, where an average thickness of the forsterite film formed on the floor of the grooves is 0.45 μm or more, and a standard deviation a of the thickness is 0.34 μm or less.

公开(公告)号：US20220267872A1

公开(公告)日：2022-08-25

申请号：US17630853

申请日：2020-07-03

Applicant: JFE STEEL CORPORATION

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

IPC: C21D8/12

Abstract: A linear groove formation method including forming a coated resist on a surface of a steel sheet, irradiating two or more laser beams onto the surface of the steel sheet while scanning the laser beams in a direction intersecting the rolling direction of the steel sheet cyclically in a rolling direction of the steel sheet, and forming linear grooves by etching portions of the steel sheet. In the laser irradiating process, the coated resist is removed continuously in a sheet transverse direction of the steel sheet by using the laser beams irradiated from respective ones of two or more laser irradiation devices arranged in the sheet transverse direction, and the laser beams are irradiated by shifting centers of two of the laser beams irradiated from two of the laser two of the laser irradiation devices adjacent to each other in the sheet transverse direction.

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.