公开(公告)号：US20230304123A1

公开(公告)日：2023-09-28

申请号：US18041798

申请日：2021-08-18

Applicant: JFE STEEL CORPORATION

Inventor： Kunihiro SENDA ,  Yoshihisa ICHIHARA ,  Takeshi OMURA

IPC: C21D10/00

CPC classification number: C21D10/005 ,  C21D2201/05 ,  C21D2221/00

Abstract: To provide a grain-oriented electrical steel sheet that can achieve both sufficiently low transformer core loss and sufficiently low noise. Disclosed is a grain-oriented electrical steel sheet having a tension coating on a surface thereof and subjected to magnetic domain refining treatment by generating linear closure domains extending in a direction within 30° of a transverse direction, in which an average interval L between adjacent closure domains is 15 mm or less, a depth ratio rd of a depth of the closure domains to a sheet thickness, calculated by a predetermined formula, is 35% or more, and a volume fraction rv of the closure domains, calculated by a predetermined formula, is 0.30% or more and 3.0% or less, and an area ratio rs of the closure domains, calculated by a predetermined formula, is 0.50% or more and 4.0% or less.

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：US20230212703A1

公开(公告)日：2023-07-06

申请号：US17997044

申请日：2021-03-26

Applicant: JFE STEEL CORPORATION

Inventor： Ryuichi SUEHIRO ,  Takeshi OMURA ,  Shigehiro TAKAJO ,  Yoshihisa ICHIHARA

IPC: C21D8/12 ,  C21D9/46 ,  C22C38/60 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/00 ,  B23K26/364 ,  B23K26/402 ,  H01F1/16

CPC classification number: C21D8/1277 ,  C21D9/46 ,  C21D8/1222 ,  C21D8/1233 ,  C21D8/1261 ,  C21D8/1272 ,  C22C38/60 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/001 ,  C22C38/002 ,  B23K26/364 ,  B23K26/402 ,  H01F1/16 ,  C22C2202/02

Abstract: To form linear grooves of desired groove width on a metal strip surface and provide a grain-oriented electrical steel sheet having excellent magnetic properties, a linear groove formation method comprises: forming a resist coating on at least one surface of a metal strip; thereafter irradiating the resist coating with a laser while scanning the laser in a direction crossing a rolling direction of the metal strip, to remove the resist coating in a part irradiated with the laser; and thereafter performing etching treatment to form a linear groove in a part of the metal strip in which the resist coating is removed, wherein the resist coating contains a predetermined amount of an inorganic compound, and on the surface of the metal strip, the laser has a predetermined elliptic beam shape.

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.

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