公开(公告)号：US20240242864A1

公开(公告)日：2024-07-18

申请号：US18562199

申请日：2022-04-27

Applicant: JFE STEEL CORPORATION

Inventor： Yoshihisa ICHIHARA ,  Takeshi OMURA ,  Kunihiro SENDA

IPC: H01F1/147 ,  B23K26/50 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/60

CPC classification number: H01F1/14783 ,  B23K26/50 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/60 ,  C22C2202/02

Abstract: Provided is a grain-oriented electrical steel sheet that achieves both low iron loss and low magnetostriction and has excellent transformer properties. The grain-oriented electrical steel sheet has a thermal strain-imparted region extending in a direction crossing the rolling direction, where the steel sheet has a closure domain inside the thermal strain-imparted region, the thermal strain-imparted region has maximum points of tensile strain on both outer sides in the rolling direction of the closure domain, and in a strain distribution in the rolling direction of the thermal strain-imparted region, the strain at both outer sides of the closure domain is tensile strain larger than the strain at the center between the maximum points.

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：US20250075300A1

公开(公告)日：2025-03-06

申请号：US18726019

申请日：2022-12-21

Applicant: JFE STEEL CORPORATION

Inventor： Hiroi YAMAGUCHI ,  Takeshi IMAMURA ,  Yoshihisa ICHIHARA ,  Takeshi OMURA

IPC: C22C38/02 ,  C22C38/00 ,  C22C38/04

Abstract: The present disclosure proposes a grain-oriented electrical steel sheet that reduces iron loss by controlling the magnetic domain structure and can maintain the iron loss reduction effect even after subjection to stress relief annealing. The grain-oriented electrical steel sheet comprising a predetermined chemical composition and a local area having a misorientation angle of 1.5 degrees or more from surrounding crystals and extending linearly in a direction crossing a rolling direction on at least one of front and back surfaces of the steel sheet, wherein the local area has a volume fraction of 0.1% or more and 2.0% or less and a residual stress of 100 MPa or less, and the surface having the local area has an average amount of roughness on a steel substrate being less than 5 μm.

公开(公告)号：US20250014800A1

公开(公告)日：2025-01-09

申请号：US18710408

申请日：2022-09-22

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi OMURA ,  Yoshihisa ICHIHARA ,  Souichiro YOSHIZAKI

IPC: H01F27/245 ,  B32B15/01 ,  H02K1/02

Abstract: A laminated core includes a stack of pieces of an electrical steel sheet that have a predetermined shape resulting from processing and includes a butted portion at which portions of a processed surface of the electrical steel sheet are abutted against each other. In the electrical steel sheet, an area ratio of regions of the processed surface that have an arithmetic mean roughness Ra of 5 μm or less is 90% or greater based on a total area of the processed surface.

公开(公告)号：US20240233991A1

公开(公告)日：2024-07-11

申请号：US18562217

申请日：2022-04-27

Applicant: JFE STEEL CORPORATION

Inventor： Yoshihisa ICHIHARA ,  Takeshi OMURA ,  Kunihiro SENDA

IPC: H01F1/147 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/60

CPC classification number: H01F1/14775 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/60 ,  C22C2202/02

Abstract: Provided is a grain-oriented electrical steel sheet that achieves both low iron loss and low magnetostriction and has excellent transformer properties. The grain-oriented electrical steel sheet has a thermal strain-imparted region extending linearly in a direction crossing the rolling direction, and in the strain distribution in the rolling direction of the thermal strain-imparted region, the strain at both ends of the thermal strain-imparted region is tensile strain larger than the strain at the center of the thermal strain-imparted region.

公开(公告)号：US20240052447A1

公开(公告)日：2024-02-15

申请号：US18258210

申请日：2021-09-22

Applicant: JFE STEEL CORPORATION

Inventor： Masanori ODACHI ,  Takeshi OMURA ,  Yoshihisa ICHIHARA

IPC: C21D8/12

CPC classification number: C21D8/1272 ,  C21D8/1233 ,  C21D8/1283 ,  C21D2201/05

Abstract: Provided is a grain-oriented electrical steel sheet that can benefit from the iron loss improving effect by groove formation while effectively suppressing a decrease in magnetic flux density. A grain-oriented electrical steel sheet comprises predetermined linear grooves, wherein in each linear groove, a proportion of predetermined flat portions to an entire length of the linear groove is 30% or more and 90% or less, the number of flat portions each of which is continuous for a predetermined length is 10 or more per 100 cm2 surface area, and a ratio of ten-point average roughness Rzjis to average depth D is 0.1 or more and 1 or less.

公开(公告)号：US20230307160A1

公开(公告)日：2023-09-28

申请号：US18040813

申请日：2021-08-26

Applicant: JFE STEEL CORPORATION

Inventor： Hiroi YAMAGUCHI ,  Takeshi IMAMURA ,  Takeshi OMURA ,  Yoshihisa ICHIHARA

IPC: H01F1/147 ,  C21D8/12 ,  C21D6/00 ,  C22C38/60 ,  C22C38/12 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00 ,  C22C38/04

CPC classification number: H01F1/147 ,  C21D8/1244 ,  C21D6/008 ,  C22C38/60 ,  C22C38/12 ,  C22C38/06 ,  C22C38/02 ,  C22C38/002 ,  C22C38/04 ,  C22C38/001 ,  C22C2202/02

Abstract: Provided is a method for manufacturing a grain-oriented electrical steel sheet to reduce iron loss by controlling the magnetic domain structure, in which the iron loss reduction effect can be maintained even when stress relief annealing is applied, and the magnetic flux density does not decrease after the magnetic domain control treatment. In the manufacturing method, on a surface of the grain oriented electrical steel sheet, a laser beam with a ring-shaped intensity distribution in which the intensity in a periphery is lower than that in a center is irradiated in a linear manner in a direction intersecting a rolling direction of the steel sheet.

公开(公告)号：US20220298599A1

公开(公告)日：2022-09-22

申请号：US17596584

申请日：2020-04-17

Applicant: JFE STEEL CORPORATION

Inventor： Yoshihisa ICHIHARA ,  Takeshi OMURA ,  Kunihiro SENDA

IPC: C21D10/00 ,  H01F1/16

Abstract: Provided is a grain-oriented electrical steel sheet that combines low iron loss and low magnetostriction, together with an advantageous production method therefor. A grain-oriented electrical steel sheet comprises a linear strain portion extending in a direction intersecting a rolling direction of the grain-oriented electrical steel sheet, wherein the linear strain portion has a stress distribution in which a compressive stress region and a tensile stress region alternate in a longitudinal direction of the linear strain portion. The linear strain portion is formed by vibrating the grain-oriented electrical steel sheet in a sheet thickness direction, while irradiating a surface of the grain-oriented electrical steel sheet with an electron beam by repeatedly moving and detaining the electron beam in the direction intersecting the rolling direction of the grain-oriented electrical steel sheet.

公开(公告)号：US20250037921A1

公开(公告)日：2025-01-30

申请号：US18715782

申请日：2022-09-22

Applicant: JFE Steel Corporation

Inventor： Takeshi OMURA ,  Yoshihisa ICHIHARA ,  Souichiro YOSHIZAKI

IPC: H01F27/245 ,  H01F1/147

Abstract: A laminated core is disclosed and includes a stack of pieces of an electrical steel sheet that have a predetermined shape resulting from processing. The electrical steel sheet includes an insulating coating on a surface. A frequency of formation of cracks propagating through the insulating coating in a region extending 100 μm toward a middle of the electrical steel sheet from a processed edge of the electrical steel sheet is less than or equal to 3.0 times the frequency of formation of cracks propagating through the insulating coating in a region extending toward the middle of the electrical steel sheet from a position more than 100 μm from the processed edge to a position 500 μm from the processed edge, where the frequency is expressed as a number per mm.

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.