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：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：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：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：US20170315093A1

公开(公告)日：2017-11-02

申请号：US15521406

申请日：2015-11-02

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi OMURA ,  Yoshiaki ZAIZEN ,  Kunihiro SENDA

IPC: G01N27/72 ,  G01R33/12

CPC classification number: G01N27/72 ,  G01R33/12 ,  H01F1/16

Abstract: To predict the iron loss of a non-oriented electrical steel sheet after shearing, a non-oriented electrical steel sheet is sheared to a certain width, and iron loss Wt(B0) of the non-oriented electrical steel sheet after shearing is estimated according to a predetermined relational expression based on iron loss Wn(B1) in a non-machining-affected zone in which no machining strain is introduced by the shearing and iron loss Wi(B2) in a machining affected zone in which machining strain is introduced.