Patents by Inventor Seiji Okabe
Seiji Okabe has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11984249Abstract: 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<t<0.27 mm, the iron loss deterioration ratio is 55% or less; and (iii) when 0.27 mm?t, the iron loss deterioration ratio is 50% or less. The iron loss deterioration ratio is calculated from ((WA?WB)/WB)×100, where WA is iron loss under 50 Hz elliptic magnetization of 1.7 T in a rolling direction and 0.6 T in a direction orthogonal to the rolling direction, and WB is iron loss under 50 Hz alternating magnetization of 1.7 T in the rolling direction.Type: GrantFiled: January 31, 2019Date of Patent: May 14, 2024Assignee: JFE STEEL CORPORATIONInventors: Hirotaka Inoue, Seiji Okabe, Takeshi Omura
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Patent number: 11961647Abstract: 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.Type: GrantFiled: March 29, 2019Date of Patent: April 16, 2024Assignee: JFE STEEL CORPORATIONInventors: Takeshi Omura, Hirotaka Inoue, Seiji Okabe
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Patent number: 11961659Abstract: 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.Type: GrantFiled: March 29, 2019Date of Patent: April 16, 2024Assignee: JFE STEEL CORPORATIONInventors: Takeshi Omura, Hirotaka Inoue, Seiji Okabe
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Patent number: 11767571Abstract: 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.Type: GrantFiled: March 8, 2017Date of Patent: September 26, 2023Assignee: JFE STEEL CORPORATIONInventors: Takeshi Omura, Hirotaka Inoue, Shigehiro Takajo, Seiji Okabe
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Patent number: 11572602Abstract: 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.Type: GrantFiled: June 17, 2021Date of Patent: February 7, 2023Assignee: JFE STEEL CORPORATIONInventors: Takeshi Omura, Hirotaka Inoue, Seiji Okabe
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Patent number: 11566302Abstract: 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.Type: GrantFiled: December 14, 2017Date of Patent: January 31, 2023Assignee: JFE STEEL CORPORATIONInventors: Takeshi Omura, Hirotaka Inoue, Kunihiro Senda, Seiji Okabe
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Patent number: 11495378Abstract: 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<t<0.27 mm, the iron loss deterioration ratio is 80% or less; and (iii) when 0.27 mm?t, the iron loss deterioration ratio is 75% or less. The iron loss deterioration ratio is calculated from ((WA?WB)/WB)×100, where WA is iron loss under 50 Hz elliptic magnetization of 1.7 T in a rolling direction and 1.0 T in a direction orthogonal to the rolling direction, and WB is iron loss under 50 Hz alternating magnetization of 1.7 T in the rolling direction.Type: GrantFiled: January 31, 2019Date of Patent: November 8, 2022Assignee: JFE STEEL CORPORATIONInventors: Hirotaka Inoue, Seiji Okabe, Takeshi Omura
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Patent number: 11430599Abstract: 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.Type: GrantFiled: March 29, 2018Date of Patent: August 30, 2022Assignee: JFE STEEL CORPORATIONInventors: Seiji Okabe, Takeshi Omura, Hirotaka Inoue
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Patent number: 11377706Abstract: This device scans a high-energy beam in a direction traversing a feed path of a grain-oriented electrical steel sheet having subjected to final annealing so as to irradiate a surface of the steel sheet being passed through with the high-energy beam to thereby perform magnetic domain refinement, the device including an irradiation mechanism for scanning the high-energy beam in a direction orthogonal to the feed direction of the steel sheet, in which the irradiation mechanism has a function of having the scanning direction of the high-energy beam oriented diagonally, relative to the orthogonal direction, toward the feed direction at an angle determined based on a sheet passing speed of the steel sheet on the feed path.Type: GrantFiled: June 15, 2020Date of Patent: July 5, 2022Assignee: JFE STEEL CORPORATIONInventors: Seiji Okabe, Shigehiro Takajo, Yasushi Kitani
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Patent number: 11255007Abstract: There is provided an amorphous alloy thin strip having a chemical composition represented by a chemical formula: FexBySiz (x: 78-83 at %, y: 8-15 at % and z: 6-13 at %) capable of stably attaining a low iron loss even when shaped into a wound core, wherein a generation density of air pockets on a face contacting with a cooling roll is not more than 8 per 1 mm2 and an arithmetic mean height Sa on portions other than the air pockets is not more than 0.3 ?m.Type: GrantFiled: February 7, 2017Date of Patent: February 22, 2022Assignee: JFE Steel CorporationInventors: Seiji Okabe, Takeshi Imamura, Katsumi Yamada
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Patent number: 11198916Abstract: 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 ?r15/50 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/?m 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.Type: GrantFiled: September 25, 2018Date of Patent: December 14, 2021Assignee: JFE STEEL CORPORATIONInventors: Kunihiro Senda, Makoto Watanabe, Seiji Okabe, Souichiro Yoshizaki
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Publication number: 20210310096Abstract: 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.Type: ApplicationFiled: June 17, 2021Publication date: October 7, 2021Applicant: JFE STEEL CORPORATIONInventors: Takeshi OMURA, Hirotaka INOUE, Seiji OKABE
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Publication number: 20210207252Abstract: There is provided an amorphous alloy thin strip having a chemical composition represented by a chemical formula: FexBySiz (x: 78-83 at %, y: 8-15 at % and z: 6-13 at %) capable of stably attaining a low iron loss even when shaped into a wound core, wherein a generation density of air pockets on a face contacting with a cooling roll is not more than 8 per 1 mm2 and an arithmetic mean height Sa on portions other than the air pockets is not more than 0.3 ?m.Type: ApplicationFiled: February 7, 2017Publication date: July 8, 2021Applicant: JFE Steel CorporationInventors: Seiji Okabe, Takeshi Imamura, Katsumi Yamada
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Publication number: 20210043358Abstract: 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<t<0.27 mm, the iron loss deterioration ratio is 55% or less; and (iii) when 0.27 mm?t, the iron loss deterioration ratio is 50% or less. The iron loss deterioration ratio is calculated from ((WA?WB)/WB)×100, where WA is iron loss under 50 Hz elliptic magnetization of 1.7 T in a rolling direction and 0.6 T in a direction orthogonal to the rolling direction, and WB is iron loss under 50 Hz alternating magnetization of 1.7 T in the rolling direction.Type: ApplicationFiled: January 31, 2019Publication date: February 11, 2021Applicant: JFE STEEL CORPORATIONInventors: Hirotaka INOUE, Seiji OKABE, Takeshi OMURA
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Publication number: 20210027939Abstract: 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.Type: ApplicationFiled: March 29, 2019Publication date: January 28, 2021Applicant: JFE STEEL CORPORATIONInventors: Takeshi OMURA, Hirotaka INOUE, Seiji OKABE
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Publication number: 20210020349Abstract: 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.Type: ApplicationFiled: March 29, 2019Publication date: January 21, 2021Applicant: JFE STEEL CORPORATIONInventors: Takeshi OMURA, Hirotaka INOUE, Seiji OKABE
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Publication number: 20200373046Abstract: 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<t<0.27 mm, the iron loss deterioration ratio is 80% or less; and (iii) when 0.27 mm?t, the iron loss deterioration ratio is 75% or less. The iron loss deterioration ratio is calculated from ((WA?WB)/WB)×100, where WA is iron loss under 50 Hz elliptic magnetization of 1.7 T in a rolling direction and 1.0 T in a direction orthogonal to the rolling direction, and WB is iron loss under 50 Hz alternating magnetization of 1.7 T in the rolling direction.Type: ApplicationFiled: January 31, 2019Publication date: November 26, 2020Applicant: JFE STEEL CORPORATIONInventors: Hirotaka INOUE, Seiji OKABE, Takeshi OMURA
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Publication number: 20200332380Abstract: This device scans a high-energy beam in a direction traversing a feed path of a grain-oriented electrical steel sheet having subjected to final annealing so as to irradiate a surface of the steel sheet being passed through with the high-energy beam to thereby perform magnetic domain refinement, the device including an irradiation mechanism for scanning the high-energy beam in a direction orthogonal to the feed direction of the steel sheet, in which the irradiation mechanism has a function of having the scanning direction of the high-energy beam oriented diagonally, relative to the orthogonal direction, toward the feed direction at an angle determined based on a sheet passing speed of the steel sheet on the feed path.Type: ApplicationFiled: June 15, 2020Publication date: October 22, 2020Inventors: Seiji OKABE, Shigehiro TAKAJO, Yasushi KITANI
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Publication number: 20200283863Abstract: 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 ?r15/50 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/?m 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.Type: ApplicationFiled: September 25, 2018Publication date: September 10, 2020Applicant: JFE STEEL CORPORATIONInventors: Kunihiro SENDA, Makoto WATANABE, Seiji OKABE, Souichiro YOSHIZAKI
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Patent number: 10745773Abstract: This device scans a high-energy beam in a direction traversing a feed path of a grain-oriented electrical steel sheet having subjected to final annealing so as to irradiate a surface of the steel sheet being passed through with the high-energy beam to thereby perform magnetic domain refinement, the device including an irradiation mechanism for scanning the high-energy beam in a direction orthogonal to the feed direction of the steel sheet, in which the irradiation mechanism has a function of having the scanning direction of the high-energy beam oriented diagonally, relative to the orthogonal direction, toward the feed direction at an angle determined based on a sheet passing speed of the steel sheet on the feed path.Type: GrantFiled: December 25, 2012Date of Patent: August 18, 2020Assignee: JFE STEEL CORPORATIONInventors: Seiji Okabe, Shigehiro Takajo, Yasushi Kitani