Patents by Inventor Masahiro Fujikura
Masahiro Fujikura 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: 10214791Abstract: A non-oriented electrical steel sheet containing: in mass%, C: 0.005% or less; Si: 0.1% to 2.0%; Mn: 0.05% to 0.6%; P: 0.100% or less; and Al: 0.5% or less, in which 10 pieces/?m3 or less in number density of non-magnetic precipitate AlN having an average diameter of 10 nm to 200 nm are contained, and an average magnetic flux density B50 in a rolling direction and in a direction perpendicular to rolling is 1.75 T or more. This non-oriented electrical steel sheet can be manufactured by two methods of a method of performing hot rolling annealing at a temperature of 750° C. to an Ac1 transformation point and a method of setting a coil winding temperature to 780° C. or higher and performing self annealing.Type: GrantFiled: May 30, 2017Date of Patent: February 26, 2019Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori
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Publication number: 20180119258Abstract: There is provided a non-oriented magnetic steel sheet according to one aspect of the present invention including a predetermined composition, wherein a structure contains 99.0% by area or more of ferrite grains which do not have an unrecrystallized structure, wherein an average crystal grain size of the ferrite grains is 30 ?m to 180 ?m, wherein the ferrite grains contain metal Cu particles of which a number density is 10,000 to 10,000,000 number/?m3 on the inside thereof, wherein the metal Cu particles on the inside of the ferrite grains contain precipitation particles having a 9R structure of which a number density is 2% to 100% with respect to the number density of the metal Cu particles, and precipitation particles having a bee structure of which a number density is 0% to 98% with respect to the number density of the metal Cu particles, and wherein an average grain size of the metal Cu particles on the inside of the ferrite grains is 2.0 nm to 10.0 nm.Type: ApplicationFiled: April 21, 2016Publication date: May 3, 2018Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masahiro FUJIKURA, Shinichi MATSUI, Shinichi KANAO, Takeo ARAMAKI, Yoshiyuki USHIGAMI
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Patent number: 9934894Abstract: A manufacturing method of a non-oriented electrical steel sheet includes: performing finish annealing of a cold-rolled steel strip; and forming a tension-applying type insulating film of not less than 1 g/m2 and not more than 6 g/m2 on a surface of the cold-rolled steel strip. The performing the finish annealing includes forming an oxide layer containing Al2O3 or (Al, Cr)2O3 and having a thickness of not less than 0.01 ?m and not more than 0.5 ?m on the surface of the cold-rolled steel strip with setting a temperature of the cold-rolled steel strip to not lower than 800° C. and not higher than 1100° C. in an atmosphere where when the total content of Si and Al of the cold-rolled steel strip is represented as X (mass %), a partial pressure ratio of water vapor to hydrogen is equal to or less than 0.005×X2.Type: GrantFiled: October 15, 2015Date of Patent: April 3, 2018Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Shuichi Yamazaki, Takeshi Kubota, Yousuke Kurosaki, Masahiro Fujikura, Takahide Shimazu
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Publication number: 20170260598Abstract: A non-oriented electrical steel sheet containing: in mass%, C: 0.005% or less; Si: 0.1% to 2.0%; Mn: 0.05% to 0.6%; P: 0.100% or less; and Al: 0.5% or less, in which 10 pieces/?m3 or less in number density of non-magnetic precipitate AlN having an average diameter of 10 nm to 200 nm are contained, and an average magnetic flux density B50 in a rolling direction and in a direction perpendicular to rolling is 1.75 T or more. This non-oriented electrical steel sheet can be manufactured by two methods of a method of performing hot rolling annealing at a temperature of 750° C. to an Ac1 transformation point and a method of setting a coil winding temperature to 780° C. or higher and performing self annealing.Type: ApplicationFiled: May 30, 2017Publication date: September 14, 2017Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masahiro FUJIKURA, Yoshiyuki USHIGAMI, Tesshu MURAKAWA, Shinichi KANAO, Makoto ATAKE, Takeru ICHIE, Kojiro HORI
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Patent number: 9728312Abstract: A non-oriented electrical steel sheet containing: in mass %, C: 0.005% or less; Si: 0.1% to 2.0%; Mn: 0.05% to 0.6%; P: 0.100% or less; and Al: 0.5% or less, in which 10 pieces/?m3 or less in number density of non-magnetic precipitate AlN having an average diameter of 10 nm to 200 nm are contained, and an average magnetic flux density B50 in a rolling direction and in a direction perpendicular to rolling is 1.75 T or more. This non-oriented electrical steel sheet can be manufactured by two methods of a method of performing hot rolling annealing at a temperature of 750° C. to an Ac1 transformation point and a method of setting a coil winding temperature to 780° C. or higher and performing self annealing.Type: GrantFiled: November 9, 2012Date of Patent: August 8, 2017Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori
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Patent number: 9721706Abstract: A value of a parameter Q represented by “Q=([Ti]/48+[V]/51+[Zr]/91+[Nb]/93)/([C]/12)” is not less than 0.9 nor more than 1.1, when contents of Ti, V, Zr, Nb, and C (mass %) are represented as [Ti], [V], [Zr], [Nb], and [C] respectively. A matrix of a metal structure is a ferrite phase, and the metal structure does not contain a non-recrystallized structure. An average grain size of ferrite grains constituting the ferrite phase is not less than 30 ?m nor more than 200 ?m. A precipitate containing at least one selected from the group consisting of Ti, V, Zr, and Nb exists with a density of 1 particle/?m3 or more in the ferrite grain. An average grain size of the precipitate is not less than 0.002 ?m nor more than 0.2 ?m.Type: GrantFiled: August 17, 2012Date of Patent: August 1, 2017Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori, Shinichi Matsui
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Patent number: 9579701Abstract: A steel having a predetermined composition is hot-rolled so as to form a steel strip, the steel strip is subjected to first cold-rolling, the steel strip is subjected to intermediate annealing, the steel strip is subjected to second cold-rolling, and the steel strip is subjected to finish annealing. A finish temperature in the hot-rolling is 900° C. or less, annealing is not performed between the hot-rolling and the first cold-rolling, and a rolling reduction in the second cold-rolling is not less than 40% nor more than 85%.Type: GrantFiled: July 29, 2011Date of Patent: February 28, 2017Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Takeshi Kubota, Masahiro Fujikura
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Patent number: 9512500Abstract: When contents of Ti, V, Zr, Nb, and C (mass %) are represented as [Ti], [V], [Zr], [Nb], and [C] respectively, a value of a parameter Q represented by “Q=([Ti]/48+[V]/51+[Zr]/91+[Nb]/93)/([C]/12)” is not less than 0.9 nor more than 1.1. A matrix of a metal structure is a ferrite phase, and the metal structure does not include a non-recrystallized structure. An average grain size of ferrite grains constituting the ferrite phase is not less than 10 ?m nor more than 200 ?m. A precipitate containing at least one selected from the group consisting of Ti, V, Zr, and Nb exists with a density of 10 ?m?3 or more in the ferrite grain. An average grain size of the precipitate is not less than 0.002 ?m nor more than 0.2 ?m.Type: GrantFiled: August 16, 2012Date of Patent: December 6, 2016Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori, Shinichi Matsui
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Patent number: 9362032Abstract: A high-strength non-oriented electrical steel sheet contains: in mass %, C: 0.010% or less; Si: not less than 2.0% nor more than 4.0%; Mn: not less than 0.05% nor more than 0.50%; Al: not less than 0.2% nor more than 3.0%; N: 0.005% or less; S: not less than 0.005% nor more than 0.030%; and Cu: not less than 0.5% nor more than 3.0%, a balance being composed of Fe and inevitable impurities. An expression (1) is established where a Mn content is represented as [Mn] and a S content is represented as [S], and not less than 1.0×104 pieces nor more than 1.0×106 pieces of sulfide having a circle-equivalent diameter of not less than 0.1 ?m nor more than 1.0 ?m are contained per 1 mm2 10?[Mn]/[S]?50??(1).Type: GrantFiled: April 11, 2012Date of Patent: June 7, 2016Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Yoshihiro Arita, Masahiro Fujikura, Hidekuni Murakami
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Publication number: 20160035469Abstract: A manufacturing method of a non-oriented electrical steel sheet includes: performing finish annealing of a cold-rolled steel strip; and forming a tension-applying type insulating film of not less than 1 g/m2 and not more than 6 g/m2 on a surface of the cold-rolled steel strip. The performing the finish annealing includes forming an oxide layer containing Al2O3 or (Al, Cr)2O3 and having a thickness of not less than 0.01 ?m and not more than 0.5 ?m on the surface of the cold-rolled steel strip with setting a temperature of the cold-rolled steel strip to not lower than 800° C. and not higher than 1100° C. in an atmosphere where when the total content of Si and Al of the cold-rolled steel strip is represented as X (mass %), a partial pressure ratio of water vapor to hydrogen is equal to or less than 0.005×X2.Type: ApplicationFiled: October 15, 2015Publication date: February 4, 2016Inventors: Shuichi Yamazaki, Takeshi Kubota, Yousuke Kurosaki, Masahiro Fujikura, Takahide Shimazu
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Patent number: 9187830Abstract: A non-oriented electrical steel sheet includes: a base iron (1); and a tension applying type insulating film (2) of not less than 1 g/m2 nor more than 6 g/m2 on a surface of the base iron (1). An oxide layer (3) containing at least one type of oxide selected from the group consisting of Si, Al, and Cr and having a thickness of not less than 0.01 ?m nor more than 0.5 ?m is formed on the surface of the base iron (1).Type: GrantFiled: February 15, 2011Date of Patent: November 17, 2015Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Shuichi Yamazaki, Takeshi Kubota, Yousuke Kurosaki, Masahiro Fujikura, Takahide Shimazu
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Publication number: 20140238558Abstract: A non-oriented electrical steel sheet containing: in mass %, C: 0.005% or less; Si: 0.1% to 2.0%; Mn: 0.05% to 0.6%; P: 0.100% or less; and Al: 0.5% or less, in which 10 pieces/?m3 or less in number density of non-magnetic precipitate AlN having an average diameter of 10 nm to 200 nm are contained, and an average magnetic flux density B50 in a rolling direction and in a direction perpendicular to rolling is 1.75 T or more. This non-oriented electrical steel sheet can be manufactured by two methods of a method of performing hot rolling annealing at a temperature of 750° C. to an Ac1 transformation point and a method of setting a coil winding temperature to 780° C. or higher and performing self annealing.Type: ApplicationFiled: November 9, 2012Publication date: August 28, 2014Inventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori
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Publication number: 20140113159Abstract: When contents of Ti, V, Zr, Nb, and C (mass %) are represented as [Ti], [V], [Zr], [Nb], and [C] respectively, a value of a parameter Q represented by “Q=([Ti]/48+[V]/51+[Zr]/91+[Nb]/93)/([C]/12)” is not less than 0.9 nor more than 1.1. A matrix of a metal structure is a ferrite phase, and the metal structure does not include a non-recrystallized structure. An average grain size of ferrite grains constituting the ferrite phase is not less than 10 ?m nor more than 200 ?m. A precipitate containing at least one selected from the group consisting of Ti, V, Zr, and Nb exists with a density of 10 ?m?3 or more in the ferrite grain. An average grain size of the precipitate is not less than 0.002 ?m nor more than 0.2 ?m.Type: ApplicationFiled: August 16, 2012Publication date: April 24, 2014Inventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori, Shinichi Matsui
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Publication number: 20140030135Abstract: A high-strength non-oriented electrical steel sheet contains: in mass %, C: 0.010% or less; Si: not less than 2.0% nor more than 4.0%; Mn: not less than 0.05% nor more than 0.50%; Al: not less than 0.2% nor more than 3.0%; N: 0.005% or less; S: not less than 0.005% nor more than 0.030%; and Cu: not less than 0.5% nor more than 3.0%, a balance being composed of Fe and inevitable impurities. An expression (1) is established where a Mn content is represented as [Mn] and a S content is represented as [S], and not less than 1.0×104 pieces nor more than 1.0×106 pieces of sulfide having a circle-equivalent diameter of not less than 0.1 ?m nor more than 1.0 ?m are contained per 1 mm2.Type: ApplicationFiled: April 11, 2012Publication date: January 30, 2014Applicant: Nippon Steel CorporationInventors: Yoshihiro Arita, Masahiro Fujikura, Hidekuni Murakami
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Publication number: 20130309525Abstract: A value of a parameter Q represented by “Q=([Ti]/48+[V]/51+[Zr]/91+[Nb]/93)/([C]/12)” is not less than 0.9 nor more than 1.1, when contents of Ti, V, Zr, Nb, and C (mass %) are represented as [Ti], [V], [Zr], [Nb], and [C] respectively. A matrix of a metal structure is a ferrite phase, and the metal structure does not contain a non-recrystallized structure. An average grain size of ferrite grains constituting the ferrite phase is not less than 30 ?m nor more than 200 ?m. A precipitate containing at least one selected from the group consisting of Ti, V, Zr, and Nb exists with a density of 1 particle/?m3 or more in the ferrite grain. An average grain size of the precipitate is not less than 0.002 ?m nor more than 0.2 ?m.Type: ApplicationFiled: August 17, 2012Publication date: November 21, 2013Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori, Shinichi Matsui
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Publication number: 20130125601Abstract: A steel having a predetermined composition is hot-rolled so as to form a steel strip, the steel strip is subjected to first cold-rolling, the steel strip is subjected to intermediate annealing, the steel strip is subjected to second cold-rolling, and the steel strip is subjected to finish annealing. A finish temperature in the hot-rolling is 900° C. or less, annealing is not performed between the hot-rolling and the first cold-rolling, and a rolling reduction in the second cold-rolling is not less than 40% nor more than 85%.Type: ApplicationFiled: July 29, 2011Publication date: May 23, 2013Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Takeshi Kubota, Masahiro Fujikura
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Publication number: 20120305140Abstract: A non-oriented electrical steel sheet includes: a base iron (1); and a tension applying type insulating film (2) of not less than 1 g/m2 nor more than 6 g/m2 on a surface of the base iron (1). An oxide layer (3) containing at least one type of oxide selected from the group consisting of Si, Al, and Cr and having a thickness of not less than 0.01 ?m nor more than 0.5 ?m is formed on the surface of the base iron (1).Type: ApplicationFiled: February 15, 2011Publication date: December 6, 2012Inventors: Shuichi Yamazaki, Takeshi Kubota, Yousuke Kurosaki, Masahiro Fujikura, Takahide Shimazu
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Patent number: 7964803Abstract: A magnetic shield structure having openings, the structure comprising a plurality of similar magnetic blind bodies 2, each blind body 2 having an imaginary blind core plane F and a plurality of magnetic material slats 1 being spaced from each other by a distance d required for magnetic shielding, each slat 1 intersecting the blind core plane F at a longitudinal central axis C thereof, the longitudinal central axes of the slats are oriented substantially in parallel to each other on the blind core plane F. The blind bodies 2a, 2b are coupled in a row by serially coupling each slat 1 in each blind body 2a to a corresponding slat 1 of adjacent blind body 2b through overlapping or abutting of slat terminal portions, whereby the blind core planes Fa, Fb of the blind bodies 2a, 2b are so coupled as to define a successive magnetic shield plane, and spaces d between adjacent slats 1 in each blind body 2a, 2b form openings in the magnetic shield structure.Type: GrantFiled: March 16, 2004Date of Patent: June 21, 2011Assignees: Nippon Steel Corporation, Nippon Steel Engineering Co., Ltd., Kajima CorporationInventors: Takeshi Saito, Masanori Karikomi, Masanori Niwa, Hiroshi Ishikawa, Satoru Miura, Masahiro Fujikura, Akira Sakaida, Yoneo Yamada, Kentaro Chikuma
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Patent number: 7456724Abstract: The present invention provides an electrical steel sheet core for a low-noise transformer capable of effectively lowering noise by suppressing vibration perpendicular to the surfaces of the steel sheets and reducing vibration, and relates to an electrical steel sheet for a low-noise transformer characterized by randomly inserting viscoelastic layers with both viscosity and elasticity into the gaps of the steel sheet lamination layers, and a low-noise transformer formed by using said electrical steel sheet.Type: GrantFiled: March 25, 2004Date of Patent: November 25, 2008Assignee: Nippon Steel CorporationInventors: Hisashi Mogi, Masahiro Fujikura, Shuichi Yamazaki, Masato Mizokami, Masao Yabumoto, Osamu Akisue
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Publication number: 20070272369Abstract: A magnetic shield structure having openings, the structure comprising a plurality of similar magnetic blind bodies 2, each blind body 2 having an imaginary blind core plane F and a plurality of magnetic material slats 1 being spaced from each other by a distance d required for magnetic shielding, each slat 1 intersecting the blind core plane F at a longitudinal central axis C thereof, the longitudinal central axes of the slats are oriented substantially in parallel to each other on the blind core plane F. The blind bodies 2a, 2b are coupled in a row by serially coupling each slat 1 in each blind body 2a to a corresponding slat 1 of adjacent blind body 2b through overlapping or abutting of slat terminal portions, whereby the blind core planes Fa, Fb of the blind bodies 2a, 2b are so coupled as to define a successive magnetic shield plane, and spaces d between adjacent slats 1 in each blind body 2a, 2b form openings in the magnetic shield structure.Type: ApplicationFiled: March 16, 2004Publication date: November 29, 2007Inventors: Takeshi Saito, Masanori Karikomi, Masanori Niwa, Hiroshi Ishikawa, Satoru Miura, Masahiro Fujikura, Akira Sakaida, Yoneo Yamada, Kentaro Chikuma