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).

  • Patent number: 10214791
    Abstract: 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: Grant
    Filed: May 30, 2017
    Date of Patent: February 26, 2019
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori
  • Publication number: 20180119258
    Abstract: 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: Application
    Filed: April 21, 2016
    Publication date: May 3, 2018
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Masahiro FUJIKURA, Shinichi MATSUI, Shinichi KANAO, Takeo ARAMAKI, Yoshiyuki USHIGAMI
  • Patent number: 9934894
    Abstract: 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: Grant
    Filed: October 15, 2015
    Date of Patent: April 3, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Shuichi Yamazaki, Takeshi Kubota, Yousuke Kurosaki, Masahiro Fujikura, Takahide Shimazu
  • Publication number: 20170260598
    Abstract: 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: Application
    Filed: May 30, 2017
    Publication date: September 14, 2017
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Masahiro FUJIKURA, Yoshiyuki USHIGAMI, Tesshu MURAKAWA, Shinichi KANAO, Makoto ATAKE, Takeru ICHIE, Kojiro HORI
  • Patent number: 9728312
    Abstract: 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: Grant
    Filed: November 9, 2012
    Date of Patent: August 8, 2017
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori
  • Patent number: 9721706
    Abstract: 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: Grant
    Filed: August 17, 2012
    Date of Patent: August 1, 2017
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori, Shinichi Matsui
  • Patent number: 9579701
    Abstract: 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: Grant
    Filed: July 29, 2011
    Date of Patent: February 28, 2017
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Takeshi Kubota, Masahiro Fujikura
  • Patent number: 9512500
    Abstract: 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: Grant
    Filed: August 16, 2012
    Date of Patent: December 6, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori, Shinichi Matsui
  • Patent number: 9362032
    Abstract: 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: Grant
    Filed: April 11, 2012
    Date of Patent: June 7, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Yoshihiro Arita, Masahiro Fujikura, Hidekuni Murakami
  • Publication number: 20160035469
    Abstract: 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: Application
    Filed: October 15, 2015
    Publication date: February 4, 2016
    Inventors: Shuichi Yamazaki, Takeshi Kubota, Yousuke Kurosaki, Masahiro Fujikura, Takahide Shimazu
  • Patent number: 9187830
    Abstract: 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: Grant
    Filed: February 15, 2011
    Date of Patent: November 17, 2015
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Shuichi Yamazaki, Takeshi Kubota, Yousuke Kurosaki, Masahiro Fujikura, Takahide Shimazu
  • Publication number: 20140238558
    Abstract: 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: Application
    Filed: November 9, 2012
    Publication date: August 28, 2014
    Inventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori
  • Publication number: 20140113159
    Abstract: 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: Application
    Filed: August 16, 2012
    Publication date: April 24, 2014
    Inventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori, Shinichi Matsui
  • Publication number: 20140030135
    Abstract: 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: Application
    Filed: April 11, 2012
    Publication date: January 30, 2014
    Applicant: Nippon Steel Corporation
    Inventors: Yoshihiro Arita, Masahiro Fujikura, Hidekuni Murakami
  • Publication number: 20130309525
    Abstract: 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: Application
    Filed: August 17, 2012
    Publication date: November 21, 2013
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori, Shinichi Matsui
  • Publication number: 20130125601
    Abstract: 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: Application
    Filed: July 29, 2011
    Publication date: May 23, 2013
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Takeshi Kubota, Masahiro Fujikura
  • Publication number: 20120305140
    Abstract: 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: Application
    Filed: February 15, 2011
    Publication date: December 6, 2012
    Inventors: Shuichi Yamazaki, Takeshi Kubota, Yousuke Kurosaki, Masahiro Fujikura, Takahide Shimazu
  • Patent number: 7964803
    Abstract: 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: Grant
    Filed: March 16, 2004
    Date of Patent: June 21, 2011
    Assignees: Nippon Steel Corporation, Nippon Steel Engineering Co., Ltd., Kajima Corporation
    Inventors: Takeshi Saito, Masanori Karikomi, Masanori Niwa, Hiroshi Ishikawa, Satoru Miura, Masahiro Fujikura, Akira Sakaida, Yoneo Yamada, Kentaro Chikuma
  • Patent number: 7456724
    Abstract: 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: Grant
    Filed: March 25, 2004
    Date of Patent: November 25, 2008
    Assignee: Nippon Steel Corporation
    Inventors: Hisashi Mogi, Masahiro Fujikura, Shuichi Yamazaki, Masato Mizokami, Masao Yabumoto, Osamu Akisue
  • Publication number: 20070272369
    Abstract: 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: Application
    Filed: March 16, 2004
    Publication date: November 29, 2007
    Inventors: Takeshi Saito, Masanori Karikomi, Masanori Niwa, Hiroshi Ishikawa, Satoru Miura, Masahiro Fujikura, Akira Sakaida, Yoneo Yamada, Kentaro Chikuma