Patents by Inventor Tesshu Murakawa

Tesshu Murakawa 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: 12024762
    Abstract: A non-oriented electrical steel sheet has a chemical composition in which ?-? transformation can occur and which contains at least, in terms of mass %, at most 0.010% of C, 1.50% to 4.00% of Si, 0.0001% to 1.0% of sol. Al, at most 0.010% of S, at most 0.010% of N, and a total of 2.50% to 5.00% of at least one selected from the group consisting of Mn, Ni, and Cu, with the balance including Fe and impurities, wherein when an average grain size of {411} crystal grains is defined as d411 and an average grain size of {111} crystal grains is defined as d111, d411/d111?1.10.
    Type: Grant
    Filed: March 31, 2022
    Date of Patent: July 2, 2024
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Minako Fukuchi, Yoshiaki Natori, Tesshu Murakawa
  • Patent number: 12009709
    Abstract: A rotating electrical machine includes a stator, a rotor, and a casing that accommodates the stator and the rotor, in which a {111}<211> orientation intensity (A) of a core material of the stator is in a range of 2 to 30, a {111}<211> orientation intensity (B) of a core material of the rotor is in a range of 1 to 15, and both the orientation intensities satisfy a relationship of an expression (1) A>B.
    Type: Grant
    Filed: March 30, 2022
    Date of Patent: June 11, 2024
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Tesshu Murakawa, Yoshiaki Natori
  • Publication number: 20240158896
    Abstract: This non-oriented electrical steel sheet has a predetermined chemical composition, when EBSD observation is performed on a surface parallel to a steel sheet surface, in a case where a total area is indicated by Stot, an area of {100} orientated grains is indicated by S100, an area of orientated grains in which a Taylor factor M becomes more than 2.8 is indicated by Styl, a total area of orientated grains in which the Taylor factor M becomes 2.8 or less is indicated by Stra, an average KAM value of the {100} orientated grains is indicated by K100, and an average KAM value of the orientated grains in which the Taylor factor M becomes more than 2.8 is indicated by Ktyl, 0.20?Styl/Stot?0.85, 0.05?S100/Stot?0.80, S100/Stot?0.5, and K100/Ktyl?0.990 are satisfied.
    Type: Application
    Filed: March 18, 2022
    Publication date: May 16, 2024
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Tesshu MURAKAWA, Satoshi KANO
  • Publication number: 20240153683
    Abstract: This non-oriented electrical steel sheet has a predetermined chemical composition, when EBSD observation is performed on a surface parallel to a steel sheet surface, in a case where a total area is indicated by Stot, an area of {411} orientated grains is indicated by S411, an area of orientated grains in which a Taylor factor M becomes more than 2.8 is indicated by Styl, a total area of orientated grains in which the Taylor factor M becomes 2.8 or less is indicated by Stra, an average KAM value of the {411} orientated grains is indicated by K411, and an average KAM value of the orientated grains in which the Taylor factor M becomes more than 2.8 is indicated by Ktyl, 0.20?Styl/Stot?0.85, 0.05?S411/Stot?0.80, S411/Stra?0.50, and K411/Ktyl?0.990 are satisfied.
    Type: Application
    Filed: March 18, 2022
    Publication date: May 9, 2024
    Applicant: NIPPON STEEL CORPORATION
    Inventor: Tesshu MURAKAWA
  • Publication number: 20240154472
    Abstract: The rotating electrical machine includes a stator, a rotor, and a casing that accommodates the stator and the rotor, in which at least one of the following conditions 1 and 2 is satisfied. Condition 1: a thermal conductivity A of a non-oriented electrical steel sheet that is used for a core of the stator is in a range of 12 to 35 W/(m·K), a thermal conductivity B of a non-oriented electrical steel sheet that is used for a core of the rotor is in a range of 10 to 33 W/(m·K), and both the thermal conductivities have a relationship of an expression (1) of A>B Condition 2: a thermal diffusivity A1 of the non-oriented electrical steel sheet that is used for the core of the stator is in a range of 3.0×10?6 to 9.0×10?6 m2/sW/(m·K), a thermal diffusivity B1 of the non-oriented electrical steel sheet that is used for the core of the rotor is in a range of 2.5×10?6 to 8.
    Type: Application
    Filed: March 30, 2022
    Publication date: May 9, 2024
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Tesshu MURAKAWA, Yoshiaki NATORI
  • Publication number: 20240141463
    Abstract: This non-oriented electrical steel sheet has a predetermined chemical composition, one or more particles that are a precipitate of a sulfide or an oxysulfide of one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd or both the sulfide and the oxysulfide and have a diameter of more than 0.5 ?m are present in a visual field of 10000 ?m2, and, when EBSD observation is performed on a surface parallel to a steel sheet surface, in a case where a total area is indicated by Stot, an area of {100} orientated grains is indicated by S100, an area of orientated grains in which a Taylor factor M becomes more than 2.8 is indicated by Styl, a total area of orientated grains in which the Taylor factor M becomes 2.8 or less is indicated by Stra, an average KAM value of the {100} orientated grains is indicated by K100, and an average KAM value of the orientated grains in which the Taylor factor M becomes more than 2.8 is indicated by Ktyl, 0.20?Styl/Stot?0.85, 0.05?S100/Stot?0.
    Type: Application
    Filed: March 18, 2022
    Publication date: May 2, 2024
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Tesshu MURAKAWA, Minako FUKUCHI
  • Patent number: 11952641
    Abstract: A non oriented electrical steel sheet consists of a silicon steel sheet and an insulation coating. The silicon steel sheet includes an internally oxidized layer containing SiO2 in a surface thereof, an average thickness of the internally oxidized layer is 0.10 to 5.0 ?m, and a Vickers hardness in the internally oxidized layer is 1.15 to 1.5 times as compared with a Vickers hardness in a thickness central area.
    Type: Grant
    Filed: March 20, 2019
    Date of Patent: April 9, 2024
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Masaru Takahashi, Takeru Ichie, Tesshu Murakawa, Shinichi Matsui, Fuminobu Murakami
  • Patent number: 11942246
    Abstract: A non-oriented electrical steel sheet of the present invention has a chemical composition capable of causing ?-? transformation, and contains 0.0005% to 0.0050% of Ti, in which, in a case where an area ratio of grains having a crystal orientation of an {hkl}<uvw> orientation (within a tolerance of 10°) when measured by EBSD is denoted as Ahkl-uvw, A411-011 is 15.0% or more, and the non-oriented electrical steel sheet has an average grain size of 10.0 ?m to 40.0 ?m.
    Type: Grant
    Filed: March 31, 2022
    Date of Patent: March 26, 2024
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Minako Fukuchi, Yoshiaki Natori, Tesshu Murakawa
  • Publication number: 20240096531
    Abstract: There is provided a non-oriented electrical steel sheet having a predetermined chemical composition, in which an area fraction of a crystal structure A composed of crystal grains having a grain size of 100 ?m or more is 1% to 30% in a cross section parallel to a rolled plane of the non-oriented electrical steel sheet, an average grain size of a crystal structure B which is a crystal structure other than the crystal structure A is 40 ?m or less, and a Vickers hardness HvA of the crystal structure A and a Vickers hardness HvB of the crystal structure B satisfy Equation 1 ((HvA2+HvB2)/2?(HvA+HvB)2/4?7.0).
    Type: Application
    Filed: March 28, 2022
    Publication date: March 21, 2024
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Ichiro TANAKA, Takeaki WAKISAKA, Tesshu MURAKAWA, Yoshiaki NATORI, Hiroshi FUJIMURA
  • Publication number: 20240043970
    Abstract: A non-oriented electrical steel sheet of the present invention has a chemical composition capable of causing ?-? transformation, in which, in a case where an area ratio of grains having a crystal orientation of an {hkl}<uvw>orientation (within a tolerance of 10°) when measured by EBSD is denoted as Ahkl-uvw, A411?011 is 15.0% or more, and the non-oriented electrical steel sheet has an average grain size of 10.0 ?m to 40.0 ?m.
    Type: Application
    Filed: March 31, 2022
    Publication date: February 8, 2024
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Minako FUKUCHI, Yoshiaki NATORI, Tesshu MURAKAWA
  • Publication number: 20240047105
    Abstract: What is provided is a non-oriented electrical steel sheet having a chemical composition in which, by mass %, C: 0.010% or less, Si: 1.50% to 4.00%, sol. Al: 0.0001% to 1.0%, S: 0.010% or less, N: 0.010% or less and one or a plurality of elements selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu and Au: 2.50% to 5.00% in total with a remainder including Fe and impurities, in which a recrystallization rate is 1% to 99% in a metallographic structure, a sheet thickness is 0.50 mm or less, and, in the case of measuring a magnetic flux density B50 after annealing the non-oriented electrical steel sheet at 800° C. for two hours, a magnetic flux density B50 in a 45° direction with respect to a rolling direction is 1.75 T or more.
    Type: Application
    Filed: November 13, 2020
    Publication date: February 8, 2024
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Tesshu MURAKAWA, Miho TOMITA, Hiroshi FUJIMURA, Satoshi KANO
  • Publication number: 20240047106
    Abstract: A non-oriented electrical steel sheet of the present invention has a chemical composition capable of causing ?-? transformation, and contains 0.0005% to 0.0050% of Ti, in which, in a case where an area ratio of grains having a crystal orientation of an {hkl}<uvw> orientation (within a tolerance of 10°) when measured by EBSD is denoted as Ahkl-uvw, A411-011 is 15.0% or more, and the non-oriented electrical steel sheet has an average grain size of 10.0 ?m to 40.0 ?m.
    Type: Application
    Filed: March 31, 2022
    Publication date: February 8, 2024
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Minako FUKUCHI, Yoshiaki NATORI, Tesshu MURAKAWA
  • Publication number: 20240035130
    Abstract: A non-oriented electrical steel sheet according to the present invention has a chemical composition in which ?-? transformation can occur and which contains at least, in terms of mass %, at most 0.010% of C, 1.50% to 4.00% of Si, 0.0001% to 1.0% of sol. Al, at most 0.010% of S, at most 0.010% of N, and a total of 2.50% to 5.00% of at least one selected from the group consisting of Mn, Ni, and Cu, with the balance including Fe and impurities, wherein when an average grain size of {411} crystal grains is defined as d411 and an average grain size of {111} crystal grains is defined as d111, d411/d111?1.10.
    Type: Application
    Filed: March 31, 2022
    Publication date: February 1, 2024
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Minako FUKUCHI, Yoshiaki NATORI, Tesshu MURAKAWA
  • Publication number: 20230353023
    Abstract: A rotating electrical machine includes a stator, a rotor, and a casing that accommodates the stator and the rotor, in which a {111}<211> orientation intensity (A) of a core material of the stator is in a range of 2 to 30, a {111}<211> orientation intensity (B) of a core material of the rotor is in a range of 1 to 15, and both the orientation intensities satisfy a relationship of an expression (1) A>B.
    Type: Application
    Filed: March 30, 2022
    Publication date: November 2, 2023
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Tesshu MURAKAWA, Yoshiaki NATORI
  • Publication number: 20230106818
    Abstract: A non-oriented electrical steel sheet has a predetermined chemical composition. The chemical composition satisfies (2×[Mn]+2.5×[Ni]+[Cu])?([Si]+2×[sol.Al]+4×[P])?1.50%. In a case where Ahkl-uvw represents the area ratio of crystal grains in an {hkl}<uvw> orientation to the entire visual field when a plane at a depth of ½ of a sheet thickness from a surface parallel to a rolled surface is measured by SEM-EBSD, A411-011 is 15.0% or more, and the average grain size is 50 ?m to 150 ?m.
    Type: Application
    Filed: March 24, 2021
    Publication date: April 6, 2023
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Minako FUKUCHI, Ichiro TANAKA, Miho TOMITA, Tesshu MURAKAWA
  • Publication number: 20220407371
    Abstract: The present invention is a stator core having a plurality of laminated electrical steel sheets, in which, among a plurality of teeth (121a to 121p) of the stator core, a width of teeth along a direction in which magnetic characteristics are excellent may be narrower than a width of teeth along a direction in which the magnetic characteristics are poor.
    Type: Application
    Filed: November 13, 2020
    Publication date: December 22, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Yasuo OHSUGI, Miho TOMITA, Tesshu MURAKAWA
  • Publication number: 20220396846
    Abstract: A method for manufacturing a non-oriented electrical steel sheet includes a step of performing hot rolling on a steel material having a predetermined chemical composition, a step of performing first cold rolling, a step of performing process annealing, a step of performing second cold rolling, and a step of performing any one or both of final annealing and stress relief annealing. A final pass of finish rolling is performed in a temperature range equal to or higher than an Ar1 temperature, the steel sheet is held for 2 hours or less in a temperature range lower than an Ac1 temperature in the final annealing, and the steel sheet is held for 1200 sec or more in a temperature range equal to or higher than 600° C. and lower than the Ac1 temperature in the stress relief annealing.
    Type: Application
    Filed: November 13, 2020
    Publication date: December 15, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Tesshu MURAKAWA, Hiroshi FUJIMURA
  • Publication number: 20220385119
    Abstract: The present invention is a stator core (21) including a plurality of split cores (30), in which the plurality of split cores (30) are configured by laminating core pieces (40) made of an electrical steel sheet, the electrical steel sheet is a predetermined electrical steel sheet, and, in the core pieces (40) of at least one split core (30) in the plurality of split cores (30), the radial directions of teeth (41) and extension directions of core backs (42) are all along a direction in which magnetic characteristics of the electrical steel sheet are excellent.
    Type: Application
    Filed: November 13, 2020
    Publication date: December 1, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Masahito KAMIKAWABATA, Miho TOMITA, Tesshu MURAKAWA
  • Publication number: 20220384085
    Abstract: A laminated core (100) has a plurality of legs having an extension direction in a direction perpendicular to a lamination direction of electrical steel sheets and a plurality of yokes having an extension direction in a direction orthogonal to the lamination direction of the electrical steel sheets and the extension direction of the legs, and, in the same position of the electrical steel sheet in the lamination direction, at least a partial region of the legs and at least a partial region of the yokes are configured by the same electrical steel sheet. The electrical steel sheet is disposed such that a first direction of directions of easy magnetization of the electrical steel sheet is along the extension direction of the legs and a second direction of the directions of easy magnetization of the electrical steel sheet is along the extension direction of the yokes.
    Type: Application
    Filed: November 13, 2020
    Publication date: December 1, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Ryu HIRAYAMA, Tesshu MURAKAWA, Miho TOMITA
  • Publication number: 20220385118
    Abstract: An electrical steel sheet (300) is formed such that centerlines of four magnetic poles (salient poles) of a rotor core (111) coincide with a direction of easy magnetization (ED1) or (ED2). In addition, the electrical steel sheets (300) are laminated such that the directions of easy magnetization (ED1) and (ED2) are aligned.
    Type: Application
    Filed: November 13, 2020
    Publication date: December 1, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Masahito KAMIKAWABATA, Miho TOMITA, Tesshu MURAKAWA