Patents by Inventor Hiroaki Toda
Hiroaki Toda 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: 11225698Abstract: Disclosed is a grain-oriented electrical steel sheet that exhibits excellent iron loss properties and a good building factor, in which damage to a tension coating is suppressed. In a grain-oriented electrical steel sheet having a tension coating, an interlaminar current is 0.15 A or less, a plurality of linear strain regions extending in a direction transverse to the rolling direction are formed, the strain regions are formed at line intervals in the rolling direction of 15 mm or less, each of the strain regions has closure domains formed therein, and each of the closure domains has a length d along the sheet thickness direction of 65 ?m or more and a length w along the rolling direction of 250 ?m or less.Type: GrantFiled: October 23, 2014Date of Patent: January 18, 2022Assignee: JFE STEEL CORPORATIONInventors: Shigehiro Takajo, Hiroaki Toda
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Patent number: 10597759Abstract: A non-oriented electrical steel sheet having a chemical composition comprising C: not more than 0.010 mass %, Si: 1.0-7.0 mass %, Mn: 0.001-3.0 mass %, sol. Al: 0.0001-3.5 mass %, P: 0.01-0.2 mass %, S: not more than 0.010 mass %, N: not more than 0.010 mass % and the remainder being Fe and inevitable impurities, wherein a ratio (P120/Fe700) of a peak-peak height P120 of P near to an electronic energy of 120 eV to a peak-peak height Fe700 of Fe near to an electronic energy of 700 eV in an Auger differential spectrum obtained by analyzing a broken surface of a grain boundary through Auger electron spectroscopy is not less than 0.1 and a sheet thickness is 0.10-0.50 mm, and a motor using such a non-oriented electrical steel sheet as an iron core.Type: GrantFiled: August 11, 2014Date of Patent: March 24, 2020Assignee: JFE STEEL CORPORATIONInventors: Tadashi Nakanishi, Shinji Koseki, Yoshihiko Oda, Hiroaki Toda
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Patent number: 10242782Abstract: According to the present invention, a high-strength electrical steel sheet that is suitable as rotor material for a high speed motor, steadily has high strength, and also has excellent magnetic properties can be obtained by setting the chemical composition thereof to include, by mass %, C: 0.005% or less, Si: more than 3.5% and 4.5% or less, Mn: 0.01% or more and 0.10% or less, Al: 0.005% or less, Ca: 0.0010% or more and 0.0050% or less, S: 0.0030% or less, and N: 0.0030% or less, Ca/S being 0.80 or more, the balance being Fe and incidental impurities, and by setting the sheet thickness to 0.40 mm or less, the non-recrystallized deformed microstructure to 10% or more and 70% or less, tensile strength (TS) to 600 MPa or more, and iron loss W10/400 to 30 W/kg or less.Type: GrantFiled: August 8, 2012Date of Patent: March 26, 2019Assignee: JFE STEEL CORPORATIONInventors: Hiroaki Toda, Tadashi Nakanishi, Masaaki Kohno, Yoshihiko Oda
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Patent number: 10102951Abstract: A non-oriented electrical steel sheet having a high magnetic flux density and a low anisotropy contains C: not more than 0.01 mass %, Si: 1-4 mass %, Mn: 0.05-3 mass %, P: 0.03-0.2 mass %, S: not more than 0.01 mass %, Al: not more than 0.004 mass %, N: not more than 0.005 mass %, As: not more than 0.003 mass %, and preferably further contains one or two of Sb: 0.001-0.1 mass % and Sn: 0.001-0.1 mass % or further contains one or two of Ca: 0.001-0.005 mass % and Mg: 0.001-0.005 mass %.Type: GrantFiled: March 11, 2014Date of Patent: October 16, 2018Assignee: JFE STEEL CORPORATIONInventors: Yoshihiko Oda, Hiroaki Toda, Shinji Koseki, Tatsuhiko Hiratani, Tadashi Nakanishi, Tomoyuki Okubo
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Patent number: 10026534Abstract: By using a hot-rolled steel sheet of a predetermined chemical composition, and annealing the hot-rolled steel sheet in nitrogen atmosphere at 1000° C. for 30 seconds, and then immersing in a solution of 7% HCl at 80° C. for 60 seconds to obtain a hot-rolled steel sheet having a pickling weight loss of 10 g/m2 or more and 35 g/m2 or less, it is possible to obtain a hot-rolled steel sheet for producing a non-oriented electrical steel sheet that not only has excellent magnetic properties such as iron loss properties and magnetic flux density, but also has reduced steel sheet surface defects and an excellent manufacturing yield.Type: GrantFiled: January 16, 2014Date of Patent: July 17, 2018Assignee: JFE STEEL CORPORATIONInventors: Hiroaki Toda, Yoshiaki Zaizen, Tadashi Nakanishi, Yoshihiko Oda
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Patent number: 10006109Abstract: A non-oriented electrical steel sheet having a high magnetic flux density and a low iron loss at not only a commercial frequency but also a high frequency zone, which has a chemical composition including C: not more than 0.0050 mass %, Si: more than 1.5 mass % but not more than 5.0 mass %, Mn: not more than 0.10 mass %, sol. Al: not more than 0.0050 mass, P: more than 0.040 mass % but not more than 0.2 mass %, S: not more than 0.0050 mass %, N: not more than 0.0040 mass % and Ca: 0.001-0.01 mass % and the remainder being Fe and inevitable impurities and a compositional ratio of CaO in oxide-based inclusions existing in a steel sheet of not less than 0.4 and/or a compositional ratio of Al2O3 of not less than 0.3, and a hot rolled steel sheet used as a raw steel material thereof.Type: GrantFiled: August 11, 2014Date of Patent: June 26, 2018Assignee: JFE STEEL CORPORATIONInventors: Tadashi Nakanishi, Shinji Koseki, Yoshihiko Oda, Hiroaki Toda
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Patent number: 9978488Abstract: A steel slab having a chemical composition including C: not more than 0.005 mass %, Si: not more than 4 mass %, Mn: 0.03-2 mass %, P: not more than 0.2 mass %, S: not more than 0.004 mass %, Al: not more than 2 mass %, N: not more than 0.004 mass %, Se: not more than 0.0010 mass % and the balance being Fe and inevitable impurities is subjected to hot rolling, cold rolling and recrystallization annealing up to 740° C. at an average heating rate of not less than 100° C./s to produce a semi-processed non-oriented electrical steel sheet being high in the magnetic flux density and low in the iron loss after stress relief annealing.Type: GrantFiled: November 21, 2013Date of Patent: May 22, 2018Assignee: JFE STEEL CORPORATIONInventors: Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda, Kazuhiro Hanazawa
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Patent number: 9947446Abstract: The pickling loss when a hot-rolled steel sheet having a predetermined chemical composition is annealed at 1000° C. for 30 seconds in a nitrogen atmosphere and then immersed in a solution of 7% HCl at 80° C. for 60 seconds is in a range of 40 g/m2 or more and 100 g/m2 or less. A hot-rolled steel sheet for production of a non-oriented electrical steel sheet with not only excellent magnetic properties such as iron loss and magnetic flux density but also excellent recyclability and steel sheet surface appearance can thus be obtained.Type: GrantFiled: October 11, 2013Date of Patent: April 17, 2018Assignee: JFE Steel CorporationInventors: Hiroaki Toda, Yoshiaki Zaizen, Tadashi Nakanishi, Yoshihiko Oda
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Patent number: 9941038Abstract: A steel slab having a chemical composition including C: not more than 0.005 mass %, Si: not more than 4 mass %, Mn: 0.03-2 mass %, P: not more than 0.2 mass %, S: not more than 0.004 mass %, Al: not more than 2 mass %, N: not more than 0.004 mass %, Se: not more than 0.0010 mass % and the balance being Fe and inevitable impurities is subjected to hot rolling, cold rolling and recrystallization annealing up to 740° C. at an average heating rate of not less than 100° C./s to produce a semi-processed non-oriented electrical steel sheet being high in the magnetic flux density and low in the iron loss after stress relief annealing.Type: GrantFiled: November 21, 2013Date of Patent: April 10, 2018Assignee: JFE STEEL CORPORATIONInventors: Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda, Kazuhiro Hanazawa
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Patent number: 9920393Abstract: A non-oriented electrical steel sheet having a high magnetic flux density and a low iron loss is produced by hot rolling a steel slab comprising C: not more than 0.005 mass %, Si: not more than 4 mass %, Mn: 0.03-3 mass %, Al: not more than 3 mass %, P: 0.03-0.2 mass %, S: present at not more than 0.005 mass %, N: not more than 0.005 mass %, Ca: 0.0005-0.01 mass %, provided that an atom ratio of Ca to S ((Ca mass %/40)/(S mass %/32)) is within a range of 0.5-3.5, and the balance being Fe and incidental impurities, hot band annealing, cold rolling, and then conducting recrystallization annealing by heating at an average temperature rising rate of not less than 100° C/s up to at least 740° C.Type: GrantFiled: March 7, 2013Date of Patent: March 20, 2018Assignee: JFE STEEL CORPORATIONInventors: Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda, Tadashi Nakanishi
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Patent number: 9767946Abstract: A non-oriented electrical steel sheet has a chemical composition having C: not more than 0.005 mass %, Si: 2-7 mass %, Mn: 0.033 mass %, Al: not more than 3 mass %, P: not more than 0.2 mass %, S: not more than 0.005 mass %, N: not more than 0.005 mass %, Se: 0.0001˜0.0005 mass %, As: 0.0005˜0.005 mass % and the remainder being Fe and inevitable impurities, and an iron loss W15/50 in excitation at 50 Hz and 1.5 T of not more than 3.5 W/kg and a ratio (x/t) of amount of shear drop x (mm) to thickness t (mm) in punching of steel sheet of not more than 0.15 and is excellent in the iron loss property before punching and less in the deterioration of the iron loss property by punching.Type: GrantFiled: August 1, 2013Date of Patent: September 19, 2017Assignee: JFE STEEL CORPORATIONInventors: Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda
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Patent number: 9761359Abstract: A method produces a high strength electrical steel sheet in which a cumulative rolling reduction ratio in rough rolling is 73.0% or more, in which in a hot band annealing step, an annealing condition is selected that satisfies an area ratio of recrystallized grains after hot band annealing of 100%, and a recrystallized grain size of 80 ?m to 300 ?m, under a condition where annealing temperature is 850° C. to 1000° C., and annealing duration is 10 seconds to 10 minutes, and in which in a final annealing step, an annealing condition is selected that satisfies an area ratio of recrystallized grains after the final annealing of 30% to 95%, and a length in the rolling direction of a connected non-recrystallized grain group of 2.5 mm or less, under a condition where annealing temperature is 670° C. to 800° C., and annealing duration is 2 seconds to 1 minute.Type: GrantFiled: February 21, 2013Date of Patent: September 12, 2017Assignee: JFE Steel CorporationInventors: Tadashi Nakanishi, Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda
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Publication number: 20170253940Abstract: Disclosed is a grain-oriented electrical steel sheet that exhibits excellent iron loss properties and a good building factor, in which damage to a tension coating is suppressed. In a grain-oriented electrical steel sheet having a tension coating, an interlaminar current is 0.15 A or less, a plurality of linear strain regions extending in a direction transverse to the rolling direction are formed, the strain regions are formed at line intervals in the rolling direction of 15 mm or less, each of the strain regions has closure domains formed therein, and each of the closure domains has a length d along the sheet thickness direction of 65 ?m or more and a length w along the rolling direction of 250 ?m or less.Type: ApplicationFiled: October 23, 2014Publication date: September 7, 2017Applicant: JFE STEEL CORPORATIONInventors: Shigehiro TAKAJO, Hiroaki TODA
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Patent number: 9748027Abstract: Provided is a method for stably obtaining a non-oriented electrical steel sheet with high magnetic flux density and excellent productivity, at a low cost by casting in a continuous casting machine a slab having a chemical composition including by mass %, C?0.0050%, 3.0%<Si?5.0%, Mn?0.10%, Al?0.0010%, 0.040%<P?0.2%, N?0.0040%, 0.0003%?S?0.0050%, Ca?0.0015%, and total of at least one element selected from Sn and Sb: 0.01% or more and 0.1% or less, balance including Fe and incidental impurities, subjecting the slab to heating, then subjecting the slab to hot rolling to obtain a hot rolled steel sheet, then subjecting the steel sheet to hot band annealing, pickling, subsequent single cold rolling to obtain a final sheet thickness, then subjecting the steel sheet to final annealing, wherein in the hot band annealing, soaking temperature is 900° C. or higher and 1050° C. or lower, and cooling rate after soaking is 5° C/s or more.Type: GrantFiled: August 8, 2013Date of Patent: August 29, 2017Assignee: JFE STEEL CORPORATIONInventors: Tadashi Nakanishi, Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda
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Publication number: 20170016085Abstract: A grain-oriented electrical steel sheet is subjected to magnetic domain refining treatment by irradiating a steel sheet surface with an electron beam having a beam diameter d of 0.40 mm or less, wherein a modulated irradiation line region is formed with repeating units connected to each other in the line region direction, a periodic distance of the repeating units in the modulated irradiation line region is ?×d mm to 2.5×d mm, a repeating interval of the modulated irradiation line region in the rolling direction is 4.0 mm to 12.5 mm, and intensity of the electron beam is not lower than an intensity with which long and narrow divided magnetic domains extending in the modulated irradiation line region direction are formed at least on an irradiated side, and not higher than an intensity with which coating damage does not occur and a plastic strain region is not formed on the irradiated side.Type: ApplicationFiled: February 24, 2015Publication date: January 19, 2017Inventors: Hiroaki TODA, Shigehiro TAKAJO, Michiro KOMATSUBARA
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Patent number: 9536657Abstract: A grain oriented electrical steel sheet is subjected to magnetic domain refinement by laser irradiation and has magnetic flux density B8 of at least 1.91T, wherein the nitrogen content in the forsterite coating is 3.0 mass % or less. The grain oriented electrical steel sheet satisfies recent demand for iron loss reduction.Type: GrantFiled: June 28, 2011Date of Patent: January 3, 2017Assignee: JFE Steel CorporationInventors: Takeshi Omura, Hiroaki Toda, Hiroi Yamaguchi, Seiji Okabe
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Patent number: 9466411Abstract: A non-oriented electrical steel sheet has a chemical composition including, in mass %, C: 0.005% or less, Si: 5% or less, Al: 3% or less, Mn: 5% or less, S: 0.005% or less, P: 0.2% or less, N: 0.005% or less, Mo: 0.001 to 0.04%, Ti: 0.0030% or less, Nb: 0.0050% or less, V: 0.0050% or less, Zr: 0.0020% or less, one or both of Sb and Sn: 0.001 to 0.1% in total, and the balance being iron and incidental impurities.Type: GrantFiled: September 26, 2012Date of Patent: October 11, 2016Assignee: JFE Steel CorporationInventors: Yoshihiko Oda, Hiroaki Toda, Tadashi Nakanishi, Yoshiaki Zaizen
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Patent number: 9396850Abstract: A grain oriented electrical steel sheet (1) suppresses the content of Cr in the grain oriented electrical steel sheet to 0.1 mass % or less; (2) sets the coating weight of a forsterite coating, in terms of basis weight of oxygen therein, to at least 3.0 g/m2 and thickness of an anchor portion as a lower portion of forsterite coating to 1.5 ?m or less; and (3) controls setting the magnitude of deflection of a test specimen having length: 280 mm to at least 10mm when the forsterite coating is provided on only one surface thereof and at least 20 mm when forsterite coating and the tension coating are provided on the surface.Type: GrantFiled: June 28, 2011Date of Patent: July 19, 2016Assignee: JFE Steel CorporationInventors: Hiroi Yamaguchi, Hiroaki Toda, Takeshi Omura, Seiji Okabe
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Publication number: 20160203895Abstract: A non-oriented electrical steel sheet having a high magnetic flux density and a low iron loss at not only a commercial frequency but also a high frequency zone, which has a chemical composition including C: not more than 0.0050 mass %, Si: more than 1.5 mass % but not more than 5.0 mass %, Mn: not more than 0.10 mass %, sol. Al: not more than 0.0050 mass, P: more than 0.040 mass % but not more than 0.2 mass %, S: not more than 0.0050 mass %, N: not more than 0.0040 mass % and Ca: 0.001-0.01 mass % and the remainder being Fe and inevitable impurities and a compositional ratio of CaO in oxide-based inclusions existing in a steel sheet of not less than 0.4 and/or a compositional ratio of Al2O3 of not less than 0.3, and a hot rolled steel sheet used as a raw steel material thereof.Type: ApplicationFiled: August 11, 2014Publication date: July 14, 2016Applicant: JFE STEEL CORPORATIONInventors: Tadashi NAKANISHI, Shinji KOSEKI, Yoshihiko ODA, Hiroaki TODA
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Publication number: 20160203896Abstract: A non-oriented electrical steel sheet having a chemical composition comprising C: not more than 0.010 mass %, Si: 1.0-7.0 mass %, Mn: 0.001-3.0 mass %, sol. Al: 0.0001-3.5 mass %, P: 0.01-0.2 mass %, S: not more than 0.010 mass %, N: not more than 0.010 mass % and the remainder being Fe and inevitable impurities, wherein a ratio (P120/Fe700) of a peak-peak height P120 of P near to an electronic energy of 120 eV to a peak-peak height Fe700 of Fe near to an electronic energy of 700 eV in an Auger differential spectrum obtained by analyzing a broken surface of a grain boundary through Auger electron spectroscopy is not less than 0.1 and a sheet thickness is 0.10-0.50 mm, and a motor using such a non-oriented electrical steel sheet as an iron core.Type: ApplicationFiled: August 11, 2014Publication date: July 14, 2016Applicant: JFE STEEL CORPORATIONInventors: Tadashi NAKANISHI, Shinji KOSEKI, Yoshihiko ODA, Hiroaki TODA