Patents by Inventor Yoshiaki Zaizen

Yoshiaki Zaizen 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: 9761359
    Abstract: 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: Grant
    Filed: February 21, 2013
    Date of Patent: September 12, 2017
    Assignee: JFE Steel Corporation
    Inventors: Tadashi Nakanishi, Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda
  • Patent number: 9748027
    Abstract: 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: Grant
    Filed: August 8, 2013
    Date of Patent: August 29, 2017
    Assignee: JFE STEEL CORPORATION
    Inventors: Tadashi Nakanishi, Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda
  • Patent number: 9466411
    Abstract: 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: Grant
    Filed: September 26, 2012
    Date of Patent: October 11, 2016
    Assignee: JFE Steel Corporation
    Inventors: Yoshihiko Oda, Hiroaki Toda, Tadashi Nakanishi, Yoshiaki Zaizen
  • Publication number: 20150357101
    Abstract: 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: Application
    Filed: November 21, 2013
    Publication date: December 10, 2015
    Applicant: JFE STEEL CORPORATION
    Inventors: Yoshiaki ZAIZEN, Yoshihiko ODA, Hiroaki TODA, Kazuhiro HANAZAWA
  • Publication number: 20150348686
    Abstract: 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: Application
    Filed: January 16, 2014
    Publication date: December 3, 2015
    Inventors: Hiroaki TODA, Yoshiaki ZAIZEN, Tadashi NAKANISHI, Yoshihiko ODA
  • Publication number: 20150270042
    Abstract: 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 % HCI 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: Application
    Filed: October 11, 2013
    Publication date: September 24, 2015
    Inventors: Hiroaki Toda, Yoshiaki Zaizen, Tadashi Nakanishi, Yoshihiko Oda
  • Publication number: 20150187475
    Abstract: 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: Application
    Filed: August 1, 2013
    Publication date: July 2, 2015
    Inventors: Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda
  • Publication number: 20150136278
    Abstract: 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% or less, Si: more than 3.0% and 5.0% or less, Mn: 0.10% or less, Al: 0.0010% or less, P: more than 0.040% and 0.2% or less, N: 0.0040% or less, S: 0.0003% or more and 0.0050% or less, Ca: 0.0015% or more, 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.
    Type: Application
    Filed: August 8, 2013
    Publication date: May 21, 2015
    Inventors: Tadashi Nakanishi, Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda
  • Publication number: 20150059929
    Abstract: 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 including 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: not more than 0.005 mass %, N: not more than 0.005 mass %, Ca: 0.0005˜0.01 mass %, provided that an atom ratio 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./sec up to at least 740° C.
    Type: Application
    Filed: March 7, 2013
    Publication date: March 5, 2015
    Inventors: Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda, Tadashi Nakanishi
  • Publication number: 20150027590
    Abstract: 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: Application
    Filed: February 21, 2013
    Publication date: January 29, 2015
    Inventors: Tadashi Nakanishi, Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda
  • Publication number: 20140345751
    Abstract: 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: Application
    Filed: September 26, 2012
    Publication date: November 27, 2014
    Inventors: Yoshihiko Oda, Hiroaki Toda, Tadashi Nakanishi, Yoshiaki Zaizen
  • Publication number: 20130306200
    Abstract: The present invention provides a non-oriented electrical steel sheet at low cost that has excellent magnetic properties and mechanical properties as well as excellent quality of steel sheet. The non-oriented electrical steel sheet has a chemical composition containing, by mass %, Si: 5.0% or less, Mn: 2.0% or less, Al: 2.0% or less, and P: 0.05% or less, in a range satisfying formula (1), and furthermore, C: 0.008% or more and 0.040% or less; N: 0.003% or less, and Ti: 0.04% or less, in a range satisfying formula (2), with the balance composed of Fe and incidental impurities: 300?85[Si %]+16[Mn %]+40[Al %]+490[P %]?430??(1) 0.008?Ti*<1.2[C %]??(2), where Ti*=Ti?3.4[N %].
    Type: Application
    Filed: February 24, 2011
    Publication date: November 21, 2013
    Applicant: JFE Steel Corporation
    Inventors: Masaaki Kohno, Yoshiaki Zaizen, Yoshihiko Oda, Akira Fujita
  • Publication number: 20130263981
    Abstract: A non-oriented electrical steel sheet having a high magnetic flux density in a rolling direction of the steel sheet is produced by hot rolling a raw steel material including C: not more than 0.03 mass %, Si: not more than 4 mass %, Mn: 0.03˜3 mass %, Al: not more than 3 mass %, S: not more than 0.005 mass %, N: not more than 0.005 mass % and the balance being Fe and inevitable impurities, and then cold rolling and finishing annealing to produce a non-oriented electrical steel sheet, characterized in that a crystal grain size before the cold rolling is rendered into not more than 100 ?M and the finishing annealing is conducted by rapidly heating up to a temperature exceeding recrystallization temperature at an average temperature rising rate of not less than 100° C./sec.
    Type: Application
    Filed: December 16, 2011
    Publication date: October 10, 2013
    Applicant: JFE STEEL CORPORATION
    Inventors: Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda
  • Publication number: 20130146187
    Abstract: Disclosed is a method for producing a non-oriented magnetic steel sheet, wherein a steel slab that consists of 0.01-0.1 mass % of C, 4 mass % or less of Si, 0.05-3 mass % of Mn, 3 mass % or less of Al, 0.005 mass % or less of S, 0.005 mass % or less of N and the balance made up of Fe and unavoidable impurities is subjected to hot rolling, cold rolling and final annealing. By carrying out the final annealing, while setting the average heating rate during the heating to 100° C./sec or more and setting the soaking temperature within the temperature range of 750-1100° C., a non-oriented magnetic steel sheet that has extremely increased magnetic flux density in the rolling direction of the steel sheet is advantageously produced.
    Type: Application
    Filed: August 25, 2011
    Publication date: June 13, 2013
    Applicant: JFE STEEL CORPORATION
    Inventors: Yoshiaki Zaizen, Yoshihiko Oda, Masaaki Kohno