Patents by Inventor Hidekazu Minami

Hidekazu Minami 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: 11492677
    Abstract: A high-strength steel sheet has a specific composition and a microstructure. In the microstructure, the area fraction of elongated ferrite phase grains having an aspect ratio of 3 or more is 1% or less, the average crystal grain size of martensite included in a region extending 50 ?m from a surface of the steel sheet is 20 ?m or less, the content of oxide particles having a minor axis length of 0.8 ?m or less in the region extending 50 ?m from the surface of the steel sheet is 1.0×1010 particles/m2 or more, and the content of coarse oxide particles having a minor axis length of more than 1 ?m in the region extending 50 ?m from the surface of the steel sheet is 1.0×108 particles/m2 or less. The content of hydrogen trapped in the steel sheet is 0.05 ppm by mass or more.
    Type: Grant
    Filed: October 9, 2018
    Date of Patent: November 8, 2022
    Assignee: JFE Steel Corporation
    Inventors: Hiroshi Hasegawa, Hidekazu Minami, Tatsuya Nakagaito, Kana Sasaki, Shoji Tanaka
  • Patent number: 11490101
    Abstract: It is configured to include a video signal compression unit that compresses a video signal for displaying, on an image inspection monitor, an image inspection screen including a first area for displaying a medical image and a second area for displaying information other than the medical image, and a transmitting unit that transmits, via a communication network, the video signal having been compressed, and the video signal compression unit compresses, in each frame of the video signal, the second area of the image inspection screen at a compression rate higher than a compression rate of the first area.
    Type: Grant
    Filed: July 1, 2019
    Date of Patent: November 1, 2022
    Assignee: Shimadzu Corporation
    Inventor: Hidekazu Minami
  • Publication number: 20220340989
    Abstract: A high-strength cold-rolled steel sheet having a high yield ratio and excellent stretch flangeability and a method for manufacturing the steel sheet. The high-strength cold-rolled steel sheet has a chemical composition including, by mass %, C: 0.10 to 0.30%, Si: 0.50 to 2.00%, Mn: 2.5 to 4.0%, P: 0.050% or less, S: 0.020% or less, Al: 0.10% or less, N: 0.01% or less, Ti: 0.100% or less, and B: 0.0003 to 0.0030%, with the balance being Fe and incidental impurities. N and Ti satisfy a specified formula, and the total area fraction of martensite and bainite is 95% or more. The number density of bainite grains having an area of 3 ?m2 or more and a carbon concentration of less than 0.7C is 1200 grains/mm2 or less.
    Type: Application
    Filed: June 19, 2020
    Publication date: October 27, 2022
    Applicant: JFE STEEL CORPORATION
    Inventors: Yuji TANAKA, Hidekazu MINAMI, Naoki TAKAYAMA, Takako YAMASHITA
  • Publication number: 20220251676
    Abstract: Provided are a high-strength hot-dip galvanized steel sheet that has a tensile strength of 1180 MPa or more and excellent ductility, stretch flangeability, bendability and LME resistance and can manufacture parts with high dimensional accuracy, and its manufacturing method. The high-strength steel sheet with a tensile strength of 1180 MPa or more has a chemical composition containing C, Si, Mn, P, S, Al and N, with [% Si], [% Mn], [% P], [% Mo] and [% Cr] satisfying a predetermined relationship and the balance being Fe and inevitable impurities, and a steel microstructure including ferrite, tempered martensite and bainite, and retained austenite, where the diffusible hydrogen amount in the steel sheet is 0.60 mass ppm or less, a thickness of softened surface layer is 5 ?m or more and 150 ?m or less, and a frequency of coincidence boundary in the steel sheet surface layer after a high-temperature tensile test is 0.45 or less.
    Type: Application
    Filed: June 19, 2020
    Publication date: August 11, 2022
    Applicant: JFE STEEL CORPORATION
    Inventors: Hidekazu MINAMI, Takeshi YOKOTA, Yoshiyasu KAWASAKI, Shotaro TERASHIMA
  • Patent number: 11408044
    Abstract: There is provided a high-strength steel sheet and a method for producing the same. The high-strength steel sheet has a specified chemical composition and a steel microstructure including, by area fraction, 75.0% or more tempered martensite, 1.0% or more and 20.0% or less fresh martensite, and 5.0% or more and 20.0% or less retained austenite. A hardness ratio of the fresh martensite to the tempered martensite is 1.5 or more and 3.0 or less, the ratio of the maximum KAM value in the tempered martensite in the vicinity of the heterophase interface between the tempered martensite and the fresh martensite to the average KAM value in the tempered martensite is 1.5 or more and 30.0 or less, and the average of ratios of grain sizes of prior austenite grains in the rolling direction to those in the thickness direction is 2.0 or less.
    Type: Grant
    Filed: February 9, 2018
    Date of Patent: August 9, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Hidekazu Minami, Fusae Shiimori, Shinjiro Kaneko, Takashi Kobayashi, Yuji Tanaka
  • Patent number: 11408058
    Abstract: There is provided a high-strength steel sheet and a method for producing the same. The steel sheet has a specified chemical composition and a microstructure including, in terms of area percentage, 20.0% or more and 60.0% or less ferrite, 40.0% or more and 80.0% or less of a hard phase composed of bainitic ferrite, tempered martensite, fresh martensite, and retained austenite, 35.0% or more and 55.0% or less bainitic ferrite with respect to the entire hard phase, 20.0% or more and 40.0% or less tempered martensite with respect to the entire hard phase, 3.0% or more and 15.0% or less fresh martensite with respect to the entire hard phase, and 5.0% or more and 20.0% or less retained austenite with respect to the entire hard phase.
    Type: Grant
    Filed: February 9, 2018
    Date of Patent: August 9, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Hidekazu Minami, Takashi Kobayashi, Shinjiro Kaneko, Yuji Tanaka
  • Patent number: 11401569
    Abstract: Provided is a high-strength steel sheet having a tensile strength (TS) of 750 MPa or more and excellent in ductility and stretch flangeability, in which the steel sheet has a predetermined chemical composition and a microstructure containing, in area ratio, ferrite: 50% to 90%, quenched martensite: 1% to 8%, tempered martensite: 3% to 40%, and retained austenite: 6% to 15%, the quenched martensite has an average grain size of 2.5 ?m or less, the quenched martensite has an average circularity index of 0.50 or more, the circularity index being defined as 4 ?M/D2, where D is a perimeter of the quenched martensite and M is an area of the quenched martensite, and the steel sheet has a ratio of an area ratio of the quenched martensite fM to a total area ratio of the quenched martensite and the tempered martensite fM+TM, fM/fM+TM, of 50% or less.
    Type: Grant
    Filed: October 29, 2018
    Date of Patent: August 2, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Seigo Tsuchihashi, Hidekazu Minami, Takashi Kobayashi
  • Patent number: 11401595
    Abstract: A high-strength steel sheet having a TS of 780 MPa or more, excellent stretch flangeability, and excellent in-plane anisotropy of TS is provided. A high-strength steel sheet comprises: a predetermined chemical composition; a steel microstructure including, in area fraction, ferrite: 20% or more and 50% or less, lower bainite: 5% or more and 40% or less, martensite: 1% or more and 20% or less, and tempered martensite: 20% or less, and including, in volume fraction, retained austenite: 5% or more, the retained austenite having an average grain size of 2 ?m or less; and a texture having an inverse intensity ratio of ?-fiber to ?-fiber of 3.0 or less.
    Type: Grant
    Filed: August 29, 2017
    Date of Patent: August 2, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Hidekazu Minami, Shinjiro Kaneko, Reiko Sugihara, Kazunori Tahara, Kazuma Mori
  • Publication number: 20220195552
    Abstract: A high-strength steel sheet comprises: a chemical composition containing C, Si, Mn, P, S, Al, N, Mo, Cr, Ca, and Sb with a balance consisting of Fe and inevitable impurities, wherein [% Si], [% Mn], [% P], [% Mo], and [% Cr] satisfy a predetermined relationship; a steel microstructure that contains ferrite, hard phase, and retained austenite and in which a carbon concentration in the retained austenite is 0.55% or more and 1.10% or less, an amount of diffusible hydrogen in the steel sheet is 0.80 mass ppm or less, a surface layer softening thickness is 5 ?m or more and 150 ?m or less, and a corresponding grain boundary frequency in a surface layer of the steel sheet after a high-temperature tensile test is 0.45 or less; and a tensile strength of 980 MPa or more.
    Type: Application
    Filed: February 21, 2020
    Publication date: June 23, 2022
    Applicant: JFE STEEL CORPORATION
    Inventors: Hidekazu MINAMI, Yuji TANAKA, Takeshi YOKOTA
  • Patent number: 11332804
    Abstract: A high-strength cold-rolled steel sheet or high-strength coated steel sheet that has a tensile strength (TS) of 780 MPa or more and has high ductility, stretch-flangeability, and in-plane stability of stretch-flangeability and methods for producing the same. The high-strength cold-rolled steel sheet has a specified chemical composition and a microstructure comprising, by area fraction, in a range of 50% to 80% of ferrite, 8% or less of martensite with an average grain size of 2.5 ?m or less, in a range of 6% to 15% of retained austenite, and in a range of 3% to 40% of tempered martensite. A ratio fM/fM+TM being 50% or less, where fM denotes the area fraction of martensite and fM+TM denotes the total area fraction of martensite and tempered martensite, and a standard deviation of the grain size of martensite at certain portions being 0.7 ?m or less.
    Type: Grant
    Filed: January 21, 2019
    Date of Patent: May 17, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Seigo Tsuchihashi, Shinsuke Komine, Tatsuya Nakagaito, Hidekazu Minami
  • Publication number: 20220098687
    Abstract: A high-strength hot-dip galvanized steel sheet includes a hot-dip galvanized layer on a surface of the steel sheet and has a specific component composition and a steel microstructure containing, on an area percentage basis, 90% to 100% of martensite and carbide-containing bainite in total and 0% to 10% of retained austenite, and containing prior austenite grains having an aspect ratio of 2.0 or less, in a region extending from 300 ?m to 400 ?m from the surface layer, in which the ratio of the average amount of C at 5 ?m from the surface layer to the average amount of C at 70 ?m from the surface layer is 0.2 to 0.8, and the ratio of the standard deviation of the amount of C to the average amount of C in a region extending from 300 ?m to 400 ?m from the surface layer is 0.40 or less.
    Type: Application
    Filed: August 23, 2019
    Publication date: March 31, 2022
    Applicant: JFE Steel Corporation
    Inventors: Hiroshi Hasegawa, Hidekazu Minami, Tatsuya Nakagaito
  • Publication number: 20220002832
    Abstract: A production method for a high-strength steel sheet having a tensile strength TS of 780 MPa or more is provided. The production method comprises: heating a steel slab having a predetermined chemical composition; hotrolling the steel slab; coiling the hot-rolled sheet; subjecting the hot-rolled sheet to pickling treatment; holding the hot-rolled sheet in a pre-determined temperature range for predetermined time; cold rolling the hot-rolled sheet to obtain a cold-rolled sheet; subjecting the cold-rolled sheet to first annealing treatment; cooling the cold-rolled sheet at a pre-determined average cooling rate; cooling the cold-rolled sheet to room temperature; reheating the clod-rolled sheet to perform second annealing treatment; cooling the cold-rolled sheet at a first average cooling rate; cooling the cold-rolled sheet at a second average cooling rate; reheating the cold-rolled sheet to a predetermined reheating temperature range; and holding the cold-rolled sheet in the reheating temperature range.
    Type: Application
    Filed: September 17, 2021
    Publication date: January 6, 2022
    Applicant: JFE STEEL CORPORATION
    Inventors: Hidekazu MINAMI, Shinjiro KANEKO
  • Publication number: 20210381075
    Abstract: A high-strength steel sheet having a tensile strength of 1,180 MPa or more, and specified chemical composition. The steel sheet includes a steel structure in which an area fraction of martensite having a carbon concentration of more than 0.7×[% C] and less than 1.5×[% C] is 55% or more, an area fraction of tempered martensite having a carbon concentration of 0.7×[% C] or less is 5% or more and 40% or less, a ratio of a carbon concentration in retained austenite to a volume fraction of retained austenite is 0.05 or more and 0.40 or less, and the martensite and the tempered martensite each have an average grain size of 5.3 ?m or less, where [% C] represents the content, by mass %, of compositional element C in steel.
    Type: Application
    Filed: August 20, 2019
    Publication date: December 9, 2021
    Applicant: JFE STEEL CORPORATION
    Inventors: Hidekazu MINAMI, Yuji TANAKA, Junya TOBATA, Takeshi YOKOTA
  • Publication number: 20210310095
    Abstract: There is provided a high-strength steel sheet in which content amounts of a specific steel composition are limited and manufacturing conditions are optimized and that has a steel structure that contains ferrite and a harder phase and in which ferrite accounts for 30% to 70% in terms of area ratio, the harder phase contains bainitic ferrite, tempered martensite, martensite (including 0%), and retained austenite (including 0%), the maximum grain diameter of ferrite dmax is 2.5 ?m or less, and the area ratio of ferrite AF and the average grain diameter of ferrite dF satisfy AF [%]/dF [?m]?15.
    Type: Application
    Filed: November 18, 2019
    Publication date: October 7, 2021
    Applicant: JFE Steel Corporation
    Inventors: Junya Tobata, Hidekazu Minami, Takashi Kobayashi
  • Patent number: 11085100
    Abstract: A high strength steel sheet having a high Young's modulus, the steel sheet having a chemical composition including, by mass %, C: 0.060% or more and 0.150% or less, Si: 0.50% or more and 2.20% or less, Mn: 1.00% or more and 3.00% or less, and one or both of Ti: 0.001% or more and 0.200% or less and Nb: 0.001% or more and 0.200% or less, in which the contents of C, N, S, Ti, and Nb satisfy the equation 500?C*?1300. The steel sheet has a microstructure including ferrite in an amount of 20% or more and martensite in an amount of 5% or more, in terms of area ratio, such that the average grain size of the ferrite is 20.0 ?m or less and the inverse intensity ratio of ?-fiber for ?-fiber is 1.00 or more in the ferrite and the martensite.
    Type: Grant
    Filed: June 26, 2019
    Date of Patent: August 10, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Hidekazu Minami, Takeshi Yokota, Kazuhiro Seto
  • Patent number: 11035019
    Abstract: A steel sheet has a microstructure that contains ferrite in an area ratio of 20% or more, martensite in an area ratio of 5% or more, and tempered martensite in an area ratio of 5% or more. The ferrite has a mean grain size of 20.0 ?m or less. An inverse intensity ratio of ?-fiber to ?-fiber in the ferrite is 1.00 or more and an inverse intensity ratio of ?-fiber to ?-fiber in the martensite and the tempered martensite is 1.00 or more.
    Type: Grant
    Filed: January 27, 2016
    Date of Patent: June 15, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Hidekazu Minami, Shinjiro Kaneko, Takeshi Yokota, Kazuhiro Seto
  • Publication number: 20210147957
    Abstract: A method of producing a hot-rolled steel sheet and a method for producing a cold-rolled full hard steel sheet are provided. The methods comprising heating a steel slab having a composition containing, in terms of mass %, C: 0.010% or more and 0.150% or less, Si: 0.20% or less, Mn: 1.00% or less, P: 0.100% or less, S: 0.0500% or less, Al: 0.001% or more and 0.100% or less, N: 0.0100% or less, and the balance being Fe and unavoidable impurities, in which 0.002%?[%P]+[%S ]?0.070% ([%M] denotes a content (mass %) of M element in steel) is satisfied.
    Type: Application
    Filed: January 26, 2021
    Publication date: May 20, 2021
    Applicant: JFE Steel Corporation
    Inventors: Hidekazu MINAMI, Yoshimasa FUNAKAWA
  • Patent number: 11008632
    Abstract: A steel sheet is provided that has a tensile strength of 540 MPa or more, includes a particular composition; and has a steel structure containing ferrite and a secondary phase, in which an area fraction of the ferrite is 50% or more, the secondary phase contains 1.0% or more and 25.0% or less of martensite in terms of area fraction with respect to the entirety, the ferrite has an average crystal grain size of 3 ?m or more, a difference in hardness between the ferrite and the martensite is 1.0 GPa or more and 8.0 GPa or less, and, in a texture of the ferrite, an inverse intensity ratio of ?-fiber to ?-fiber is 0.8 or more and 7.0 or less.
    Type: Grant
    Filed: March 7, 2017
    Date of Patent: May 18, 2021
    Assignee: JFE Steel Corporation
    Inventors: Hidekazu Minami, Yoshimasa Funakawa, Shinjiro Kaneko
  • Patent number: 10941461
    Abstract: A steel sheet is provided, having a tensile strength of 340 MPa or more, a particular composition and a steel structure in which ferrite has an average crystal grain size of 5 ?m or more and 25 ?m or less, 40% or more of cementite in terms of area fraction precipitates in ferrite grain boundaries, and the ferrite has a texture in which an inverse intensity ratio of ?-fiber to ?-fiber is 0.8 or more and 7.0 or less.
    Type: Grant
    Filed: March 7, 2017
    Date of Patent: March 9, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Hidekazu Minami, Yoshimasa Funakawa
  • Publication number: 20210062282
    Abstract: A high-strength steel sheet has a specific composition and a microstructure. In the microstructure, the area fraction of elongated ferrite phase grains having an aspect ratio of 3 or more is 1% or less, the average crystal grain size of martensite included in a region extending 50 ?m from a surface of the steel sheet is 20 ?m or less, the content of oxide particles having a minor axis length of 0.8 ?m or less in the region extending 50 ?m from the surface of the steel sheet is 1.0×1010 particles/m2 or more, and the content of coarse oxide particles having a minor axis length of more than 1 ?m in the region extending 50 ?m from the surface of the steel sheet is 1.0×108 particles/m2 or less. The content of hydrogen trapped in the steel sheet is 0.05 ppm by mass or more.
    Type: Application
    Filed: October 9, 2018
    Publication date: March 4, 2021
    Applicant: JFE Steel Corporation
    Inventors: Hiroshi Hasegawa, Hidekazu Minami, Tatsuya Nakagaito, Kana Sasaki, Shoji Tanaka