Patents by Inventor Hidetaka Kawabe

Hidetaka Kawabe 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).

  • Publication number: 20200377980
    Abstract: Provided is a hot-rolled and annealed ferritic stainless steel sheet excellent in surface quality after bending work has been performed. A hot-rolled and annealed ferritic stainless steel sheet has a thickness of 5.0 mm or more and a chemical composition containing, by mass %, C: 0.001% to 0.025%, Si: 0.05% to 0.70%, Mn: 0.05% to 0.50%, P: 0.050% or less, S: 0.01% or less, Cr: 10.0% to 18.0%, Ni: 0.01% to 1.00%, Al: 0.001% to 0.10%, N: 0.001% to 0.025%, Ti: 0.01% to 0.40%, and a balance of Fe and inevitable impurities, in which a difference between maximum and minimum values of an average crystal grain diameter determined by using measuring method 1 is 50 ?m or less, and in which a difference between maximum and minimum values of a crystal grain elongation rate determined by using measuring method 2 is 5.0 or less.
    Type: Application
    Filed: September 21, 2018
    Publication date: December 3, 2020
    Applicant: JFE Steel Corporation
    Inventors: Hidetaka Kawabe, Mitsuyuki Fujisawa, Hiroshi Shimizu, Tomohiko Uchino
  • Publication number: 20200347475
    Abstract: The present invention provides a ferritic stainless steel sheet and a method for manufacturing the same. A ferritic stainless steel sheet has a composition containing C: 0.001 to 0.020%, Si: 0.05 to 0.35%, Mn: 0.05 to 1.00%, P: 0.04% or less, S: 0.01% or less, Al: 0.001 to 0.300%, Cr: 10.0 to 13.0%, Ni: 0.75 to 1.50%, Ti: 0.05 to 0.35%, and N: 0.001 to 0.020%, with the balance being Fe and inevitable impurities, in which ?I [AD] represented by formula (1) below is 65% or more, and a metal structure has an average crystal grain size of 45 ?m or less: ?I [%]=24Ni+12Mn+6Cu?18Si?12Cr?12Mo+188 (1), where Ni, Mn, Cu, Si, Cr, and Mo represent contents of the respective elements (percent by mass), and an element not contained represents 0.
    Type: Application
    Filed: October 16, 2018
    Publication date: November 5, 2020
    Applicant: JFE Steel Corporation
    Inventors: Keishi Inoue, Hidetaka Kawabe, Masataka Yoshino, Mitsuyuki Fujisawa
  • Publication number: 20200308677
    Abstract: Provided is a ferritic stainless steel sheet excellent in shape of weld zone and corrosion resistance of a weld zone with a material of a different kind formed by performing welding with austenitic stainless steel. A ferritic stainless steel sheet having a chemical composition containing, by mass %, C: 0.003% to 0.020%, Si: 0.01% to 1.00%, Mn: 0.01% to 0.50%, P: 0.040% or less, S: 0.010% or less, Cr: 20.0% to 24.0%, Cu: 0.20% to 0.80%, Ni: 0.01% to 0.60%, Al: 0.01% to 0.08%, N:. 0.003% to 0.020%, Nb: 0.40% to 0.80%, Ti: 0.01% to 0.10%, Zr: 0.01% to 0.10%, and the balance being Fe and inevitable impurities, in which relational expression (1) below is satisfied: 3.0?Nb/(2Ti+Zr+0.5 Si+5 Al)?1.5 ??(1), here, in relational expression (1), each of the atomic symbols denotes the content (mass %) of the corresponding chemical element.
    Type: Application
    Filed: June 15, 2017
    Publication date: October 1, 2020
    Applicant: JFE Steel Corporation
    Inventors: Hidetaka Kawabe, Shuji Nishida, Mitsuyuki Fujisawa, Chikara Kami
  • Patent number: 10266906
    Abstract: A high-strength galvanized steel sheet has a chemical composition containing, by mass %, C: 0.16% or more and 0.24% or less, Si: 0.8% or more and 1.8% or less, Mn: 1.0% or more and 3.0% or less, P: 0.020% or less, S: 0.0040% or less, Al: 0.01% or more and 0.1% or less, N: 0.01% or less, Ca: 0.0001% or more and 0.0020% or less, and the balance including Fe and incidental impurities, and a microstructure, in which the total area ratio of a ferrite phase and a bainite phase with respect to the whole microstructure is 30% or more and 70% or less, in which the area ratio of a tempered martensite phase with respect to the whole microstructure is 20% or more and 40% or less, in which the area ratio of a retained austenite phase with respect to the whole microstructure is 10% or more and 20% or less, and in which the area ratio of a martensite phase with respect to the whole microstructure is 2% or more and 20% or less.
    Type: Grant
    Filed: March 26, 2014
    Date of Patent: April 23, 2019
    Assignee: JFE STEEL CORPORATION
    Inventors: Hidetaka Kawabe, Takeshi Yokota
  • Patent number: 10260133
    Abstract: There is provided a high-strength steel sheet having a tensile strength (TS) of 900 MPa or more and excellent elongation, stretch flangeability, and bendability in a component system in which an expensive alloy element is not intentionally added. A high-strength steel sheet includes a composition including, on a mass % basis, C: 0.15 to 0.40%, Si: 1.0 to 2.0%, Mn: 1.5 to 2.5%, P: 0.020% or less, S: 0.0040% or less, Al: 0.01 to 0.1%, N: 0.01% or less, and Ca: 0.0020% or less, with the balance including Fe and incidental impurities. The high-strength steel sheet has a microstructure including 40% to 70% of a ferrite phase and a bainite phase in total, 20% to 50% of a martensite phase, and 10% to 30% of a retained austenite phase in terms of an area fraction relative to the entire microstructure.
    Type: Grant
    Filed: March 26, 2014
    Date of Patent: April 16, 2019
    Assignee: JFE Steel Corporation
    Inventors: Hidetaka Kawabe, Takeshi Yokota, Reiko Sugihara, Kazunori Tahara
  • Patent number: 10100394
    Abstract: A high-strength galvannealed steel sheet has a chemical composition containing, by mass %, C: 0.14% or more and 0.24% or less, Si: 0.8% or more and 1.8% or less, Mn: 1.0% or more and 3.0% or less, P: 0.020% or less, S: 0.0040% or less, Al: 0.01% or more and 0.1% or less, N: 0.01% or less, Ca: 0.0001% or more and 0.
    Type: Grant
    Filed: March 26, 2014
    Date of Patent: October 16, 2018
    Assignee: JFE Steel Corporation
    Inventors: Hidetaka Kawabe, Takeshi Yokota
  • Patent number: 10072316
    Abstract: A cold-rolled steel sheet having a steel composition comprising, by mass %, 0.12% to 0.22% C, 0.8% to 1.8% Si, 1.8% to 2.8% Mn, 0.020% or less P, 0.0040% or less S, 0.005% to 0.08% Al, 0.008% or less N, 0.001% to 0.040% Ti, 0.0001% to 0.0020% B, 0.0001% to 0.0020% Ca, and Fe and incidental impurities. The steel sheet includes a microstructure in which ferrite and bainite phases are 50% to 70% of the total area, the average grain size of the ferrite and bainite phase is 1 to 3 ?m, a tempered martensite phase is 25% to 45% of the total area, the average grain size of the tempered martensite phase is 1 to 3 ?m, and a retained austenite phase is 2% to 10% of the total area.
    Type: Grant
    Filed: October 16, 2013
    Date of Patent: September 11, 2018
    Assignee: JFE STEEL CORPORATION
    Inventors: Hidetaka Kawabe, Takeshi Yokota, Reiko Sugihara, Daigo Itoh, Kazunori Tahara
  • Patent number: 9657380
    Abstract: A slab has a steel composition including 0.020% to 0.065% of C, 0.1% or less of Si, 0.40% to less than 0.80% of Mn, 0.030% or less of P, 0.005% or less of S, 0.08% to 0.16% of Ti, 0.005% to 0.1% of Al, 0.005% or less of N, and the balance being Fe and incidental impurities, in which Ti*(=Ti?(48/14)×N) satisfies [Ti*?0.08] and [0.300?C/Ti*?0.375], is subjected to hot rolling to obtain a hot-rolled steel sheet in which the steel microstructure includes, in terms of area fraction, 95% or more of a ferrite phase; the average ferrite grain size is 10 ?m or less; the average grain size of Ti carbides precipitated in steel is 10 nm or less; and Ti in the amount of 80% or more of Ti* is precipitated as Ti carbides.
    Type: Grant
    Filed: April 26, 2012
    Date of Patent: May 23, 2017
    Assignee: JFE Steel Corporation
    Inventors: Noriaki Kosaka, Kazuhiro Seto, Hidetaka Kawabe
  • Patent number: 9631250
    Abstract: A steel sheet has a microstructure including ferrite phase: 40% to 60%, bainite phase: 10% to 30%, tempered martensite phase: 20% to 40%, and retained austenite phase: 5% to 20% by volume fraction, and satisfying a condition that a ratio of tempered martensite phase having major axis length ?5 ?m to a total volume fraction of the tempered martensite phase is 80% to 100%.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: April 25, 2017
    Assignee: JFE Steel Corporation
    Inventors: Hidetaka Kawabe, Takeshi Yokota, Reiko Sugihara, Shigeyuki Aizawa, Kazuki Nakazato
  • Publication number: 20160168656
    Abstract: A high-strength cold-rolled steel sheet having excellent elongation, stretch flangeability, and bendability and a method for producing the same.
    Type: Application
    Filed: October 16, 2013
    Publication date: June 16, 2016
    Inventors: Hidetaka KAWABE, Takeshi YOKOTA, Reiko SUGIHARA, Daigo ITOH, Kazunori TAHARA
  • Publication number: 20160083819
    Abstract: There is provided a high-strength steel sheet having a tensile strength (TS) of 900 MPa or more and excellent elongation, stretch flangeability, and bendability in a component system in which an expensive alloy element is not intentionally added. A high-strength steel sheet includes a composition including, on a mass % basis, C: 0.15 to 0.40%, Si: 1.0 to 2.0%, Mn: 1.5 to 2.5%, P: 0.020% or less, S: 0.0040% or less, Al: 0.01 to 0.1%, N: 0.01% or less, and Ca: 0.0020% or less, with the balance including Fe and incidental impurities. The high-strength steel sheet has a microstructure including 40% to 70% of a ferrite phase and a bainite phase in total, 20% to 50% of a martensite phase, and 10% to 30% of a retained austenite phase in terms of an area fraction relative to the entire microstructure.
    Type: Application
    Filed: March 26, 2014
    Publication date: March 24, 2016
    Applicant: JFE STEEL CORPORATION
    Inventors: Hidetaka Kawabe, Takeshi Yokota, Reiko Sugihara, Kazunori Tahara
  • Patent number: 9284618
    Abstract: A high strength hot-rolled steel sheet with a tensile strength of not less than 590 MPa which exhibits excellent bake hardenability and stretch-flangeability has a chemical composition including, in terms of mass %, C at 0.040 to 0.10%, Si at not more than 0.3%, Mn at 1.7 to 2.5%, P at not more than 0.030%, S at not more than 0.005%, Al at not more than 0.1% and N at 0.006 to 0.025%, and microstructure wherein a bainite phase represents not less than 60%, the total of a ferrite phase and a pearlite phase represents not more than 10%, and the bainite phase includes grains among which cementite grains have been precipitated at not less than 1.4×104 grains/mm2 and the cementite grains have an average grain diameter of not more than 1.5 ?m.
    Type: Grant
    Filed: May 23, 2011
    Date of Patent: March 15, 2016
    Assignee: JFE Steel Corporation
    Inventors: Noriaki Kohsaka, Kazuhiro Seto, Hidetaka Kawabe, Yasushi Tanaka
  • Publication number: 20160047011
    Abstract: A high-strength galvanized steel sheet has a chemical composition containing, by mass %, C: 0.16% or more and 0.24% or less, Si: 0.8% or more and 1.8% or less, Mn: 1.0% or more and 3.0% or less, P: 0.020% or less, S: 0.0040% or less, Al: 0.01% or more and 0.1% or less, N: 0.01% or less, Ca: 0.0001% or more and 0.0020% or less, and the balance including Fe and incidental impurities, and a microstructure, in which the total area ratio of a ferrite phase and a bainite phase with respect to the whole microstructure is 30% or more and 70% or less, in which the area ratio of a tempered martensite phase with respect to the whole microstructure is 20% or more and 40% or less, in which the area ratio of a retained austenite phase with respect to the whole microstructure is 10% or more and 20% or less, and in which the area ratio of a martensite phase with respect to the whole microstructure is 2% or more and 20% or less.
    Type: Application
    Filed: March 26, 2014
    Publication date: February 18, 2016
    Applicant: JFE STEEL CORPORATION
    Inventors: Hidetaka Kawabe, Takeshi Yokota
  • Publication number: 20160047025
    Abstract: A high-strength galvannealed steel sheet has a chemical composition containing, by mass %, C: 0.14% or more and 0.24% or less, Si: 0.8% or more and 1.8% or less, Mn: 1.0% or more and 3.0% or less, P: 0.020% or less, S: 0.0040% or less, Al: 0.01% or more and 0.1% or less, N: 0.01% or less, Ca: 0.0001% or more and 0.
    Type: Application
    Filed: March 26, 2014
    Publication date: February 18, 2016
    Applicant: JFE STEEL CORPORATION
    Inventors: Hidetaka Kawabe, Takeshi Yokota
  • Patent number: 9073292
    Abstract: A high strength galvanized steel sheet includes a steel sheet which is a base sheet and a galvanized layer on a surface of the steel sheet, the steel sheet has a composition including, by mass %, 0.08 to 0.15% of C, 0.5 to 1.5% of Si, 0.5 to 1.5% of Mn, 0.1% or less of P, 0.01% or less of S, 0.01 to 0.1% of Al, 0.005% or less of N, and the balance Fe with inevitable impurities, and a microstructure composed of 75 to 90% of a ferrite phase as a main phase and 10 to 25% of a second phase including at least pearlite in terms of an area fraction with respect to the entire microstructure; an average grain size of the pearlite is 5 ?m or smaller; and the pearlite has an area fraction of 70% or greater with respect to the total area of the second phase.
    Type: Grant
    Filed: June 29, 2011
    Date of Patent: July 7, 2015
    Assignee: JFE Steel Corporation
    Inventors: Kenji Kawamura, Hidetaka Kawabe, Kazuhiro Seto
  • Publication number: 20150101717
    Abstract: A slab has a steel composition including 0.020% to 0.065% of C, 0.1% or less of Si, 0.40% to less than 0.80% of Mn, 0.030% or less of P, 0.005% or less of S, 0.08% to 0.16% of Ti, 0.005% to 0.1% of Al, 0.005% or less of N, and the balance being Fe and incidental impurities, in which Ti*(=Ti?(48/14)×N) satisfies [Ti*?0.08] and [0.300?C/Ti*?0.375], is subjected to hot rolling to obtain a hot-rolled steel sheet in which the steel microstructure includes, in terms of area fraction, 95% or more of a ferrite phase; the average ferrite grain size is 10 ?m or less; the average grain size of Ti carbides precipitated in steel is 10 nm or less; and Ti in the amount of 80% or more of Ti* is precipitated as Ti carbides.
    Type: Application
    Filed: April 26, 2012
    Publication date: April 16, 2015
    Applicant: JFE STEEL CORPORATION
    Inventors: Noriaki Kosaka, Kazuhiro Seto, Hidetaka Kawabe
  • Publication number: 20150034219
    Abstract: A steel sheet has a microstructure including ferrite phase: 40% to 60%, bainite phase: 10% to 30%, tempered martensite phase: 20% to 40%, and retained austenite phase: 5% to 20% by volume fraction, and satisfying a condition that a ratio of tempered martensite phase having major axis length ?5 ?m to a total volume fraction of the tempered martensite phase is 80% to 100%.
    Type: Application
    Filed: February 28, 2013
    Publication date: February 5, 2015
    Inventors: Hidetaka Kawabe, Takeshi Yokota, Reiko Sugihara, Shigeyuki Aizawa, Kazuki Nakazato
  • Publication number: 20130244056
    Abstract: A high strength galvanized steel sheet having excellent formability, includes a steel sheet which is a base sheet and a galvanized layer on a surface of the steel sheet, wherein the steel sheet is a high strength steel sheet which has a composition including, by mass %, 0.08 to 0.15% of C, 0.5 to 1.5% of Si, 0.5 to 1.5% of Mn, 0.1% or less of P, 0.01% or less of S, 0.01 to 0.1% of Al, 0.005% or less of N, and the balance Fe with inevitable impurities, and a microstructure composed of 75 to 90% of a ferrite phase as a main phase and 10 to 25% of a second phase including at least pearlite in terms of an area fraction with respect to the entire microstructure; an average grain size of the pearlite is 5 ?m or smaller; and the pearlite has an area fraction of 70% or greater with respect to the total area of the second phase.
    Type: Application
    Filed: June 29, 2011
    Publication date: September 19, 2013
    Applicant: JFE STEEL CORPORATION
    Inventors: Kenji Kawamura, Hidetaka Kawabe, Kazuhiro Seto
  • Publication number: 20130233453
    Abstract: A thin high strength steel sheet having excellent formability has a composition which includes, by mass %, 0.08 to 0.15% of C, 0.5 to 1.5% of Si, 0.5 to 1.5% of Mn, 0.01 to 0.1% of Al, and 0.005% or less of N to form a hot rolled sheet is conducted.
    Type: Application
    Filed: June 29, 2011
    Publication date: September 12, 2013
    Applicant: JFE STEEL CORPORATION
    Inventors: Kenji Kawamura, Hidetaka Kawabe, Kazuhiro Seto, Noriyuki Katayama
  • Publication number: 20130199678
    Abstract: A high strength hot-rolled steel sheet with a tensile strength of not less than 590 MPa which exhibits excellent bake hardenability and stretch-flangeability has a chemical composition including, in terms of mass %, C at 0.040 to 0.10%, Si at not more than 0.3%, Mn at 1.7 to 2.5%, P at not more than 0.030%, S at not more than 0.005%, Al at not more than 0.1% and N at 0.006 to 0.025%, and microstructure wherein a bainite phase represents not less than 60%, the total of a ferrite phase and a pearlite phase represents not more than 10%, and the bainite phase includes grains among which cementite grains have been precipitated at not less than 1.4×104 grains/mm2 and the cementite grains have an average grain diameter of not more than 1.5 ?m.
    Type: Application
    Filed: May 23, 2011
    Publication date: August 8, 2013
    Applicant: JFE STEEL CORPORATION
    Inventors: Noriaki Kohsaka, Kazuhiro Seto, Hidetaka Kawabe, Yasushi Tanaka