Patents by Inventor Sota Goto

Sota Goto 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: 20210238719
    Abstract: The high-strength hot-rolled coated steel sheet includes a steel sheet having a chemical composition containing, by mass %, C: 0.03% to 0.09%, Si: 0.01% to 1.60%, Mn: 2.20% to 3.60%, P: 0.100% or less, S: 0.0100% or less, Ti: 0.05% to 0.18%, B: 0.0005% to 0.0050%, Al: 0.005% to 0.40%, N: 0.010% or less, and a balance of Fe and inevitable impurities, in which a CSM value expressed by the equation 33.8[% C][% Mn]+12.4[% Si]/[% Mn] is 3.3 to 12.0, and a steel microstructure containing bainite in an amount of 85% or more in terms of area fraction and martensite in an amount of 2.0% or more and 15.0% or less in terms of area fraction and includes a coating layer or an alloyed coating layer on a surface of the steel sheet.
    Type: Application
    Filed: June 10, 2019
    Publication date: August 5, 2021
    Applicant: JFE Steel Corporation
    Inventors: Sota Goto, Kazuhiko Yamazaki, Thi Huyen Doan, Yoshihiko Ono
  • Patent number: 11053564
    Abstract: A high-strength high-toughness electric-resistance-welded steel pipe having high resistance to post-weld heat treatment is provided. The steel pipe having a composition including C: 0.01% to 0.12%, Si: 0.05% to 0.50%, Mn: 1.0% to 2.2%, P: 0.03% or less, S: 0.005% or less, Al: 0.001% to 0.10%, N: 0.006% or less, Nb: 0.010% to 0.100%, and Ti: 0.001% to 0.050%. The steel pipe having a structure composed of a 90% or more by volume of a bainitic ferrite phase as a main phase and 10% or less (including 0%) by volume of a second phase. The bainitic ferrite phase having an average grain size of 10 ?m or less, and the structure containing fine Nb precipitates having a particle size of less than 20 nm dispersed in a base material portion. The steel pipe having high strength, toughness, and high resistance that is maintained through post-weld heat treatment.
    Type: Grant
    Filed: December 15, 2015
    Date of Patent: July 6, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Sota Goto, Takatoshi Okabe, Yukihiko Okazaki
  • Patent number: 11041223
    Abstract: A high-strength high-toughness electric-resistance-welded steel pipe having high resistance to post-weld heat treatment is provided. The steel pipe having a composition including C: 0.01% to 0.12%, Si: 0.05% to 0.50%, Mn: 1.0% to 2.2%, P: 0.03% or less, S: 0.005% or less, Al: 0.001% to 0.10%, N: 0.006% or less, Nb: 0.010% to 0.100%, and Ti: 0.001% to 0.050%. The steel pipe having a structure composed of 90% or more by volume of a bainitic ferrite phase and 10% or less (including 0%) by volume of a second phase. The bainitic ferrite phase having an average grain size of 10 ?m or less, and the structure containing fine Nb precipitates having a particle size of less than 20 nm dispersed in a base material portion. The steel pipe having high strength and toughness that is maintained through post-weld heat treatment, including heating to a temperature of 600° C. or more.
    Type: Grant
    Filed: December 15, 2015
    Date of Patent: June 22, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Sota Goto, Takatoshi Okabe, Yukihiko Okazaki
  • Publication number: 20210129491
    Abstract: Provided is a high-strength hot-rolled coated steel sheet with excellent formability, A high-strength hot-rolled coated steel sheet has a constituent composition containing, in a mass percent, C: 0.03% to 0.15%, Si: 0.4% or less, Mn: 1.2% to 1.9%, Ti: 0.05% to 0.25%, B: 0.0005% to 0.0050%, P: 0.03% or less, S: 0.005% or less, Al: 0.005% to 0.4%, and N: 0.01% or less, the balance being Fe and incidental impurities. The total area fraction of one or more of ferrite and tempered bainite is 90% or more. The steel sheet has a structure in which the volume fraction of Ti carbides having particle sizes of 20 nm or less is 0.05 vol % or more.
    Type: Application
    Filed: February 26, 2018
    Publication date: May 6, 2021
    Applicant: JFE Steel Corporation
    Inventors: Sota Goto, Kazuhiko Yamazaki, Taro Kizu, Shunsuke Toyoda
  • Patent number: 10900104
    Abstract: A method for manufacturing a hot rolled steel sheet having a low yield ratio and that is excellent in low-temperature toughness, the steel sheet having a specified chemical composition. The method comprises hot rolling a steel material into a steel sheet, cooling the steel material using a cooling process comprising a first cooling and a second cooling, and performing a coiling process on the steel sheet in such a manner that the coiling temperature is 450° C. or more in terms of surface temperature of the steel sheet.
    Type: Grant
    Filed: July 5, 2018
    Date of Patent: January 26, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Chikara Kami, Sota Goto
  • Patent number: 10584405
    Abstract: A resistance welded steel pipe is provided. A hot-rolled steel sheet having a composition containing, in mass %, C: 0.025 to 0.168%, Si: 0.10 to 0.30%, Mn: 0.60 to 1.90%, and one or at least two selected from Ca, Nb, V, and Ti such that Pcm is 0.20 or less is subjected to continuous cold roll forming to obtain a pipe-shaped body. Tapered grooves are formed in the steel sheet such that the ratio of the tapered portions to the wall thickness of the steel sheet is 10 to 80%. Then end surfaces of the pipe-shaped body are butted against each other and subjected to electric resistance welding. Ultrasonic waves are transmitted toward the electric resistance weld surface such that a beam width is within the range of 0.1 to 4.0 mm, and the reflected waves are used for ultrasonic flaw detection using an ultrasonic flaw detector.
    Type: Grant
    Filed: November 17, 2015
    Date of Patent: March 10, 2020
    Assignee: JFE Steel Corporation
    Inventors: Shunsuke Toyoda, Takatoshi Okabe, Sota Goto, Yutaka Matsui, Satoru Yabumoto
  • Patent number: 10385417
    Abstract: By using, as a raw material, a thick hot-rolled steel sheet having a chemical composition containing, by mass %, C: 0.02% or more and 0.10% or less, Si: 0.05% or more and 0.30% or less, Mn: 0.80% or more and 2.00% or less, and Nb: 0.010% or more and 0.100% or less and satisfying the condition that a carbon equivalent Ceq is 0.25% or more and 0.50% or less, a microstructure including a bainitic ferrite phase and/or a bainite phase, a high strength of 52 ksi or more in terms of yield strength and a high toughness of ?45° C. or lower in terms of fracture transition temperature vTrs, and satisfying the condition that the ratio of the average crystal grain size of the coarsest-grain portion to the average crystal grain size of the finest-grain portion is 2.0 or less in every portion in the wall thickness direction is obtained.
    Type: Grant
    Filed: July 8, 2014
    Date of Patent: August 20, 2019
    Assignee: JFE Steel Corporation
    Inventors: Sota Goto, Shunsuke Toyoda, Takatoshi Okabe
  • Publication number: 20190211430
    Abstract: A hot-rolled steel sheet for a heavy-wall, high-strength line pipe, the steel sheet having a chemical composition including, in mass %, C: 0.02 to 0.20%, Mn: 0.80 to 2.10%, Si: 0.01 to 0.50%, P: 0.034% or less, S: 0.0050% or less, Nb: 0.01 to 0.15%, Ti: 0.001 to 0.030%, and Al: 0.001 to 0.080%, the balance being Fe and incidental impurities, the steel sheet having a microstructure in which a main phase is a continuous cooling transformation structure and in which {001}? grains in a plane whose normal direction is the sheet width direction constitute an area fraction of 10% or less and have a combined size of 10 ?m or less, wherein the steel sheet has a tensile strength of 520 MPa or greater, and, in a drop weight tear test, a temperature at which a percent ductile fracture reaches 85% is ?25° C. or lower.
    Type: Application
    Filed: June 6, 2017
    Publication date: July 11, 2019
    Applicant: JFE Steel Corporation
    Inventors: Sota Goto, Hiroshi Nakata, Junji Shimamura
  • Patent number: 10287661
    Abstract: A hot-rolled steel sheet is provided having high strength and excellent toughness and ductility includes a composition that contains, on a mass percent basis, 0.04% or more and 0.15% or less of C, 0.01% or more and 0.55% or less of Si, 1.0% or more and 3.0% or less of Mn, 0.03% or less P, 0.01% or less S, 0.003% or more and 0.1% or less of Al, 0.006% or less N, 0.035% or more and 0.1% or less Nb, 0.001% or more and 0.1% or less of V, 0.001% or more and 0.1% or less Ti, and the balance being Fe and incidental impurities, in which the hot-rolled steel sheet includes a microstructure in which the proportion of precipitated Nb to the total amount of Nb is 35% or more and 80% or less, the volume fraction of tempered martensite and/or tempered bainite having a lath interval of 0.2 ?m or more and 1.6 ?m or less is 95% or more at a position 1.0 mm from a surface of the sheet in the thickness direction, and the volume fraction of ferrite having a lath interval of 0.2 ?m or more and 1.
    Type: Grant
    Filed: March 20, 2014
    Date of Patent: May 14, 2019
    Assignee: JFE STEEL CORPORATION
    Inventors: Tomoaki Shibata, Sota Goto
  • Patent number: 10273554
    Abstract: A hot-rolled steel sheet has a chemical composition containing, by mass %, C: 0.030% or more and 0.120% or less, Si: 0.05% or more and 0.50% or less, Mn: 1.00% or more and 2.20% or less, P: 0.025% or less, S: 0.0050% or less, N: 0.0060% or less, Al: 0.005% or more and 0.100% or less, Nb: 0.020% or more and 0.100% or less, Mo: 0.05% or more and 0.50% or less, Ti: 0.001% or more and 0.100% or less, Cr: 0.05% or more and 0.50% or less, Ca: 0.0005% or more and 0.0050% or less, and the balance being Fe and inevitable impurities, and has a microstructure including bainitic ferrite as a main phase and martensite and retained austenite as second phases, wherein a volume fraction of the main phase is 90% or more, an average grain diameter of the main phase is 10 ?m or less, a volume fraction of the martensite is 0.5% or more and 9.5% or less, and a volume fraction of the retained austenite is 0.5% or more and 9.
    Type: Grant
    Filed: November 20, 2014
    Date of Patent: April 30, 2019
    Assignee: JFE Steel Corporation
    Inventors: Tomoaki Shibata, Sota Goto
  • Publication number: 20180312945
    Abstract: A method for manufacturing a hot rolled steel sheet having a low yield ratio and that is excellent in low-temperature toughness, the steel sheet having a specified chemical composition. The method comprises hot rolling a steel material into a steel sheet, cooling the steel material using a cooling process comprising a first cooling and a second cooling, and performing a coiling process on the steel sheet in such a manner that the coiling temperature is 450° C. or more in terms of surface temperature of the steel sheet.
    Type: Application
    Filed: July 5, 2018
    Publication date: November 1, 2018
    Applicant: JFE STEEL CORPORATION
    Inventors: Chikara KAMI, Sota GOTO
  • Publication number: 20180243809
    Abstract: Provided are an electric resistance welded stainless clad steel manufactured by forming a hot-rolled steel strip of clad steel including low-carbon low-alloy steel and stainless steel into a cylindrical shape, and electric resistance welding the edges of the hot-rolled steel strip, characterized in that the flattening characteristic of an electric resistance weld, as-welded, satisfies the formula h/D<0.3, wherein h is the flattened height at fracture (mm) and D is the outer diameter of the pipe (mm), and a method of manufacturing the same.
    Type: Application
    Filed: February 18, 2016
    Publication date: August 30, 2018
    Applicant: JFE STEEL CORPORATION
    Inventors: Takatoshi Okabe, Sota Goto, Yuji Hashimoto, Yasushi Kato, Atsushi Matsumoto, Shinsuke Ide, Hiroki Ota
  • Patent number: 10047416
    Abstract: A high strength hot rolled steel sheet is provided with low yield ratio and that is excellent in low-temperature toughness. The hot rolled steel sheet can be used as a raw material of a steel pipe. The steel sheet has a chemical composition containing C: 0.03% or more and 0.10% or less, Si: 0.01% or more and 0.50% or less, Mn: 1.4% or more and 2.2% or less, P: 0.025% or less, S: 0.005% or less, Al: 0.005% or more and 0.10% or less, Nb: 0.02% or more and 0.10% or less, Ti: 0.001% or more and 0.030% or less, Mo: 0.01% or more and 0.50% or less, Cr: 0.01% or more and 0.50% or less, and Ni: 0.01% or more and 0.50% or less, in which the condition that Moeq is 1.4% or more and 2.2% or less.
    Type: Grant
    Filed: September 11, 2013
    Date of Patent: August 14, 2018
    Assignee: JFE STEEL CORPORATION
    Inventors: Chikara Kami, Sota Goto
  • Publication number: 20180030557
    Abstract: Provided is a high-strength electric resistance welded steel pipe having excellent bendability and which includes a composition containing, on a mass % basis, C: 0.04% to 0.15%, Si: 0.10% to 0.50%, Mn: 1.0% to 2.2%, P: 0.050% or less, S: 0.005% or less, Cr: 0.2% to 1.0%, Ti: 0.005% to 0.030%, and Al: 0.010% to 0.050%, the balance being Fe and unavoidable impurities, and a microstructure including polygonal ferrite with a volume fraction of 70% or more and retained austenite with a volume fraction of 3% to 20%, the balance being at least one selected from martensite, bainite, and pearlite, wherein the polygonal ferrite has an average grain size of 5 ?m or more and an aspect ratio of 1.40 or less.
    Type: Application
    Filed: February 18, 2016
    Publication date: February 1, 2018
    Applicant: JFE STEEL CORPORATION
    Inventors: Sota Goto, Shunsuke Toyoda, Takatoshi Okabe
  • Patent number: 9873164
    Abstract: Electric resistance welded steel pipes or steel tubes with a tensile property TS of not less than 434 MPa which have electric resistance welded parts exhibiting both excellent HIC resistance and excellent low-temperature toughness, and methods for manufacturing such steel pipes or steel tubes.
    Type: Grant
    Filed: September 20, 2013
    Date of Patent: January 23, 2018
    Assignee: JFE STEEL CORPORATION
    Inventors: Shunsuke Toyoda, Sota Goto, Takatoshi Okabe, Atsushi Yonemoto
  • Publication number: 20170369962
    Abstract: A high-strength high-toughness electric-resistance-welded steel pipe having high resistance to post-weld heat treatment is provided. The steel pipe having a composition including C: 0.01% to 0.12%, Si: 0.05% to 0.50%, Mn: 1.0% to 2.2%, P: 0.03% or less, S: 0.005% or less, Al: 0.001% to 0.10%, N: 0.006% or less, Nb: 0.010% to 0.100%, and Ti: 0.001% to 0.050%. The steel pipe having a structure composed of 90% or more by volume of a bainitic ferrite phase and 10% or less (including 0%) by volume of a second phase. The bainitic ferrite phase having an average grain size of 10 ?m or less, and the structure containing fine Nb precipitates having a particle size of less than 20 nm dispersed in a base material portion. The steel pipe having high strength and toughness that is maintained through post-weld heat treatment, including heating to a temperature of 600° C. or more.
    Type: Application
    Filed: December 15, 2015
    Publication date: December 28, 2017
    Applicant: JFE Steel Corporation
    Inventors: Sota GOTO, Takatoshi OKABE, Yukihiko OKAZAKI
  • Publication number: 20170362678
    Abstract: A high-strength high-toughness electric-resistance-welded steel pipe having high resistance to post-weld heat treatment is provided. The steel pipe having a composition including C: 0.01% to 0.12%, Si: 0.05% to 0.50%, Mn: 1.0% to 2.2%, P: 0.03% or less, S: 0.005% or less, Al: 0.001% to 0.10%, N: 0.006% or less, Nb: 0.010% to 0.100%, and Ti: 0.001% to 0.050%. The steel pipe having a structure composed of a 90% or more by volume of a bainitic ferrite phase as a main phase and 10% or less (including 0%) by volume of a second phase. The bainitic ferrite phase having an average grain size of 10 ?m or less, and the structure containing fine Nb precipitates having a particle size of less than 20 nm dispersed in a base material portion. The steel pipe having high strength, toughness, and high resistance that is maintained through post-weld heat treatment.
    Type: Application
    Filed: December 15, 2015
    Publication date: December 21, 2017
    Applicant: JFE STEEL CORPORATION
    Inventors: Sota GOTO, Takatoshi OKABE, Yukihiko OKAZAKI
  • Publication number: 20170356071
    Abstract: A resistance welded steel pipe is provided. A hot-rolled steel sheet having a composition containing, in mass %, C: 0.025 to 0.168%, Si: 0.10 to 0.30%, Mn: 0.60 to 1.90%, and one or at least two selected from Ca, Nb, V, and Ti such that Pcm is 0.20 or less is subjected to continuous cold roll forming to obtain a pipe-shaped body. Tapered grooves are formed in the steel sheet such that the ratio of the tapered portions to the wall thickness of the steel sheet is 10 to 80%. Then end surfaces of the pipe-shaped body are butted against each other and subjected to electric resistance welding. Ultrasonic waves are transmitted toward the electric resistance weld surface such that a beam width is within the range of 0.1 to 4.0 mm, and the reflected waves are used for ultrasonic flaw detection using an ultrasonic flaw detector.
    Type: Application
    Filed: November 17, 2015
    Publication date: December 14, 2017
    Applicant: JFE STEEL CORPORATION
    Inventors: Shunsuke TOYODA, Takatoshi OKABE, Sota GOTO, Yutaka MATSUI, Satoru YABUMOTO
  • Patent number: 9841124
    Abstract: A high-strength thick-walled electric resistance welded steel pipe has excellent low-temperature toughness and excellent HIC resistance and a yield strength of 400 MPa or more. The steel has a chemical composition consisting of C: 0.025% to 0.084%, Si: 0.10% to 0.30%, Mn: 0.70% to 1.80%, controlled amounts of P, S, Al, N, and O, Nb: 0.001% to 0.065%, V: 0.001% to 0.065%, Ti: 0.001% to 0.033%, and Ca: 0.0001% to 0.0035% on a mass percent basis and the remainder being Fe and incidental impurities, and satisfies Pcm of 0.20 or less.
    Type: Grant
    Filed: April 11, 2013
    Date of Patent: December 12, 2017
    Assignee: JFE Steel Corporation
    Inventors: Shunsuke Toyoda, Sota Goto, Takatoshi Okabe, Tomohiro Inoue, Motoharu Egi, Atsushi Yonemoto
  • Patent number: 9551047
    Abstract: A high strength electric resistance welded steel pipe has a yield strength of 450 MPa or more and excellent resistance to softening for a long period in an intermediate temperature range and a method of manufacturing the steel pipe are provided. The steel pipe has a chemical composition containing, by mass%, C: 0.026% or more and 0.084% or less, Si: 0.10% or more and 0.30% or less, Mn: 0.70% or more and 1.90% or less, Al: 0.01% or more and 0.10% or less, Nb: 0.001% or more and 0.070% or less, V: 0.001% or more and 0.065% or less, Ti: 0.001% or more and 0.033% or less, Ca: 0.0001% or more and 0.0035% or less, in which the condition that Pcm is 0.20 or less is satisfied.
    Type: Grant
    Filed: June 17, 2013
    Date of Patent: January 24, 2017
    Assignee: JFE Steel Corporation
    Inventors: Shunsuke Toyoda, Sota Goto, Takatoshi Okabe, Tomohiro Inoue