Patents by Inventor Hyo Jung KWAK

Hyo Jung KWAK 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: 10533241
    Abstract: The present invention relates to a hot-rolled steel sheet for a high strength galvanized steel sheet, having excellent surface quality, and a method for producing the same, the hotrolled steel sheet comprising, by weight %: C: 0.08 to 0.2%, Si: 0.03 to 0.15%, Mn: 1.4 to 2%, P: 0.001 to 0.05%, S: 0.001 to 0.03%, Al: 0.002 to 0.05%, and the remainder being Fe and unavoidable impurities. The weight ratio of Mn/Si is 20 to 30, the weight ratio of C/Si is 1 to 5, and the weight ratio of Si/P is 3 to 10. The hot-rolled steel sheet has a microstructure consisting of, in area fraction, 10 to 40% of bainite, 20 to 30% of pearlite and 40 to 60% of ferrite, and includes a ternary eutectic compound of FeO, Fe2SiO4 and Fe3(PO4)2 formed within 50 ?m from the surface.
    Type: Grant
    Filed: December 24, 2014
    Date of Patent: January 14, 2020
    Assignee: POSCO
    Inventors: Young-Ha Kim, Hyo Jung Kwak, Seok Jong Seo
  • Patent number: 10351927
    Abstract: The present invention relates to a hot-rolled steel sheet for a high strength galvanized steel sheet, having excellent surface quality, and a method for producing the same, the hot-rolled steel sheet comprising, by weight %: C: 0.05 to 0.15%, Si: 0.03 to 0.10%, Mn: 0.7 to 1.39%, P: 0.001 to 0.05%, S: 0.001 to 0.03%, Al: 0.002 to 0.035%, and the remainder being Fe and unavoidable impurities. The weight ratio of Mn/Si is 15 to 25, the weight ratio of C/Si is 1 to 5, and the weight ratio of Si/P is 3 to 10. The hot-rolled steel sheet has a microstructure consisting of, in area fraction, 10 to 40% of bainite, 20 to 30% of pearlite and 40 to 60% of ferrite, and includes a ternary eutectic compound of FeO, Fe2SiO4 and Fe3(PO)4 formed within 50 ?m from the surface.
    Type: Grant
    Filed: December 24, 2014
    Date of Patent: July 16, 2019
    Assignee: POSCO
    Inventors: Hyo Jung Kwak, Young-Ha Kim, Seok Jong Seo
  • Publication number: 20170342529
    Abstract: The present invention relates to a hot-rolled steel sheet for a high strength galvanized steel sheet, having excellent surface quality, and a method for producing the same, the hot-rolled steel sheet comprising, by weight %: C: 0.08 to 0.2%, Si: 0.03 to 0.15%, Mn: 1.4 to 2%, P: 0.001 to 0.05%, S: 0.001 to 0.03%, Al: 0.002 to 0.05%, and the remainder being Fe and unavoidable impurities. The weight ratio of Mn/Si is 20 to 30, the weight ratio of C/Si is 1 to 5, and the weight ratio of Si/P is 3 to 10. The hot-rolled steel sheet has a microstructure consisting of, in area fraction, 10 to 40% of bainite, 20 to 30% of pearlite and 40 to 60% of ferrite, and includes a ternary eutectic compound of FeO, Fe2SiO4 and Fe3(PO)4 formed within 50 ?m from the surface.
    Type: Application
    Filed: December 24, 2014
    Publication date: November 30, 2017
    Inventors: Young-Ha Kim, Hyo Jung Kwak, Seok Jong SEO
  • Publication number: 20170342522
    Abstract: The present invention relates to a hot-rolled steel sheet for a high strength galvanized steel sheet, having excellent surface quality, and a method for producing the same, the hot-rolled steel sheet comprising, by weight %: C: 0.05 to 0.15%, Si: 0.03 to 0.10%, Mn: 0.7 to 1.39%, P: 0.001 to 0.05%, S: 0.001 to 0.03%, Al: 0.002 to 0.035%, and the remainder being Fe and unavoidable impurities. The weight ratio of Mn/Si is 15 to 25, the weight ratio of C/Si is 1 to 5, and the weight ratio of Si/P is 3 to 10. The hot-rolled steel sheet has a microstructure consisting of, in area fraction, 10 to 40% of bainite, 20 to 30% of pearlite and 40 to 60% of ferrite, and includes a ternary eutectic compound of FeO, Fe2SiO4 and Fe3(PO)4 formed within 50 ?m from the surface.
    Type: Application
    Filed: December 24, 2014
    Publication date: November 30, 2017
    Applicant: POSCO
    Inventors: Hyo Jung KWAK, Young-Ha KIM, Seok Jong SEO