Patents by Inventor Yeon-Jung Hwang

Yeon-Jung Hwang 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: 20230347444
    Abstract: A hot-stamped article and a method of manufacturing same use a tailor welded blank (TWB) method capable of controlling the microstructure of a weld portion to prevent fracture of the weld portion. The method includes: preparing a first sheet and a second sheet having different upper austenite transformation temperatures (A3 temperatures); welding the first sheet and the second sheet using a TWB method to prepare a welded sheet obtained as a result of the first sheet and the second sheet being welded to each other via a weld portion; and hot-stamping the welded sheet heated within a temperature range between an A3 temperature of the first sheet and an A3 temperature of the second sheet.
    Type: Application
    Filed: June 7, 2023
    Publication date: November 2, 2023
    Applicants: HYUNDAI MOTOR COMPANY, KIA CORPORATION
    Inventors: Chang Wook Lee, Yeon Jung Hwang
  • Patent number: 11724338
    Abstract: A hot-stamped article and method of manufacturing same use a tailor welded blank (TWB) method capable of controlling the microstructure of a weld portion to prevent fracture of the weld portion. The hot-stamped article is manufactured by welding a first sheet and a second sheet made of different kinds of materials to each other using the TWB method and hot-stamping a welded sheet. The first sheet and the second sheet have different upper austenite transformation temperatures (A3 temperatures), the first sheet and the second sheet are welded to each other via a weld portion, each of the first sheet and the weld portion has a composite structure comprising ferrite, bainite, and martensite, and the second sheet has a martensite structure.
    Type: Grant
    Filed: April 30, 2021
    Date of Patent: August 15, 2023
    Assignees: HYUNDAI MOTOR COMPANY, KIA CORPORATION
    Inventors: Chang Wook Lee, Yeon Jung Hwang
  • Publication number: 20230193417
    Abstract: Disclosed is a hot stamped part, which has improved toughness while maintaining high strength and high hardness, and a method for manufacturing the same. The hot stamped part is formed by performing hot stamping using an iron-based alloy, and includes a reinforced portion formed to have a martensite structure, a softened portion formed to have ferrite and bainite structures, and a transition portion formed between the reinforced portion and the softened portion. The reinforced portion, the transition portion and the softened portion are formed in the thickness direction of the hot stamped part.
    Type: Application
    Filed: February 15, 2023
    Publication date: June 22, 2023
    Inventors: Yeon Jung Hwang, Jae Ik Yoon, Chang Wook Lee
  • Patent number: 11649521
    Abstract: A hot stamping component and a manufacturing method thereof include: (a) preparing a blank including 0.27 to 0.33 wt % of carbon (C), more than 0 and 0.40 wt % or less of silicon (Si), 1.10 to 1.60 wt % of manganese (Mn), more than 0 and 0.030 wt % or less of phosphorus (P), more than 0 and 0.015 wt % or less of sulfur (S), 0.10 to 0.60 wt % of chromium (Cr), more than 0 and 0.1 wt % or less of titanium (Ti), and 0.0008 to 0.0050 wt % of boron (B); (b) heat-treating the blank; and (c) molding the heat-treated blank and cooling the molded blank. The component and method may stably provide high strength by minimizing hydrogen charging in a hot stamping manufacturing process and preventing hydrogen delayed fracture due to the hydrogen charging.
    Type: Grant
    Filed: May 7, 2021
    Date of Patent: May 16, 2023
    Assignees: HYUNDAI MOTOR COMPANY, KIA CORPORATION
    Inventors: Chang-Wook Lee, Yeon-Jung Hwang
  • Publication number: 20220161360
    Abstract: A hot-stamped article and method of manufacturing same use a tailor welded blank (TWB) method capable of controlling the microstructure of a weld portion to prevent fracture of the weld portion. The hot-stamped article is manufactured by welding a first sheet and a second sheet made of different kinds of materials to each other using the TWB method and hot-stamping a welded sheet. The first sheet and the second sheet have different upper austenite transformation temperatures (A3 temperatures), the first sheet and the second sheet are welded to each other via a weld portion, each of the first sheet and the weld portion has a composite structure comprising ferrite, bainite, and martensite, and the second sheet has a martensite structure.
    Type: Application
    Filed: April 30, 2021
    Publication date: May 26, 2022
    Applicants: HYUNDAI MOTOR COMPANY, KIA CORPORATION
    Inventors: Chang Wook Lee, Yeon Jung Hwang
  • Publication number: 20220162722
    Abstract: A hot stamping component and a manufacturing method thereof include: (a) preparing a blank including 0.27 to 0.33 wt % of carbon (C), more than 0 and 0.40 wt % or less of silicon (Si), 1.10 to 1.60 wt % of manganese (Mn), more than 0 and 0.030 wt % or less of phosphorus (P), more than 0 and 0.015 wt % or less of sulfur (S), 0.10 to 0.60 wt % of chromium (Cr), more than 0 and 0.1 wt % or less of titanium (Ti), and 0.0008 to 0.0050 wt % of boron (B); (b) heat-treating the blank; and (c) molding the heat-treated blank and cooling the molded blank. The component and method may stably provide high strength by minimizing hydrogen charging in a hot stamping manufacturing process and preventing hydrogen delayed fracture due to the hydrogen charging.
    Type: Application
    Filed: May 7, 2021
    Publication date: May 26, 2022
    Applicants: HYUNDAI MOTOR COMPANY, KIA CORPORATION
    Inventors: Chang-Wook Lee, Yeon-Jung Hwang
  • Publication number: 20220154305
    Abstract: Disclosed is a hot stamped part, which has improved toughness while maintaining high strength and high hardness, and a method for manufacturing the same. The hot stamped part is formed by performing hot stamping using an iron-based alloy, and includes a reinforced portion formed to have a martensite structure, a softened portion formed to have ferrite and bainite structures, and a transition portion formed between the reinforced portion and the softened portion. The reinforced portion, the transition portion and the softened portion are formed in the thickness direction of the hot stamped part.
    Type: Application
    Filed: May 4, 2021
    Publication date: May 19, 2022
    Inventors: Yeon Jung Hwang, Jae Ik Yoon, Chang Wook Lee
  • Patent number: 10864595
    Abstract: A method of projection welding hardware to a plated steel sheet for hot stamping, may include pressing hardware and a plated steel sheet in a state in which a welding projection on the hardware is in contact with the plated steel sheet, supplying a primary current to the hardware and the plated steel sheet in a state in which they are pressed, and supplying a secondary current to the hardware and the plated steel sheet.
    Type: Grant
    Filed: December 28, 2017
    Date of Patent: December 15, 2020
    Assignees: Hyundai Motor Company, Kia Motors Corporation
    Inventors: Yeon-Jung Hwang, Young-Tae Kim
  • Publication number: 20180250766
    Abstract: A method of projection welding hardware to a plated steel sheet for hot stamping, may include pressing hardware and a plated steel sheet in a state in which a welding projection on the hardware is in contact with the plated steel sheet, supplying a primary current to the hardware and the plated steel sheet in a state in which they are pressed, and supplying a secondary current to the hardware and the plated steel sheet.
    Type: Application
    Filed: December 28, 2017
    Publication date: September 6, 2018
    Applicants: Hyundai Motor Company, Kia Motors Corporation
    Inventors: Yeon-Jung Hwang, Young-Tae Kim