Patents by Inventor Hyung-Gook Lee

Hyung-Gook Lee 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: 11535294
    Abstract: Carbon steel for a rack bar contains 0.50 to 0.55% by weight of carbon (C), 0.15 to 0.35% by weight of silicon (Si), 0.75 to 0.95% by weight of manganese (Mn), 0.025% by weight or less of phosphorus (P), 0.025% by weight or less of sulfur (S), 0.65 to 0.85% by weight of chrome (Cr), 0.20% by weight or less of molybdenum (Mo), 0.001 to 0.02% by weight of aluminum (Al), 5 to 50 ppm of boron (B), and iron (Fe) as a remainder and unavoidable impurities. A method for manufacturing the rack bar includes quenching, tempering, and drawing the carbon steel and warm forging the drawn carbon steel.
    Type: Grant
    Filed: February 24, 2021
    Date of Patent: December 27, 2022
    Assignees: HYUNDAI MOTOR COMPANY, KIA MOTORS CORPORATION, HYUNDAI STEEL COMPANY
    Inventors: Hyung Gook Lee, Jae Han Lim
  • Publication number: 20220161843
    Abstract: Carbon steel for a rack bar contains 0.50 to 0.55% by weight of carbon (C), 0.15 to 0.35% by weight of silicon (Si), 0.75 to 0.95% by weight of manganese (Mn), 0.025% by weight or less of phosphorus (P), 0.025% by weight or less of sulfur (S), 0.65 to 0.85% by weight of chrome (Cr), 0.20% by weight or less of molybdenum (Mo), 0.001 to 0.02% by weight of aluminum (Al), 5 to 50 ppm of boron (B), and iron (Fe) as a remainder and unavoidable impurities. A method for manufacturing the rack bar includes quenching, tempering, and drawing the carbon steel and warm forging the drawn carbon steel.
    Type: Application
    Filed: February 24, 2021
    Publication date: May 26, 2022
    Applicants: HYUNDAI MOTOR COMPANY, KIA MOTORS CORPORATION, HYUNDAI STEEL COMPANY
    Inventors: Hyung Gook Lee, Jae Han Lim
  • Publication number: 20200216923
    Abstract: Disclosed are a method for heat-treating a surface of a spheroidal graphite cast iron, particularly, heat-treating an uppermost surface of spheroidal graphite cast iron, and spheroidal graphite cast iron heat-treated by the same. The method may include first heat treating for forming ferrite and second heat treating for oxy-nitriding. The spheroidal graphite cast iron heat-treated includes an oxidation layer and a compound layer having a thickness of about 15 to 30 ?m, which may be uniform. The method of the heat-treating may decrease the pearlite fraction in the uppermost surface of spheroidal graphite cast iron and increase the ferrite fraction by forming ferrite, thereby forming a compound layer having a thickness of about 15 to 30 ?m during an oxy-nitriding heat treatment.
    Type: Application
    Filed: October 24, 2019
    Publication date: July 9, 2020
    Inventors: Eun-Soo Kwon, Hyung-Gook Lee, Yong-Bo Sim