Patents by Inventor Yong-Sun Yi

Yong-Sun Yi 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: 7782994
    Abstract: This invention relates to an inhibitor of lead-induced stress corrosion cracking including nickel boride in the secondary side of steam generator tubes in nuclear power plants and an inhibition method using the same, and more particularly, to an inhibitor of lead-induced stress corrosion cracking, in which nickel boride is added to secondary side cooling water of the steam generator in an amount of 0.2˜6 g/l, and to an inhibition method using the same. According to this invention, when the inhibitor of lead-induced stress corrosion cracking is added to the secondary side of the steam generator tube in nuclear power plants, stress corrosion cracking of the tubes, which occurs in the lead-containing neutral or caustic solution, and a crack growth rate are decreased, thus increasing elongation. Further, a stress corrosion cracking ratio is decreased, and therefore the stress corrosion cracking resistance of metal or alloy can be improved.
    Type: Grant
    Filed: March 23, 2007
    Date of Patent: August 24, 2010
    Assignees: Korea Atomic Energy Research Institute, Korea Hydro & Nuclear Power Co. Ltd.
    Inventors: Oh-Chul Kwon, Yong-Sun Yi, Hong-Pyo Kim, Joung-Soo Kim
  • Publication number: 20080093584
    Abstract: This invention relates to an inhibitor of lead-induced stress corrosion cracking including nickel boride in the secondary side of steam generator tubes in nuclear power plants and an inhibition method using the same, and more particularly, to an inhibitor of lead-induced stress corrosion cracking, in which nickel boride is added to secondary side cooling water of the steam generator in an amount of 0.2˜6 g/l, and to an inhibition method using the same. According to this invention, when the inhibitor of lead-induced stress corrosion cracking is added to the secondary side of the steam generator tube in nuclear power plants, stress corrosion cracking of the tubes, which occurs in the lead-containing neutral or caustic solution, and a crack growth rate are decreased, thus increasing elongation. Further, a stress corrosion cracking ratio is decreased, and therefore the stress corrosion cracking resistance of metal or alloy can be improved.
    Type: Application
    Filed: March 23, 2007
    Publication date: April 24, 2008
    Inventors: Oh-Chul Kwon, Yong-Sun Yi, Hong-Pyo Kim, Joung-Soo Kim
  • Publication number: 20060266450
    Abstract: The present invention relates to a cerium-containing austenitic nickel-base alloy having enhanced IGA(intergranular attack) and SCC(stress corrosion cracking) resistances, and a preparation method thereof. The cerium-containing alloy according to the present invention is prepared by adding cerium to an austenitic nickel-base alloy, which is used as a material of steam generator tube in a nuclear power plant. The cerium-containing alloy has a refiner grain size than the conventional alloy without cerium, a semi-continuous distribution of intergranular carbides, and improved intergranular attack and stress corrosion cracking resistances in the environment of high temperature and base.
    Type: Application
    Filed: January 10, 2006
    Publication date: November 30, 2006
    Inventors: Oh Kwon, Yong-Sun Yi
  • Publication number: 20060266449
    Abstract: The present invention relates to a cerium-containing austenitic nickel-base alloy having enhanced IGA(intergranular attack) and SCC(stress corrosion cracking) resistances, and a preparation method thereof. The cerium-containing alloy according to the present invention is prepared by adding cerium to an austenitic nickel-base alloy, which is used as a material of heat tubes of a steam generator in a nuclear power plant. The cerium-containing alloy has a refiner grain size than the conventional alloy without cerium, a semi-continuous distribution of intergranular carbides, and improved intergranular attack and stress corrosion cracking resistances in the environment of high temperature and base.
    Type: Application
    Filed: May 24, 2005
    Publication date: November 30, 2006
    Inventors: Oh Kwon, Yong-sun Yi, Joung-Soo Kim