Patents by Inventor Yoshiyuki Watannabe

Yoshiyuki Watannabe 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: 20090053097
    Abstract: The present invention provides a fire-resistant steel material superior in HAZ toughness of a welded joint which is high in high temperature yield strength at an envisioned fire temperature of 700 to 800° C. and is free of embrittlement of the welded joint even if exposed at this envisioned fire temperature and a method of production of the same, that is, a fire-resistant steel material of a composition containing, by mass %, C: 0.005% to less than 0.03%, Si: 0.01 to 0.50%, Mn: 0.05 to 0.40%, Cr: 1.50 to 5.00%, V: 0.05 to 0.50%, and N: 0.001 to 0.005% and restricted in contents of Ni, Cu, Mo, B, P, S, and O obtained by heating a steel slab to 1150 to 1300° C., then hot working or hot rolling the slab to an end temperature of 880 degrees or more, acceleratedly cooling the worked or rolled steel material under conditions of a cooling rate at a position of the slowest cooling rate of at least 2° C.
    Type: Application
    Filed: September 20, 2007
    Publication date: February 26, 2009
    Inventors: Yasushi Hasegawa, Suguru Yoshida, Yoshiyuki Watannabe