Patents by Inventor Yoshihito Sekito

Yoshihito Sekito 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: 20160067760
    Abstract: Provided is a surface layer grain refining hot-shearing method including: heating and keeping a steel sheet in a temperature range of from Ac3 to 1400° C. to austenitize the steel sheet; subsequently shearing the steel sheet in a state in which the steel sheet is placed on a die; and quenching by rapidly cooling the sheared steel sheet, wherein a start temperature of the shearing is set to be a temperature (° C.) obtained by adding a temperature of from 30° C. to 140° C. to a previously measured Ar3 of the steel sheet.
    Type: Application
    Filed: May 9, 2013
    Publication date: March 10, 2016
    Inventors: Takashi MATSUNO, Yoshihito SEKITO, Tamaki SUZUKI, Kaoru KAWASAKI, Atsushi SETO
  • Publication number: 20130095347
    Abstract: A hot-stamped steel according to the present invention includes, by mass %, C: 0.20% to 0.35%, Si: 0.1% to 0.5%, the total of at least one selected from Mn and Cr: 1% to 3%, Al: 0.005% to 0.06%, Ti: 0.002% to 0.1%, Nb: 0.002% to 0.1%, O: 0.003% to 0.007%, and a balance of iron and inevitable impurities, wherein P is limited to 0.015% or less, S is limited to 0.01% or less, N is limited to 0.004% or less, the dimensional ratio of the lengths of prior austenite grains in a rolling direction to the lengths of the prior austenite grains in the sheet thickness direction is 1.3 to 2.5, the average grain size of the prior austenite grains is 6 ?m or less, the microstructure includes 98% or more of martensite, and the tensile strength is 1470 MPa or more.
    Type: Application
    Filed: June 14, 2011
    Publication date: April 18, 2013
    Inventors: Kaoru Kawasaki, Kohichi Sano, Yoshihito Sekito