Patents by Inventor Nobuo Aoyagi

Nobuo Aoyagi 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).

  • Method for producing hot-rolled steel sheets having a low yield ratio and a high tensile strength due to dual phase structure
    Patent number: 4502897
    Abstract: The present invention aims to obtain C-Si-Mn-Cr system of hot-rolled dual phase structured steel sheets having a low yield ratio YR of not greater than 65%, an excellent strength-elongation balance M, a low variation in quality and an excellent cold formability through stepwise cooling regulation in the course of cooling from the final rolling to coiling.The present invention is a method for producing hot-rolled steel sheets having a low yield ratio and a high tensile strength due to dual phase structure by effecting the final rolling of a hot-rolled steel sheet containing 0.02-0.2% of C, 0.05-2.0% of Si, 0.5-2.0% of Mn and 0.3-1.5% of Cr as the essential components at a temperature of finishing the final rolling of 780.degree. C., rapidly cooling the thus treated steel sheet at a cooling rate of more than 40.degree. C./S to the temperature range wherein the transformation of .gamma. into .alpha.
    Type: Grant
    Filed: October 15, 1982
    Date of Patent: March 5, 1985
    Assignee: Kawasaki Steel Corporation
    Inventors: Masahiko Morita, Junichi Mano, Minoru Nishida, Tomoo Tanaka, Nobuo Aoyagi, Syoichi Takizawa