Patents by Inventor Yoshimasa HIMEI

Yoshimasa HIMEI 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: 20190242000
    Abstract: Provided is a method for manufacturing a high-strength galvanized steel sheet. Heating in a first half of oxidizing treatment is performed at a temperature of 400° C. to 750° C. in an atmosphere having a particular O2 concentration and a particular H2O concentration, and heating in a second half of the oxidizing treatment is performed at a temperature of 600° C. to 850° C. in an atmosphere having a particular O2 concentration and a particular H2O concentration. Subsequently, heating in a heating zone for reduction annealing is performed to a temperature of 650° C. to 900° C. at a particular heating rate in an atmosphere having a particular H2 concentration and a particular H2O concentration with the balance being N2 and inevitable impurities, and soaking in a soaking zone for the reduction annealing is performed in an atmosphere having a particular H2 concentration and a particular H2O concentration with the balance being N2 and inevitable impurities.
    Type: Application
    Filed: September 14, 2017
    Publication date: August 8, 2019
    Applicant: JFE Steel Corporation
    Inventors: Yoichi Makimizu, Gentaro Takeda, Hiroshi Hasegawa, Yoshimasa Himei, Yoshikazu Suzuki
  • Publication number: 20190185954
    Abstract: Provided are a steel sheet having a tensile strength of 950 MPa or more and good toughness and a method for manufacturing the same. The steel sheet has a specific composition and a metallographic structure containing: a ferrite area fraction of 30% or less (including 0%), a tempered martensite area fraction of 70% or more (including 100%), and a retained austenite area fraction of 4.5% or less (including 0%), wherein the average aspect ratio of an iron based carbide, precipitated in tempered martensite grains, having a grain size in the largest 10% is 3.5 or more.
    Type: Application
    Filed: August 29, 2017
    Publication date: June 20, 2019
    Applicant: JFE Steel Corporation
    Inventors: Noriaki Kohsaka, Yoshikazu Suzuki, Takeo Kikuchi, Yoshimasa Himei
  • Publication number: 20190040511
    Abstract: A high-strength galvanized steel sheet having improved post-work impact resistance, a method for producing the high-strength galvanized steel sheet, and a high-strength member produced using the steel sheet. The high-strength galvanized steel sheet includes a steel sheet having a microstructure including ferrite and carbide-free bainite, martensite and carbide-containing bainite, and retained austenite, the total area fraction of ferrite and carbide-free bainite being 0% to 55%, the total area fraction of martensite and carbide-containing bainite being 45% to 100%, and the area fraction of retained austenite being 0% to 5%. Additionally, a galvanizing layer is disposed on the steel sheet. The density of gaps that cut across the entire thickness of the galvanizing layer in a cross section of the galvanizing layer, which is taken in the thickness direction so as to be perpendicular to the rolling direction, is 10 gaps/mm or more.
    Type: Application
    Filed: January 26, 2017
    Publication date: February 7, 2019
    Applicant: JFE STEEL CORPORATION
    Inventors: Hiroshi HASEGAWA, Yoshimasa FUNAKAWA, Hiromi YOSHITOMI, Yoichi MAKIMIZU, Yoshitsugu SUZUKI, Gentaro TAKEDA, Yoshikazu SUZUKI, Yoshimasa HIMEI
  • Publication number: 20190032186
    Abstract: High strength steel sheets that have excellent ductility and low-temperature toughness and methods for producing such high strength steel sheets. A high strength steel sheet includes a composition containing, on a mass % basis, C: 0.05% to 0.30%, Si: 0.5% to 2.5%, Mn: 0.5% to 3.5%, P: 0.003% to 0.100%, S: 0.02% or less, Al: 0.010% to 1.5%, and N: 0.01% or less, the balance being Fe and unavoidable impurities, and a steel microstructure including a ferrite phase with an area fraction of 10% to 70%, a hard second phase with an area fraction of 30% to 90%, and a carbide that is at an interface between a ferrite phase and a hard second phase and that has an average equivalent-circle diameter of 200 nm or less.
    Type: Application
    Filed: January 20, 2017
    Publication date: January 31, 2019
    Applicant: JFE Steel Corporation
    Inventors: Takashi UENO, Hiroshi HASEGAWA, Yoshimasa FUNAKAWA, Yoshimasa HIMEI, Yoshikazu SUZUKI
  • Publication number: 20180237896
    Abstract: A method includes: annealing a steel strip by conveying the steel strip through a heating zone, a soaking zone, and a cooling zone in this order inside an annealing furnace; and applying a hot-dip galvanized coating onto the steel strip discharged from the cooling zone. Reducing gas or non-oxidizing gas supplied into the soaking zone includes humidified gas and dry gas. While a width and a sheet passing speed of the steel strip passing through the soaking zone are constant, a variation of pressure in the annealing furnace is suppressed by adjusting a flow rate of the dry gas, and a variation range of an amount of moisture supplied into the soaking zone by the humidified gas is limited to 20% or less.
    Type: Application
    Filed: August 5, 2016
    Publication date: August 23, 2018
    Applicant: JFE STEEL CORPORATION
    Inventors: Gentaro TAKEDA, Hideyuki TAKAHASHI, Yoichi MAKIMIZU, Yoshikazu SUZUKI, Yoshimasa HIMEI