Patents by Inventor Masahito Sakaki

Masahito Sakaki 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: 12221669
    Abstract: A hot-rolled steel sheet which has excellent rigidity along with high strength, excellent workability, and excellent LME resistance is provided. A hot-rolled steel sheet of the present embodiment consists of, in mass %, C: 0.040 to 0.120%, Si: 0.01 to 0.60%, Mn: 0.50 to 1.50%, P: 0.025% or less, S: 0.010% or less, Al: 0.010 to 0.070%, N: 0.0070% or less, Ti: 0.055 to 0.200%, and B: 0.0010 to 0.0050%, with the balance being Fe and impurities. In the microstructure of the hot-rolled steel sheet, an area fraction of bainitic ferrite is 85% or more and the dislocation density is 8.0×1013 to 100.0×1013/m2. The average equivalent circular diameter of Ti carbides in the hot-rolled steel sheet is 10 nm or less, and the average equivalent circular diameter of grains of the bainitic ferrite is 15 ?m or less.
    Type: Grant
    Filed: September 22, 2022
    Date of Patent: February 11, 2025
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Kentarou Hirata, Masaharu Oka, Masahito Sakaki, Mamoru Saito
  • Publication number: 20240425945
    Abstract: A hot-rolled steel sheet which has excellent rigidity along with high strength, excellent workability, and excellent LME resistance is provided. A hot-rolled steel sheet of the present embodiment consists of, in mass %, C: 0.040 to 0.120%, Si: 0.01 to 0.60%, Mn: 0.50 to 1.50%, P: 0.025% or less, S: 0.010% or less, Al: 0.010 to 0.070%, N: 0.0070% or less, Ti: 0.055 to 0.200%, and B: 0.0010 to 0.0050%, with the balance being Fe and impurities. In the microstructure of the hot-rolled steel sheet, an area fraction of bainitic ferrite is 85% or more and the dislocation density is 8.0×1013 to 100.0×1013/m2. The average equivalent circular diameter of Ti carbides in the hot-rolled steel sheet is 10 nm or less, and the average equivalent circular diameter of grains of the bainitic ferrite is 15 ?m or less.
    Type: Application
    Filed: September 22, 2022
    Publication date: December 26, 2024
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Kentarou HIRATA, Masaharu OKA, Masahito SAKAKI, Mamoru SAITO
  • Patent number: 10562084
    Abstract: Provided is a clad steel plate with excellent thermal conductivity that can be used suitably in cookware and the like. The present invention is a three-layer clad steel plate having a carbon steel base material and stainless steel mating material disposed respectively on both surface sides of the base material, wherein a plate thickness ratio L given by Equation (1) is 1.0-5.0 and at least one surface of the clad steel plate has a plurality of protrusions and recesses. Plate thickness ratio L=the plate thickness of the base material/the total thickness of the mating material . . . Equation (1) Here, the base material thickness and the mating material thickness are the thicknesses at the protrusions.
    Type: Grant
    Filed: October 14, 2016
    Date of Patent: February 18, 2020
    Assignee: NIPPON STEEL NISSHIN CO., LTD.
    Inventors: Masahito Sakaki, Kouki Tomimura
  • Publication number: 20180304326
    Abstract: Provided is a clad steel plate with excellent thermal conductivity that can be used suitably in cookware and the like. The present invention is a three-layer clad steel plate having a carbon steel base material and stainless steel mating material disposed respectively on both surface sides of the base material, wherein a plate thickness ratio L given by Equation (1) is 1.0-5.0 and at least one surface of the clad steel plate has a plurality of protrusions and recesses. Plate thickness ratio L=the plate thickness of the base material/the total thickness of the mating material . . . Equation (1) Here, the base material thickness and the mating material thickness are the thicknesses at the protrusions.
    Type: Application
    Filed: October 14, 2016
    Publication date: October 25, 2018
    Inventors: Masahito SAKAKI, Kouki TOMIMURA
  • Patent number: 7150800
    Abstract: When a metastable austenitic stainless steel strip with a value Md(N), which is calculated from a composition, of 20–100 is ring-rolled to a steel belt, the relationship of ?0.3913T+0.5650Md(N)+60.46??65.87 is established among a material temperature T, an equivalent strain ? and the value Md(N). Due to the controlled rolling, a stainless steel belt for a continuously variable transmission is bestowed with fatigue properties similar or superior to those of a 18%-Ni maraging steel belt. The value Md(N) is defined by the equation of Md(N)=580?520C?2Si?16Mn?16Cr?23Ni?300N?10Mo, and the equivalent strain ? is defined by the equation of ?=?{square root over (4(1n(1?R))2/3)} (R: reduction). Furthermore, the steel belt is stabilized in its quality and profile by confining a variation ?T of the material temperature T within a range of ±6.4° C.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: December 19, 2006
    Assignee: Nisshin Steel Co.
    Inventors: Katsuhide Nishio, Masahito Sakaki, Yoshiyuki Umakoshi, Kenji Hara, Kouki Tomimura
  • Publication number: 20040112481
    Abstract: When a metastable austenitic stainless steel strip with a value Md(N), which is calculated from a composition, of 20-100 is ring-rolled to a steel belt, the relationship of −0.3913T+0.5650Md(N)+60.46&egr;≧65.87 is established among a material temperature T, an equivalent strain &egr; and the value Md(N). Due to the controlled rolling, a stainless steel belt for a continuously variable transmission is bestowed with fatigue properties similar or superior to those of a 18%-Ni maraging steel belt. The value Md(N) is defined by the equation of Md(N)=580−520C−2Si−16Mn−16Cr−23Ni−300N−10Mo, and the equivalent strain &egr; is defined by the equation of E={square root}{square root over (4(1n(1−R))2/3)} (R: reduction). Furthermore, the steel belt is stabilized in its quality and profile by confining a variation &Dgr;T of the material temperature T within a range of ±6.4° C.
    Type: Application
    Filed: October 16, 2003
    Publication date: June 17, 2004
    Inventors: Katsuhide Nishio, Masahito Sakaki, Yoshiyuki Umakoshi, Kenji Hara, Kouki Tomimura