Patents by Inventor Toyohiko Kakihara

Toyohiko Kakihara 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: 11946126
    Abstract: A welded structure including a base material made of duplex stainless steel and a welded portion formed by welding the base materials to each other, wherein the base material has a predetermined chemical composition, a volume fraction of a ferrite phase in a metallographic structure of a weld metal of the welded portion is 45 to 75%, a ratio of a hardness of the weld metal to a hardness of the base material is 0.80 to 1.20, and an amount of precipitates formed in the ferrite phase of the weld metal is less than 10% in area fraction.
    Type: Grant
    Filed: March 31, 2021
    Date of Patent: April 2, 2024
    Assignee: NIPPON STEEL STAINLESS STEEL CORPORATION
    Inventors: Eiichiro Ishimaru, Takuya Sakuraba, Yuji Kaga, Toyohiko Kakihara
  • Publication number: 20220411909
    Abstract: A welded structure including a base material made of duplex stainless steel and a welded portion formed by welding the base materials to each other, wherein the base material has a predetermined chemical composition, a volume fraction of a ferrite phase in a metallographic structure of a weld metal of the welded portion is 45 to 75%, a ratio of a hardness of the weld metal to a hardness of the base material is 0.80 to 1.20, and an amount of precipitates formed in the ferrite phase of the weld metal is less than 10% in area fraction.
    Type: Application
    Filed: March 31, 2021
    Publication date: December 29, 2022
    Applicant: NIPPON STEEL STAINLESS STEEL CORPORATION
    Inventors: Eiichiro ISHIMARU, Takuya SAKURABA, Yuji KAGA, Toyohiko KAKIHARA
  • Patent number: 8628631
    Abstract: The present invention provides a ferritic stainless steel casting and a sheet thereof excellent in deep drawability, punch stretchability and ridging resistance and a method for producing the casting and the sheet. In the present invention, a chemical composition is controlled so that the amounts of C, N, Si, Mn, P and Ti may be reduced to the utmost for securing high workability and, on the basis of the chemical composition, the roping and ridging of a steel sheet product is reduced by adding Mg, thus dispersing Mg containing oxides that accelerate the formation of nuclei for solidification and, resultantly, suppressing the development of coarse columnar crystals in a casting. The present invention is characterized in that the average composition of the Mg containing oxides dispersing in a casting satisfies the following expressions <2> and <3>, 17.4(Al2O3)+3.9(MgO)+0.3(MgAl2O4)+18.7(CaO)?500??<2>, (Al2O3)+(MgO)+(MgAl2O4)+(CaO)?95??<3>.
    Type: Grant
    Filed: April 5, 2011
    Date of Patent: January 14, 2014
    Assignee: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Akihiko Takahashi, Junichi Hamada, Ken Kimura, Takashi Morohoshi, Yoshihito Yamada, Toyohiko Kakihara, Satoshi Hashimoto
  • Patent number: 8293038
    Abstract: The present invention provides a ferritic stainless steel casting and a sheet thereof excellent in deep drawability, punch stretchability and ridging resistance and a method for producing the casting and the sheet. In the present invention, a chemical composition is controlled so that the amounts of C, N, Si, Mn, P and Ti may be reduced to the utmost for securing high workability and, on the basis of the chemical composition, the roping and ridging of a steel sheet product is reduced by adding Mg, thus dispersing Mg containing oxides that accelerate the formation of nuclei for solidification and, resultantly, suppressing the development of coarse columnar crystals in a casting. The present invention is characterized in that the average composition of the Mg containing oxides dispersing in a casting satisfies the following expressions <2> and <3>, 17.4(Al2O3)+3.9(MgO)+0.3(MgAl2O4)+18.7(CaO)?500??<2>, (Al2O3)+(MgO)+(MgAl2O4)+(CaO)?95??<3>.
    Type: Grant
    Filed: November 13, 2007
    Date of Patent: October 23, 2012
    Assignee: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Akihiko Takahashi, Junichi Hamada, Ken Kimura, Takashi Morohoshi, Yoshihito Yamada, Toyohiko Kakihara, Satoshi Hashimoto
  • Publication number: 20110186184
    Abstract: The present invention provides a ferritic stainless steel casting and a sheet thereof excellent in deep drawability, punch stretchability and ridging resistance and a method for producing the casting and the sheet. In the present invention, a chemical composition is controlled so that the amounts of C, N, Si, Mn, P and Ti may be reduced to the utmost for securing high workability and, on the basis of the chemical composition, the roping and ridging of a steel sheet product is reduced by adding Mg, thus dispersing Mg containing oxides that accelerate the formation of nuclei for solidification and, resultantly, suppressing the development of coarse columnar crystals in a casting. The present invention is characterized in that the average composition of the Mg containing oxides dispersing in a casting satisfies the following expressions <2> and <3>, 17.4(Al2O3)+3.9(MgO)+0.3(MgAl2O4)+18.7(CaO)?500??<2>, (Al2O3)+(MgO)+(MgAl2O4)+(CaO)?95??<3>.
    Type: Application
    Filed: April 5, 2011
    Publication date: August 4, 2011
    Applicant: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Akihiko Takahashi, Junichi Hamada, Ken Kimura, Takashi Morchoshi, Yoshihito Yamada, Toyohiko Kakihara, Satoshi Hashimoto
  • Publication number: 20080142123
    Abstract: The present invention provides a ferritic stainless steel casting and a sheet thereof excellent in deep drawability, punch stretchability and ridging resistance and a method for producing the casting and the sheet. In the present invention, a chemical composition is controlled so that the amounts of C, N, Si, Mn, P and Ti may be reduced to the utmost for securing high workability and, on the basis of the chemical composition, the roping and ridging of a steel sheet product is reduced by adding Mg, thus dispersing Mg containing oxides that accelerate the formation of nuclei for solidification and, resultantly, suppressing the development of coarse columnar crystals in a casting. The present invention is characterized in that the average composition of the Mg containing oxides dispersing in a casting satisfies the following expressions <2> and <3>, 17.4(Al2O3)+3.9(MgO)+0.3(MgAl2O4)+18.7(CaO)?500<2>, (Al2O3)+(MgO)+(MgAl2O4)+(CaO)?95<3>.
    Type: Application
    Filed: November 13, 2007
    Publication date: June 19, 2008
    Applicant: Nippon Steel Corporation
    Inventors: Akihiko Takahashi, Junichi Hamada, Ken Kimura, Takashi Morohoshi, Yoshihito Yamada, Toyohiko Kakihara, Satoshi Hashimoto
  • Publication number: 20040154708
    Abstract: The present invention provides a ferritic stainless steel casting and a sheet thereof excellent in deep drawability, punch stretchability and ridging resistance and a method for producing the casting and the sheet. In the present invention, a chemical composition is controlled so that the amounts of C, N, Si, Mn, P and Ti may be reduced to the utmost for securing high workability and, on the basis of the chemical composition, the roping and ridging of a steel sheet product is reduced by adding Mg, thus dispersing Mg containing oxides that accelerate the formation of nuclei for solidification and, resultantly, suppressing the development of coarse columnar crystals in a casting.
    Type: Application
    Filed: November 25, 2003
    Publication date: August 12, 2004
    Inventors: Akihiko Takahashi, Junichi Hamada, Ken Kimura, Takashi Morohoshi, Yoshihito Yamada, Toyohiko Kakihara, Satoshi Hashimoto