Patents by Inventor Fumio Tohyama

Fumio Tohyama 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: 8097097
    Abstract: Disclosed is a stainless steel containing, by mass, 0.05% or less carbon, 1.5 to smaller than 3.5% Si, 3.0% or less Mn, 6.0 to 12.0% Cr, 4.0 to 10.0% Ni, 10.0% or less Co, 6.0% or less Cu, 0.5 to 3.0% Ti, 0 to 2.0% Al, less than 0.4% Mo, not more than 0.01% nitrogen, and the balance of Fe and unavoidable impurities. Preferably, it has a hardness of not lower than 59 HRC and may contain not more than 1.0% Nb and/or not more than 1.0% Ta. Alternatively, the stainless steel may further contain not more than 0.1% of Zr. The process for producing the steel includes producing a steel having a composition as described above by a consumable electrode remelting process, and then subjecting the steel to a solution treatment at a temperature of 1000 to 1150° C. and an aging treatment at a temperature of 400 to 550° C., thereby aging the stainless steel to a hardness of not lower than 59 HRC.
    Type: Grant
    Filed: December 22, 2008
    Date of Patent: January 17, 2012
    Assignee: Hitachi Metals Ltd.
    Inventors: Yoshiyuki Inoue, Fumio Tohyama
  • Publication number: 20090110588
    Abstract: Disclosed is a stainless steel containing, by mass, 0.05% or less carbon, 1.5 to smaller than 3.5% Si, 3.0% or less Mn, 6.0 to 12.0% Cr, 4.0 to 10.0% Ni, 10.0% or less Co, 6.0% or less Cu, 0.5 to 3.0% Ti, 0 to 2.0% Al, less than 0.4% Mo, not more than 0.01% nitrogen, and the balance of Fe and unavoidable impurities. Preferably, it has a hardness of not lower than 59 HRC and may contain not more than 1.0% Nb and/or not more than 1.0% Ta. Alternatively, the stainless steel may further contain not more than 0.1% of Zr. The process for producing the steel includes producing a steel having a composition as described above by a consumable electrode remelting process, and then subjecting the steel to a solution treatment at a temperature of 1000 to 1150° C. and an aging treatment at a temperature of 400 to 550° C., thereby aging the stainless steel to a hardness of not lower than 59 HRC.
    Type: Application
    Filed: December 22, 2008
    Publication date: April 30, 2009
    Applicant: HITACHI METALS, LTD.
    Inventors: Yoshiyuki INOUE, Fumio Tohyama
  • Patent number: 7513960
    Abstract: Disclosed is a stainless steel containing, by mass, 0.05% or less carbon, 1.5 to smaller than 3.5% Si, 3.0% or less Mn, 6.0 to 12.0% Cr, 4.0 to 10.0% Ni, 10.0% or less Co, 6.0% or less Cu, 0.5 to 3.0% Ti, 0 to 2.0% Al, not more than 1.0% Mo, not more than 0.01% nitrogen, and the balance of Fe and unavoidable impurities. Preferably, it has a hardness of not lower than 59 HRC and may contain not more than 1.0% Nb and/or not more than 1.0% Ta. Alternatively, the stainless steel may further contain not more than 0.1% of Zr. The process for producing the steel includes producing a steel having a composition as described above by a consumable electrode remelting process, and then subjecting the steel to a solution treatment at a temperature of 1000 to 1150° C. and an aging treatment at a temperature of 400 to 550° C., thereby aging the stainless steel to a hardness of not lower than 59 HRC.
    Type: Grant
    Filed: February 15, 2006
    Date of Patent: April 7, 2009
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yoshiyuki Inoue, Fumio Tohyama
  • Publication number: 20060201593
    Abstract: Disclosed is a stainless steel containing, by mass, 0.05% or less carbon, 1.5 to smaller than 3.5% Si, 3.0% or less Mn, 6.0 to 12.0% Cr, 4.0 to 10.0% Ni, 10.0% or less Co, 6.0% or less Cu, 0.5 to 3.0% Ti, 0 to 2.0% Al, not more than 1.0% Mo, not more than 0.01% nitrogen, and the balance of Fe and unavoidable impurities. Preferably, it has a hardness of not lower than 59 HRC and may contain not more than 1.0% Nb and/or not more than 1.0% Ta. Alternatively, the stainless steel may further contain not more than 0.1% of Zr. The process for producing the steel includes producing a steel having a composition as described above by a consumable electrode remelting process, and then subjecting the steel to a solution treatment at a temperature of 1000 to 1150° C. and an aging treatment at a temperature of 400 to 550° C., thereby aging the stainless steel to a hardness of not lower than 59 HRC.
    Type: Application
    Filed: February 15, 2006
    Publication date: September 14, 2006
    Inventors: Yoshiyuki Inoue, Fumio Tohyama