Patents by Inventor Sumie Suda

Sumie Suda 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: 8007716
    Abstract: A steel wire has tempered martensite, comprises, as essential components, by mass, C: 0.53 to 0.68%; Si: 1.2 to 2.5%; Mn: 0.2 to 1.5%; Cr: 1.4 to 2.5%; Al: 0.05% or less; further comprises, as a selective component, Ni: 0.4% or less; V: 0.4% or less; Mo: 0.05 to 0.5%; or Nb: 0.05 to 0.5%; and further comprises remainder essentially consisting of Fe and inevitable impurities, wherein the grain size number of prior austenite is 11.0 or larger, and the proof stress ratio (?0.2/?B), namely, a ratio of 0.2% proof stress (?0.2) to tensile strength (?B) is 0.85 or lower. Satisfying the above requirements makes it possible to produce a steel wire for high-strength spring excellent both in workability (cold workability), and in sag resistance and fatigue properties.
    Type: Grant
    Filed: March 25, 2004
    Date of Patent: August 30, 2011
    Assignees: Kabushiki Kaisha Kobe Seiko Sho, NHK Spring Co., Ltd., Shinko Wire Co., Ltd.
    Inventors: Sumie Suda, Nobuhiko Ibaraki, Noritoshi Takamura, Naoki Terakado, Satoru Tendo, Tadayoshi Fujiwara, Tetsuo Jinbo
  • Patent number: 7763123
    Abstract: Disclosed is a hard-drawn spring which exhibits fatigue strength and sag resistance equal or superior to springs produced using an oil-tempered wire. The hard-drawn spring is produced using a steel wire containing 0.5 to 0.7 mass % of C, 1.0 to 1.95 mass % of Si, 0.5 to 1.5 mass % of Mn and 0.5 to 1.5 mass % of Cr, with the balance being Fe and inevitable impurities. In the steel wire, the number of carbides having circle-equivalent diameters of 0.1 ?m or more is 5 particles/100 ?m2 or less.
    Type: Grant
    Filed: July 22, 2009
    Date of Patent: July 27, 2010
    Assignees: Kabushiki Kaisha Kobe Seiko Sho, Suncall Corporation
    Inventors: Sumie Suda, Nobuhiko Ibaraki, Nao Yoshihara, Shigetsugu Yoshida, Koji Harada
  • Publication number: 20090283181
    Abstract: Disclosed is a hard-drawn spring which exhibits fatigue strength and sag resistance equal or superior to springs produced using an oil-tempered wire. The hard-drawn spring is produced using a steel wire containing 0.5 to 0.7 mass % of C, 1.0 to 1.95 mass % of Si, 0.5 to 1.5 mass % of Mn and 0.5 to 1.5 mass % of Cr, with the balance being Fe and inevitable impurities. In the steel wire, the number of carbides having circle-equivalent diameters of 0.1 ?m or more is 5 particles/100 ?m2 or less.
    Type: Application
    Filed: July 22, 2009
    Publication date: November 19, 2009
    Applicants: KABUSHIKI KAISHA KOBE SEIKO SHO, SUNCALL Corporation
    Inventors: Sumie SUDA, Nobuhiko Ibaraki, Nao Yoshihara, Shigetsugu Yoshida, Koji Harada
  • Patent number: 7615099
    Abstract: The present invention relates to a high-cleanliness steel having a high fatigue strength and high cold workability, and a method of making the high-cleanliness steel. The method adds a Li—Si alloy having a Li content between 20 and 40% and/or Li2CO3 as a Li-containing substance to a molten steel. The Li-containing substance is added to the molten steel after the completion of a series of steps of a ladle refining process including composition adjustment, temperature adjustment and slag refining. The high-cleanliness steel has a total-Li content between 0.020 and 20 ppm by mass and contains 1.0 or below oxide inclusion particle having a major diameter of 20 ?m or above at a maximum in 50 g of the steel wire. The steel contains an oxide inclusion that has a CaO content between 15 and 55%, SiO2 content between 20 and 70%, an Al2O3 content of 35% or below, a MgO content of 20% or below and a Li2O content between 0.5 and 20%.
    Type: Grant
    Filed: April 23, 2008
    Date of Patent: November 10, 2009
    Assignee: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Koichi Sakamoto, Tomoko Sugimura, Atsuhiko Yoshida, Yoshio Fukuzaki, Sumie Suda
  • Patent number: 7615186
    Abstract: The spring steel according to the present invention is a spring steel excellent in sag resistance and fatigue property containing: C: 0.5 to 0.8% by mass (hereinafter, referred to as %), Si: 1.2 to 2.5%, Mn: 0.2 to 1.5%, Cr: 1.0 to 4.0%, V: 0.5% or less (including 0%), P: 0.02% or less (excluding 0%), S: 0.02% or less (excluding 0%), Al: 0.05% or less (excluding 0%), and Fe and inevitable impurities as the balance, wherein the Si content and the Cr content satisfy the following formula (1): 0.8×[Si]+[Cr]?2.6??(1) (wherein, [Si] and [Cr] respectively represent the Si content (%) and the Cr content (%)). The spring steel is useful in improving both sag resistance and fatigue property.
    Type: Grant
    Filed: March 25, 2004
    Date of Patent: November 10, 2009
    Assignee: Kobe Steel, Ltd.
    Inventors: Sumie Suda, Nobuhiko Ibaraki
  • Patent number: 7608130
    Abstract: The present invention relates to a high-cleanliness steel having a high fatigue strength and high cold workability, and a method of making the high-cleanliness steel. The method adds a Li—Si alloy having a Li content between 20 and 40% and/or Li2CO3 as a Li-containing substance to a molten steel. The Li-containing substance is added to the molten steel after the completion of a series of steps of a ladle refining process including composition adjustment, temperature adjustment and slag refining. The high-cleanliness steel has a total-Li content between 0.020 and 20 ppm by mass and contains 1.0 or below oxide inclusion particle having a major diameter of 20 ?m or above at a maximum in 50 g of the steel wire. The steel contains an oxide inclusion that has a CaO content between 15 and 55%, SiO2 content between 20 and 70%, an Al2O3 content of 35% or below, a MgO content of 20% or below and a Li2O content between 0.5 and 20%.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: October 27, 2009
    Assignee: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Koichi Sakamoto, Tomoko Sugimura, Atsuhiko Yoshida, Yoshio Fukuzaki, Sumie Suda
  • Patent number: 7597768
    Abstract: Disclosed is a hard-drawn spring which exhibits fatigue strength and sag resistance equal or superior to springs produced using an oil-tempered wire. The hard-drawn spring is produced using a steel wire containing 0.5 to 0.7 mass % of C, 1.0 to 1.95 mass % of Si, 0.5 to 1.5 mass % of Mn and 0.5 to 1.5 mass % of Cr, with the balance being Fe and inevitable impurities. In the steel wire, the number of carbides having circle-equivalent diameters of 0.1 ?m or more is 5 particles/100 ?m2 or less.
    Type: Grant
    Filed: March 26, 2003
    Date of Patent: October 6, 2009
    Assignees: Kabushiki Kaisha Kobe Seiko Sho, Suncall Corporation
    Inventors: Sumie Suda, Nobuhiko Ibaraki, Nao Yoshihara, Shigetsugu Yoshida, Koji Harada
  • Patent number: 7429301
    Abstract: Disclosed herein is an ultra clean spring steel which contains inclusions easily elongated and broken into fine particles by hot rolling and which is easily adaptive to cold rolling and yields springs excelling in fatigue characteristics. The spring steel is characterized in that the wire contains oxide inclusions with a sulfur concentration no more than 10 mass % such that no less than 70% (in terms of numbers) of such inclusions, which exist in the outer layer outside one quarter of the diameter of the wire and have a width no smaller than 3 ?m, satisfies the formula (1) below, CaO+Al2O3+SiO2+MnO+MgO>80 (mass %) .
    Type: Grant
    Filed: November 23, 2005
    Date of Patent: September 30, 2008
    Assignee: Kobe Steel, Ltd.
    Inventors: Tomoko Sugimura, Koichi Sakamoto, Atsuhiko Yoshida, Sumie Suda
  • Publication number: 20080202289
    Abstract: The present invention relates to a high-cleanliness steel having a high fatigue strength and high cold workability, and a method of making the high-cleanliness steel. The method adds a Li—Si alloy having a Li content between 20 and 40% and/or Li2CO3 as a Li-containing substance to a molten steel. The Li-containing substance is added to the molten steel after the completion of a series of steps of a ladle refining process including composition adjustment, temperature adjustment and slag refining. The high-cleanliness steel has a total-Li content between 0.020 and 20 ppm by mass and contains 1.0 or below oxide inclusion particle having a major diameter of 20 ?m or above at a maximum in 50 g of the steel wire. The steel contains an oxide inclusion that has a CaO content between 15 and 55%, SiO2 content between 20 and 70%, an Al2O3 content of 35% or below, a MgO content of 20% or below and a Li2O content between 0.5 and 20%.
    Type: Application
    Filed: April 23, 2008
    Publication date: August 28, 2008
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd)
    Inventors: Koichi Sakamoto, Tomoko Sugimura, Atsuhiko Yoshida, Yoshio Fukuzaki, Sumie Suda
  • Publication number: 20070163680
    Abstract: The spring steel according to the present invention is a spring steel excellent in sag resistance and fatigue property containing: C: 0.5 to 0.8% by mass (hereinafter, referred to as %), Si: 1.2 to 2.5%, Mn: 0.2 to 1.5%, Cr: 1.0 to 4.0%, V: 0.5% or less (including 0%), P: 0.02% or less (excluding 0%), S: 0.02% or less (excluding 0%), Al: 0.05% or less (excluding 0%), and Fe and inevitable impurities as the balance, wherein the Si content and the Cr content satisfy the following formula (1): 0.8×[Si]+[Cr]?2.6??(1) (wherein, [Si] and [Cr] respectively represent the Si content (%) and the Cr content (%)). The spring steel is useful in improving both sag resistance and fatigue property.
    Type: Application
    Filed: March 25, 2004
    Publication date: July 19, 2007
    Applicant: Kabushiki kaisha Kobe Seiko Sho(Kobe Steel, Ltd)
    Inventors: Sumie Suda, Nobuhiko Ibaraki
  • Publication number: 20060201588
    Abstract: A steel wire has tempered martensite, comprises, as essential components, by mass, C: 0.53 to 0.68%; Si: 1.2 to 2.5%; Mn: 0.2 to 1.5%; Cr: 1.4 to 2.5%; Al: 0.05% or less; further comprises, as a selective component, Ni: 0.4% or less; V: 0.4% or less; Mo: 0.05 to 0.5%; or Nb: 0.05 to 0.5%; and further comprises remainder essentially consisting of Fe and inevitable impurities, wherein the grain size number of prior austenite is 11.0 or larger, and the proof stress ratio (?0.2/?B), namely, a ratio of 0.2% proof stress (?0.2) to tensile strength (?B) is 0.85 or lower. Satisfying the above requirements makes it possible to produce a steel wire for high-strength spring excellent both in workability (cold workability), and in sag resistance and fatigue properties.
    Type: Application
    Filed: March 25, 2004
    Publication date: September 14, 2006
    Inventors: Sumie Suda, Nobuhiko Ibaraki, Noritoshi Takamura, Naoki Terakado, Satoru Tendo, Tadayoshi Fujiwara, Tetsuo Jinbo
  • Publication number: 20060156864
    Abstract: The present invention relates to a high-cleanliness steel having a high fatigue strength and high cold workability, and a method of making the high-cleanliness steel. The method adds a Li—Si alloy having a Li content between 20 and 40% and/or Li2CO3 as a Li-containing substance to a molten steel. The Li-containing substance is added to the molten steel after the completion of a series of steps of a ladle refining process including composition adjustment, temperature adjustment and slag refining. The high-cleanliness steel has a total-Li content between 0.020 and 20 ppm by mass and contains 1.0 or below oxide inclusion particle having a major diameter of 20 ?m or above at a maximum in 50 g of the steel wire. The steel contains an oxide inclusion that has a CaO content between 15 and 55%, SiO2 content between 20 and 70%, an Al2O3 content of 35% or below, a MgO content of 20% or below and a Li2O content between 0.5 and 20%.
    Type: Application
    Filed: December 17, 2004
    Publication date: July 20, 2006
    Applicant: Kabushiki Kaisha Kobe Seiko Sho
    Inventors: Koichi Sakamoto, Tomoko Sugimura, Atsuhiko Yoshida, Yoshio Fukuzaki, Sumie Suda
  • Patent number: 7074282
    Abstract: Disclosed is a steel wire rod for hard-drawn springs capable of exhibiting fatigue strength and sag resistance equivalent to or higher than springs made of an oil-tempered wire. The steel wire rod contains carbon in a range from 0.5 to less than 0.7 mass %, silicon in a range from 1.4 to 2.5 mass %, manganese in a range from 0.5 to 1.5 mass %, chromium in a range from 0.05 to 2.0 mass %, and vanadium in a range from 0.05 to 0.40 mass %, and has an area ratio Rp with respect to pearlite which satisfies the mathematical expression (1): Rp(area %)?55×[C]+61??(1) where [C] denotes the content (mass %) of carbon.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: July 11, 2006
    Assignees: Kabushiki Kaisha Kobe Seiko Sho, NHK Spring Co., Ltd., Shinko Wire Co., Ltd.
    Inventors: Nobuhiko Ibaraki, Atushi Inada, Sumie Suda, Noritoshi Takamura, Satoru Tendoh, Tadayoshi Fujiwara, Tetsuo Jinbo
  • Publication number: 20060108027
    Abstract: Disclosed herein is an ultra clean spring steel which contains inclusions easily elongated and broken into fine particles by hot rolling and which is easily adaptive to cold rolling and yields springs excelling in fatigue characteristics.
    Type: Application
    Filed: November 23, 2005
    Publication date: May 25, 2006
    Applicant: Kabushiki Kaisha Kobe Seiko Sho(Kobe steel, Ltd.)
    Inventors: Tomoko Sugimura, Koichi Sakamoto, Atsuhiko Yoshida, Sumie Suda
  • Publication number: 20050173028
    Abstract: Disclosed is a hard-drawn spring which exhibits fatigue strength and sag resistance equal or superior to springs produced using an oil-tempered wire. The hard-drawn spring is produced using a steel wire containing 0.5 to 0.7 mass % of C, 1.0 to 1.95 mass % of Si, 0.5 to 1.5 mass % of Mn and 0.5 to 1.5 mass % of Cr, with the balance being Fe and inevitable impurities. In the steel wire, the number of carbides having circle-equivalent diameters of 0.1 ?m or more is 5 particles/100 ?m2 or less.
    Type: Application
    Filed: March 26, 2003
    Publication date: August 11, 2005
    Inventors: Sumie Suda, Nobuhiko Ibaraki, Nao Yoshihara, Shigetsugu Yoshida, Koji Harada
  • Publication number: 20030024610
    Abstract: Disclosed is a steel wire rod for hard-drawn springs capable of exhibiting fatigue strength and sag resistance equivalent to or higher than springs made of an oil-tempered wire. The steel wire rod contains carbon in a range from 0.5 to less than 0.7 mass %, silicon in a range from 1.4 to 2.5 mass %, manganese in a range from 0.5 to 1.5 mass %, chromium in a range from 0.05 to 2.0 mass %, and vanadium in a range from 0.05 to 0.
    Type: Application
    Filed: August 27, 2002
    Publication date: February 6, 2003
    Inventors: Nobuhiko Ibakaki, Atsushi Inada, Sumie Suda, Noritoshi Takamura, Satoru Tendoh, Tadayoshi Fujiwara, Tetsuo Jinbo