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).
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Patent number: 8007716Abstract: 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: GrantFiled: March 25, 2004Date of Patent: August 30, 2011Assignees: 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
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Patent number: 7763123Abstract: 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: GrantFiled: July 22, 2009Date of Patent: July 27, 2010Assignees: Kabushiki Kaisha Kobe Seiko Sho, Suncall CorporationInventors: Sumie Suda, Nobuhiko Ibaraki, Nao Yoshihara, Shigetsugu Yoshida, Koji Harada
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Publication number: 20090283181Abstract: 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: ApplicationFiled: July 22, 2009Publication date: November 19, 2009Applicants: KABUSHIKI KAISHA KOBE SEIKO SHO, SUNCALL CorporationInventors: Sumie SUDA, Nobuhiko Ibaraki, Nao Yoshihara, Shigetsugu Yoshida, Koji Harada
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Patent number: 7615186Abstract: 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: GrantFiled: March 25, 2004Date of Patent: November 10, 2009Assignee: Kobe Steel, Ltd.Inventors: Sumie Suda, Nobuhiko Ibaraki
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Patent number: 7615099Abstract: 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: GrantFiled: April 23, 2008Date of Patent: November 10, 2009Assignee: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Koichi Sakamoto, Tomoko Sugimura, Atsuhiko Yoshida, Yoshio Fukuzaki, Sumie Suda
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Patent number: 7608130Abstract: 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: GrantFiled: December 17, 2004Date of Patent: October 27, 2009Assignee: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Koichi Sakamoto, Tomoko Sugimura, Atsuhiko Yoshida, Yoshio Fukuzaki, Sumie Suda
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Patent number: 7597768Abstract: 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: GrantFiled: March 26, 2003Date of Patent: October 6, 2009Assignees: Kabushiki Kaisha Kobe Seiko Sho, Suncall CorporationInventors: Sumie Suda, Nobuhiko Ibaraki, Nao Yoshihara, Shigetsugu Yoshida, Koji Harada
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Patent number: 7429301Abstract: 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: GrantFiled: November 23, 2005Date of Patent: September 30, 2008Assignee: Kobe Steel, Ltd.Inventors: Tomoko Sugimura, Koichi Sakamoto, Atsuhiko Yoshida, Sumie Suda
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Publication number: 20080202289Abstract: 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: ApplicationFiled: April 23, 2008Publication date: August 28, 2008Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd)Inventors: Koichi Sakamoto, Tomoko Sugimura, Atsuhiko Yoshida, Yoshio Fukuzaki, Sumie Suda
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Publication number: 20070163680Abstract: 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: ApplicationFiled: March 25, 2004Publication date: July 19, 2007Applicant: Kabushiki kaisha Kobe Seiko Sho(Kobe Steel, Ltd)Inventors: Sumie Suda, Nobuhiko Ibaraki
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Publication number: 20060201588Abstract: 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: ApplicationFiled: March 25, 2004Publication date: September 14, 2006Inventors: Sumie Suda, Nobuhiko Ibaraki, Noritoshi Takamura, Naoki Terakado, Satoru Tendo, Tadayoshi Fujiwara, Tetsuo Jinbo
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Publication number: 20060156864Abstract: 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: ApplicationFiled: December 17, 2004Publication date: July 20, 2006Applicant: Kabushiki Kaisha Kobe Seiko ShoInventors: Koichi Sakamoto, Tomoko Sugimura, Atsuhiko Yoshida, Yoshio Fukuzaki, Sumie Suda
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Patent number: 7074282Abstract: 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: GrantFiled: December 19, 2001Date of Patent: July 11, 2006Assignees: 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
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Publication number: 20060108027Abstract: 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: ApplicationFiled: November 23, 2005Publication date: May 25, 2006Applicant: Kabushiki Kaisha Kobe Seiko Sho(Kobe steel, Ltd.)Inventors: Tomoko Sugimura, Koichi Sakamoto, Atsuhiko Yoshida, Sumie Suda
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Publication number: 20050173028Abstract: 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: ApplicationFiled: March 26, 2003Publication date: August 11, 2005Inventors: Sumie Suda, Nobuhiko Ibaraki, Nao Yoshihara, Shigetsugu Yoshida, Koji Harada
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Publication number: 20030024610Abstract: 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: ApplicationFiled: August 27, 2002Publication date: February 6, 2003Inventors: Nobuhiko Ibakaki, Atsushi Inada, Sumie Suda, Noritoshi Takamura, Satoru Tendoh, Tadayoshi Fujiwara, Tetsuo Jinbo