Patents by Inventor TAKEHIKO ITAGAKI
TAKEHIKO ITAGAKI 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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Publication number: 20190099829Abstract: A method for spot-welding metallic materials includes: sandwiching the metallic materials with a pair of electrodes; a pre-heating step for pre-heating a region different from a given region which should be welded by applying electric power having a high frequency to the pair of electrodes; and a welding step for spot-welding a given region of the metallic materials by applying electric power for welding to the pair of electrodes. The heating time in the pre-heating step and that in the welding step are independently controlled.Type: ApplicationFiled: November 30, 2018Publication date: April 4, 2019Applicants: NETUREN CO., LTD., NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Takahiko KANAI, Munehisa HATTA, Fumiaki IKUTA, Kazuhiro KAWASAKI, Eizaburo NAKANISHI, Tsuyoshi YOSHIDA, Kotobu NAGAI, Masao HAYAKAWA, Takehiko ITAGAKI
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Patent number: 10189112Abstract: A welding equipment for metallic materials capable of performing heat treatment such as tempering based on partial heating in spot welding is provided. The welding equipment sandwiches metallic materials with a pair of electrodes, and heats different regions of the metallic materials by energization, with the pair of electrodes maintained at the same position with respect to the metallic materials. The welding equipment includes a first heating means connected to the pair of electrodes for heating and welding the internal region of the circle defined by projecting the cross-sectional area of the axis of the electrodes on the metallic materials by applying power having a low first frequency, a second heating means for heating a ring-shaped region along the circle by applying power having a second frequency that is higher than the first frequency, and an energization control unit for independently controlling the first and the second heating means.Type: GrantFiled: June 12, 2015Date of Patent: January 29, 2019Assignees: NETUREN CO., LTD., NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Takahiko Kanai, Munehisa Hatta, Fumiaki Ikuta, Kazuhiro Kawasaki, Eizaburo Nakanishi, Tsuyoshi Yoshida, Kotobu Nagai, Masao Hayakawa, Takehiko Itagaki
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Patent number: 9498840Abstract: A welding structural part 1 is manufactured by overlapping the surfaces of steel sheets 2, and forming a weld zone by spot welding. The weld zone 3 includes: a weld nugget 4; and a heat affected zone 5 surrounding the weld nugget 4, wherein the hardness in the weld zone increases along an exterior region 6 of the heat affected zone 5 toward the heat affected zone 5, and then decreases along the heat affected zone 5 toward the central region of the weld nugget 4. In the boundary region between the weld nugget 4 and the heat affected zone 5, the weld nugget 4 may have a convex portion 4A bulging into the heat affected zone 5 along the overlapped portion. The steel sheets 2 contain carbon in 0.15 mass % or more.Type: GrantFiled: July 30, 2010Date of Patent: November 22, 2016Assignees: NETUREN CO., LTD., NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Takahiko Kanai, Munehisa Hatta, Fumiaki Ikuta, Kazuhiro Kawasaki, Eizaburou Nakanishi, Masayuki Miyake, Kotobu Nagai, Masao Hayakawa, Takehiko Itagaki
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Publication number: 20150306696Abstract: A welding equipment for metallic materials capable of performing heat treatment such as tempering based on partial heating in spot welding is provided. The welding equipment sandwiches metallic materials with a pair of electrodes, and heats different regions of the metallic materials by energization, with the pair of electrodes maintained at the same position with respect to the metallic materials. The welding equipment includes a first heating means connected to the pair of electrodes for heating and welding the internal region of the circle defined by projecting the cross-sectional area of the axis of the electrodes on the metallic materials by applying power having a low first frequency, a second heating means for heating a ring-shaped region along the circle by applying power having a second frequency that is higher than the first frequency, and an energization control unit for independently controlling the first and the second heating means.Type: ApplicationFiled: June 12, 2015Publication date: October 29, 2015Applicants: NATIONAL INSTITUTE FOR MATERIALS SCIENCE, NETUREN CO., LTD.Inventors: Takahiko KANAI, Munehisa HATTA, Fumiaki IKUTA, Kazuhiro KAWASAKI, Eizaburo NAKANISHI, Tsuyoshi YOSHIDA, Kotobu NAGAI, Masao HAYAKAWA, Takehiko ITAGAKI
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Patent number: 9079266Abstract: A welding equipment for metallic materials capable of performing heat treatment such as tempering based on partial heating in spot welding is provided. The welding equipment 1 sandwiches metallic materials 9 with a pair of electrodes 4, 4, and heats different regions of the metallic materials 9 by energization, with the pair of electrodes 4, 4 maintained at the same position with respect to the metallic materials 9. The welding equipment includes a first heating means 6 connected to the pair of electrodes 4, 4 for heating and welding the internal region of the circle defined by projecting the cross-sectional area of the axis of the electrodes on the metallic materials by applying power having a low first frequency, a second heating means 8 for heating a ring-shaped region along the circle by applying power having a second frequency that is higher than the first frequency, and an energization control unit 10 for independently controlling the first and the second heating means 6, 8.Type: GrantFiled: September 30, 2009Date of Patent: July 14, 2015Assignees: NETUREN CO., LTD., NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Takahiko Kanai, Munehisa Hatta, Fumiaki Ikuta, Kazuhiro Kawasaki, Eizaburo Nakanishi, Tsuyoshi Yoshida, Kotobu Nagai, Masao Hayakawa, Takehiko Itagaki
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Publication number: 20120129006Abstract: A welding structural part 1 is manufactured by overlapping the surfaces of steel sheets 2, and forming a weld zone by spot welding. The weld zone 3 includes: a weld nugget 4; and a heat affected zone 5 surrounding the weld nugget 4, wherein the hardness in the weld zone increases along an exterior region 6 of the heat affected zone 5 toward the heat affected zone 5, and then decreases along the heat affected zone 5 toward the central region of the weld nugget 4. In the boundary region between the weld nugget 4 and the heat affected zone 5, the weld nugget 4 may have a convex portion 4A bulging into the heat affected zone 5 along the overlapped portion. The steel sheets 2 contain carbon in 0.15 mass % or more.Type: ApplicationFiled: July 30, 2010Publication date: May 24, 2012Applicants: NETUREN CO., LTD., NATIONAL INSTITUTE FOR MATERIALS SCIENCE, NISSAN MOTOR CO., LTD.Inventors: Takahiko Kanai, Munehisa Hatta, Fumiaki Ikuta, Kazuhiro Kawasaki, Eizaburou Nakanishi, Masayuki Miyake, Kotobu Nagai, Masao Hayakawa, Takehiko Itagaki
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Publication number: 20110303655Abstract: A welding equipment for metallic materials capable of performing heat treatment such as tempering based on partial heating in spot welding is provided. The welding equipment 1 sandwiches metallic materials 9 with a pair of electrodes 4, 4, and heats different regions of the metallic materials 9 by energization, with the pair of electrodes 4, 4 maintained at the same position with respect to the metallic materials 9. The welding equipment includes a first heating means 6 connected to the pair of electrodes 4, 4 for heating and welding the internal region of the circle defined by projecting the cross-sectional area of the axis of the electrodes on the metallic materials by applying power having a low first frequency, a second heating means 8 for heating a ring-shaped region along the circle by applying power having a second frequency that is higher than the first frequency, and an energization control unit 10 for independently controlling the first and the second heating means 6, 8.Type: ApplicationFiled: September 30, 2009Publication date: December 15, 2011Applicants: NATIONAL INSTITUTE FOR MATERIALS SCIENCE, NETUREN CO., LTD.Inventors: Takahiko Kanai, Munehisa Hatta, Fumiaki Ikuta, Kazuhiro Kawasaki, Eizaburo Nakanishi, Tsuyoshi Yoshida, Kotobu Nagai, Masao Hayakawa, Takehiko Itagaki
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Publication number: 20060054253Abstract: The invention provides a ferritic heat-resistant steel having excellent high-temperature oxidation resistance, especially excellent steam oxidation-resistant characteristics. In high-Cr ferritic heat-resistant steel, ultra-fine oxide particles having a size of not larger than 1 ?m are formed just below the oxide films and formed on the steel base, whereby the adhesiveness between the films and the base is enhanced. The ferritic heat-resistant steel contains Cr in an amount of from 8.0 to 13.0% by weight, and at least one of Rh and Ir in a total amount of from 0.3 to 5.0% by weight.Type: ApplicationFiled: October 17, 2005Publication date: March 16, 2006Inventors: Nobuyuki Fujitsuna, Fujio Abe, Takehiko Itagaki, Masaaki Igarashi, Seiichi Muneki, Kazuhiro Kimura, Hideaki Kushima
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Publication number: 20040250923Abstract: A high Cr ferritic heat-resistant steel (Cr content of 15 mass % or less), which, at least a region 10 &mgr;m in depth as measured from the surface has a worked texture comprising elongated ferritic grains or a fine crystal grain texture comprising ferritic grains of 3 &mgr;m or less in diameter, and has a protective coating film on the surface; it is a high Cr ferritic heat-resistant steel improved in oxidation resistance without causing drop in high temperature strength or in toughness.Type: ApplicationFiled: August 13, 2004Publication date: December 16, 2004Inventors: Takehiko Itagaki, Shiro Torizuka, Hiroyuki Kutsumi
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Publication number: 20040060621Abstract: The invention provides a ferritic heat-resistant steel having excellent high-temperature oxidation resistance, especially excellent steam oxidation-resistant characteristics. In high-Cr ferritic heat-resistant steel, ultra-fine oxide particles having a size of not larger than 1 &mgr;m are formed just below the oxide films and formed on the steel base, whereby the adhesiveness between the films and the base is enhanced. The ferritic heat-resistant steel contains Cr in an amount of from 8.0 to 13.0% by weight, and at least one of Rh and Ir in a total amount of from 0.3 to 5.0% by weight.Type: ApplicationFiled: September 30, 2003Publication date: April 1, 2004Inventors: Nobuyuki Fujitsuna, Fujio Abe, Takehiko Itagaki, Masaki Igarashi, Seiichi Muneki, Kazuhiro Kimura, Hideaki Kushima
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Publication number: 20030127163Abstract: The invention provides a ferritic heat-resistant steel having excellent high-temperature oxidation resistance, especially excellent steam oxidation-resistant characteristics. In high-Cr ferritic heat-resistant steel, ultra-fine oxide particles having a size of not larger than 1 &mgr;m are formed just below the oxide films and formed on the steel base, whereby the adhesiveness between the films and the base is enhanced. The ferritic heat-resistant steel contains Cr in an amount of from 8.0 to 13.0% by weight, and at least one of Rh and Ir in a total amount of from 0.3 to 5.0% by weight.Type: ApplicationFiled: July 22, 2002Publication date: July 10, 2003Inventors: Nobuyuki Fujitsuna, Fujio Abe, Takehiko Itagaki, Masaaki Igarashi, Seiichi Muneki, Kazuhiro Kimura, Hideaki Kushima
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Publication number: 20020011285Abstract: The invention provides a ferritic heat-resistant steel having excellent high-temperature oxidation resistance, especially excellent steam oxidation-resistant characteristics. In high-Cr ferritic heat-resistant steel, ultra-fine oxide particles having a size of not larger than 1 &mgr;m are formed just below the oxide films and formed on the steel base, whereby the adhesiveness between the films and the base is enhanced. The ferritic heat-resistant steel contains Cr in an amount of from 8.0 to 13.0% by weight, and at least one of Rh and Ir in a total amount of from 0.3 to 5.0% by weight.Type: ApplicationFiled: September 21, 1998Publication date: January 31, 2002Inventors: NOBUYUKI FUJITSUNA, FUJIO ABE, TAKEHIKO ITAGAKI, MASAAKI IGARASHI, SEIICHI MUNEKI, KAZUHIRO KIMURA, HIDEAKI KUSHIMA