Patents by Inventor Shigeaki Takajo

Shigeaki Takajo 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: 6827757
    Abstract: A magnetite-iron based composite powder includes magnetite with a ratio of X-ray diffraction intensity to that of &agr;-Fe of about 0.001 to about 50 and has an average primary particle size of about 0.1 to about 10 &mgr;m. The composite powder can highly dehalogenate organic halogen compounds and exhibits satisfactory absorption power of high frequency electromagnetic waves after molding. An ultrafine nonferrous inorganic compound powder may adhere to the surface of the composite powder, or at least the composite powder may adhere to the surfaces of small particles of a nonferrous inorganic compound to thereby yield a composite powder composition. The composite powder can be produced by partial reduction of a material powder containing a hematite based powder or by complete reduction and subsequent partial oxidation of the material powder.
    Type: Grant
    Filed: May 29, 2002
    Date of Patent: December 7, 2004
    Assignee: JFE Steel Corporation
    Inventors: Yukiko Ozaki, Satoshi Uenosono, Hiroki Nakamaru, Yukiko Nakamura, Shigeaki Takajo, Shigeru Unami, Shingo Saito
  • Publication number: 20040226404
    Abstract: A magnetite-iron based composite powder includes magnetite with a ratio of X-ray diffraction intensity to that of &agr;-Fe of about 0.001 to about 50 and has an average primary particle size of about 0.1 to about 10 &mgr;m. The composite powder can highly dehalogenate organic halogen compounds and exhibits satisfactory absorption power of high frequency electromagnetic waves after molding. An ultrafine nonferrous inorganic compound powder may adhere to the surface of the composite powder, or at least the composite powder may adhere to the surfaces of small particles of a nonferrous inorganic compound to thereby yield a composite powder composition. The composite powder can be produced by partial reduction of a material powder containing a hematite based powder or by complete reduction and subsequent partial oxidation of the material powder.
    Type: Application
    Filed: June 10, 2004
    Publication date: November 18, 2004
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Yukiko Ozaki, Satoshi Uenosono, Hiroki Nakamaru, Yukiko Nakamura, Shigeaki Takajo, Sawae Takajo, Shigeru Unami, Shingo Saito
  • Publication number: 20030116745
    Abstract: A magnetite-iron based composite powder includes magnetite with a ratio of X-ray diffraction intensity to that of &agr;-Fe of about 0.001 to about 50 and has an average primary particle size of about 0.1 to about 10 &mgr;m. The composite powder can highly dehalogenate organic halogen compounds and exhibits satisfactory absorption power of high frequency electromagnetic waves after molding. An ultrafine nonferrous inorganic compound powder may adhere to the surface of the composite powder, or at least the composite powder may adhere to the surfaces of small particles of a nonferrous inorganic compound to thereby yield a composite powder composition. The composite powder can be produced by partial reduction of a material powder containing a hematite based powder or by complete reduction and subsequent partial oxidation of the material powder.
    Type: Application
    Filed: May 29, 2002
    Publication date: June 26, 2003
    Applicant: KAWASAKI STEEL CORPORATION
    Inventors: Yukiko Ozaki, Satoshi Uenosono, Hiroki Nakamaru, Yukiko Nakamura, Shigeaki Takajo, Sawae Takajo, Shigeru Unami, Shingo Saito
  • Patent number: 6416592
    Abstract: Electromagnetic steel sheet having excellent magnetic properties and a texture gratly integrated in the {100}<001> orientation, and an uncomplicated and low cost production method; with about a 15 &mgr;&OHgr;·cm or more specific resistivity, about a 2.0 or more {100}<001> integration degree/{111}<uvw> integration degree and about a 10 &mgr;m to 500 &mgr;m grain diameter; when about 0.1 to 3.5% by weight of Si is present, the {100}<001> integration degree is about 10 or more; when about 0.2 to 1.2% by weight of P is present, the{100}<001> integration degree is about 3 or more; by applying a large reduction ratio to a steel slab in the vicinity of the final stage of hot rolling, with the hot rolling finishing temperature controlled at about 750 to 1150° C., hot rolled steel having a texture highly integrated in the {100}<001> orientation is economically produced.
    Type: Grant
    Filed: February 8, 2001
    Date of Patent: July 9, 2002
    Assignee: Kawasaki Steel Corporation
    Inventors: Osamu Kondo, Akihiro Matsuzaki, Shigeaki Takajo
  • Patent number: 6364962
    Abstract: Electromagnetic steel sheets which contain Cr in an amount of from about 1.5 to 20% by weight and Si in an amount of from about 2.5 to 10% by weight, while having a total amount of C and N of not larger than about 100 ppm by weight, and which has a specific resistivity of not smaller than about 60 &mgr;&OHgr;·cm.
    Type: Grant
    Filed: August 29, 2000
    Date of Patent: April 2, 2002
    Inventors: Shigeaki Takajo, Takako Yamashita, Akihiro Matsuzaki, Osamu Kondo
  • Patent number: 6322638
    Abstract: Electromagnetic steel sheets which contain Cr in an amount of from about 1.5 to 20% by weight and Si in an amount of from about 2.5 to 10% by weight, while having a total amount of C and N of not larger than about 100 ppm by weight, and which has a specific resistivity of not smaller than about 60 &mgr;&OHgr;·cm.
    Type: Grant
    Filed: August 29, 2000
    Date of Patent: November 27, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Shigeaki Takajo, Takako Yamashita, Akihiro Matsuzaki, Osamu Kondo
  • Patent number: 6322639
    Abstract: A magnetic steel sheet used for an alternating current core, and having excellent magnetic properties in both a rolling direction, and the direction perpendicular thereto, and a method of producing the magnetic steel sheet. The magnetic steel sheet in a recrystallized cold-rolled condition is characterized in that the intensity ratio of {100}<001> orientation to random orientation is 2.0 or more, the intensity ratio of {011}<100> orientation to random orientation thereof is 2.0 to 10.0, and the intensity ratio of <001>//ND orientation to random orientation is preferably 2.0 or less. The method of producing a magnetic steel sheet includes hot-rolling a silicon steel slab so that the intensity ratio of (015)[100] orientation to random orientation of the recrystallized hot-rolled sheet is 3.0 or more.
    Type: Grant
    Filed: January 4, 2000
    Date of Patent: November 27, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Akihiro Matsuzaki, Osamu Kondo, Takako Yamashita, Shigeaki Takajo
  • Publication number: 20010020497
    Abstract: Electromagnetic steel sheet having excellent magnetic properties and a texture gratly integrated in the {100}<001> orientation, and an uncomplicated and low cost production method; with about a 15 &mgr;&OHgr;·cm or more specific resistivity, about a 2.0 or more {100}<001> integration degree/{111}<uvw> integration degree and about a 10 &mgr;m to 500 &mgr;m grain diameter; when about 0.1 to 3.5% by weight of Si is present, the {100}<001> integration degree is about 10 or more; when about 0.2 to 1.2% by weight of P is present, the{100}<001> integration degree is about 3 or more; by applying a large reduction ratio to a steel slab in the vicinity of the final stage of hot rolling, with the hot rolling finishing temperature controlled at about 750 to 1150° C., hot rolled steel having a texture highly integrated in the {100}<001> orientation is economically produced.
    Type: Application
    Filed: February 8, 2001
    Publication date: September 13, 2001
    Applicant: Kawasaki Steel Corporation
    Inventors: Osamu Kondo, Akihiro Matsuzaki, Shigeaki Takajo
  • Patent number: 6248185
    Abstract: Electromagnetic steel sheet having excellent magnetic properties and a texture gratly integrated in the {100}<001> orientation, and an uncomplicated and low cost production method; with about a 15 &mgr;&OHgr;·cm or more specific resistivity, about a 2.0 or more {100}<001> integration degree /{111}<uvw> integration degree and about a 10 &mgr;m to 500 &mgr;m grain diameter; when about 0.1 to 3.5% by weight of Si is present, the {100}<001> integration degree is about 10 or more; when about 0.2 to 1.2% by weight of P is present, the {100}<001> integration degree is about 3 or more; by applying a large reduction ratio to a steel slab in the vicinity of the final stage of hot rolling, with the hot rolling finishing temperature controlled at about 750 to 1150° C., hot rolled steel having a texture highly integrated in the {100}<001> orientation is economically produced.
    Type: Grant
    Filed: August 14, 1998
    Date of Patent: June 19, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Osamu Kondo, Akihiro Matsuzaki, Shigeaki Takajo
  • Patent number: 6207103
    Abstract: Fe—Cr—Si steel sheet having an excellent corrosion resistance and high toughness and method for manufacturing the same; the amount of Cr is about 10-30 wt %, the total amount of C and N is not more than about 100 ppm and the remainder consists of Fe and incidental impurities; when a cast piece of this steel is subjected to hot rolling to roll into a thickness of not more than about 3 mm, the hot rolled sheet can be subjected to cold rolling or to warm rolling without annealing.
    Type: Grant
    Filed: July 29, 1998
    Date of Patent: March 27, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Shigeaki Takajo, Takako Yamashita, Akihiro Matsuzaki, Osamu Kondo
  • Patent number: 6162306
    Abstract: Electromagnetic steel sheets which contain Cr in an amount of from about 1.5 to 20% by weight and Si in an amount of from about 2.5 to 10% by weight, while having a total amount of C and N of not larger than about 100 ppm by weight, and which has a specific resistivity of not smaller than about 60 .mu..OMEGA..multidot.cm.
    Type: Grant
    Filed: October 28, 1998
    Date of Patent: December 19, 2000
    Assignee: Kawasaki Steel Corporation
    Inventors: Shigeaki Takajo, Takako Yamashita, Akihiro Matsuzaki, Osamu Kondo
  • Patent number: 5476534
    Abstract: An iron-based powder mixture for powder metallurgy essentially consists of a melted mixture, as a binder, which includes about 0.1% to about 1.0% by weight of a powder of at least one organic compound selected from stearic acid, oleic acid amide, and stearic acid amide, and about 0.1% to about 1.0% by weight of a powder of stearic acid bisamide; and the balance which is an iron-based powder, to the surface of which adhered about 0.1% to about 3.0% by weight of an alloying powder and/or a powder for improving machinability. Disclosed also is a method of producing the mixture.
    Type: Grant
    Filed: August 2, 1993
    Date of Patent: December 19, 1995
    Assignee: Kawasaki Steel Corporation
    Inventors: Kuniaki Ogura, Shigeaki Takajo, Hiroyuki Ishikawa, Akio Sonobe, Yoshiaki Maeda, Toshiyuki Minegishi
  • Patent number: 5308702
    Abstract: Improved iron-base powder composition for use in powder metallurgy comprising an iron-base powder to the surfaces of the particles of which either an Fe-Ni powder alloy containing 5-70 wt % Ni or an Fe-Mo alloy powder containing 20-70 wt % Mo or both alloy powders is adhered means of a binder or binders. This iron-base powder composition can be obtained by a process in which either an Fe-Ni alloy powder containing 5-70 wt % Ni or an Fe-Mo alloy powder containing 20-70 wt % Mo or both alloy powders is adhered by thermally melting a binder. The thus obtained iron-base powder composition can be shaped and sintered to produce an iron-base sintered material. The iron-base powder composition is suitable for use in the powder metallurgical manufacture of iron-base sintered parts that require high density, high strength, toughness, wear resistance and good dimensional change stability.
    Type: Grant
    Filed: January 29, 1992
    Date of Patent: May 3, 1994
    Assignee: Kawasaki Steel Corporation
    Inventors: Osamu Furukimi, Koji Yano, Shigeaki Takajo
  • Patent number: 5279640
    Abstract: An iron-based powder mixture for powder metallurgy essentially consists of a melted mixture, as a binder, which includes about 0.1% to about 1.0% by weight of a powder of at least one organic compound selected from stearic acid, oleic acid amide, and stearic acid amide, and about 0.1% to about 1.0% by weight of a powder of stearic acid bisamide; and the balance which is an iron-based powder, to the surface of which adhered about 0.1% to about 3.0% by weight of an alloying powder and/or a powder for improving machinability. Disclosed also is a method of producing the mixture.
    Type: Grant
    Filed: September 22, 1992
    Date of Patent: January 18, 1994
    Assignee: Kawasaki Steel Corporation
    Inventors: Kuniaki Ogura, Shigeaki Takajo, Hiroyuki Ishikawa, Akio Sonobe, Yoshiaki Maeda, Toshiyuki Minegishi
  • Patent number: 5135566
    Abstract: An iron base powder mixture for powder metallurgy, comprising an iron based powder and an alloying powder and/or a powder for improving machinability, wherein the alloying powder and/or the powder for improving machinability are adhered to the surface of the ferrous powder by means of a melted-together binder composed of an oil and a metal soap or wax.
    Type: Grant
    Filed: April 17, 1991
    Date of Patent: August 4, 1992
    Assignee: Kawasaki Steel Corporation
    Inventors: Ichio Sakuranda, Ritsuo Okabe, Takao Omura, Yoshisato Kiyota, Shigeaki Takajo
  • Patent number: 5067979
    Abstract: A process is provided for the production of a sintered body. The process includes the following consecutive steps: i) mixing and kneading one or more metal powders and/or one or more alloy powder with a binder into a compound, said metal and alloy powders having an average particle size not greater than 30 .mu.m, ii) injection-molding the compound into a green body; iii) debinding the green body to form a debound body; and iv) subjecting the debound body to a first-stage sintering at 1,050.degree.-1,250.degree. C. in a reduced-pressure atmosphere and then to second-stage sintering at a temperature in a range of 1,100.degree.-400.degree. C. which is higher than that of the first-stage sintering. This process can provide sintered Ti bodies and sintered magnetic bodies of the Fe-Si type, which have a density ratio of at least 95%.
    Type: Grant
    Filed: July 6, 1990
    Date of Patent: November 26, 1991
    Assignee: Kawasaki Steel Corporation
    Inventors: Yoshisato Kiyota, Junichi Ohta, Hiroshi Ohtsubo, Shigeaki Takajo
  • Patent number: 4985309
    Abstract: An alloyed steel powder for metallurgy is provided with a water-atomized alloyed steel powder wherein an alloy component, an oxide of which is difficult to be reduced with hydrogen in the production of the powder, has been prealloyed in a composition range not exerting a bad influence upon compressibility of the steel powder, and an alloy component or components easier to be reduced with hydrogen than the above alloy component, the said easily reducible alloy component or components being partially diffused and adhered in a powdered form to the particle surfaces of the water-atomized alloyed steel powder.The composite powder of the invention has a coating layer of at least one element selected from nickel, copper, molybdenum and tungsten which is partially diffused and adhered in a powder form to the surface of a chromium containing prealloyed steel powder.
    Type: Grant
    Filed: August 1, 1988
    Date of Patent: January 15, 1991
    Assignee: Kawasaki Steel Corporation
    Inventors: Kuniaki Ogura, Junichi Oota, Teruyoshi Abe, Shigeaki Takajo
  • Patent number: 4971755
    Abstract: It is disclosed a method for preparing a large-sized powder metallurgical sintered product having a superior characteristic by charging mixtures of three types of metallic powder composed of coarse particles, middle particles and fine particles into the molding die while vibrating it, heating the charged material together with the molding die, sintering them, and infiltrating metal of low melting point into the sintered body. According to this method, it is possible to get a large-sized sintered body having a superior strength and surface smoothness or a sintered body prohibiting any cracks or slits by arranging the proper particle size.
    Type: Grant
    Filed: June 20, 1989
    Date of Patent: November 20, 1990
    Assignee: Kawasaki Steel Corporation
    Inventors: Masaki Kawano, Kuniaki Ogura, Shigeaki Takajo, Hiroshi Ohtsubo, Keisuke Yoshimura, Yoshiaki Maeda
  • Patent number: 4964907
    Abstract: A process is provided for the production of a sintered body. The process includes the following consecutive steps: (i) mixing and kneading one or more metal powders and/or one or more alloy powder with a binder into a compound, said metal and alloy powders having an average particle size not greater than 30 .mu.m, (ii) injection-molding the compound into a green body; (iii) debinding the green body to form a debound body; and (iv) subjecting the debound body to first-stage sintering at 1,050.degree.-1,250.degree. C. in a reducing or reduced-pressure atmosphere and then to second-stage sintering at a temperature in a range of 1,100.degree.-1,400.degree. C. which is higher than that of the first-stage sintering. This process can provide sintered Ti bodies and sintered magnetic bodies of the Fe-Si type, which have a density ratio of at least 95%.
    Type: Grant
    Filed: August 14, 1989
    Date of Patent: October 23, 1990
    Assignee: Kawasaki Steel Corp.
    Inventors: Yoshisato Kiyota, Junichi Ohta, Hiroshi Ohtsubo, Shigeaki Takajo
  • Patent number: 4954171
    Abstract: Provided herein are high-strength high-toughness sintered alloy steel and composite alloy steel powder useful for the production thereof. The sintered alloy steel contains, as the alloy components in the final product, Ni, Mo, and/or W, and C, if necessary, said alloy being composed of 0.50-3.50 wt % of Ni, 0.65-3.50 wt % of Mo+1/2W, (and 0.3-0.8 wt % of C, if necessary), and the remainder of Fe and inevitable impurities, and has a density higher than 7.0 g/cm.sup.3 and a tensile strength higher than 130 kgf/mm.sup.2 after quenching and tempering. The composite alloy steel powder is composed of iron powder particles and powdery alloy components attached by diffusion to part of the surface of the iron powder particles, with the content of Ni and the content of Mo+1/2W in the steel powder of particle diameter smaller than 45 .infin.m being in the range of 2.0-4.2 times the average content in the entire steel powder.
    Type: Grant
    Filed: July 14, 1989
    Date of Patent: September 4, 1990
    Assignee: Kawasaki Steel Corp.
    Inventors: Shigeaki Takajo, Osamu Furukimi, Kuniaki Ogura, Keiichi Maruta, Teruyoshi Abe, Ichio Sakurada