Specific Crystallographic Orientation Patents (Class 148/308)
  • Patent number: 11161163
    Abstract: The method includes treating a metal sheet having a bcc structure and a surface satisfying conditions (a) or (b), molding the metal sheet to cause plane strain tensile deformation and biaxial tensile deformation, and allowing at least one part of the metal sheet to have a sheet thickness decrease rate of from 10% to 30%. Condition (a): an area fraction of crystal grains having a crystal orientation of 15° or less relative to a (001) plane parallel to a surface of the metal sheet is from 0.20 to 0.35. Condition (b): the area fraction of crystal grains having a crystal orientation of 15° or less relative to a (001) plane parallel to a surface of the metal sheet is 0.45 or less, the average crystal grain size thereof is 15 ?m or less. The molded product satisfies conditions (a) or (b).
    Type: Grant
    Filed: February 20, 2020
    Date of Patent: November 2, 2021
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Masahiro Kubo, Yoshiaki Nakazawa, Hiroshi Yoshida
  • Patent number: 10704113
    Abstract: A magnetic domain refining treatment is performed by dividing a surface of a steel sheet into a plurality of regions in a widthwise direction, disposing a laser irradiation apparatus or an electron beam irradiation apparatus in each of the regions, and forming beam-irradiated regions through beam irradiation, wherein beams are irradiated so that a nature of a juncture between beam-irradiated regions satisfies 0???0.3×a and ?1.2×a+0.02×w?0.5×??6.5????0.13×a?200×(1/w)+5.4 when TD spacing ? at the juncture between the beam-irradiated regions is ?3 to 0 mm, whereby a grain oriented electrical steel sheet having an excellent iron loss property is produced in a good productivity.
    Type: Grant
    Filed: January 8, 2015
    Date of Patent: July 7, 2020
    Assignee: JFE Steel Corporation
    Inventors: Hirotaka Inoue, Shigehiro Takajo, Seiji Okabe
  • Patent number: 10643770
    Abstract: When a steel sheet containing Si: 2-5 mass % after cold rolling is subjected to a primary recrystallization annealing and a finishing annealing for secondary recrystallization to form a grain-oriented electrical steel sheet, the primary recrystallization annealing is performed by rapid heating in the heating process and temperature keeping treatment at a certain temperature in the course of the heating to thereby obtain a grain-oriented electrical steel sheet having plural peaks in a distribution of misorientation angle between crystal orientation of secondary recrystallized grains and Goss orientation, wherein misorientation angle of the second smallest peak among the plural peaks is preferably not less than 5° and a grain size of secondary recrystallized grains is not more than 15 mm.
    Type: Grant
    Filed: December 11, 2013
    Date of Patent: May 5, 2020
    Assignee: JFE STEEL CORPORATION
    Inventors: Takeshi Imamura, Yukihiro Shingaki, Ryuichi Suehiro, Toshito Takamiya
  • Patent number: 10644234
    Abstract: A method for producing a magnetic memory includes: forming a magnetic film having a non-magnetic layer between a first magnetic layer and a second magnetic layer on a substrate having an electrode layer; performing annealing treatment at a first treatment temperature in a state where a magnetic field is applied in a direction perpendicular to a film surface of the first or the second magnetic layer in vacuum; forming a magnetic tunnel junction element; forming a protective film protecting the magnetic tunnel junction element; a formation accompanied by thermal history, in which a constituent element of a magnetic memory is formed after the protective film formation on the substrate; and implementing annealing treatment at a second treatment temperature lower than the first treatment temperature on the substrate in an annealing treatment chamber, in vacuum or inert gas wherein no magnetic field is applied.
    Type: Grant
    Filed: August 28, 2017
    Date of Patent: May 5, 2020
    Assignee: TOHOKU UNIVERSITY
    Inventors: Kenchi Ito, Tetsuo Endoh, Shoji Ikeda, Hideo Sato, Hideo Ohno, Sadahiko Miura, Masaaki Niwa, Hiroaki Honjo
  • Patent number: 10626474
    Abstract: A grain-oriented electrical steel sheet that includes a base coating with a high TiN ratio advantageous for the application of tension to the steel sheet and has excellent magnetic property is provided. The grain-oriented electrical steel sheet includes: a base coating having a peak value PTiN of TiN in the form of osbornite, observed in a range of 42°<2?<43° and a peak value PMg2SiO4 of Mg2SiO4 in the form of forsterite, observed in a range of 35°<2?<36° of both more than 0 and satisfying a relationship PTiN?PMg2SiO4, in thin-film X-ray diffraction analysis; and an iron loss W17/50 of 1.0 W/kg or less.
    Type: Grant
    Filed: December 24, 2015
    Date of Patent: April 21, 2020
    Assignee: JFE STEEL CORPORATION
    Inventors: Yukihiro Shingaki, Tomoyuki Okubo, Hirotaka Inoue
  • Patent number: 10087529
    Abstract: Provided is a treatment solution for chromium-free tension coating that can simultaneously achieve excellent moisture absorption resistance and a high iron loss reduction effect obtained by imparting sufficient tension, by using an inexpensive Ti source instead of expensive Ti chelate. The treatment solution for chromium-free tension coating contains: one or more of phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn; colloidal silica in an amount of 50 parts by mass to 120 parts by mass per 100 parts by mass of the phosphate in terms of solid content of SiO2; Ti source in an amount of 30 parts by mass to 50 parts by mass per 100 parts by mass of the phosphate in terms of solid content of TiO2; and H3PO4, and the number of moles of metallic elements in the phosphate and of phosphorus in the treatment solution satisfy: 0.20?([Mg]+[Ca]+[Ba]+[Sr]+[Zn]+[Mn]+1.5[Al])/[P]?0.45??(1).
    Type: Grant
    Filed: January 14, 2015
    Date of Patent: October 2, 2018
    Assignee: JFE STEEL CORPORATION
    Inventors: Takashi Terashima, Makoto Watanabe, Masanori Uesaka, Ryuichi Suehiro, Toshito Takamiya
  • Patent number: 9646749
    Abstract: The present invention proposes a method that can reduce the noise generated by a transformer core and the like when formed by laminations of a grain-oriented electrical steel sheet in which core loss has been reduced by a magnetic domain refinement process. In this steel sheet, linear distortion extending with an orientation in which an angle formed with a direction perpendicular to the rolling direction of the steel sheet is an angle of 30° or less is periodic in the direction of rolling of the steel sheet, core loss (W17/50) is 0.720 W/kg or less, and magnetic flux density (B8) is 1.930 T. The volume of the closure domain arising in the distortion part is 1.00-3.00% of the total magnetic domain volume within the steel sheet.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: May 9, 2017
    Assignee: JFE STEEL CORPORATION
    Inventors: Ryuichi Suehiro, Hiroi Yamaguchi, Seiji Okabe, Hirotaka Inoue, Shigehiro Takajo
  • Patent number: 9330839
    Abstract: A grain oriented electrical steel sheet is subjected to magnetic domain refining treatment by electron beam irradiation and exhibits excellent low-noise properties when assembled as an actual transformer, in which a ratio (Wa/Wb) of a film thickness (Wa) of the forsierite film on a strain-introduced side of the steel sheet to a film thickness (Wb) of the forsierite film on a non-strain-introduced side of the steel sheet is 0.5 or higher, a magnetic domain discontinuous portion in a surface of the steel sheet on the strain-introduced side has an average width of 150 to 300 ?m, and a magnetic domain discontinuous portion in a surface of the steel sheet on the non-strain-introduced side has an average width of 250 to 500 ?m.
    Type: Grant
    Filed: August 3, 2011
    Date of Patent: May 3, 2016
    Assignee: JFE Steel Corporation
    Inventors: Takeshi Omura, Hiroi Yamaguchi, Seiji Okabe
  • Patent number: 8911565
    Abstract: On at least one surface of a base metal plate (1) of an ?-? transforming Fe or Fe alloy, a metal layer (2) containing ferrite former is formed. Next, the base metal plate (1) and the metal layer (2) are heated to an A3 point of the Fe or the Fe alloy, whereby the ferrite former are diffused into the base metal plate (1) to form an alloy region (1b) in a ferrite phase in which an accumulation degree of {200} planes is 25% or more and an accumulation degree of {222} planes is 40% or less. Next, the base metal plate (1) is heated to a temperature higher than the A3 point of the Fe or the Fe alloy, whereby the accumulation degree of the {200} planes is increased and the accumulation degree of the {222} planes is decreased while the alloy region (11b) is maintained in the ferrite phase.
    Type: Grant
    Filed: October 27, 2010
    Date of Patent: December 16, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Tooru Inaguma, Miho Tomita, Youji Mizuhara, Hiroaki Sakamoto
  • Patent number: 8366836
    Abstract: A silicon steel material is heated in a predetermined temperature range according to contents of B, N, Mn, S, and Se (step S1), and is subjected to hot rolling (step S2). Further, a finish temperature Tf of finish rolling in the hot rolling is performed in a predetermined temperature range according to the content of B. Through these treatments, a certain amount of BN is made to precipitate compositely on MnS and/or MnSe.
    Type: Grant
    Filed: July 13, 2010
    Date of Patent: February 5, 2013
    Assignee: Nippon Steel Corporation
    Inventors: Yoshiyuki Ushigami, Norikazu Fujii
  • Patent number: 8361243
    Abstract: An iron or iron-base alloy sheet having high proportion of {100} texture and a method of manufacturing the same. A method of forming grains having {100} plane parallel to the sheet surface is disclosed. A Fe or Fe-base alloy sheet is annealed at austenite (?) temperature while minimizing an effect of oxygen in the sheet or on surfaces of the sheet or a heat treatment atmosphere, and then the above sheet is subject to phase transformation to ferrite (?). On surfaces of the resulting sheet, a high proportion of {100} texture develops. A method of manufacturing electrical steel sheet is disclosed. The grains with {100} texture on surfaces grow to have a grain size of at least half the thickness of the sheet by a ??? transformation. By adopting the above disclosed methods, an iron or iron-base alloy sheet with excellent texture can be simply manufactured within short time.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: January 29, 2013
    Inventor: Jin Kyung Sung
  • Patent number: 8333846
    Abstract: A manufacturing method of oriented Si steel with high electric-magnetic property comprises the following steps: smelting steel in converter or electric furnace; refining molten steel in two stages; continuous casting to obtain slab; hot rolling; first cold rolling; decarburizing annealing; secondary cold rolling; applying an annealing separator based on MgO and annealing at high temperature; applying an insulating coating and leveling tension annealing. The slab comprises (in wt %): C 0.020-0.050%, Si 2.6-3.6%, S 0.015-0.025%, Als 0.008-0.028%, N 0.005-0.020%, Mn 0.15-0.5%, Cu 0.3-1.2%, balance Fe and inevitable impurities, in which 10?Mn/S?20 and Cu/Mn?2. The method could produce oriented Si steel with high magnetic induction intensity and low iron loss at low cost.
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: December 18, 2012
    Assignee: Baoshan Iron & Steel Co., Ltd.
    Inventors: Guohua Yang, Huande Sun, Yaming Ji, Guobao Li, Hongxu Hei
  • Patent number: 8303730
    Abstract: A slab with a predetermined composition is heated at 1280° C. to 1390° C. to make a substance functioning as an inhibitor to be solid-solved (step S1). Next, the slab is hot-rolled to obtain a steel strip (step S2). The steel strip is annealed to form a primary inhibitor in the steel strip (step S3). Next, the steel strip is cold-rolled once or more (step S4). Next, the steel strip is annealed to perform decarburization and to cause primary recrystallization (step S5). Next, nitriding treatment is performed on the steel strip in a mixed gas of hydrogen, nitrogen and ammonia under a state where the steel strip runs, to form a secondary inhibitor in the steel strip (step S6). Next, the steel strip is annealed to induce secondary recrystallization (step S7).
    Type: Grant
    Filed: September 8, 2009
    Date of Patent: November 6, 2012
    Assignee: Nippon Steel Corporation
    Inventors: Tomoji Kumano, Yoshiyuki Ushigami, Shuichi Nakamura, Yohichi Zaizen
  • Patent number: 8304953
    Abstract: A rotating electrical machine includes: a rotor comprising a rotor core and a field winding wound round the rotor core; and a stator comprising a stator core and a stator winding wound round the stator core. The stator is arranged in opposition to the rotor with a predetermined spacing therebetween. the stator core is formed by punching a split piece, which comprises teeth for insertion of the stator winding thereinto and a core back on an outer periphery thereof, from a magnetic steel sheet, and laminating a plurality of those circular configurations in an axial direction, in which a plurality of the split pieces are arranged in a circle in a circumferential direction. The stator core has magnetic steel sheets, which are different in magnetic permeability in a diametrical direction, laminated at an axial end region of and in an axial central region of the stator core.
    Type: Grant
    Filed: February 25, 2011
    Date of Patent: November 6, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Akihito Nakahara, Hiroyuki Mikami, Kazumasa Ide, Kazuhiko Takahashi, Kenichi Hattori
  • Patent number: 8277574
    Abstract: There is provided a method for manufacturing a grain-oriented electromagnetic steel sheet whose iron losses are reduced by laser beam irradiation, capable of improving the iron losses in both the L-direction and the C-direction while easily ensuring high productivity. The method for manufacturing a grain-oriented electromagnetic steel sheet reduces iron losses by scanning and irradiating a grain-oriented electromagnetic steel sheet with a continuous-wave laser beam condensed into a circular or elliptical shape at constant intervals in a direction substantially perpendicular to a rolling direction of the grain-oriented electromagnetic steel sheet, wherein when an average irradiation energy density Ua is defined as Ua=P/(Vc×PL) (mJ/mm2), where P (W) is average power of the laser beam, Vc (m/s) is a beam scanning velocity, and PL (mm) is an irradiation interval in a rolling direction, PL and Ua are in the following ranges: 1.0 mm?PL?3.0 mm, 0.8 mJ/mm2?Ua?2.0 mJ/mm2.
    Type: Grant
    Filed: December 11, 2008
    Date of Patent: October 2, 2012
    Assignee: Nippon Steel Corporation
    Inventors: Tatsuhiko Sakai, Hideyuki Hamamura, Masao Yabumoto
  • Patent number: 8268097
    Abstract: A grain-oriented electrical steel sheet has a tension film that does not include chromium. In the present invention, the tension film, including a phosphate and silica as constituents, includes a manganese compound and a potassium compound. The mole ratio K/Mn of potassium to manganese in the film is set to a certain range. The film can be produced by preparing a coating solution by adding a compound, which includes the phosphate and the silica and also includes the potassium and the manganese, and applying the coating solution on a grain-oriented electrical steel sheet after final annealing is completed, followed by drying and baking.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: September 18, 2012
    Assignee: Nippon Steel Corporation
    Inventors: Fumiaki Takahashi, Kazutoshi Takeda, Hiroyasu Fujii, Shuichi Yamazaki, Yoshiaki Natori
  • Patent number: 8236110
    Abstract: The invention produces a grain-oriented electrical steel sheet having a primary recrystallization structure in which Goss-oriented crystal grains and crystal grains having a coincidence orientation relationship to the Goss orientation are aligned in the rolling direction. It is characterized heating a slab containing, in mass %, C: 0.025 to 0.10%, Si: 2.5 to 4.5%, Mn: 0.03 to 0.55%, and Al: 0.007 to 0.040% to 1,100 to 1,450° C.
    Type: Grant
    Filed: April 22, 2008
    Date of Patent: August 7, 2012
    Assignee: Nippon Steel Corporation
    Inventors: Takao Mukai, Shinya Hayashi, Atsushi Tanaka, Hiroyuki Mimura, Hisataka Uto
  • Patent number: 8231739
    Abstract: A method of manufacturing oriented Si steel containing Cu with high electric-magnetic property comprises: hot rolling slab; after first cold rolling, heating it to 800° C. or higher temperature and performing intermediate decarburization annealing in a protective atmosphere with PH2O/PH2 of 0.50˜0.88 for 3-8 minutes, to decrease carbon content of the steel plate to less than 30 ppm; then peening and acid-pickling to remove oxide of Fe on surface and to control oxygen content to lower than 500 ppm; secondary cold rolling to final thickness and coating separation agent in water-slurry form; drying to decrease water content to lower than 1.5%; high-temperature annealing in a protective atmosphere containing hydrogen with oxidation degree (PH2O/PH2) of 0.0001-0.2; finally applying a tension coating and leveling tension annealing.
    Type: Grant
    Filed: April 24, 2009
    Date of Patent: July 31, 2012
    Assignee: Baoshan Iron & Steel Co., Ltd.
    Inventors: Yaming Ji, Huande Sun, Guohua Yang, Yongjie Yang, Yunpeng Xu, Changguo Huang, Guobao Li
  • Patent number: 8177920
    Abstract: The present invention provides a grain-oriented electrical steel sheet produced by a method for promoting secondary recrystallization without an inhibitor, the grain-oriented electrical steel sheet including 2.0% or more and 4.5% or less of Si and 0.01% or more and 0.5% or less of Mn on a mass % basis, wherein the number of oxide particles having a diameter of 1 to 3 ?m among that (oxide particles) of containing Ca and/or Mg is 400 or less per unit area (1 cm2) in a transverse cross-section perpendicular to a rolling direction. Therefore, the grain-oriented electrical steel sheet has excellent stable magnetic properties throughout the length of a coil.
    Type: Grant
    Filed: November 28, 2005
    Date of Patent: May 15, 2012
    Assignee: JFE Steel Corporation
    Inventors: Yukihiro Shingaki, Minoru Takashima, Tadashi Nakanishi, Takeshi Murai
  • Patent number: 8088229
    Abstract: A method for producing high-quality grain oriented magnetic steel sheet utilizes a steel alloy with (in wt %) Si: 2.5-4.0%, C: 0.02-0.10%, Al: 0.01-0.065%, N: 0.003-0.015%. The method utilizes an operational sequence whose individual steps (secondary metallurgical treatment of the molten metal, continuous casting of the molten metal into a strand, dividing of the strand into thin slabs, heating of the thin slabs, continuous hot rolling of the thin slabs into hot strip, cooling of the hot strip, coiling of the hot strip, cold rolling of the hot strip into cold strip, recrystallization and decarburization annealing of the cold strip, application of an annealing separator, final annealing of the recrystallization and decarburization annealed cold strip to form a Goss texture) are harmonized with one another, so that a magnetic steel sheet with optimized electromagnetic properties is obtained using conventional apparatus.
    Type: Grant
    Filed: July 20, 2006
    Date of Patent: January 3, 2012
    Assignee: ThyssenKrupp Steel AG
    Inventors: Klaus Günther, Ludger Lahn, Andreas Ploch, Eberhard Sowka
  • Patent number: 8038806
    Abstract: A method, which makes it possible to economically produce high-quality grain oriented magnetic steel sheet, utilizes a steel alloy with (in wt %) Si: 2.5-4.0%, C: 0.01-0.10 %, Mn: 0.02-0.50%, S and Se in contents, whose total amounts to 0.005-0.04%. The method utilizes an operational sequence whose individual routine steps (secondary metallurgical treatment of the molten metal in a vacuum-or ladle facility, continuous casting of the molten metal into a strand, dividing of the strand, heating in a facility standing inline, continuous hot rolling in a multi-stand hot rolling mill standing inline, cooling, coiling, cold rolling, recrystallization and decarburization annealing, application of an annealing separator, final annealing to form a Goss texture) are harmonized with one another, so that a magnetic steel sheet with optimized electromagnetic properties is obtained using conventional apparatus.
    Type: Grant
    Filed: July 20, 2006
    Date of Patent: October 18, 2011
    Assignee: ThyssenKrupp Steel AG
    Inventors: Klaus Günther, Ludger Lahn, Andreas Ploch, Eberhard Sowka
  • Patent number: 8034196
    Abstract: A grain-oriented electrical steel plate is characterized in that grooves having a width of 10 ?m to 200 ?m and a depth of 10 ?m to 30 ?m exist in at least one of a front surface and a rear surface of a steel plate at intervals of 1 mm to 10 mm, an angle between a direction in which the grooves extend and a rolling direction of the steel plate is 60 degrees to 120 degrees, and tensile stresses having a maximum value of 20 MPa to 300 MPa act in the rolling direction within ranges of 10 ?m to 300 ?m from side surfaces of the grooves.
    Type: Grant
    Filed: February 13, 2009
    Date of Patent: October 11, 2011
    Assignee: Nippon Steel Corporation
    Inventors: Keiji Iwata, Hideyuki Hamamura
  • Patent number: 8016951
    Abstract: An object of the present invention is to provide a grain-oriented electrical steel sheet with low core loss and low magnetostriction and a method for producing the same. The grain-oriented electrical steel sheet is excellent in reduced core loss and magnetostriction while under a high flux density of 1.9 T, comprises a refined magnetic domain comprising a laser irradiated portion which has melted and resolidified to form a solidified layer, wherein the thickness of the solidified layer is 4 ?m or less. The grain-oriented electrical steel sheet may further comprise a laser irradiated portion where a surface roughness Rz is small and a cross section viewed from a transverse direction has a concave portion having a width of 200 ?m or less and a depth of 10 ?m or less for further improvement.
    Type: Grant
    Filed: April 26, 2006
    Date of Patent: September 13, 2011
    Assignee: Nippon Steel Corporation
    Inventors: Satoshi Arai, Hideyuki Hamamura, Tatsuhiko Sakai, Kaoru Sato, Hideyuki Kobayashi
  • Patent number: 7998284
    Abstract: Grain-oriented electrical steel sheet having a chrome-free high tensile strength insulating film characterized by comprising steel sheet on the surface of which is formed an insulating film containing a phosphate and colloidal silica as main ingredients and containing crystalline magnesium phosphate uniformly dispersed over the entire surface.
    Type: Grant
    Filed: May 18, 2007
    Date of Patent: August 16, 2011
    Assignee: Nippon Steel Corporation
    Inventors: Kazutoshi Takeda, Fumiaki Takahashi, Shuichi Yamazaki, Hiroyasu Fujii, Fumikazu Andou
  • Patent number: 7981223
    Abstract: The present invention is a grain-oriented electrical steel sheet characterized in that Bi is present at 0.01 to less than 1,000 ppm in terms of mass at the interface of the substrate steel and the primary film of the grain-oriented electrical steel sheet. The grain-oriented electrical steel sheet is produced by any of the processes of: before decarburization annealing, applying preliminary annealing for 1 to 20 sec. at 700° C. or higher and controlling an atmosphere in the temperature range; controlling the maximum attaining temperature B (° C.) before final cold rolling so that the maximum attaining temperature B may satisfy the expression, ?10×ln(A)+1,100?B?10×ln(A)+1,220, in accordance with a Bi content A (ppm) and at the same time heating the steel sheet cold rolled to the final thickness to 700° C. or higher within 10 sec. or at a heating rate of 100° C./sec. or more before decarburization annealing, or immediately thereafter applying preliminary annealing for 1 to 20 sec. at 700° C.
    Type: Grant
    Filed: June 27, 2008
    Date of Patent: July 19, 2011
    Assignee: Nippon Steel Corporation
    Inventors: Eiichi Nanba, Katsuyuki Yanagihara, Satoshi Arai, Shuichi Yamazaki, Fumikazu Ando, Kazutoshi Takeda, Yousuke Kurosaki, Nobuo Tachibana
  • Patent number: 7976644
    Abstract: The present invention provides a method of production of grain-oriented electrical steel sheet comprising making a slab heating temperature 1280° C. or less, annealing hot rolled sheet by (a) a process of heating it to a predetermined temperature of 1000 to 1150° C. to cause recrystallization, then annealing by a temperature lower than that of 850 to 1100° C. or by (b) decarburizing in annealing the hot rolled sheet so that a difference in amounts of carbon of the steel sheet before and after annealing the hot rolled sheet becomes 0.002 to 0.02 mass % and performing the heating in the temperature elevation process of the decarburization annealing under conditions of a heating rate of 40° C. or more, preferably 75 to 125° C./s while the temperature of the steel sheet is in a range from 550° C. to 720° C. and utilizing induction heating for rapid heating in the temperature elevation process of decarburization annealing.
    Type: Grant
    Filed: May 22, 2007
    Date of Patent: July 12, 2011
    Assignee: Nippon Steel Corporation
    Inventors: Yoshiyuki Ushigami, Norikazu Fujii, Takeshi Kimura, Maremizu Ishibashi, Shuichi Nakamura, Koji Yamasaki
  • Patent number: 7976645
    Abstract: In a production of grain-oriented electrical steel sheet that is heated at a temperature of not higher than 1350° C., (a) the hot-rolled sheet is heated to a prescribed temperature of 1000° C. to 1150° C., and after recrystallization is annealed for a required time at a lower temperature of 850° C. to 1100° C., or (b) in the hot-rolled sheet annealing process decarburization is conducted to adjust the difference in the amount of carbon before and after decarburization to 0.002 to 0.02 mass %. In the temperature elevation process used in the decarburization annealing of the steel sheet, heating is conducted in the temperature range of 550° C. to 720° C. at a heating rate of at least 40° C./s, preferably 75 to 125° C./s, utilizing induction heating for the rapid heating used in the temperature elevation process in decarburization annealing.
    Type: Grant
    Filed: May 23, 2007
    Date of Patent: July 12, 2011
    Assignee: Nippon Steel Corporation
    Inventors: Yoshiyuki Ushigami, Norikazu Fujii, Tomoji Kumano
  • Patent number: 7942982
    Abstract: Grain-oriented electrical steel sheet excellent in coating adhesion is provided. The steel sheet contains Si: 2 to 7% mass % and has a primary coating composed mainly of forsterite on its surface. A compound (A) containing one or more elements selected from among Ca, Sr and Ba, at least one rare earth metal, and sulfur is incorporated in the primary coating so as to reside in the interface layer between the primary coating and the steel sheet. As a result, occurrence of primary coating exfoliation at regions that are strongly worked during manufacture of a wound core transformer or the like is prevented.
    Type: Grant
    Filed: November 15, 2007
    Date of Patent: May 17, 2011
    Assignee: Nippon Steel Corporation
    Inventors: Yuji Kubo, Eiichi Nanba, Satoshi Arai, Hotaka Honma, Kazumi Mizukami, Koki Tanaka
  • Patent number: 7887645
    Abstract: The present invention provides a method of producing a high permeability grain oriented electrical steel having excellent mechanical and magnetic properties. A hot band having a thickness of about 1.5 to about 4.0 mm has a chemistry comprising about 2.5 to about 4.5% silicon, about 0.1 to about 1.2% chromium, about 0.02 to about 0.08% carbon, about 0.01 to about 0.05% aluminum, up to about 0.1% sulfur, up to about 0.14% selenium, about 0.03 to about 0.15% manganese, up to about 0.2% tin, up to about 1% copper, and balance being essentially iron and residual elements, all percentages by weight. The band has a volume resistivity of at least about 45 ??-cm, an austenite volume fraction (?1150° C.) of at least 20% and the strip has an isomorphic layer thickness of at least about 2% of the total thickness on at least one surface of the hot processed band. The band is rapidly cooled after the anneal prior to cold rolling at a rate of at least 30° C./second from 875-950° C. to a temperature below 400° C.
    Type: Grant
    Filed: May 2, 2001
    Date of Patent: February 15, 2011
    Assignee: AK Steel Properties, Inc.
    Inventors: Jerry W. Schoen, Norris A. Dahlstrom, Robert J. Comstock, Jr.
  • Patent number: 7857915
    Abstract: Reheating a grain-oriented electrical steel sheet slab comprising predetermined components to 1280° C. or more and a solid solution temperature of inhibitor substances or more, hot rolling, annealing, and cold rolling it, decarburization annealing it, nitriding it in a strip running state, coating an annealing separator, and finish annealing it during which making a precipitation ratio of N as AlN after hot rolling 20% or less, making a mean grain size of primary recrystallization 7 ?m to less than 20 ?m, and making a nitrogen increase ?N in the nitridation within a range of Equation (1) and making nitrogen contents ?N1 and ?N2 (front and back, mass %) of a 20% thickness portion of one surface of the steel strip (sheet) within a range of Equation (2): 0.007?([N]?14/48×[Ti])??N?[solAl]×14/27?([N]?14/48×[Ti])+0.0025??Equation (1) |?N1??N2|/?N?0.35??Equation (2).
    Type: Grant
    Filed: May 19, 2006
    Date of Patent: December 28, 2010
    Assignee: Nippon Steel Corporation
    Inventors: Tomoji Kumano, Kenichi Murakami, Yoshiyuki Ushigami
  • Patent number: 7850792
    Abstract: The present invention provides a grain-oriented electrical steel sheet product having a superior corrosion resistance, annealing resistance, film tension, and the like in insulating treatment based on a phosphate not containing chromium and a treatment agent for the same, so provides grain-oriented electrical steel sheet having an insulating film not containing chromium characterized by the insulating film containing a phosphate and one or more compounds selected from inorganic compounds of Fe, Ni, Co, Cu, Sr, and Mo in an amount, as metal elements, of 0.06 to 2.10 moles per mole of phosphate, and an insulating film agent of the same.
    Type: Grant
    Filed: July 14, 2005
    Date of Patent: December 14, 2010
    Assignees: Nippon Steel Corporation, Nittetsu Plant Designing Corporation
    Inventors: Osamu Tanaka, Norikazu Fujii, Hiroyasu Fujii, Kazutoshi Takeda
  • Patent number: 7815754
    Abstract: Grain-oriented electrical steel sheet superior in core loss characteristic containing Si: 0.8 to 7 mass % and having a secondary recrystallized texture with a {110}<001> orientation as the main orientation, characterized in that average deviation angles ?, ?, and ? from the {110}<001> ideal orientation of the secondary recrystallized texture satisfy (?2+?2)1/2??, where ?: average deviation angle from {110}<001> ideal orientation around rolling surface normal direction (ND) of secondary recrystallized texture, ?: average deviation angle from {110}<001> ideal orientation around traverse direction (TD) of secondary recrystallized texture, and ?: average deviation angle from {110}<001> ideal orientation around rolling direction (RD) of secondary recrystallized texture.
    Type: Grant
    Filed: May 7, 2007
    Date of Patent: October 19, 2010
    Assignee: Nippon Steel Corporation
    Inventors: Yoshiyuki Ushigami, Norikazu Fujii, Kenichi Murakami, Nobusato Morishige
  • Patent number: 7736444
    Abstract: Grain oriented electrical steel is made in a manner that the grains are selectively grown to obtain a crystal structure known as cube-on-edge and the grains are largely aligned in the rolling direction. Selection of chemistry and process route along with thin slab continuous casting enables the production of Grain oriented electrical steel such that less energy is consumed in the process, certain process steps can be combined, yield is better and the product can be manufactured within a wider process control tolerance.
    Type: Grant
    Filed: April 16, 2007
    Date of Patent: June 15, 2010
    Assignee: Silicon Steel Technology, Inc.
    Inventors: Vladimir Pavlovich Shumilov, Alexandr G. Shalimov, Leonard Mironov, Urij Christiakov
  • Patent number: 7678204
    Abstract: The present invention: provides a good-workability and high-strength cold-rolled steel sheet excellent in post-painting corrosion resistance to the extent of securing excellent resistance to salt warm water immersion which is a good-workability and high-strength cold-rolled steel sheet excellent in post-painting corrosion resistance characterized in that: said steel sheet contains, in mass, 0.16 to 0.19% C, 1.10 to 1.30% Si, 1.50 to 1.60% Mn, not more than 0.1% P and 0.015 to 0.050% Al, with the balance consisting of Fe and unavoidable impurities; the average of the amount of Si incrassating on the surface of said steel sheet is not more than 20 times the Si concentration in said steel sheet; and the area percentage of the portions where the ratio of the Si concentration on the surface of said steel sheet to the Si concentration in said steel sheet is not less than 10 is not more than 95%.
    Type: Grant
    Filed: December 9, 2003
    Date of Patent: March 16, 2010
    Assignees: Nippon Steel Corporation, Honda Motor Co., Ltd.
    Inventors: Toshiyuki Katsumi, Kazuhiko Honda, Koki Tanaka, Kaoru Yamazaki, Takahiro Tanae, Katsuyoshi Kaneko, Yoshikazu Umeno, Yoshitaka Okitsu
  • Patent number: 7628099
    Abstract: A method of controllably producing chips with a desired shape and size. The method generally entails machining a body with a cutting tool while superimposing modulation on the cutting tool so as to move the cutting tool relative to the body being machined and cause instantaneous and periodic separation between the cutting tool and the body at a point of contact between the cutting tool and the body, wherein each separation between the cutting tool and the body yields a chip. In this manner, the shapes and sizes of the chips are determined at least in part by the modulation cycle, and particularly the length of time the cutting tool is engaged with the body being machined.
    Type: Grant
    Filed: May 3, 2006
    Date of Patent: December 8, 2009
    Assignee: Purdue Research Foundation
    Inventors: James B. Mann, M. Ravi Shankar, Srinivasan Chandrasekar, W. Dale Compton, Wilfredo Moscoso
  • Patent number: 7399369
    Abstract: The present invention is a grain-oriented electrical steel sheet characterized in that Bi is present at 0.01 to less than 1,000 ppm in terms of mass at the interface of the substrate steel and the primary film of the grain-oriented electrical steel sheet. The grain-oriented electrical steel sheet is produced by any of the processes of: before decarburization annealing, applying preliminary annealing for 1 to 20 sec. at 700° C. or higher and controlling an atmosphere in the temperature range; controlling the maximum attaining temperature B (° C.) before final cold rolling so that the maximum attaining temperature B may satisfy the expression, ?10×ln(A)+1,100?B?10×ln(A)+1,220, in accordance with a Bi content A (ppm) and at the same time heating the steel sheet cold rolled to the final thickness to 700° C. or higher within 10 sec. or at a heating rate of 100° C./sec. or more before decarburization annealing, or immediately thereafter applying preliminary annealing for 1 to 20 sec. at 700° C.
    Type: Grant
    Filed: July 16, 2002
    Date of Patent: July 15, 2008
    Assignee: Nippon Steel Corporation
    Inventors: Eiichi Nanba, Katsuyuki Yanagihara, Satoshi Arai, Shuichi Yamazaki, Fumikazu Ando, Kazutoshi Takeda, Yousuke Kurosaki, Nobuo Tachibana
  • Patent number: 7291230
    Abstract: The present invention: relates to a grain-oriented electrical steel sheet and a double-oriented electrical steel sheet which are used as soft magnetic materials for electrical machinery and apparatus; and is a grain-oriented electrical steel sheet extremely excellent in film adhesiveness, characterized by: containing, in mass, 2.5 to 4.5% Si, 0.01 to 0.4% Ti, and not more than 0.005% as to each of C, N, S and O, with the balance substantially consisting of Fe and unavoidable impurities; and having films comprising compounds of C with Ti or Ti and one or more of Nb, Ta, V, Hf, Zr, Mo, Cr and W on the surfaces of said steel sheet, and a method for producing the steel sheet.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: November 6, 2007
    Assignee: Nippon Steel Corporation
    Inventors: Hotaka Homma, Yoshiaki Hirota, Yasumitsu Kondo, Yuji Kubo, Takehide Senuma, Shuichi Nakamura
  • Patent number: 7192492
    Abstract: In the production of electrical steel strips, a special islab-reheating treatment before hot rolling is carried out so that the maximum temperature within the furnace is reached by the slab well before its extraction from the furnace. During the heating stage and performance at the highest temperatures of the thermal cycle, second phase particles are dissolved and segregated elements are distributed in the metallic matrix, while during cooling and temperature equalising steps of the slab in the furnace a controlled amount of small second phases particles are more homogeneously re-precipitated from the metallic matrix. Differently from all the conventional processes for the production of electrical steels, the slab reheating furnace become a site in which it is performed the precipitation of a controlled amount of second phases particles for the necessary grain growth control during the successive process steps.
    Type: Grant
    Filed: August 8, 2001
    Date of Patent: March 20, 2007
    Assignee: Thyssenkrupp Acciai Speciali Terni S.p.A.
    Inventors: Stefano Fortunati, Stefano Cicale′, Claudia Rocchi, Giuseppe Abbruzzese
  • Patent number: 7045025
    Abstract: A low core loss grain-oriented electrical steel sheet that does not have a significant deterioration in a magnetic flux density and a decrease of a space factor, and which may withstand stress-relieving annealing is provided. Melted and re-solidified layers can be formed on either or both of the surfaces of the grain-oriented electrical steel sheet that extend in a direction that is perpendicular to the rolling direction (e.g., in the direction of the width thereof), at a cyclic interval of not less than approximately 2 mm to less than approximately 5 mm in the rolling direction. The melted and re-solidified layers may be provided on each surface of the grain-oriented electrical steel sheet, and can have an aspect ratio that is a ratio of the depth to the width of the melted and re-solidified layer of not less than approximately 0.20 and a depth of not less than approximately 15 ?m. In addition, the melted and re-solidified layers can be formed by using a laser.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: May 16, 2006
    Assignee: Nippon Steel Corporation
    Inventors: Hideyuki Hamamura, Tatsuhiko Sakai, Naoya Hamada
  • Patent number: 7041148
    Abstract: High-permeability, low-core-loss soft magnetic composite materials, compositions containing the same, and methods for making the same are described. These magnetic materials are made by forming fiber or flake shaped particles from a ferromagnetic material, annealing the particles, and then coating an insulating material on the particles. These particles can then be compacted to form an article that has high permeability, high saturation, low core loss, and is a suitable replacement for laminations in various applications, such as motors.
    Type: Grant
    Filed: March 3, 2003
    Date of Patent: May 9, 2006
    Assignee: General Electric Company
    Inventors: Luana Emiliana Iorio, Paul Alfred Siemers, Gerald Burt Kliman, Krishnamurthy Anand, Amitabh Verma
  • Patent number: 6942740
    Abstract: A grain oriented electromagnetic steel sheet is free from an undercoating mainly composed of forsterite (Mg2SiO4), excellent in processability and magnetic properties and useful to production cost, and has a composition containing, by % by mass, 2.0 to 8.0% of Si, wherein secondary recrystallized grains contains fine crystal grains having a grain diameter of 0.15 mm to 0.50 mm at a rate of 2 grains/cm2 or more. In the process of producing the steel sheet, inhibitors are not utilized, and the fine crystal grains are achieved by high purification and low temperature final annealing.
    Type: Grant
    Filed: January 17, 2002
    Date of Patent: September 13, 2005
    Assignee: JFE Steel Corporation
    Inventors: Yasuyuki Hayakawa, Mitsumasa Kurosawa, Seiji Okabe, Takeshi Imamura
  • Patent number: 6918966
    Abstract: The object of the present invention is to provide a low iron loss and low noise grain-oriented electrical steel sheet for securing both low core loss and low noise of a transformer at the same time. The present invention relates to a grain-oriented electrical steel sheet containing Si: 1.0-4.0 wt % produced by controlling, with regard to ?O, which is defined as a 0-p value when a grain-oriented electrical steel sheet is magnetized up to a saturated magnetic flux density, and ?17, which is defined as the value obtained by subtracting a 0-p value at the magnetization magnetic flux density of 1.7 T from a 0-p value at a saturated magnetic flux density, ?OC and ?17L, which are absolute values deviated by forming a tension film and a forsterite film, and ?OL and ?17L, which are absolute values deviated by irradiating laser after the film formation, in adequate ranges respectively, and further controlling ?17, which is a 0-p value at the magnetization magnetic flux density of 1.
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: July 19, 2005
    Assignee: Nippon Steel Corporation
    Inventors: Masahiro Fujikura, Satoshi Arai, Masato Mizokami, Hisashi Mogi, Takeshi Kubota
  • Patent number: 6811900
    Abstract: When plural-layer ceramic coatings are formed on a surface of an grain-oriented silicon steel sheet after finish annealing according to the invention, TiNO coating is formed as a first coating layer by a hollow cathode process under an application of a high bias voltage to the steel sheet, whereby ceramic tension coatings having excellent coating adhesion property and hence tension applying effect can be formed. As a result, ultra-low iron loss grain-oriented silicon steel sheets having an excellent iron loss property even after stress relief annealing at high temperatures for a long time can be stably obtained.
    Type: Grant
    Filed: January 28, 2003
    Date of Patent: November 2, 2004
    Assignee: JFE Steel Corporation
    Inventor: Yukio Inokuti
  • Patent number: 6758915
    Abstract: The invention is a grain-oriented magnetic steel sheet having extremely low iron loss, suitable for use as an iron core material for transformers and power generators, and a method for producing the same. The method includes forming a coating layer on a surface of a steel sheet having a thickness of 0.27 mm or less by vapor deposition in a low oxidizing atmosphere with an oxygen partial pressure (Po2) of less than 0.1 atm and a total pressure of 0.1 atm or more. The steel sheet has extremely low iron loss with a thickness of 0.27 mm or less and includes a coating layer formed by vapor deposition on a matrix surface.
    Type: Grant
    Filed: December 5, 2002
    Date of Patent: July 6, 2004
    Assignee: JFE Steel Corporation
    Inventors: Minoru Takashima, Mineo Muraki, Hiroi Yamaguchi, Mitsumasa Kurosawa, Michiro Komatsubara
  • Publication number: 20040074565
    Abstract: A grain oriented electromagnetic steel sheet is free from an undercoating mainly composed of forsterite (Mg2SiO4), excellent in processability and magnetic properties and useful to production cost, and has a composition containing, by % by mass, 2.0 to 8.0% of Si, wherein secondary recrystallized grains contains fine crystal grains having a grain diameter of 0.15 mm to 0.50 mm at a rate of 2 grains/cm2 or more. In the process of producing the steel sheet, inhibitors are not utilized, and the fine crystal grains are achieved by high purification and low temperature final annealing.
    Type: Application
    Filed: November 27, 2002
    Publication date: April 22, 2004
    Inventors: Yasuyuki Hayakawa, Mitsumasa Kurosawa, Seiji Okabe, Takeshi Imamura
  • Patent number: 6723914
    Abstract: There is provided a composite magnetic tape which can be easily applied irrespective of the inside or outside of an electronic equipment, prevent radiation of undesired electromagnetic waves from the inside of the equipment and reflection into the inside of the equipment, and shield electromagnetic noise from the outside of the equipment. The tape may be in the form of an adhesive tape or a self-welding tape. The tape is constituted of a composite magnetic layer formed by dispersing soft magnetic powder into an organic binding agent. Alternatively, it may have a stacked structure of a composite magnetic layer and a conductor layer.
    Type: Grant
    Filed: February 23, 2000
    Date of Patent: April 20, 2004
    Assignee: NEC Tokin Corp
    Inventors: Koji Kamei, Norihiko Ono, Mitsuharu Sato
  • Patent number: 6602357
    Abstract: A grain oriented electrical steel sheet comprises metal part containing Si: about 2.5 to about 5.0 mass % and Cr: about 0.05 to about 1.0 mass %, and an insulation coating formed on a surface of the metal part. A tension imparted to the metal part in the rolling direction by the insulation coating is not smaller than about 3.0 MPa. Magnetic flux density B8 satisfies a specific relation formula. A plurality of linear strains or grooves are formed in a surface of the steel sheet and linearly extended at an angle of not larger than about 45° (in each direction) relative to a direction perpendicular to a rolling direction such that an interval D of the linear strains or grooves satisfies a specific relation formula depending on the Cr content. A grain oriented electrical steel sheet is thereby obtained which has lower iron loss after domain refining treatment than conventional values.
    Type: Grant
    Filed: January 24, 2002
    Date of Patent: August 5, 2003
    Assignee: Kawasaki Steel Corporation
    Inventors: Kunihiro Senda, Toshito Takamiya, Tadashi Nakanishi, Mitsumasa Kurosawa, Hiroaki Toda
  • Patent number: 6565674
    Abstract: A high flux density grain-oriented electrical steel sheet excellent in high magnetic field core loss property containing, in percentage by weight, not greater than 0.005% of C, 2.0-7.0% of Si, not greater than 0.2% of Mn, one or both of S and Se in a total amount of not greater than 0.005%, the balance being of Fe and unavoidable impurities, optionally containing, in percentage by weight, of not greater than 0.065% of Al, not greater than 0.005% of N and 0.003-0.3% each of one or more of Sb, Sn, Cu, Mo, Ge, B, Te, As, Cr and Bi, the steel sheet having a grain orientation deviating from an ideal {110}<001> orientation by an average of not greater than 5°, having an average 180° magnetic domain width of not greater than 0.30 mm, preferably not greater than 0.26 mm or greater than 0.26 mm and not greater than 0.30 mm, and having an area ratio of magnetic domains of a width greater than 0.4 mm of greater than 3% and not greater than 20%.
    Type: Grant
    Filed: May 30, 2000
    Date of Patent: May 20, 2003
    Assignee: Nippon Steel Corporation
    Inventors: Yousuke Kurosaki, Masahiro Fujikura
  • Patent number: 6562473
    Abstract: Electrical steel sheets having superior magnetic properties, anti-noise properties, and workability, are ideal for use a compact iron core material in electric apparatuses, such as compact transformers, motors, and electric generators. A totally new electrical steel sheet and a manufacturing method therefor are proposed, in which the electrical steel sheet is not only most advantageous in magnetic properties but also advantageous from economic point of view. That is, the electrical steel sheet of the present invention is composed of from about 2.0 to 8.0 wt % Si, from about 0.005 to 3.0 wt % Mn, from about 0.0010 to 0.020 wt % Al, balance essentially iron. The magnetic flux density B50(L) in a rolling direction and the magnetic flux density B50(C) in the direction perpendicular thereto are 1.70 T or more, and the B50(L)/B50(C) is 1.005 to 1.100.
    Type: Grant
    Filed: November 27, 2000
    Date of Patent: May 13, 2003
    Assignee: Kawasaki Steel Corporation
    Inventors: Seiji Okabe, Yasuyuki Hayakawa, Takeshi Imamura, Mitsumasa Kurosawa
  • Patent number: 6527876
    Abstract: A silicon steel sheet having low iron loss of high frequency has a surface layer of the steel sheet which has Si concentration higher than Si concentration of a center portion of the steel sheet. Si concentration of sheet thickness center is 3.4 wt. % or more and Si concentration of the surface layer of the steel sheet is 5 wt. % or more. Si concentration in a surface layer portion is 5 to 8 wt. %. The production method comprises siliconizing treatment and diffusing treatment. Velocity of siliconizing and diffusing are controlled, and Si concentration distribution in the sheet thickness direction of the steel sheet is controlled.
    Type: Grant
    Filed: January 24, 2000
    Date of Patent: March 4, 2003
    Assignee: NKK Corporation
    Inventors: Misao Namikawa, Yoshikazu Takada, Shoji Kasai, Hironori Ninomiya, Tsunehiro Yamaji, Tatsuhiko Hiratani