With Special Compositions Patents (Class 148/113)
  • Patent number: 10428403
    Abstract: Disclosed is a method for manufacturing a grain-oriented electrical steel sheet using an inhibitor-less technique, in which cold rolling includes final cold rolling with a total cold rolling reduction being set to 85% or more and a rolling reduction per pass being set to 32% or more. The final cold rolling includes one or more passes and a final pass succeeding the one or more passes and uses work rolls having a surface roughness Ra of 0.25 ?m or less in at least one of the one or more passes other than the final pass. According to this method, it is possible to stably manufacture a grain-oriented electrical steel sheet exhibiting excellent magnetic properties at low cost.
    Type: Grant
    Filed: November 26, 2015
    Date of Patent: October 1, 2019
    Assignee: JFE STEEL CORPORATION
    Inventors: Yasuyuki Hayakawa, Masayasu Ueno
  • Patent number: 10431359
    Abstract: In a method for producing a grain-oriented electrical steel sheet by hot rolling a steel slab comprising C: 0.04-0.12 mass %, Si: 1.5-5.0 mass %, Mn: 0.01-1.0 mass %, sol. Al: 0.010-0.040 mass %, N: 0.004-0.02 mass %, one or two of S and Se: 0.005-0.05 mass % in total of S and Se, cold rolling, and subjecting to primary recrystallization annealing and further to final annealing, a content ratio of sol. Al to N in the steel slab (sol. Al/N) and a final thickness d (mm) satisfy an equation of 4d+1.52?sol. Al/N?4d+2.32, and the steel sheet in the heating process of the final annealing is held at a temperature of 775-875° C. for 40-200 hours and then heated in a temperature region of 875-1050° C. at a heating rate of 10-60° C./hr to preform secondary recrystallization and purification treatment, whereby an extremely-thin grain-oriented electrical steel sheet having a low iron loss and a small deviation in coil is produced.
    Type: Grant
    Filed: February 27, 2013
    Date of Patent: October 1, 2019
    Assignee: JFE Steel Corporation
    Inventors: Masanori Uesaka, Minoru Takashima, Takeshi Imamura
  • Patent number: 10403417
    Abstract: An electrical steel sheet is provided with insulating coating. The insulating coating contains Si and Fe. The coating weight of Si in the insulating coating in terms of SiO2 is 50% to 99% of the total coating weight. The ratio (Fe/Si) of the content of Fe to the content of Si in the insulating coating is 0.01 to 0.6 on a molar basis. The ratio (C (the organic resin+the lubricant)/(Fe2O3+SiO2)) of the coating weight of the organic resin and/or the lubricant in terms of C to the sum of the coating weight of Fe in terms of Fe2O3 and the coating weight of Si in terms of SiO2 preferably is 0.05 to 0.8.
    Type: Grant
    Filed: November 11, 2014
    Date of Patent: September 3, 2019
    Assignee: JFE Steel Corporation
    Inventors: Kazumichi Sashi, Nobuko Nakagawa, Naoki Muramatsu, Chiyoko Tada, Nobue Fujibayashi
  • Patent number: 10004763
    Abstract: An object of the present invention is to provide magnesium oxide that can be preferably used for pharmaceutical applications or as a food additive. In particular, the object is to provide magnesium oxide granules with which tableting problems and quality defects can be reduced, and in more particular, to provide magnesium oxide granules with which tableting problems and quality defects can be reduced and which has less heavy metal incorporation and high purity of magnesium oxide. Provided are magnesium oxide granules for pharmaceutical applications or for addition to food having a BET specific surface area of 7 to 50 m2/g and CAA80/CAA40 of 2 to 7.
    Type: Grant
    Filed: February 25, 2014
    Date of Patent: June 26, 2018
    Assignee: KONOSHIMA CHEMICAL CO., LTD.
    Inventor: Kensho Sakamoto
  • Patent number: 9805851
    Abstract: In a method of producing a grain-oriented electrical steel sheet by hot rolling a steel slab comprising C: 0.001˜0.10 mass %, Si: 1.0˜5.0 mass %, Mn: 0.01˜1.0 mass %, one or two of S and Se: 0.01˜0.05 mass % in total, sol. Al: 0.003˜0.050 mass % and N: 0.001˜0.020 mass %, cold rolling, subjecting to primary recrystallization annealing, applying an annealing separator and finally subjecting to final annealing, the primary recrystallization annealing is conducted so as to control a heating rate S1 between 500 and 600° C. to not less than 100° C./s and a heating rate S2 between 600 and 700° C. to not less than 30° C./s but not more than 0.6×S1, and as a main ingredient of the annealing separator is used MgO having an expected value ?(A) of citric acid activity distribution of 3.5˜3.8, a cumulative frequency F of 25˜45% when an activity A is not less than 4.0.
    Type: Grant
    Filed: October 16, 2012
    Date of Patent: October 31, 2017
    Assignee: JFE Steel Corporation
    Inventors: Makoto Watanabe, Yukihiro Shingaki, Toshito Takamiya, Tomoyuki Okubo
  • Patent number: 9469769
    Abstract: The anti-corrosion treatment composition for steel rebar embedded in concrete is a composition for coating steel rebar before the steel rebar is embedded in concrete. The coating of the steel rebar with the anti-corrosion treatment composition forms a treatment film on the steel rebar which controls both uniform corrosion and pitting corrosion of the steel rebar after it has been embedded in the concrete. The anti-corrosion treatment composition includes an inorganic acid, an organic acid, polyethylene glycol and water. The inorganic acid forms between approximately 3.9 wt % and approximately 15.0 wt % of the anti-corrosion treatment composition, the organic acid forms between approximately 0.1 wt % and approximately 2.9 wt % of the anti-corrosion treatment composition, the polyethylene glycol forms between approximately 2.0 wt % and approximately 10.7 wt % of the anti-corrosion treatment composition, and the remainder of the anti-corrosion treatment composition is water.
    Type: Grant
    Filed: December 30, 2015
    Date of Patent: October 18, 2016
    Assignee: KING SAUD UNIVERSITY
    Inventors: Raja Rizwan Hussain, Abdulrahman M. Alhozaimy, Abdulaziz I. Al-Negheimish, Devendra Deo Narain Singh
  • Patent number: 9396850
    Abstract: A grain oriented electrical steel sheet (1) suppresses the content of Cr in the grain oriented electrical steel sheet to 0.1 mass % or less; (2) sets the coating weight of a forsterite coating, in terms of basis weight of oxygen therein, to at least 3.0 g/m2 and thickness of an anchor portion as a lower portion of forsterite coating to 1.5 ?m or less; and (3) controls setting the magnitude of deflection of a test specimen having length: 280 mm to at least 10mm when the forsterite coating is provided on only one surface thereof and at least 20 mm when forsterite coating and the tension coating are provided on the surface.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: July 19, 2016
    Assignee: JFE Steel Corporation
    Inventors: Hiroi Yamaguchi, Hiroaki Toda, Takeshi Omura, Seiji Okabe
  • Patent number: 9273371
    Abstract: A predetermined steel containing Te: 0.0005 mass % to 0.0050 mass % is heated to 1320° C. or lower to be subjected to hot rolling, and is subjected to annealing, cold rolling, decarburization annealing, and nitridation annealing, and thereby a decarburized nitrided steel sheet is obtained. Further, an annealing separating agent is applied on the surface of the decarburized nitrided steel sheet and finish annealing is performed, and thereby a glass coating film is formed. The N content of the decarburized nitrided steel sheet is set to 0.0150 mass % to 0.0250 mass % and the relationship of 2×[Te]+[N]?0.0300 mass % is set to be established. Note that [Te] represents the Te content and [N] represents the N content.
    Type: Grant
    Filed: March 15, 2011
    Date of Patent: March 1, 2016
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Kenichi Murakami, Chie Hama, Kazumi Mizukami, Yoshiyuki Ushigami, Shuichi Nakamura
  • Patent number: 9267194
    Abstract: A cast slab containing C: less than 0.02 mass % and made of an Fe-based metal of an ?-? transforming component is subjected to hot rolling at a temperature of an A3 point or higher and is subjected to ?-region rolling at a temperature of 300° C. or higher and lower than the A3 point, and thereby a base metal sheet having a {100} texture in a surface layer portion is fabricated. Then, by performing a heat treatment under predetermined conditions, an Fe-based metal sheet is obtained in which a Z value is not less than 2.0 nor more than 200 when intensity ratios of respective {001}<470>, {116}<6 12 1>, and {223}<692> directions in a sheet plane by X-ray diffraction are set to A, B, and C respectively and Z =(A+0.97B)/0.98C is satisfied.
    Type: Grant
    Filed: April 27, 2012
    Date of Patent: February 23, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Tooru Inaguma, Miho Tomita, Hiroaki Sakamoto, Youji Mizuhara
  • Patent number: 9240266
    Abstract: A grain oriented electrical steel sheet has sufficiently low iron loss and having less conventionally-concerned warpage of the steel sheet even after the steel sheet is subjected to artificial magnetic domain refining treatment, where strain-introducing treatment is conducted with high energy so that an iron loss-reducing effect can be maximized. The grain oriented electrical steel sheet is obtained by adjusting tension to be applied to a tension-applying insulating coating, or to both surfaces of the steel sheet by the tension-applying insulating coating, before strain-introducing treatment in the range of Formula (1): 1.0?(tension applied to non-strain-introduced surface)/(tension applied to strain-introduced surface)?2.0??(1), and by controlling the amount of warpage of the steel sheet toward the strain-introduced surface side after strain-introducing treatment in the range of 1 mm or more and 10 mm or less.
    Type: Grant
    Filed: August 4, 2011
    Date of Patent: January 19, 2016
    Assignee: JFE Steel Corporation
    Inventors: Masanori Takenaka, Minoru Takashima, Hiroi Yamaguchi, Takeshi Omura
  • Patent number: 8906990
    Abstract: Disclosed is a surface treatment agent for galvanized steel sheets, which comprises epoxy-containing silane derivates, alkyl-containing silane derivates, alkoxy silane derivates and one or more selected from the group consisting of a cationic polymer aqueous dispersion, a non-ionic polymer aqueous dispersion and a water-soluble polymer. Also disclosed is a method for producing it, which comprises mixing each component uniformly for 0.5 to 8 hours at 5 to 70° C. Further provided are galvanized steel sheets coated with the surface treatment agent on the surface and a production method thereof. The surface treatment agent for galvanized steel sheets has excellent corrosion resistance, alkali resistance, solvent resistance, recoating property, high temperature resistance and electrical conductivity.
    Type: Grant
    Filed: June 27, 2011
    Date of Patent: December 9, 2014
    Inventors: Frank Wan, Jimmy Zhang, Kevin Meagher
  • Patent number: 8657968
    Abstract: This method of manufacturing a grain-oriented electrical steel sheet includes, between a cold rolling process and a winding process, a groove formation process of irradiating the surface of a silicon steel sheet with a laser beam multiple times at predetermined intervals in a sheet passing direction, over an area from one end edge to the other end edge, in a sheet width direction of the silicon steel sheet, thereby forming a groove along a locus of the laser beam.
    Type: Grant
    Filed: September 9, 2011
    Date of Patent: February 25, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Tatsuhiko Sakai, Hideyuki Hamamura
  • Patent number: 8535455
    Abstract: A treatment solution for an insulation coating for a grain oriented electrical steel sheet includes at least one member selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn, and colloidal silica in a proportion of 0.5 to 10 mol in terms of SiO2 and at least one member selected from permanganates of Mg, Sr, Zn, Ba, and Ca in a proportion of 0.02 to 2.5 mol in terms of metal elements in the permanganates, relative to PO4:1 mol in the phosphates.
    Type: Grant
    Filed: August 20, 2008
    Date of Patent: September 17, 2013
    Assignee: JFE Steel Corporation
    Inventors: Minoru Takashima, Mineo Muraki, Makoto Watanabe, Tomofumi Shigekuni
  • Patent number: 8409368
    Abstract: A nitriding treatment (Step S6) in which an N content of a decarburization-annealed steel strip is increased is performed between start of a decarburization annealing (Step S4) and occurrence of secondary recrystallization in a finish annealing (Step S5). In hot rolling (Step S1), a silicon steel material is held in a temperature range between 1000° C. and 800° C. for 300 seconds or longer, and then finish rolling is performed.
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: April 2, 2013
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Yoshiyuki Ushigami, Norikazu Fujii
  • 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: 8337638
    Abstract: A powder for a dust core comprising a silicon-containing layer formed within a depth of less than 0.15 D from the surface of the surface layer of a soft magnetic metal powder having a particle diameter D and a method for producing the same are provided.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: December 25, 2012
    Assignees: Toyota Jidosha Kabushiki Kaisha, Fine Sinter Co., Ltd
    Inventors: Yusuke Oishi, Eisuke Hoshina, Toshiya Yamaguchi, Kazuhiro Kawashima
  • 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: 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: 8157928
    Abstract: A main object thereof is to provide a non-oriented electrical steel sheet being excellent in surface characteristics and having both excellent mechanical characteristics and magnetic characteristics necessary for a rotor of rotating machines such as motors and generators which rotate at a high speed, and a method for producing the same. To achieve the object, the present invention provides a non-oriented electrical steel sheet comprising in % by mass: 0.06% or less of C; 3.5% or less of Si; from 0.05% or more to 3.0% or less of Mn; 2.5% or less of Al; 0.30% or less of P; 0.04% or less of S; 0.02% or less of N; at least one element selected from the group consisting of Nb, Ti, Zr and V in the predetermined range; and a balance consisting of Fe and impurities; and having a recrystallized fraction being less than 90%.
    Type: Grant
    Filed: November 2, 2010
    Date of Patent: April 17, 2012
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Ichirou Tanaka, Hiroshi Fujimura, Hirokatsu Nitomi, Hiroyoshi Yashiki, Kouji Nishida, Hiroki Takamaru
  • Patent number: 8128754
    Abstract: The pickling process designed for pickling electrical steel strip in a continuous fashion comprising immersing the strip in at least one pickling tub. The pickling tub contains a mixture of HCl, Fe2+, and Fe3+ and a low concentration of HF. Upon exiting the final pickling tub, the strip may be brushed or scrubbed to loosen any residual scale to form a clean strip.
    Type: Grant
    Filed: November 12, 2009
    Date of Patent: March 6, 2012
    Assignee: AK Steel Properties, Inc.
    Inventors: Vijay N. Madi, Amanda Glass, Ronald Rodabaugh
  • 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: 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: 7887646
    Abstract: The present invention provides oriented magnetic steel plate with excellent coating adhesion, in particular coating edge peeling resistance, that is, oriented magnetic steel plate with excellent coating adhesion containing, by mass %, Si: 1.8 to 7% and having a primary coating having forsterite as its main ingredient on its surface, said oriented magnetic steel plate characterized in that said primary coating contains one or more of Ce, La, Pr, Nd, Sc, and Y in an areal weight per side of 0.001 to 1000 mg/m2; characterized in that said primary coating contains Ti in an areal weight per side of 1 to 800 mg/m2; and characterized in that said primary coating contains one or more of Sr, Ca, and Ba in an areal weight per side of 0.01 to 100 mg/m2.
    Type: Grant
    Filed: May 19, 2006
    Date of Patent: February 15, 2011
    Assignee: Nippon Steel Corporation
    Inventors: Eiichi Nanba, Yuji Kubo, Kazutoshi Takeda, Satoshi Arai, Hotaka Honma, Kenichi Murakami, Hideyuki Kobayashi
  • 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: 7833360
    Abstract: The invention provides a method of producing a grain-oriented electrical steel sheet of the complete solid solution nitrided type that is good in glass film formation and excellent in magnetic properties, which method comprises: C: 0.025 to 0.09%, hot-rolling the steel slab containing Si: 2.5 to 4.0% and acid-soluble Al into a hot-rolled steel strip; controlling the rate at which N contained in the hot-rolled steel strip is precipitated as AlN to a precipitation rate of 20% or less; conducting hot-rolled strip annealing and cold rolling conducting decarburization-annealing combined with primary recrystallization by during the former part of the process in an atmosphere whose PH2O/PH2 is 0.30 to 0.70 and then during the latter part thereof in an atmosphere whose PH2O/PH2 is 0.
    Type: Grant
    Filed: January 12, 2007
    Date of Patent: November 16, 2010
    Assignees: Nippon Steel Corporation, Nittetsu Plant Designing Corporation
    Inventors: Tomoji Kumano, Shyuichi Yamazaki, Osamu Tanaka
  • 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: 7727644
    Abstract: In a grain-oriented electrical steel sheet having phosphate-based coatings, which contain no chromium and which impart a tension, on the surfaces of a steel sheet with ceramic underlying films therebetween, the coating amount of oxygen in the underlying film is 2.0 g/m2 or more and 3.5 g/m2 or less relative to both surfaces of the steel sheet. Consequently, a grain-oriented electrical steel sheet with a chromium-less coating is provided. The resulting steel sheet has coating properties at the same level as those of a steel sheet with chromium-containing coatings and realizes high hygroscopicity resistance and a low iron loss without variations.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: June 1, 2010
    Assignee: JFE Steel Corporation
    Inventors: Makoto Watanabe, Hiroaki Toda, Mineo Muraki
  • Patent number: 7465364
    Abstract: An Fe—Cr—Si based non-oriented electrical steel sheet contains 2.5% to 10% by mass of Si, 1.5% to 20% by mass of Cr, 0.006% by mass or less of C, 0.002% by mass or less of N, 0.005% by mass or less of S, 0.005% by mass or less of Ti, 0.005% by mass or less of Nb, and as necessary, 0.1% to 2% by mass of Al and at least one of 0.005% to 1% by mass of Sb and 0.005% to 1% by mass of Sn, and the balance being Fe and incidental impurities, wherein the electrical resistivity of the steel is 60 ??cm or more, and the number of nitrides containing chromium per mm2 in the interior of the steel sheet is 2,500 or less. Consequently, the problem that high electrical resistance resulting from the high Si content and high Cr content is not satisfactorily utilized is advantageously solved, and it is possible to provide a non-oriented electrical steel sheet having excellent magnetic properties in the high-frequency range, in particular, in a frequency range of 1 kHz or more.
    Type: Grant
    Filed: December 18, 2003
    Date of Patent: December 16, 2008
    Assignee: JFE Steel Corporation
    Inventors: Takeshi Omura, Masaaki Kohno, Masaki Kawano
  • Patent number: 7442260
    Abstract: The present invention provides a grain-oriented electrical steel sheet with an extremely low core loss by scanning by a small focused laser beam spot and a method of production of the same, that is, a grain-oriented electrical steel sheet improved in electrical characteristics by scanning by a continuous wave fiber laser of the TEM00 mode with a wavelength ? of 1.07???2.10 ?m substantially perpendicular to the steel sheet rolling direction and at substantially constant spacing and a method of production of the same, wherein a rolling direction focused spot diameter d (mm) of the irradiated beam, a linear scan rate V (mm/s) of the laser beam, an average output P (W) of the laser, a width of the formed laser scribing traces or with of the electrical domains Wl (mm), and a rolling direction Pl (mm) of the laser scribing traces are in the following ranges: 0<d?0.20 0.001?P/V?0.012 0<Wl?0.20 1.5?Pl?11.0.
    Type: Grant
    Filed: March 5, 2004
    Date of Patent: October 28, 2008
    Assignee: Nippon Steel Corooration
    Inventors: Tatsuhiko Sakai, Hideyuki Hamamura, Naoya Hamada
  • Patent number: 7435304
    Abstract: There are provided a coating composition for siliconizing, and a method for manufacturing a high silicon electrical steel sheet using the same. The coating composition includes: a Fe—Si-based composite compound sintered powder having a grain size of ?325 mesh and containing 20-70% silicon by weight; and a colloidal silica solution containing 15-30 part by weight of silica solid matter with respect to 100 part by weight of the sintered powder.
    Type: Grant
    Filed: November 11, 2003
    Date of Patent: October 14, 2008
    Assignee: POSCO
    Inventors: Kyu-Seung Choi, Jong-Soo Woo
  • Patent number: 7371291
    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: June 6, 2005
    Date of Patent: May 13, 2008
    Assignee: JFE Steel Corporation
    Inventors: Yasuyuki Hayakawa, Mitsumasa Kurosawa, Seiji Okabe, Takeshi Imamura
  • Patent number: 7364629
    Abstract: In a method for manufacturing grain-oriented silicon steel with mirror-like surface by applying an aqueous slurry of an annealing separator, magnetic properties are stabilized by controlling the amount of moisture, carried in the annealing separator consisting mainly of alumina after application and drying thereof, to not more than 1.5%, controlling the partial water vapor pressure during finish-annealing and eliminating the variation (instability) in secondary recrystallization caused by the inhibitor reaction at the interface.
    Type: Grant
    Filed: January 7, 2003
    Date of Patent: April 29, 2008
    Assignee: Nippon Steel Corporation
    Inventors: Yoshiyuki Ushigami, Shuichi Nakamura, Hiroyasu Fujii, Kenichi Murakami
  • 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: 7282102
    Abstract: A method for manufacturing a high silicon grain-oriented electrical steel sheet. In a method for manufacturing a high silicon grain-oriented electrical steel sheet, comprising the steps of: reheating and hot-rolling a steel slab to produce a hot-rolled steel sheet; annealing the hot-rolled sheet and cold rolling the annealed steel sheet so as to adjust a thickness of the steel sheet; decarburization annealing the cold rolled steel sheet; and finish-annealing the decarburization annealed steel sheet for secondary recrystallization, the improved method further comprising the step of: coating a powder coating agent for siliconization on a surface of the decarburization annealed steel sheet in a slurry state, the powder coating agent including 100 part by weight of MgO powder and 0.
    Type: Grant
    Filed: November 11, 2003
    Date of Patent: October 16, 2007
    Assignee: Posco
    Inventors: Kyu-Seung Choi, Jong-Soo Woo, Jae-Kwan Kim
  • Patent number: 7198682
    Abstract: A process for the production of electrical steel strips, in which a strip is directly cast from molten steel and contains alloy elements apt to generate a precipitation of sulphides and/or nitrides apt to inhibit the grain growth. The strip is hot rolled in-line with the casting operation at a temperature between 1250 and 1000° C., and in which the strip is coiled after hot rolling at a temperature of less than 780° C. if sulphides are utilized, or at a temperature of less than 600° C. if nitrides, or nitrides plus sulphides, are utilized.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: April 3, 2007
    Assignee: Thyssenkrupp Acciai Speciali Terni S.p.A.
    Inventors: Stefano Cicale′, Stefano Fortunati, Giuseppe Abbruzzese
  • 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: 7077919
    Abstract: Disclosed herein is an insulating material between adjacent metal layers of a soft magnetic core, and a process for forming this insulating material. The insulating material is composed of the native metal oxides of the metallic core material.
    Type: Grant
    Filed: June 5, 2003
    Date of Patent: July 18, 2006
    Assignee: Magnetic Metals Corporation
    Inventors: Richard Wood, Richard Lathlaen, William C. Beckham
  • 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: 6936792
    Abstract: Furnace cart assembly for loading high temperature vacuum furnaces for treating target material, for example, metal parts, under extreme temperature and vacuum environments. The furnace cart includes electrical heating elements as an integral part of the cart, which elements are adapted for releasable connection to the furnace electrical supply. When so connected the furnace cart heating elements can form a part of the heating system of the furnace. The lower part of the furnace cart assembly, including a frame above and supported on wheels, the frame having heat reflection means on at least Its upper surfaces providing some protection from heat is preferably also protected from heat during furnace operation by insulating material above the frame (the material desirably supported by the frame but separated therefrom).
    Type: Grant
    Filed: May 22, 2002
    Date of Patent: August 30, 2005
    Inventor: William R. Jones
  • Patent number: 6929704
    Abstract: A grain-oriented electromagnetic steel sheet having a multiplicity of fine grains having a diameter of about 3 mm or less on the surface of the steel sheet, in a numerical ratio of about 65% or more and of about 98% or less relative to the constituting grains that penetrate the sheet along the direction parallel to its thickness, and a method for producing the same. The fine grains are artificially created and regularly disposed with a random orientation in the steel sheet, and contribute to decreasing the strain susceptibility of the steel. More preferably, a treatment for finely dividing magnetic domains is applied on the surface of the steel sheet. Transformers based upon the steel sheet have excellent magnetic characteristics (iron loss and magnetic flux density) together with strain resistance, and the steel sheet has good practical device characteristics (building factor) after being assembled into a transformer.
    Type: Grant
    Filed: June 6, 2002
    Date of Patent: August 16, 2005
    Assignee: JFE Steel Corporation
    Inventors: Michiro Komatsubara, Toshito Takamiya, Kunihiro Senda
  • Patent number: 6899768
    Abstract: The present invention is related to a magnesium oxide particle aggregate with the requirement of a first inflection point diameter is more than 0.30×10?6 to 0.60×10?6 m, a particle void volume is 0.50×10?3 to 0.90×10?3 m3·kg?1, and a micropore volume is 0.04×10?3 to 0.11×10?3 m3·kg?1 in the cumulative intrusion volume curve of said particle by having controlled particle aggregation structure so that the solid phase-solid phase reaction between magnesium oxide and the SiO2 film on the surface can be appropriately controlled.
    Type: Grant
    Filed: October 25, 2001
    Date of Patent: May 31, 2005
    Assignee: Tateho Chemical Industries Co., Ltd.
    Inventors: Atsuo Toutsuka, Yutaka Hiratsu
  • Patent number: 6835250
    Abstract: An object of the present invention is to provide a magnesium oxide particle aggregate having a controlled particle aggregation structure so that the solid phase-solid phase reaction between magnesium oxide and the SiO2 film on the surface can be appropriately controlled. The object can be achieved by a magnesium oxide particle aggregate characterized in that a first inflection point diameter is 0.30×10−6 m or less, an interparticle void volume is 1.40×10−3 to 2.20×10−3 m3/kg and a particle void volume is 0.55×10−3 to 0.80×10−3 m3/kg in a cumulative intrusion volume curve of the particle aggregate.
    Type: Grant
    Filed: October 29, 2002
    Date of Patent: December 28, 2004
    Assignee: Tateho Chemical Industries Co., Ltd.
    Inventors: Yutaka Hiratsu, Toshio Kiyokawa, Atsuo Toutsuka
  • 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
  • Patent number: 6733599
    Abstract: The present invention provides a method for producing a grain-oriented silicon steel sheet not having inorganic mineral films by using an annealing separator capable of preventing the inorganic mineral films composed of forsterite (Mg2SiO4), and so on, from forming during final annealing, comprising the steps of decarburization annealing followed by coating of annealing separator and final annealing, wherein alumina powder calcined at a calcination temperature of 900 to 1,400° C., or further having a BET specific surface area of 1 to 100 m2/g, an oil absorption of 1 to 70 ml/100 g, and/or having a gamma ratio of 0.001 to 2.0, is used as the annealing separator. Magnesia having a BET specific surface area of 0.5 to 5 m2/g may be added to said alumina powder.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: May 11, 2004
    Assignee: Nippon Steel Corporation
    Inventors: Hiroyasu Fujii, Yoshiyuki Ushigami, Shuichi Nakamura, Kenichi Murakami, Norihiro Yamamoto, Kiyoshi Sawano, Shuichi Yamazaki
  • Publication number: 20040074566
    Abstract: A ferromagnetic resonator for use in a marker in a magnetomechanical electronic article surveillance system is manufactured at reduced cost by being continuously annealed with a tensile stress applied along the ribbon axis and by providing an amorphous magnetic alloy containing iron, cobalt and nickel and in which the portion of cobalt is less than about 4 at %.
    Type: Application
    Filed: October 8, 2003
    Publication date: April 22, 2004
    Applicant: Vacuumschmelze GmbH & Sensormatic Electronics Corp
    Inventors: Giselher Herzer, Nen-Chin Liu
  • Patent number: 6613160
    Abstract: The present invention, in a method to produce a grain-oriented electrical steel sheet, proposes conditions for stable production by clarifying the causes by which secondary recrystallization is rendered unstable when primary recrystallization is controlled by raising the heating rate of decarburization annealing. The primary recrystallization structure is controlled by changing the heating rate and the oxide layer of a steel sheet is controlled by changing the conditions of soaking annealing in the decarburization annealing. The composition of the (Al, Si)N inhibitor is also controlled in the nitriding treatment thereafter.
    Type: Grant
    Filed: August 7, 2001
    Date of Patent: September 2, 2003
    Assignee: Nippon Steel Corporation
    Inventors: Yoshiyuki Ushigami, Shuichi Nakamura, Kenichi Murakami, Hiroyasu Fujii, Norihiro Yamamoto