Silicon Steel Patents (Class 148/110)
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Patent number: 10730103Abstract: A system for forming a bulk material having insulated boundaries from a metal material and a source of an insulating material is provided. The system includes a heating device, a deposition device, a coating device, and a support configured to support the bulk material. The heating device heats the metal material to form particles having a softened or molten state and the coating device coats the metal material with the insulating material from the source and the deposition device deposits particles of the metal material in the softened or molten state on the support to form the bulk material having insulated boundaries.Type: GrantFiled: June 29, 2012Date of Patent: August 4, 2020Assignee: Persimmon Technologies CorporationInventor: Martin Hosek
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Patent number: 10062483Abstract: A grain-oriented electrical steel sheet, on which magnetic domain refining treatment by strain application has been performed, has an insulating coating with excellent insulation properties and corrosion resistance. The grain-oriented electrical steel sheet is obtained by irradiating a steel sheet with a high-energy beam to apply, to the steel sheet, linear strain extending in a direction that intersects a rolling direction of the steel sheet, and then re-forming an insulating coating on the steel sheet, in which in an irradiation mark region due to the high-energy beam, a ratio of an area containing defects on the insulating coating is 40% or less, a maximum width of the irradiation mark region in the rolling direction is 250 ?m or less, and a thickness of the insulating coating is 0.3 ?m or more and 2.0 ?m or less.Type: GrantFiled: December 27, 2012Date of Patent: August 28, 2018Assignee: JFE Steel CorporationInventors: Hirotaka Inoue, Shigehiro Takajo, Hiroi Yamaguchi, Seiji Okabe, Kazuhiro Hanazawa
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Patent number: 10020101Abstract: Disclosed is a grain-oriented electrical steel sheet exhibiting low hysteresis loss and low coercive force, in which an increase in hysteresis loss due to laser irradiation or electron beam irradiation, which has been a conventional concern, is effectively inhibited. The grain-oriented electrical steel sheet has closure domain regions (X) formed to divide the magnetic domains in a rolling direction, from one end to the other in the width direction of the steel sheet, provided that Expression (1) is satisfied: ?(500t?80)×s+230?w??(500t?80)×s+330?? Expression (1), where t represents a sheet thickness (mm); w represents a smaller one of the widths (?m) of the regions measured on the front and rear surfaces of the steel sheet, respectively, by using a Bitter method; and s represents an average number of the regions present within one crystal grain.Type: GrantFiled: December 21, 2012Date of Patent: July 10, 2018Assignee: JFE STEEL CORPORATIONInventors: Shigehiro Takajo, Seiji Okabe
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Manufacture method of high-efficiency non-oriented silicon steel with excellent magnetic performance
Patent number: 9816152Abstract: A manufacture method of high-efficiency non-oriented silicon steel with excellent magnetic property includes the steps of smelting a chemical composition of non-oriented silicon steel, by weight percent, is: C?0.0040%, Si:0.1˜0.8%, Al:0.002˜1.0%, Mn:0.10˜1.50%, P:?0.2%, Sb:0.04˜0.08%, S?0.0030%, N?0.0020%, Ti?0.0020%, and the rest is Fe and unavoidable inclusions. The molten steel is then cast into billets which are hot-rolled into a hot-rolled product. The heating temperature for the billet is 1100°˜1150° and the finish-rolling temperature is 860°˜920°. The hot-rolled product is then air cooled for a period of time within a range determined by air cooling time t: (2+30xSb %)s?t?7 s. The hot-rolled product is reeled at a temperature ?720° and cold-rolled to form cold-rolled plate with a target thickness at a reduction ratio of 70˜78% followed by heating up the cold-rolled plate to 800˜1000° at heating rate of ?15°/s, and holding time of 10 s˜25 s.Type: GrantFiled: April 27, 2011Date of Patent: November 14, 2017Assignee: Baoshan Iron & Steel Co., Ltd.Inventors: Aihua Ma, Bo Wang, Shishu Xie, Zhanyuan Hu, Liang Zou, Zitao Wang, Yuhua Zhu, Jie Huang, Bingzhong Jin, Xiandong Liu -
Patent number: 9767946Abstract: A non-oriented electrical steel sheet has a chemical composition having C: not more than 0.005 mass %, Si: 2-7 mass %, Mn: 0.033 mass %, Al: not more than 3 mass %, P: not more than 0.2 mass %, S: not more than 0.005 mass %, N: not more than 0.005 mass %, Se: 0.0001˜0.0005 mass %, As: 0.0005˜0.005 mass % and the remainder being Fe and inevitable impurities, and an iron loss W15/50 in excitation at 50 Hz and 1.5 T of not more than 3.5 W/kg and a ratio (x/t) of amount of shear drop x (mm) to thickness t (mm) in punching of steel sheet of not more than 0.15 and is excellent in the iron loss property before punching and less in the deterioration of the iron loss property by punching.Type: GrantFiled: August 1, 2013Date of Patent: September 19, 2017Assignee: JFE STEEL CORPORATIONInventors: Yoshiaki Zaizen, Yoshihiko Oda, Hiroaki Toda
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Patent number: 9659694Abstract: Disclosed are a non-oriented electrical steel plate with low iron loss and high magnetic conductivity and a manufacturing process therefor. The casting blank of the steel plate comprises the following components: Si: 0.1-2.0 wt %, Al: 0.1-1.0 wt %, Mn: 0.10-1.0 wt %, C: ?0.005 wt %, P: ?0.2 wt %, S: ?0.005 wt %, N: ?0.005 wt %, the balance being Fe and unavoidable impurities. The magnetic conductivity of the steel plate meets the following relationship formula: ?10+?13+?15?13982?586.5P15/50; ?10+?13+?15?10000, wherein P15/50 is the iron loss at a magnetic induction intensity of 1.5 T at 50 Hz; ?10, ?13, and ?15 are relative magnetic conductivities at induction intensities of 1.0 T, 1.3 T, and 1.5 T at 50 Hz, respectively. The steel plate can be used for manufacturing highly effective and ultra-highly effective electric motors.Type: GrantFiled: March 27, 2012Date of Patent: May 23, 2017Assignee: BAOSHAN IRON & STEEL CO., LTD.Inventors: Aihua Ma, Bo Wang, Xiandong Liu, Liang Zou, Shishu Xie, Hongxu Hei
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Patent number: 9579701Abstract: A steel having a predetermined composition is hot-rolled so as to form a steel strip, the steel strip is subjected to first cold-rolling, the steel strip is subjected to intermediate annealing, the steel strip is subjected to second cold-rolling, and the steel strip is subjected to finish annealing. A finish temperature in the hot-rolling is 900° C. or less, annealing is not performed between the hot-rolling and the first cold-rolling, and a rolling reduction in the second cold-rolling is not less than 40% nor more than 85%.Type: GrantFiled: July 29, 2011Date of Patent: February 28, 2017Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Takeshi Kubota, Masahiro Fujikura
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Patent number: 8900688Abstract: To provide a grain oriented electrical steel sheet that can securely suppress propagation of lateral strain, and can make a product even from a portion where the lateral strain occurs. A grain oriented electrical steel sheet of the present invention has a linearly altered portion 14 generated in a glass coating film 12 at one of side edges of a steel sheet 11, in a continuous line or in a discontinuous broken line in a direction parallel with a rolling direction of the steel sheet, and having a composition different from a composition in other portions of the glass coating film. An average value of a deviation angle of a direction of an axis of easy magnetization of crystal grains relative to the rolling direction is 0° or more and 20° or less in a base metal iron portion of the steel sheet 11 at a position along a width direction of the steel sheet, the position corresponding to the linearly altered portion 14.Type: GrantFiled: May 28, 2012Date of Patent: December 2, 2014Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Tatsuhiko Sakai, Yoshio Nakamura, Kazuyuki Tashiro, Shohji Nagano, Shuichi Yamazaki, Koji Hirano
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Patent number: 8157928Abstract: 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: GrantFiled: November 2, 2010Date of Patent: April 17, 2012Assignee: Sumitomo Metal Industries, Ltd.Inventors: Ichirou Tanaka, Hiroshi Fujimura, Hirokatsu Nitomi, Hiroyoshi Yashiki, Kouji Nishida, Hiroki Takamaru
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Patent number: 7922834Abstract: 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: GrantFiled: December 6, 2005Date of Patent: April 12, 2011Assignee: Sumitomo Metal Industries, Ltd.Inventors: Ichirou Tanaka, Hiroshi Fujimura, Hirokatsu Nitomi, Hiroyoshi Yashiki, Kouji Nishida, Hiroki Takamaru
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Patent number: 7465361Abstract: In a method for manufacturing a grain-oriented electrical steel sheet using steel containing less than 100 ppm of Al and 50 ppm or less each of N, S, and Se as a starting material, purification annealing is performed at 1050° C. or more, the partial pressure of hydrogen in the atmosphere being adjusted to 0.4 atm or less in a temperature range above 1170° C. for a purification annealing conducted at a temperature above 1170° C., or 0.8 atm or less in a temperature range of 1050° C. or more for a purification annealing conducted at a temperature of 1170° C. or less, to prevent deterioration of the bend properties due to the impurities.Type: GrantFiled: October 27, 2003Date of Patent: December 16, 2008Assignee: JFE Steel CorporationInventors: Takashi Terashima, Minoru Takashima, Yasuyuki Hayakawa
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Patent number: 7442260Abstract: 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: GrantFiled: March 5, 2004Date of Patent: October 28, 2008Assignee: Nippon Steel CoroorationInventors: Tatsuhiko Sakai, Hideyuki Hamamura, Naoya Hamada
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Patent number: 7368166Abstract: A metallic glass-coated microwire has controllable surface porosity. The porosity is achieved by etching the metallic glass-coated microwire or other shapes of glass-coated bodies with acid after annealing to produce a multi-phase glass coating. Porous metallic glass-coated microwires are found to make superior PCR machines, which find use in a variety of in vivo, biochemical, and chemical sensors. Advantageously, the PCR apparatus is smaller, less expensive to construct than conventional units. It readily carries out in vivo passive or active operations.Type: GrantFiled: April 4, 2005Date of Patent: May 6, 2008Assignee: Demodulation, Inc.Inventors: Alan H. Goldstein, William C. LaCourse, Howard H. Liebermann
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Patent number: 7364629Abstract: 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: GrantFiled: January 7, 2003Date of Patent: April 29, 2008Assignee: Nippon Steel CorporationInventors: Yoshiyuki Ushigami, Shuichi Nakamura, Hiroyasu Fujii, Kenichi Murakami
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Patent number: 7282102Abstract: 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: GrantFiled: November 11, 2003Date of Patent: October 16, 2007Assignee: PoscoInventors: Kyu-Seung Choi, Jong-Soo Woo, Jae-Kwan Kim
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Patent number: 7233249Abstract: A glass-coated amorphous metallic microwire is encoded with multi-bit digital information. Encoding is achieved magnetically, optically or through a combination of magnetic and optical encoding processes. Magnetic encoding is carried out by modifying the constituent magnetic domain structure through selective relief of interfacial stress between the glass coating and the amorphous metallic alloy core. It is also achieved by selective surface crystallization of the amorphous metallic core in order to produce a controlled magnetic bias field. Optical encoding is associated with the glass coating. It is readily achieved by fluorescent element deposition, patterned removal of fluorescent element coating, Bragg grating, and thermally activated pattern deposition. The magnetic and optical multi-bit encoding approaches for glass-coated amorphous metallic microwire can be used individually or collectively in either a redundant or a complementary manner.Type: GrantFiled: September 7, 2004Date of Patent: June 19, 2007Assignee: Demodulation, Inc.Inventors: Howard H. Liebermann, William C. LaCourse, Alexis G. Clare, Wesley A. King, James E. O'Keefe, Jr.
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Publication number: 20040040629Abstract: 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 &mgr;m. In addition, the melted and re-solidified layers can be formed by using a laser.Type: ApplicationFiled: May 30, 2003Publication date: March 4, 2004Inventors: Hideyuki Hamamura, Tatsuhiko Sakai, Naoya Hamada
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Patent number: 6666929Abstract: It has been found out that in the laser treatment for the control of the magnetic domain sizes in grain oriented electrical silicon steel sheets, by optimizing some essential parameters of the treatment such as specific radiation energy, the distance among the scribed traces, the scanning speed and the dwell time, a contemporaneous improvement of the magnetostriction, induction and core losses can be obtained.Type: GrantFiled: February 21, 2002Date of Patent: December 23, 2003Assignee: Acciai Speciali Terni, S.p.A.Inventor: Gabor Ban
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Patent number: 6562473Abstract: 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: GrantFiled: November 27, 2000Date of Patent: May 13, 2003Assignee: Kawasaki Steel CorporationInventors: Seiji Okabe, Yasuyuki Hayakawa, Takeshi Imamura, Mitsumasa Kurosawa
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Publication number: 20020038678Abstract: 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.Type: ApplicationFiled: August 7, 2001Publication date: April 4, 2002Inventors: Yoshiyuki Ushigami, Shuichi Nakamura, Kenichi Murakami, Hiroyasu Fujii, Norihiro Yamamoto
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Publication number: 20020033206Abstract: A process for the production of oriented-grain electrical steel sheet with high magnetic characteristics, and more precisely a process in which the slab obtained from continuous casting is continuously nitrided by a reaction between aluminium and nitrogen is described. Amount, size and distribution of precipitates are controlled, enabling a high-temperature continuous heat treatment during which the primarv-recrystallization and a high-temperature nitriding are realised.Type: ApplicationFiled: June 22, 1999Publication date: March 21, 2002Inventors: STEFANO CICALE', STEFANO FORTUNATI, GIUSPEPPE ABBRUZZESE
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Patent number: 6312531Abstract: Soft magnetic powder of Fe—Al—Si system of which magnetostrictive constant &lgr; takes a positive value at the room temperature is employed to produce a magnetic composite article so that a temperature characteristic of core-loss of the article takes a negative value at the room temperature. Excellent magnetic characteristics such as a low core-loss and a high permeability can be obtained at a high frequency band.Type: GrantFiled: December 22, 1998Date of Patent: November 6, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Nobuya Matsutani, Yuji Mido, Kazuaki Onishi
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Patent number: 6280862Abstract: Ultra-low iron grain-oriented silicon steel sheet which is made by forming a ceramic tensile coating including at least inner and outer portions of a nitride and/or a carbide, the outer portion having a coefficient of thermal expansion that is lower than that of the inner portion, and wherein the outermost portion has an insulating property.Type: GrantFiled: November 23, 1998Date of Patent: August 28, 2001Assignee: Kawasaki Steel CorporationInventor: Yukio Inokuti
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Patent number: 6136456Abstract: Grain oriented electrical steel sheet with a very low iron loss and a method for producing the same, wherein the surface of the iron substrate of the grain oriented electrical steel sheet is subjected to an enhancement treatment of crystal grain orientation or surface smoothing to a mean roughness of about 0.20 .mu.m or less, electroplating a chromium plating layer on the substrate with heterogeneous growth, and applying a tension coating film to the plating layer.Type: GrantFiled: October 23, 1998Date of Patent: October 24, 2000Assignee: Kawasaki Steel CorporationInventors: Michiro Komatsubara, Hiroi Yamaguchi, Minoru Takashima, Mineo Muraki
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Patent number: 5565272Abstract: A grain oriented silicon steel sheet having excellent primary glass film property and magnetic property, comprising 2.0 to 5.0% by weight of Si, wherein a primary glass film formed during secondary recrystallization annealing is composed mainly of forsterite (Mg.sub.2 SiO.sub.4) and an oxide containing Al, mainly of spinel (MgAl.sub.2 O.sub.4), or Al and Si, mainly of cordierite (MgO.sub.2 Al.sub.4 Si.sub.5 O.sub.18) and/or sapphirine (Mg.sub.4 Al.sub.10 Si.sub.2 O.sub.23), and in an analysis of the surface of the steel sheet by glow discharge optical emission spectrometry analysis (GDS analysis), a peak derived from Al is separated from a peak derived from Mg, and, preferably, the peak derived from Al is separated from the peak derived from Mg and the distance (time) from the surface of the steel sheet at which the peak derived from Al is 1.2 times or more the distance from the surface of the steel sheet at which the peak derived from Mg appears.Type: GrantFiled: July 10, 1992Date of Patent: October 15, 1996Assignee: Nippon Steel CorporationInventors: Hiroaki Masui, Morio Shiozaki, Nobuyuki Takahashi, Hisashi Kabayashi, Takeo Nagashima, Shuichi Yamazaki, Hiroyasu Fujii
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Patent number: 5547519Abstract: The present invention provides an annealing separator composition for coating grain oriented electrical steel prior to the final high temperature anneal for secondary grain growth. The magnesia based coating contains at least 20% silica on a water free basis. The large silica additions limit the interface between the coating and the base metal and results in a thick glass which is easily removed. The magnesia coating develops excellent magnetic properties and does not require the normal strong acid cleaning or special abrasive means to remove the glass film which forms. The bare electrical steel, which may be coated to enhance the punching properties, has improved the die life because the hard glass film has been substantially removed.Type: GrantFiled: June 5, 1995Date of Patent: August 20, 1996Assignee: Armco Inc.Inventor: Robin A. Murphy
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Patent number: 5417772Abstract: Method for producing a magnetic steel strip having a thickness of less than 5 mm and containing, in composition by weight, more than 2% silicon, less than 0.1% carbon and a suitable amount of secondary recrystallization inhibiting elements, the balance being iron, obtained by a direct casting on one roll or between two rolls, characterized in that it comprises creating a crystallization structure comprising oriented grains {110} <001> in the skin, i.e. on the surface of a quench zone, by the sudden cooling of the steel in contact with the roll or rolls whose surface temperature is lower than 400.degree. C.Type: GrantFiled: October 28, 1992Date of Patent: May 23, 1995Assignees: Ugine S.A., Thyssen Stahl AktiengesellschaftInventors: Jean-Claude Bavay, Philippe Demarez, Frederic Mazurier
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Patent number: 5393321Abstract: A method of producing continuous lengths of metallic strip comprises the steps of forming a spray of molten metal particles, causing the particles to be deposited onto a surface of a hollow receptor roll, rotating and internally heating the receptor roll to form continuous lengths of metallic strip, holding the deposited particles in contact with the receptor roll surface by means of a roll positioned immediately upstream of the knife in the direction of rotation of the receptor roll, and peeling from the receptor roll surface such continuous lengths of metallic strip by means of a knife positioned adjacent to or in contact with the receptor roll surface. Apparatus for performing this process is also disclosed.Type: GrantFiled: October 28, 1993Date of Patent: February 28, 1995Assignee: British Steel PLCInventor: Gordon C. Eadie
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Patent number: 5352490Abstract: A reaction gas or a gas containing a reaction gas is blown through blowing nozzles onto a steel material in a chemical vapor deposition treating chamber at a velocity sufficient to forcibly remove reacted products from reacted surfaces of a steel material while suppressing irregular thickness of a deposited film.Type: GrantFiled: July 6, 1992Date of Patent: October 4, 1994Assignee: NKK CorporationInventors: Masahiro Abe, Kazuhisa Okada, Shuzo Fukuda
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Patent number: 5089061Abstract: The present invention relates to a method for producing high silicon steel strip in a continuous treatment line through chemical vapor deposition (called "CVD" hereinafter), wherein the steel strip is subjected continuously to siliconization at temperatures between 1023.degree. and 1200.degree. C. by CVD in a non-oxidizing gas atmosphere containing SiCl.sub.4 between 5% and 35% in molar fraction. Subsequently a diffusion treatment is performed in a non-oxidizing gas atmosphere not containing SICl.sub.4 for diffusing Si uniformly throughout the steel strip, which is then cooled and coiled. If required, the steel strip may be coated with an insolating film and subjected to a baking treatment, before cooling and coiling.Type: GrantFiled: September 22, 1988Date of Patent: February 18, 1992Assignee: NKK CorporationInventors: Masahiro Abe, Kazuhisa Okada, Shuzo Fukuda, Yasushi Tanaka, Masayuki Yamato, Yoshikazu Takada
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Patent number: 5089062Abstract: A steel sheet (10) having a stress-relief annealed, structure with a plurality of magnetic domains (12) is made by drilling a plurality of closely spaced, small holes (15) through the entire thickness of the steel sheet, where the drilling is effective to form additional domain walls (17) and subdivide the magnetic domains.Type: GrantFiled: March 1, 1991Date of Patent: February 18, 1992Assignee: ABB Power T&D Company, Inc.Inventors: Norman M. Pavlik, John Sefko, Richard A. Miller
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Patent number: 5085411Abstract: An apparatus for processing grain-oriented electrical steel strip has a groove-scribing unit, which comprises a groove-scribing roll mounted above a pressing roll, disposed on the entry side of an insulation coating unit. A bridle roll is provided above the groove-scribing roll so that the strip may be passed to the groove-scribing and insulating coating units via the bridle roll. The apparatus also has a device for guiding the travel of the bridle roll from above the groove-scribing roll to below the horizontal pass line of the strip and vice versa. A moving device attached to the bridle roll permits the bridle roll to travel up and down along the guiding device together with the strip passed therearound. When the bridle roll is positioned above the groove-scribing roll, the groove-scribing and support rolls are kept close to each other, thereby scribing grooves in the surface of the strip held between the two rolls before the strip is passed to the insulation coating unit.Type: GrantFiled: December 4, 1990Date of Patent: February 4, 1992Assignee: Nippon Steel CorporationInventors: Yoshinao Tanaka, Takaaki Ohsawa, Akira Tanabe
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Patent number: 5080326Abstract: A method is provided for improving the electrical characteristics of grain-oriented silicon steel sheet by heating the steel to temperatures above 1000.degree. F. and then deforming grooves to refine the magnetic domains, optionally, post heat treating to form fine recrystallized grains in the vicinity of the hot deformations, preferably using protrusions on a scribing roll as the sheet moves between a scribing roll and a back-up anvil roll at deforming pressures range up to 120,000 pounds per square inch.Type: GrantFiled: January 4, 1991Date of Patent: January 14, 1992Assignee: Allegheny Ludlum CorporationInventors: Leroy R. Price, Jeffrey M. Breznak
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Patent number: 5062906Abstract: The present invention is to produce non-oriented electrical steel sheet by a hot direct rolling. The slab is directly sent to the hot rolling without the brief soaking, whereby others than AlN inevitably precipitated check the precipitation of AlN, a roughing and a finish rolling are performed at determined reduction rates, and a delay time is taken between the roughing and the finish rolling, and besides a finish rolling is performed at not more than Ar.sub.3 so that precipitating nuclei of AlN are effectively introduced into the steel, and uniform and coarse AlN precipitation is formed by a coiling at temperature of more than 700.degree. C., thereby to enable to provide uniform and satisfied ferrite grain growth at the recrystallization annealing.Type: GrantFiled: October 12, 1989Date of Patent: November 5, 1991Assignee: NKK CorporationInventors: Akihiko Nishimoto, Yoshihiro Hosoya, Kunikazu Tomita, Toshiaki Urabe, Masaharu Jitsukawa
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Patent number: 5045129Abstract: The present invention concerns a process for the production of semiprocessed non oriented grain electrical steel. More precisely it provides a solution to the technical problem of obtaining non oriented grain sheet or strip characterized by high magnetic permeability and low magnetic losses. According to the invention, starting from a steel with a low S, N and C content, through appropriate selection of hot-rolling variables and high-temperature annealing prior to cold rolling, a big improvement is achieved in the magnetic characteristics of the product, thanks to a better compromise between grain size and crystal orientation.Type: GrantFiled: December 18, 1990Date of Patent: September 3, 1991Assignee: Centro Sviluppo Materiali S.p.A.Inventor: Mario Barisoni
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Patent number: 5026439Abstract: The present invention provides a wound core having a low core loss and not susceptible to a disappearance of the core loss lowering effect due to a magnetic domain refining even when stress-relief annealing is conducted after fabrication of a steel strip into a wound core, through a process which comprises, fabricating a very thin silicon steel strip comprising by 6.5% weight or less of silicon with the balance consisting essentially of iron and having a sheet thickness of 100 .mu.m or less and a magnetic flux density (B.sub.8 value) of 1.80T or more into a wound core, subjecting the wound core to stress-relief annealing, unwinding the very thin silicon steel strip from the core, introducing into the very thin silicon steel strip a linear or dotted local strain in a direction at an angle of 45.degree. to 90.degree. to the rolling direction of the thin strip, and rewinding the thin strip onto the core.Type: GrantFiled: October 12, 1990Date of Patent: June 25, 1991Assignee: Nippon Steel CorporationInventors: Masaki Tanaka, Norito Abe, Masao Yabumoto, Yoshiyuki Ushigami, Tadao Nozawa
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Patent number: 5013373Abstract: Permanent domain refinement of grain oriented electrical steel strip is obtained in a high speed two-stage process. The process removes the glass in narrow regions which just expose the base metal. An electrolytic etch is then used to deepen the region into the base metal and minimize damage to the remaining glass film. Control of acid concentration and temperature in the electrolytic bath allows a greater increase in productivity. A further feature of the process is the use of permeability measurements to optimize the depth of the etched regions. The improved core loss produced by the process will survive a stress relief anneal.Type: GrantFiled: March 1, 1990Date of Patent: May 7, 1991Assignee: Armco, Inc.Inventor: Wayne F. Block
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Patent number: 4968361Abstract: A method is provided for domain refinement of final texture annealed grain-oriented silicon steel by removing portions of the base coating to substantially expose a line pattern of the underlying silicon steel by applying in the pattern an agent to the coated steel, heating the agent to activate it to cause substantial removal of the base coating in the line pattern and effecting heat resistant domain refinement and reduced core loss by allowing thermal and chemical treatment activity on the exposed steel.Type: GrantFiled: March 23, 1989Date of Patent: November 6, 1990Assignee: Allegheny Ludlum CorporationInventors: S. Leslie Ames, Charles D. Boyer
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Patent number: 4904312Abstract: This invention relates to a method of enhancing linear impressions formed in the surface of grain oriented electrical steel strip, by electrolytically etching said impressions with e.g. citric acid. The impressions may be formed by mechanical wheel scribing or by surface ablation, e.g. by spark discharge or laser treatment, and may be continuous or discontinuous in the form of spots or lines. In accordance with this invention therefore, the initial generation of light impressions in steel strip formed by mechanical wheel scribing or spark ablation techniques can readily be enhanced by application of the electrolytic etching technique to produce a material exhibiting values of power loss (reduced from the original unscribed loss value) which are substantially anneal-proof. In comparison, conventionally scribed material shows no resistance to a high temperature anneal as far as loss reduction is concerned.Type: GrantFiled: August 10, 1988Date of Patent: February 27, 1990Assignee: British Steel plcInventors: Philip Beckley, David Snell
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Patent number: 4832762Abstract: An ordinarily made thin steel sheet is placed in an atmosphere bearing SiCl.sub.4, and subjecting to Si penetrating treatment at temperatures between 1100.degree. C. and 1200.degree. C. for a determined period of time. A heating rate is used which is more than 50.degree. C./sec at the temperatures of more than 1000.degree. C. in the SiCl.sub.4 atmosphere.Thereby, it is possible to manufacture thin steel sheet of high magnetic permeability without internal defects.Type: GrantFiled: March 3, 1986Date of Patent: May 23, 1989Assignee: Nippon Kokan Kabushiki KaishaInventors: Kazuhide Nakaoka, Yoshikazu Takada, Yasushi Tanaka
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Patent number: 4439252Abstract: A grain-oriented silicon steel sheet having excellent magnetic properties can be stably produced by adjusting properly the C content in a silicon steel to be used as a starting material depending upon the Si content in the steel, removing a proper amount of C from the steel during the course after the hot rolling and before the final cold rolling, and further carrying out the final cold rolling at a reduction rate of 40-80%.Type: GrantFiled: September 23, 1982Date of Patent: March 27, 1984Assignee: Kawasaki Steel CorporationInventors: Katsuo Iwamoto, Tomomichi Goto, Yoshinori Kobayashi, Yoshiaki Iida, Isao Matoba
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Patent number: 4437909Abstract: The present invention relates to a process for producing a grain-oriented silicon steel sheet or strip, wherein the crystals of the steel sheet or strip have an orientation of {110}<001> and, further, the steel is easily magnetized in the rolling direction.Since the slab-heating temperature for a grain-oriented silicon steel is considerably higher than that for low carbon steel grades, coarsening of the crystal grains is likely to occur during heating, and the coarse crystal grains are elongated during hot-rolling in the rolling direction and remain in the hot-rolled steel sheet as portions of the grain-oriented silicon steel strip or sheet, where secondary recrystallization becomes incomplete, or as so-called streaks.It is an object of the present invention to provide a novel hot-rolling technique capable of preventing the generation of streaks and capable of enhancing the magnetic flux density of the final product in terms of the B.sub.Type: GrantFiled: May 25, 1982Date of Patent: March 20, 1984Assignee: Nippon Steel CorporationInventors: Kensuke Mori, Hiromi Matsumoto, Yozo Suga, Tadashi Nakayama, Fumio Matsumoto
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Patent number: 4371405Abstract: In a process for producing a grain-oriented silicon steel strip, comprising the steps of: hot rolling, annealing, if necessary; heavy cold rolling; decarburization-annealing, and; final annealing, an improvement which comprises controlling a coiling temperature after the finish rolling of the hot rolling step within a range of from 700.degree. to 1000.degree. C. As a result of the coiling temperature control, the annealing of the hot rolled strip can be simplified or omitted, while the behavior of a grain-growth inhibitor is equivalent to that in the conventional process including the annealing step. The magnetic flux density of the material produced by the process of the present invention is excellent, notwithstanding the simplification or omission of the annealing.Type: GrantFiled: August 15, 1980Date of Patent: February 1, 1983Assignee: Nippon Steel CorporationInventors: Jiro Harase, Kunihide Takashima, Shozaburo Nakashima
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Patent number: 4311538Abstract: The use of coarse sand particles having an average size of 0.5-10 mm in the sealing of the lower end portion of an inner cover, which is arranged in a box annealing furnace, at the final annealing, in the production of grain-oriented silicon steel sheets, can maintain the interior of the inner cover at a low dew point atmosphere. It can also substantially prevent the exfoliation of forsterite insulating film from the coiled steel sheet surface at the upper and lower edge portions of the coiled steel sheet.Type: GrantFiled: July 7, 1980Date of Patent: January 19, 1982Assignee: Kawasaki Steel CorporationInventor: Nobuyuki Morito
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Patent number: 4108694Abstract: A continuously cast steel slab for production of a grain-oriented electrical steel sheet having excellent magnetic properties in which at least 95% of the total number of grains constituting an equi-axed crystal zone in said slab has a cross sectional dimension less than 9 mm.sup.2 per one grain.Type: GrantFiled: August 10, 1977Date of Patent: August 22, 1978Assignee: Nippon Steel CorporationInventors: Morio Shiozaki, Yozo Suga, Hiromu Fujii, Kohichi Fujiwara
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Patent number: 4050957Abstract: A process for the passivation of discrete particles of ferrosilicon containing 30-90% by weight silicon comprises contacting the particles with a gaseous oxidizing agent at a temperature between 800.degree.-1150.degree. C for a time ranging between 1-12 hours. The treated particles can be admixed with a binding agent to form a paste which, in turn, is used as a coating for shielded arc electrodes.Type: GrantFiled: October 8, 1975Date of Patent: September 27, 1977Assignee: Societe Pyreneenne du Silico-ManganeseInventor: Maurice Sales
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Patent number: 4043805Abstract: A silicon-containing high strength steel sheet having isotropic high ductility and toughness in all directions independently of the rolling direction comprising 0.03 to 0.15% C, 0.7 to 2.3% Si, 0.7 to 2.0% Mn with the balance being iron and unavoidable impurities, in which the ratio of Si/Mn is between 0.6 and 1.5 and the content of S is maintained in an amount as low as possible below that normally contained as an unavoidable impurity.Type: GrantFiled: November 17, 1975Date of Patent: August 23, 1977Assignee: Nippon Steel CorporationInventors: Satohiro Hayami, Jun Imamura, Hiroshi Hayakawa, Tadatzugu Yabuta
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Patent number: 4006044Abstract: A steel slab containing silicon for use as an electrical steel sheet and strip and having no blister occurrence in the final product manufactured by continuous casting, characterized in that said slab comprises 2.5 - 4.0 wt.% of silicon, less than 0.04% of aluminium, less than 3 ppm of hydrogen or less than 3 ppm of hydrogen together with less than 80 ppm of oxygen, and less than [Al(%) .times. 10.sup.3 + 50] ppm of nitrogen, with the remainder being essentially iron.Type: GrantFiled: April 1, 1975Date of Patent: February 1, 1977Assignee: Nippon Steel CorporationInventors: Tatsuo Oya, Minoru Motoyoshi, Masfumi Okamoto, Kiyoshi Tanaka, Takayasu Sugiyama
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Patent number: 3986902Abstract: A process for producing grain oriented silicon sheet steel having excellent magnetic properties in which the manganese and sulfur contents are critically controlled so that the product of manganese content, in weight percent, times sulfur content, in weight percent, is within the range 0.0007 to 0.0012, and aluminum is added to the deoxidized steel just prior to teeming to minimize the formation of insoluble oxide precipitates within the body of the teemed steel, the amount of aluminum added being limited so as to avoid appreciable aluminum remaining in solution in the teemed steel. The slab resulting from the above steel can then be preheated to a temperature of 2,130.degree. to 2,390.degree. F prior to hot rolling without sacrificing magnetic quality.Type: GrantFiled: October 9, 1975Date of Patent: October 19, 1976Assignee: United States Steel CorporationInventor: Lester J. Regitz
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Patent number: 3960616Abstract: A melt for cold rolled, non-oriented silicon steel is deoxidized and thereafter treated with mischmetal or a mischmetal alloy to desulfurize the melt to 0.012% by weight sulfur or less without the formation of a polluting smoke. The deoxidation is carried out to the extent that, and the mischmetal is added in an amount such that, the melt composition, has a total cerium content of up to about 400 ppm. and preferably from about 75 to about 250 ppm.Type: GrantFiled: June 19, 1975Date of Patent: June 1, 1976Assignee: Armco Steel CorporationInventors: James D. Evans, William R. Long, Jr.