Continuous Casting Patents (Class 148/541)
-
Patent number: 7117925Abstract: A cast carbon steel strip is prepared by continuously casting in a twin roll caster and cooling to transform the strip from austenite to ferrite at a temperature range between 400° C. and 850° C. at cooling the strip to transform the austenite to ferrite within a temperature range between 400° C. and 850° C. at a cooling rate of greater than 100° C./sec without inhibiting the cooling rate to form cast strip that is less than about 1% austenite and has a packet size of at least 10% greater than 300 ?m, is either (i) a mixture of polygonal ferrite and low temperature transformation products or (ii) predominantly low temperature transformation products, and has a yield strength of at least 450 MPa. The cast strip before cooling is passed through a hot rolling mill to reduce the thickness of strip by at least 15% and up to 50%.Type: GrantFiled: August 4, 2005Date of Patent: October 10, 2006Assignee: Nucor CorporationInventors: Lazar Strezov, Kannappar Mukunthan, Walter Blejde, Rama Mahaptra
-
Patent number: 7004228Abstract: To make a raw alloy, consisting mostly of amorphous structure, highly productively and at a reduced cost for a nanocomposite magnet, a molten alloy represented by Fe100-x-y-zRxQyMz (where R is at least one element selected from Pr, Nd, Dy and Tb; Q is B and/or C; M is at least one element selected from Co, Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Ag, Pt, Au and Pb; and 1 at %?x<6 at %, 15 at %?y?30 at % and 0 at %?z?7 at %) is prepared. This molten alloy is rapidly cooled by a strip casting process in which the alloy is fed onto a chill roller, rotating at a peripheral velocity of 3 m/s to less than 20 m/s, at a feeding rate per unit contact width of 0.2 kg/min/cm to 5.2 kg/min/cm. In this manner, an alloy including at least 60 volume percent of amorphous phase can be obtained.Type: GrantFiled: September 25, 2001Date of Patent: February 28, 2006Assignees: Santoku Corporation, Neomax Co., Ltd.Inventors: Ryo Murakami, Hirokazu Kanekiyo, Satoshi Hirosawa
-
Patent number: 6953627Abstract: A process for the production of thin walled parts of steel, wherein there are layers that are at least partly differently treatable relating to their strength and hardness qualities. This process can include creating a composite material from a plurality of different layers by connecting at least one core layer and at least one surface layer together. At least one layer of the core or surface layer is cast adjacent to another layer to form a composite material having an alloy gradient that is flat at each interface between any of the core layer or the surface layer. Next, the process can include deforming the composite material along a length of these layers. Finally the process can include heat treating the layers to transform the strength and hardness qualities of at least one of these layers.Type: GrantFiled: January 5, 2001Date of Patent: October 11, 2005Assignee: C.D. Walzholz-Brockhaus GmbHInventor: Hans-Toni Junius
-
Patent number: 6896747Abstract: Austenitic alloy for high-temperature strength with improved pourability and manufacturing, of which the composition comprises, in weight-%: 0.010%<carbon<0.04% 0%<nitrogen<0.01% silicon<2% 16%<nickel<19.9% manganese<8% 18.1%<chromium<21% 1.8%<titanium<3% molybdenum<3% copper<3% aluminum<1.5% boron<0.01% vanadium<2% sulfur<0.2% phosphorous<0.04% and possibly up to 0.5% of at least one element chosen from among yttrium, cerium, lanthanum and other rare earths, the remainder being iron and impurities resulting from manufacturing or deoxidizing, the said composition also satisfying the two following relationships: in relationship to the solidification mode: remainder a=eq. Nia?0.5×eq. Cra<3.60 where eq. Cra=Cr+0.7×Si+0.2×Mn+1.37×Mo+3×Ti+6×Al+4×V, and where eq. Nia=Ni+22×C+0.5×Cu, in relationship to the rate of residual ferrite: remainder b=eq. Nib?2×eq. Crb>?41 where eq. Crb=Cr+0.7×Si+1.37×Mo+3×Ti+6×Al+4×V, and where eq. Nib=Ni+22×C+0.5×Cu+0.Type: GrantFiled: November 1, 2002Date of Patent: May 24, 2005Assignee: UsinorInventors: Jean-Michel Hauser, Christophe Bourgin
-
Patent number: 6896034Abstract: A method of controlling a continuous steel strip casting process based on customer-specified requirements includes a general purpose computer in which product specifications of steel product ordered by a customer is entered. The computer is configured to automatically map the product specifications to process parameters/set points for controlling the continuous steel strip casting process in a manner to produce the customer ordered product, and in one embodiment produces a process change report detailing such process parameters/set points for operator use in physically implementing such process parameters/set points in the strip casting process. Alternatively, the computer may provide the process parameters/set points directly to the strip casting process for automatic control thereof in producing the customer ordered steel product.Type: GrantFiled: April 22, 2003Date of Patent: May 24, 2005Assignee: Nucor CorporationInventors: Lazar Strezov, Kannapar Mukunthan, Walter Bleide, Rama Mahapatra
-
Patent number: 6855218Abstract: The invention relates to a method for producing hot strip which features good forming ability and increased strength. This is achieved in that a hot strip (W) which is produced in particular from continuous casting in the shape of reheated slabs or slabs obtained directly from the casting heat, from thin slabs or cast strip, based on a steel comprising (in mass %) C: 0.001-1.05%; Si: ?1.5%; Mn: 0.05-3.5%; Al: ?2.Type: GrantFiled: February 24, 2000Date of Patent: February 15, 2005Assignee: Thyssen Krupp Stahl AGInventors: Rudolf Kawalla, Hans Pircher, Thomas Heller, Bernhard Engl, Pino Tesè
-
Patent number: 6852180Abstract: The invention relates to the iron and steel industry. More specifically, the invention describes the manufacture of steel strip intended to be converted into thin packaging, such as for drinks and preserved food.Type: GrantFiled: September 20, 2000Date of Patent: February 8, 2005Assignee: UsinorInventors: Michel Faral, Michel Guttmann, Jean-Hubert Schmitt, Catherine Juckum, Helene Regle
-
Patent number: 6835253Abstract: The invention relates to a method for producing a hot strip, in particular for producing a hot strip intended for the production of a cold strip with good deep-drawing characteristics; in which a steel melt comprising (in % by weight) C:≦0.07%, Si:≦0.5%, Mn:≦2.5%, Al:≦0.1%, N:≦0.01%, P:≦0.025, B:≦0.05, if need be up to a total of 0.Type: GrantFiled: July 22, 2002Date of Patent: December 28, 2004Assignee: Thyssenkrupp Stahl AGInventors: Rudlof Kawalla, Bernhard Engl, Thomas Heller, Wolfgang Rasim, Eberhard Sowka
-
Publication number: 20040250927Abstract: A method of die casting spheroidal graphite cast iron able to prevent formation of chill crystals to allow the crystallization of fine spheroidal graphite and simultaneously prevent the formation of internal defects, including the steps of preparing a die formed with a heat insulation layer at inside walls of a cavity, filling molten metal having a composition of the spheroidal graphite cast iron through a runner into the cavity, closing the runner so as to seal the cavity right before the molten metal in the cavity starts to solidify, and allowing the molten metal to solidify by the action of the inside pressure caused by crystallization of the spheroidal graphite in the sealed cavity.Type: ApplicationFiled: January 22, 2004Publication date: December 16, 2004Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, AISIN TAKAOKA CO., LTD.Inventors: Kazumi Ohtake, Akira Manabe, Yoshihiro Hibino, Takahiro Sato, Kazufumi Niwa
-
Patent number: 6818079Abstract: A method for manufacturing a steel sheet comprising continuously casting a steel containing 0.04 to 0.2 wt. % C, 0.25 to 2 wt. % Si, 0.5 to 2.5 wt. % Mn, and 0.1 wt. % or less Al to form a slab; hot-rolling by rough-rolling the slab to form a sheet bar and finish-rolling the sheet bar with a reduction in thickness at the final stand of less than 30%, the finish-rolling being completed at a temperature from the Ar3 transformation point to the Ar3 transformation point +60° C.; primary-cooling the hot-rolled steel sheet, the primary cooling being started within 1 second after the completion of hot-rolling and conducting the cooling at a cooling speed of higher than 200° C./sec down to a temperature of Ar3 −30° C. to the Ar1 transformation point; slow cooling or air-cooling the primary-cooled steel sheet at a temperature of the Ar3 transformation point to the Ar1 transformation point at 10° C.Type: GrantFiled: May 27, 2003Date of Patent: November 16, 2004Assignee: NKK CorporationInventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroyasu Kikuchi, Yoshimasa Funakawa, Hiroshi Nakata, Sadanori Imada, Toru Inazumi
-
Publication number: 20040163741Abstract: A steel sheet with a thickness of at least 0.30 mm is made of an ultra-low carbon steel with a chemical composition including C: at most 0.010%, Si: at most 0.5%, Mn: at most 1.5%, P: at most 0.12%, S: at most 0.030%, Ti: at most 0.10%, Al: at most 0.08%, and N: at most 0.0080%. The total number of non-metallic inclusions observed under a microscope in sixty fields in a sample prepared in accordance with JIS G0555 is at most 20. During manufacture of the steel, the amount of FeO+MnO in slag in a ladle at the time of continuous casting is controlled to at most 15%, and the throughput at the time of casting is made at most 5 tons per minute. The steel sheet does not develop pin hole defects or press cracks caused by inclusions when used for applications such as motor housings or oil filter housings requiring severe press forming.Type: ApplicationFiled: January 16, 2004Publication date: August 26, 2004Applicant: Sumitomo Metal Industries, Ltd.Inventors: Syuji Nakai, Tatsuo Kanai, Yoshihiko Higuchi, Sei Hiraki
-
Patent number: 6773522Abstract: A process and device for producing a high-strength steel strip. In the process, liquid steel is cast in at least one continuous-casting machine (1) with one or more strands to form a slab and, utilizing the casting heat, is conveyed through a furnace device (7). The slab undergoes preliminary rolling in a preliminary rolling device (10) and, in a final rolling device (14), is finishing-rolled to form a steel strip with the desired final thickness. In a continuous, endless or semi-endless process, the slab undergoes preliminary rolling in, essentially, the austenitic range in the preliminary rolling device (10) and, in the final rolling device (14), is rolled in the austenitic range or, in at lest one stand of the final rolling device (14), is rolled in the two-phase austenitic-ferritic range, the austenitic or austenitic, ferritic rolled strip. After leaving the final rolling device (14), the strip is cooled rapidly to obtain the desired structure.Type: GrantFiled: August 14, 2000Date of Patent: August 10, 2004Assignee: Corus Staal BVInventors: André Bodin, Thomas Martinus Hoogendoorn
-
Patent number: 6767415Abstract: A killed and vacuum-degassed very-low-carbon steel containing, by weight, between 0.10 and 0.35% manganese, less than 0.006% nitrogen, less than 0.025% phosphorus, less than 0.020% sulphur, less than 0.020% silicon, at most 0.08% of at least one of the elements copper, nickel and chromium, as well as aluminum. The steel is cast in the form of a slab, the slab is hot rolled in order to obtain a hot-rolled sheet, the hot-rolled sheet is coiled, the hot-rolled sheet is cold rolled in two rolling operations separated by a continuous annealing operation. The steel contains at most 0.006% carbon by weight and 0.010% aluminum and the hot-rolled sheet is coiled at a temperature below 620° C. Preferably, the steel is killed by mixing with a slag containing adjusted amounts of aluminum and of alumina.Type: GrantFiled: August 5, 1998Date of Patent: July 27, 2004Assignee: SollacInventors: Veronique Sardoy, Gilles Dahmen, Isabelle Poissonnet, Anne Blanchard, Pascal Choquet, Bernard Debiesme
-
Patent number: 6764528Abstract: A method of producing a high nitrogen, ultra low carbon steel suitable to rolling material for use in cold rolled steel sheets having excellent age hardening property by an age hardening treatment after forming by working, with no defects in slabs or steel sheets, reliably, at a reduced cost and with a high productivity is proposed. The method for producing a rolling material for use in ultra low carbon steel sheets at: C≦0.0050 mass % comprises; applying primary decarburization refining to molten iron from a blast furnace, then controlling the composition in the molten steel after primary decarburization refining to a range satisfying the following relation: [mass % N]−0.15[mass % C]≧0.0060, subsequently conducting secondary decarburization refining to a ultra low carbon concentration region while suppressing denitridation using a vacuum degassing facility, then conducting deoxidation by Al and, further, controlling the composition.Type: GrantFiled: August 8, 2002Date of Patent: July 20, 2004Assignee: JFE Steel CorporationInventors: Seiji Nabeshima, Shuji Takeuchi, Hisashi Ogawa, Yuki Nabeshima, Yasuyuki Masumoto
-
Publication number: 20040123924Abstract: [Object] To provide a high carbon steel sheet having excellent hardenability and toughness, and low planar anisotropy of tensile properties affecting workability, and a method of producing the same.Type: ApplicationFiled: September 19, 2003Publication date: July 1, 2004Applicant: NKK CORPORATIONInventors: Nobuyuki Nakamura, Takeshi Fujita, Katsutoshi Ito, Yasuyuki Takada
-
Publication number: 20040112482Abstract: The present invention relates to a high strength steel sheet consisting essentially of 0.04 to 0.1% C, 0.5% or less Si, 0.5 to 2% Mn, 0.05% or less P, 0.005% or less O, 0.005% or less S, by weight, having 10 &mgr;m or less of average ferritic grain size, and 20 mm/mm2 or less of generation frequency A, which generation frequency A is defined as the total length of a banded secondary phase structure observed per 1 mm2 of steel sheet cross section along the rolling direction thereof. The steel sheet is manufactured by, for example, a method comprising the steps of: hot-rolling a continuously cast slab having the composition described above at temperatures of Ar3 transformation point or above directly or after reheating thereof; and cooling the hot-rolled steel sheet within 2 seconds down to the temperatures of from 600 to 750° C. at cooling speeds of from 100 to 2,000° C./sec, followed by coiling the cooled steel sheet at temperatures of from 450 to 650° C.Type: ApplicationFiled: July 23, 2003Publication date: June 17, 2004Applicant: NKK CORPORATIONInventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroyasu Kikuchi, Sadanori Imada, Yasunobu Nagataki, Toru Inazumi
-
Patent number: 6699338Abstract: A steel material excellent in weathering resistance by defining the chemical ingredients in the steel each to a predetermined range and setting an ingredient parameter formula in accordance with the working circumstance thereby reducing the flow rust and, particularly, forming stable rust with good protective property even in a salty circumstance such as in coast districts is provided. Further, also considering the amount of A type inclusions and B type inclusions according to JIS G 0555, a steel material of excellent earthquake proofness and weathering proofness also including weld heat affect zone is provided.Type: GrantFiled: September 9, 2002Date of Patent: March 2, 2004Assignee: JFE Steel CorporationInventors: Tatsumi Kimura, Kazuhiko Shiotani, Fumimaru Kawabata, Keniti Amano
-
Patent number: 6689229Abstract: A high strength cold rolled steel sheet consists essentially of 0.0040 to 0.01% C, not more than 0.05% Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, not more than 0.02% S, 0.01 to 0.1% sol.Al, not more than 0.004% N, 0.01 to 0.14% Nb, by weight, and a balance of substantially Fe and inevitable impurities, and having an n value of not less than 0.21 calculated from two points (1% and 10%) of nominal strain determined by the uniaxial tensile test, and a method for manufacturing the cold rolled steel sheet. The high strength cold rolled steel sheet has excellent combined formability, resistance to embrittlement during secondary operation, formability at welded portions, and anti-burring performance, and has a desirable surface appearance and uniformity of material in a coil, and thus can be desirably used for automobile exterior panels.Type: GrantFiled: April 15, 2002Date of Patent: February 10, 2004Assignee: NKK CorporationInventors: Takeshi Fujita, Fusato Kitano, Yoshihiro Hosoya, Toru Inazumi, Yuji Yamasaki, Masaya Morita, Yasunobu Nagataki, Kohei Hasegawa, Hiroshi Matsuda, Moriaki Ono
-
Publication number: 20040020570Abstract: A high strength cold rolled steel sheet consists essentially of 0.0040 to 0.01% C, 0.05% or less Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, 0.02% or less S, 0.01 to 0.1% sol.Al, 0.004% or less N, 0.01 to 0.14% Nb, optionally 0.05% or less Ti, optionally 0.Type: ApplicationFiled: July 29, 2003Publication date: February 5, 2004Applicant: NKK CORPORATIONInventors: Takeshi Fujita, Fusato Kitano, Yoshihiro Hosoya, Toru Inazumi, Yuji Yamasaki, Masaya Morita, Yasunobu Nagataki, Kohei Hasegawa, Hiroshi Matsuda, Moriaki Ono
-
Patent number: 6675869Abstract: A plain carbon steel strip is continuously cast in a twin roll caster and passes to a run out table on which it is subjected to accelerated cooling by means of cooling headers whereby it is cooled to transform the strip from austenite to ferrite at a temperature range between 850° C. and 400° C. at a cooling rate of not less than 90° C./sec, such that the strip has a yield strength of greater than 450 MPa. The strip after casting and before cooling is passed through a hot rolling mill to reduce the thickness of strip by at least 15% and up to 50%.Type: GrantFiled: September 28, 2001Date of Patent: January 13, 2004Assignee: Nucor CorporationInventors: Lazar Strezov, Kannappar Mukunthan, Walter Blejde, Rama Mahapatra
-
Publication number: 20040003875Abstract: Steel strips and methods for producing strip are provided. The method for producing steel strips comprises continuously casting low carbon, silicon/manganese killed or aluminum killed molten steel into a strip, the molten steel comprising a concentration of residuals of 2.0 equal to or less than about 2.0 wt % is selected with regard to the microstructure of the finished strip to provide a desired yield strength, where the residuals are selected in desired amounts from the group consisting of copper, nickel, chromium, molybdenum and tin, and cooling the strip to transform the strip from austenite to ferrite in a desired temperature range. Cast steel with improved yield strength properties is produced by such method.Type: ApplicationFiled: March 27, 2003Publication date: January 8, 2004Inventors: Lazar Strezov, Kannappar Mukunthan, Walter N. Blejde, Rama Ballav Mahapatra
-
Publication number: 20040003872Abstract: The invention relates to an Al—Zn—Mg—Cu alloy worked product, characterised in that contains (percentage by weight) 1 Mg 4.85-5.35 Mn 0.20-0.50 Zn 0.20-0.45 Si < 0.20 Fe < 0.30 Cu < 0.25 Cr < 0.15 Ti < 0.15 Zr < 0.Type: ApplicationFiled: March 20, 2003Publication date: January 8, 2004Inventors: Georges Pillet, Jerome Guillemenet, Ronan Dif, Christine Henon, Herve Ribes
-
Patent number: 6669789Abstract: A composition and method of making a high-strength low-alloy hot-rolled steel sheet, strip, or plate bearing titanium as the principal or only microalloy strengthening element. The steel is substantially ferritic and has a microstructure that is at least 20% acicular ferrite. The steel has a minimum yield strength of at least 345 MPa (50 ksi) and even over 621 MPa (90 ksi) adding titanium as the lone microalloy element for strengthening, with elongation of 15% and more. Addition of vanadium, niobium, or a combination thereof can result in yield strengths exceeding 621 MPa (90 ksi). Effective titanium content, being the content of titanium in the steel not in the form of nitrides, oxides, or sulfides, is in the range of 0.01 to 0.12% by weight. The manufacturing process includes continuously casting a thin slab and reducing the slab thickness using thermomechanical controlled processing, including dynamic recrystallization controlled rolling.Type: GrantFiled: August 31, 2001Date of Patent: December 30, 2003Assignee: Nucor CorporationInventors: Daniel Geoffrey Edelman, Steven Leonard Wigman
-
Patent number: 6663725Abstract: The present invention relates to a high strength steel sheet consisting essentially of 0.04 to 0.1% C, 0.5% or less Si, 0.5 to 2% Mn, 0.05% or less P, 0.005% or less 0, 0.005% or less S, by weight, having 10 &mgr;m or less of average ferritic grain size, and 20 mm/mm2 or less of generation frequency A, which generation frequency A is defined as the total length of a banded secondary phase structure observed per 1 mm2 of steel sheet cross section along the rolling direction thereof. The steel sheet is manufactured by, for example, a method comprising the steps of: hot-rolling a continuously cast slab having the composition described above at temperatures of Ar3 transformation point or above directly or after reheating thereof; and cooling the hot-rolled steel sheet within 2 seconds down to the temperatures of from 600 to 750° C. at cooling speeds of from 100 to 2,000° C./sec, followed by coiling the cooled steel sheet at temperatures of from 450 to 650° C.Type: GrantFiled: April 5, 2001Date of Patent: December 16, 2003Assignee: NKK CorporationInventors: Tadashi Inoue, Hiroyasu Kikuchi, Sadanori Imada, Takayuki Odake
-
Patent number: 6652670Abstract: The method for manufacturing steel sheet comprises the steps of: rough-rolling to form a sheet bar; finish-rolling the sheet bar to form a steel strip; applying primary cooling and secondary cooling to the finish-rolled steel strip; and coiling the secondary-cooled steel strip. The primary cooling is conducted at cooling speeds of 120° C./sec or more down to the temperatures of from 500 to 800° C. The secondary cooling is conducted at cooling speeds of less than 60° C./sec.Type: GrantFiled: April 18, 2001Date of Patent: November 25, 2003Inventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroyasu Kikuchi, Yasuhide Ishiguro, Sadanori Imada, Toru Inazumi
-
Patent number: 6648991Abstract: Low-alloy carbon steel for the manufacture of seamless pipes having improved resistance to corrosion, particularly the “sweet corrosion” that occurs in the media rich in CO2, for using in exploration and production of oil and/or natural gas. The steel contains: 1.5-4.0% by weight of Cr, 0.06-0.10% by weight of C, 0.3-0.8% by weight of Mn, not more than 0.005% by weight of S, not more than 0.015% by weight of P, 0.20-0.35% by weight of Si, 0.25-0.35% by weight of Mo, 0.06-0.9% by weight of V, approximately 0.22% by weight of Cu, approximately 0.001% by weight of Nb, approximately 0.028% by weight of Ti, not more than a total value of O of 25 ppm, with the balance being Fe and unavoidable impurities.Type: GrantFiled: March 13, 2002Date of Patent: November 18, 2003Assignee: Siderca S.A.I.C.Inventors: Gustavo Javier López Turconi, Teresa Estela Pérez, Juan Carlos González
-
Publication number: 20030205302Abstract: A method for manufacturing a steel sheet comprising continuously casting a steel containing 0.04 to 0.2 wt. % C, 0.25 to 2 wt. % Si, 0.5 to 2.5 wt. % Mn, and 0.1 wt. % or less Al to form a slab; hot-rolling by rough-rolling the slab to form a sheet bar and finish-rolling the sheet bar with a reduction in thickness at the final stand of less than 30%, the finish-rolling being completed at a temperature from the Ar3 transformation point to the Ar3 transformation point +60° C.; primary-cooling the hot-rolled steel sheet, the primary cooling being started within 1 second after the completion of hot-rolling and conducting the cooling at a cooling speed of higher than 200° C./sec down to a temperature of Ar3 −30° C. to the Ar1 transformation point; slow cooling or air-cooling the primary-cooled steel sheet at a temperature of the Ar3 transformation point to the Ar1 transformation point at 10° C.Type: ApplicationFiled: May 27, 2003Publication date: November 6, 2003Applicant: NKK CORPORATIONInventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroyasu Kikuchi, Yoshimasa Funakawa, Hiroshi Nakata, Sadanori Imada, Toru Inazumi
-
Patent number: 6635313Abstract: A method of coating dual phase high strength cold rolled steel having controlled amounts of carbon, manganese, and molybdenum is used as a starting material in a galvanizing/galvannealing process. Conditions in a multi-zone furnace of the galvanizing line can be controlled in a conventional manner while still effectively coating the high strength steel. A dual phase high strength steel product is made having a uniform coating of zinc in spite of the high manganese content of the steel.Type: GrantFiled: November 15, 2001Date of Patent: October 21, 2003Assignee: ISG Technologies, Inc.Inventors: Rajendra Pradhan, C. Ramadeva Shastry
-
Patent number: 6632298Abstract: The present invention aims at providing a sophisticated segregation reducing technique which a conventional technique cannot achieve by finding the relationship between the casting structure and the segregation of components at the time of solidification and the heat treatment conditions. That is, the present invention aims at providing material for shadow masks which exhibits excellent quality with respect to streaks. A material for a shadow mask of the present invention is formed of a casting slab for preparing the shadow mask which comprises an Ni—Fe alloy containing 30 to 45% of Ni. The casting slab has a cast structure comprising a columnar crystal and/or a chill crystal in an amount of 99% or more. In particular, it is preferred that the casting slab contains no equiaxed crystal.Type: GrantFiled: February 26, 2002Date of Patent: October 14, 2003Assignees: Toyo Kohan Co., Ltd., Nippon Yakin Kogyo Co., Ltd.Inventors: Syun-ichi Morita, Taizo Sato, Jun Agari, Tsutomu Omori, Tatsuya Itoh, Shigeru Hirata
-
Patent number: 6623573Abstract: The method for manufacturing steel sheet comprises the steps of: forming a sheet bar; forming a steel strip; primary-cooling; air-cooling; secondary-cooling; and coiling. The sheet bar is finish-rolled at finish temperatures of (Ar3 transformation point −20° C.) or more. The primary cooling cools the finish-rolled steel strip at cooling speeds of more than 120° C./sec down to the temperatures ranging from 500 to 800° C.Type: GrantFiled: April 19, 2001Date of Patent: September 23, 2003Assignee: NKK CorporationInventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroyasu Kikuchi, Sadanori Imada
-
Patent number: 6616778Abstract: A process for producing a ferritically rolled steel strip, in which liquid steel is cast in a continuous-casting machine (1) to form a slab and, utilizing the casting heat, is conveyed through a furnace device (7) undergoes preliminary rolling in a preliminary rolling device (10) and, in a final rolling device (14), is finishing-rolled to form the ferritic steel strip with a desired final thickness, in which process, in a completely continuous, an endless or a semi-endless process, the slab is rolled in the austenitic range in the preliminary rolling device (10) and, after rolling in the austenitic range, is cooled to a temperature at which the steel has a substantially ferritic structure, and the strip is rolled, in the final rolling device, at speeds which substantially correspond to the speed at which it enters the final rolling device (14) and the following thickness reduction stages, and in at least one stand of the final rolling device (14), the strip is ferritically rolled at a temperature of between 8Type: GrantFiled: July 6, 2000Date of Patent: September 9, 2003Assignee: Corus Staal BVInventor: André Bodin
-
Publication number: 20030131914Abstract: A welding structural steel product having fine complex precipitates of TiN and CuS is provided which contains, in terms of percent by weight, 0.03 to 0.17%C, 0.01 to 0.05% Si, 0.4 to 2.0% Mn, 0.005 to 0.2% Ti, 0.0005 to 0.1% Al, 0.008 to 0.030% N, 0.0003 to 0.01% B, 0.001 to 0.2% W, 0.1 to 1.5% Cu, at most 0.03% P, 0.003 to 0.05% S, at most 0.005% O, and balance Fe and incidental impurities while satisfying conditions of 1.2≦Ti/N≦2.5, 10≦N/B≦40, 2.5≦Al/N≦7, 6.5≦(Ti+2Al+4B)/N≦14, and 10≦Cu/S≦90, and having a microstructure essentially consisting of a complex structure of ferrite and pearlite having a grain size of 20 &mgr;m or less.Type: ApplicationFiled: July 16, 2002Publication date: July 17, 2003Inventors: Hong-Chul Jeong, Hae-Chang Choi
-
Patent number: 6585030Abstract: Steel strips and methods for producing steel strips are provided. In an illustrated embodiment, a method includes continuously casting molten low carbon steel into a strip of no more than 5 mm thickness having austenite grains that are coarse grains of 100-300 micron width; and providing desired yield strength in the cast strip by cooling the strip to transform the austenite grains to ferrite in a temperature range between 850° C. and 400° C. at a selected cooling rate of at least 0.01° C./sec to produce a microstructure that provides a strip having a yield strength of at least 200 MPa. The low carbon steel produced desired microstructure.Type: GrantFiled: September 28, 2001Date of Patent: July 1, 2003Assignee: Nucor CorporationInventors: Lazar Strezov, Kannappar Mukunthan, Walter Blejde, Rama Mahapatra
-
Patent number: 6585799Abstract: A cast steel with excellent workability, characterized in that not less than 60% of the total cross section thereof is occupied by equiaxed crystals, the diameters (mm) of which satisfy the following formula: D<1.2X1/3+0.75, wherein D designates each diameter (mm) of equiaxed crystals in terms of internal structure in which the crystal orientations are identical, and X the distance (mm) from the surface of the cast steel. The cast steel and the steel material obtained by processing the cast steel have very few surface flaws and internal defects.Type: GrantFiled: December 7, 2000Date of Patent: July 1, 2003Assignee: Nippon Steel CorporationInventors: Masafumi Zeze, Takashi Morohoshi, Ryusuke Miura, Shintaro Kusunoki, Yasuhiro Kinari, Masayuki Abe, Hiroshi Sugano, Kenichiro Miyamoto, Masaharu Oka, Yuji Koyama
-
Patent number: 6581672Abstract: A method of controlling a continuous steel strip casting process based on customer-specified requirements includes a general purpose computer in which product specifications of steel product ordered by a customer is entered. The computer is configured to automatically map the product specifications to process parameters/set points for controlling the continuous steel strip casting process in a manner to produce the customer ordered product, and in one embodiment produces a process change report detailing such process parameters/set points for operator use in physically implementing such process parameters/set points in the strip casting process. Alternatively, the computer may provide the process parameters/set points directly to the strip casting process for automatic control thereof in producing the customer ordered steel product.Type: GrantFiled: October 1, 2001Date of Patent: June 24, 2003Assignee: Nucor CorporationInventors: Lazar Strezov, Kannappar Mukunthan, Walter Blejde, Rama Mahapatra
-
Publication number: 20030106621Abstract: A steel strip is produced having a tensile strength of at least 680 MPa but is such that the total elongation to break off of the strip after annealing is in the range 8% to 12%. Cold rolling may produce a cold reduction of the strip thickness in the range 40% to 80%. The continuously cast strip may he optionally in-line hot rolled prior to coiling to produce an initial strip thickness in the range 40% to 60%.Type: ApplicationFiled: December 26, 2002Publication date: June 12, 2003Inventors: Lazar Strezov, Kannappar Mukunthan
-
Patent number: 6558486Abstract: Method of producing strip comprising continuously casting plain carbon steel into a strip of no more than 5 mm thickness and coiling the strip. The strip is subsequently uncoiled and cold rolled then annealed to produce a stress relieved microstructure therein. The cold rolling produces a cold reduction sufficient to increase the tensile strength of the strip to at least 680 MPa but is such that the total elongation to break off the strip after the annealing is in the range 8% to 12%. The cold rolling may produce a cold reduction of the strip thickness in the range 40% to 80%. The continuously cast strip may be optionally in-line hot rolled prior to coiling to produce an initial strip thickness in the range 40% to 60%.Type: GrantFiled: August 31, 2001Date of Patent: May 6, 2003Assignee: Castrip, LLCInventors: Lazar Strezov, Kannappar Mukunthan
-
Patent number: 6544355Abstract: A vitreous enamel steel sheet produced by a continuous casting, excellent in formability, bubbling and black spot resistance and adhesiveness, which comprises, in terms of mass %, 0.002% or less of C, 0.05 to 0.2% of Mn, 0.01% or less of Si, 0.004% or less of N, 0.015 to 0.05% of 0, less than 0.01% of P, 0.025% or less of S, 0.02 to 0.04% of Cu, 0.03 to 0.05% of Nb, and 0.03 to 0.07% of V, satisfying the inequality: 0.2>Mn (%)−2.0·O (%)+0.8·V (%)+0.5·Nb (%), and the balance consisting of Fe and unavoidable impurities, and a method for producing the same.Type: GrantFiled: March 12, 2001Date of Patent: April 8, 2003Assignee: Nippon Steel CorporationInventors: Satoshi Nishimura, Masayoshi Suehiro, Shiro Sanagi
-
Patent number: 6544354Abstract: The object of the present invention is to provide high-strength steel sheets exhibiting high impact energy absorption properties, as steel sheets to be used for shaping and working into such parts to front side members which absorb impact energy upon collision, as well as a method for their production.Type: GrantFiled: July 28, 1999Date of Patent: April 8, 2003Assignee: Nippon Steel CorporationInventors: Osamu Kawano, Junichi Wakita, Yuzo Takahashi, Hidesato Mabuchi, Manabu Takahashi, Akihiro Uenishi, Yukihisa Kuriyama, Riki Okamoto, Yasuharu Sakuma
-
Publication number: 20030062101Abstract: A steel material excellent in weathering resistance by defining the chemical ingredients in the steel each to a predetermined range and setting an ingredient parameter formula in accordance with the working circumstance thereby reducing the flow rust and, particularly, forming stable rust with good protective property even in a salty circumstance such as in coast districts is provided.Type: ApplicationFiled: September 9, 2002Publication date: April 3, 2003Applicant: KAWASAKI STEEL CORPORATIONInventors: Tatsumi Kimura, Kazuhiko Shiotani, Fumimaru Kawabata, Keniti Amano
-
Patent number: 6533876Abstract: Process for producing a steel strip or sheet, in which liquid steel is cast in a continuous-casting machine to form a thin plate and, while making use of the casting heat, is fed through a furnace device, is roughed in a roughing stand to a pass-over thickness and is rerolled in a finishing rolling stand to form a steel strip or sheet of the desired final thickness, in which (a) to produce a ferritically rolled steel strip, the strip, the plate or a part thereof is fed without interruption at least from the furnace device, at speeds which essentially correspond to the speed of entry into the roughing stand and the following reductions in thickness, from the roughing stand to a processing device which is disposed downstream of the finishing rolling stand, the strip coming out of the roughing stand being cooled to a temperature at which the steel has an essentially ferritic structure; (b) to produce an austenitically rolled steel strip, the strip coming out of the roughing roll is brought to or held at a temperType: GrantFiled: September 3, 1999Date of Patent: March 18, 2003Assignee: Corus StaalInventors: Marcus Cornelis Maria Cornelissen, Aldricus Maria Groot, Huibert Willem Den Hartog
-
Patent number: 6527882Abstract: A method and an installation for the endless production of hot-rolled, flat products from thin cast strip. The installation includes a casting machine for producing cast strip, a device for cooling the cast strip under inert gas, a single-stand roughing train, a multi-stand finishing train, a device for cooling, heating or maintaining the temperature of the hot-rolled strip, according to choice, between the roughing train and the finishing train, shears for separating the hot-rolled strip from coil to coil, a delivery roller table with devices for cooling the hot-rolled strip and with coiling machines arranged downstream of the finishing train for coiling up the finished strip.Type: GrantFiled: August 15, 2000Date of Patent: March 4, 2003Assignees: SMS Demag AG, Salzgitter AGInventors: Harald Wehage, Ulrich Skoda-Dopp, Horst Jacobi
-
Patent number: 6524408Abstract: To produce sheet steel components optimised for loading, a steel strip is cast between two cooled rolls with a variable nip and the thickness of the steel strip is changed by changing the time of contact between the strand shells and the rolls or by changing the cooling intensity of the rolls on the molten steel cast into the gusset formed by the rolls, thereby changing the thickness of the steel strip. Such a strip has a homogeneous structure and can subsequently be given a special quality by hot or cold rolling for its particular purpose of use.Type: GrantFiled: June 18, 2001Date of Patent: February 25, 2003Assignee: Thyssen Krupp Stahl AGInventors: Wilhelm Schmitz, Dieter Senk, Ulrich Albrecht-Früh, Reiner Kopp
-
Patent number: 6524726Abstract: Disclosed is a cold-rolled steel sheet excellent in formability, panel shapeability and dent-resistance, comprising 0.005 to 0.015% by weight of C, 0.01 to 0.2% by weight of Si, 0.2 to 1.5% by weight of Mn, 0.01 to 0.07% by weight of P, 0.006 to 0.015% by weight of S, 0.01 to 0.08% by weight of sol. Al, not higher than 0.004% by weight of N (N≦0.004%), not higher than 0.003% by weight of O (O≦0.003%), 0.04 to 0.23% by weight of Nb, 1.0≦(Nb %×12)/(C %×93)≦3.0, and a balance of Fe and unavoidable impurities, said cold-rolled steel sheet meeting the relationship given below: exp(&egr;)×(5.29×exp(&egr;)−4.19)≦&sgr;/&sgr;0.2≦exp(&egr;)×(5.64×exp(&egr;)−4.49) where 0.002<&egr;≧0.096, &egr; represents a true strain, &sgr;0.2 represents a 0.2% proof stress, and &sgr; represents a true stress relative to &egr;.Type: GrantFiled: December 23, 1999Date of Patent: February 25, 2003Assignee: NKK CorporationInventors: Fusato Kitano, Masaya Morita, Yoshihiro Hosoya, Takeshi Fujita, Tadashi Inoue, Masahiro Iwabuchi, Takeo Ishii
-
Publication number: 20030019549Abstract: Low-alloy carbon steel for the manufacture of seamless pipes having improved resistance to corrosion, particularly the “sweet corrosion” that occurs in the media rich in CO2, for using in exploration and production of oil and/or natural gas. The steel contains: 1.5-4.0% by weight of Cr, 0.06-0.10% by weight of C, 0.3-0.8% by weight of Mn, not more than 0.005% by weight of S, not more than 0.015% by weight of P, 0.20-0.35% by weight of Si, 0.25-0.35% by weight of Mo, 0.06-0.9% by weight of V, approximately 0.22% by weight of Cu, approximately 0.001% by weight of Nb, approximately 0.028% by weight of Ti, not more than a total value of O of 25 ppm, with the balance being Fe and unavoidable impurities.Type: ApplicationFiled: March 13, 2002Publication date: January 30, 2003Inventors: Gustavo Javier Lopez Turconi, Teresa Estela Perez, Juan Carlos Gonzalez
-
Publication number: 20030015260Abstract: A cast steel with excellent workability, characterized in that not less than 60% of the total cross section thereof is occupied by equiaxed crystals, the diameters (mm) of which satisfy the following formula:Type: ApplicationFiled: August 16, 2002Publication date: January 23, 2003Applicant: Nippon Steel CorporationInventors: Masafumi Zeze, Takashi Morohoshi, Ryusuke Miura, Shintaro Kusunoki, Yasuhiro Kinari, Masayuki Abe, Hiroshi Sugano, Kenichiro Miyamoto, Masaharu Oka, Yuji Koyama
-
Patent number: 6506268Abstract: A process of producing a high toughness iron-based amorphous alloy strip, using a single roll liquid quenching method, the strip having a thickness of more than 55 &mgr;m up to 100 &mgr;m and a width of 20 mm or more and having a fracture strain &egr;f satisfying the relationship &egr;f>0.1 where &egr;f=t/(D-t), t=thickness of the strip, and D=bent diameter upon fracture, &egr;f being determined by bending the strip with a free cooling surface thereof facing outward, the process comprising the steps of: ejecting a molten metal alloy through a nozzle; applying the ejected molten metal alloy to a surface of a rotating roll; allowing the applied molten metal alloy to be quenched by the roll surface to form an amorphous strip of the metal alloy, the strip being quenched at a cooling rate, determined at a free surface thereof, of 103° C./sec or more in a temperature range of from 500° C. to 200° C.; and continuously coiling the quenched strip at a temperature of 200° C.Type: GrantFiled: October 30, 1996Date of Patent: January 14, 2003Assignee: Nippon Steel CorporationInventors: Hiroaki Sakamoto, Toshio Yamada, Takashi Sato
-
Patent number: 6494969Abstract: The present invention relates to a very low C—Nb cold rolled steel sheet giving 340 to 440 MPa of tensile strength. For example, the cold rolled steel sheet consists essentially of 0.0040 to 0.01% C, not more than 0.05% Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, not more than 0.02% S, 0.01 to 0.1% sol.Al, not more than 0.004% N, 0.01 to 0.14% Nb, by weight, and balance of substantially Fe and inevitable impurities, and has not less than 0.21 of n value calculated from two points (1% and 10%) of nominal strain determined by the uniaxial tensile test, and relates to a method for manufacturing the cold rolled steel sheet. The present invention provides a high strength cold rolled steel sheet for automobile exterior panels having excellent combined formability, resistance to embrittlement during secondary operation, formability at welded portions, anti-burring performance, good surface appearance, and uniformity of material in a coil.Type: GrantFiled: August 3, 2000Date of Patent: December 17, 2002Assignee: NKK CorporationInventors: Takeshi Fujita, Fusato Kitano, Yoshihiro Hosoya, Toru Inazumi, Yuji Yamasaki, Masaya Morita, Yasunobu Nagataki, Kohei Hasegawa, Hiroshi Matsuda, Moriaki Ono
-
Patent number: 6491771Abstract: A process and device for the production of continuously cast billets in a production plant employs a vertical, round strand-casting machine with horizontal run-out, at least one descaling device, and several following roll stands. For the production of round billets with diameters in the range of 90-300 mm, after the solidifying round billet has left the mold but before it has entered the following rolling unit, its surface is descaled and the area near the surface is cooled in defined manner to a temperature which is optimum for the grade of steel in question before the round billet is worked, first over the course of at least three successive horizontal passes then in a vertical pass, the surface of the preworked billet being descaled again before the last pass.Type: GrantFiled: August 3, 2001Date of Patent: December 10, 2002Assignee: SMS Demag AGInventors: Ingo von Hagen, Harald Wehage, Uwe Quitmann, Walter Weischedel
-
Patent number: 6478899Abstract: A stainless steel band is continuously cast. The stainless steel band is descaled and cold rolled. The cold rolled band is annealed and descaled or bright annealed. The band is finish formed and finally coiled. The stainless steel band is not coiled after being continuously cast and before being finally coiled.Type: GrantFiled: October 10, 2000Date of Patent: November 12, 2002Assignee: Ugine S.A.Inventors: Hugues Legrand, Luc Vendeville, Jean Veyer, Francis Chassagne, Jean-Michel Damasse, Yann Breviere, Henri Giraud, Jean-Pierre Malingriaux, Michel Ternisien, Bernard Tetu, Bernard Vialatte