Including Cooling (e.g., Quenching, Etc.) Patents (Class 148/654)
  • Patent number: 10738366
    Abstract: The present invention provides electric-resistance welded steel pipe optimal for applications such as production of shale gas which is comprised of steel having a chemical composition which contains, by mass %, respectively, C: 0.08 to 0.18%, Si: 0.01% to 0.50%, Mn: 1.30 to 2.1%, Al: 0.001 to 0.10%, Nb: 0.005 to 0.08%, and Ti: 0.005 to 0.03%, is limited to N 0.008% or less, P: 0.020% or less, and S: 0.010% or less, and has a balance of Fe and unavoidable impurities, wherein a structure at a center part of thickness is 40% to 70% by area of ferrite phase having a circle-equivalent diameter of 1.0 ?m to 10.0 ?m and a balance of a low temperature transformation phase comprising a bainite phase, and Ceq satisfies 0.32?Ceq?0.60.
    Type: Grant
    Filed: December 20, 2013
    Date of Patent: August 11, 2020
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Hideki Hamatani, Keinosuke Iguchi, Masakazu Ozaki, Takaaki Fukushi, Takuya Asano
  • Patent number: 10697039
    Abstract: Provided are a high-strength steel sheet and a method for manufacturing the steel sheet. The high-strength steel sheet has a specified chemical composition with the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 25% or less of a ferrite phase, 75% or more of a bainite phase and/or a martensite phase, and 5% or less of cementite, in which, in a surface layer that is a region within 50 ?m from the surface in the thickness direction, the area ratio of a ferrite phase is 5% to 20%, and a tensile strength is 1180 MPa or more.
    Type: Grant
    Filed: August 28, 2015
    Date of Patent: June 30, 2020
    Assignee: JFE Steel Corporation
    Inventors: Nobusuke Kariya, Yoshihiko Ono, Yoshimasa Funakawa, Kazuma Mori, Reiko Sugihara, Kenji Kawamura
  • Patent number: 10563281
    Abstract: A heat-treated steel sheet member having a composition including, by mass %: C: 0.05 to 0.50%; Si: 0.50 to 5.0%; Mn: 1.5 to 4.0%; P: 0.05% or less; S: 0.05% or less; N: 0.01% or less; Ti: 0.01 to 0.10%; B: 0.0005 to 0.010%; Cr: 0 to 1.0%; Ni: 0 to 2.0%; Cu; 0 to 1.0%; Mo: 0 to 1.0%; V: 0 to 1.0%; Ca: 0 to 0.01%; Al: 0 to 1.0%; Nb: 0 to 1.0%; REM: 0 to 0.1%; and the balance: Fe and impurities. The steel sheet member has a microstructure comprising mainly martensite and retained austenite of which a volume ratio is 0.2 to 1.0%, a number density of retained carbide in the steel sheet member having circle-equivalent diameters of 0.1 mm or larger is 4.0×103/mm2 or lower, a tensile strength is 1.4 GPa or higher, and a yield ratio is 0.65 or higher.
    Type: Grant
    Filed: April 7, 2016
    Date of Patent: February 18, 2020
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Yoshihiro Suwa, Shinichiro Tabata, Masafumi Azuma, Kazuo Hikida
  • Patent number: 10487372
    Abstract: A high-strength bolt is provided that has high strength and excellent hydrogen embrittlement resistance characteristics. A bolt according to this invention has a chemical composition consisting of, in mass %, C: 0.22 to 0.40%, Si: 0.10 to 1.50%, Mn: 0.20 to less than 0.40%, P: 0.020% or less, S: 0.020% or less, Cr: 0.70 to 1.45%, Al: 0.005 to 0.060%, Ti: 0.010 to 0.045%, B: 0.0003 to 0.0040%, N: 0.0015 to 0.0080% and O: 0.0020% or less, with a balance being Fe and impurities, and satisfying Formula (1) and Formula (2), and with the high-strength bolt having a tensile strength of 1000 to 1300 MPa. 0.50?C+Si/10+Mn/5+5Cr/22?0.85??(1) Si/Mn>1.0??(2) Where, a content (mass %) of a corresponding element is substituted for each symbol of an element in Formula (1) and Formula (2).
    Type: Grant
    Filed: November 15, 2016
    Date of Patent: November 26, 2019
    Assignee: Nippon Steel Corporation
    Inventors: Yutaka Neishi, Naoyuki Sano, Naoki Matsui
  • Patent number: 10421112
    Abstract: A mold for hot stamping is disclosed. The mold may include: a base plate configured to receive and exhaust coolant, at least one lower mold and at least one upper mold. The at least one lower mold may be mounted at a surface of the base plate, and configured to receive the coolant from the base plate. The lower mold may also have the same shape as a lower shape of a product so as to form the lower shape of the product during hot stamping. The upper mold is made of material different from that of the lower mold, coupled to an upper portion of the lower mold, has the same shape as an upper shape of the product so as to form the upper shape of the product, and is configured to receive the coolant from the lower mold such that the coolant flows in the upper mold.
    Type: Grant
    Filed: October 12, 2015
    Date of Patent: September 24, 2019
    Assignee: Hyundai Motor Company
    Inventor: Seung Sang Lee
  • Patent number: 9896748
    Abstract: A steel composition and method from making a dual phase steel therefrom. The dual phase steel may have carbon of about 0.05% by weight to about 0.12 wt %; niobium of about 0.005 wt % to about 0.03 wt %; titanium of about 0.005 wt % to about 0.02 wt %; nitrogen of about 0.001 wt % to about 0.01 wt %; silicon of about 0.01 wt % to about 0.5 wt %; manganese of about 0.5 wt % to about 2.0 wt %; and a total of molybdenum, chromium, vanadium and copper less than about 0.15 wt %. The steel may have a first phase consisting of ferrite and a second phase having one or more of carbide, pearlite, martensite, lower bainite, granular bainite, upper bainite, and degenerate upper bainite. A solute carbon content in the first phase may be about 0.01 wt % or less.
    Type: Grant
    Filed: January 30, 2012
    Date of Patent: February 20, 2018
    Assignee: Exxon Mobil Upstream Research Company
    Inventors: Jayoung Koo, Narasimha-Rao V. Bangaru, Swarupa Soma Bangaru, Hyun-Woo Jin, Adnan Ozekcin, Raghavan Ayer, Douglas P. Fairchild, Danny L. Beeson, Douglas S. Hoyt, James B. LeBleu, Jr., Shigeru Endo, Mitsuhiro Okatsu, Shinichi Kakihara, Moriyasu Nagae
  • Patent number: 9896823
    Abstract: The present disclosure relates to a cast steel for construction equipment bucket parts and parts for a construction equipment bucket manufactured by using the same, and the cast steel includes 0.27 to 0.34 wt % of carbon (C), 1.2 to 1.8 wt % of chromium (Cr), 0.8 to 1.7 wt % of silicon (Si), 1.0 to 1.4 wt % of manganese (Mn), 0.2 to 0.4 wt % of molybdenum (Mo), 0.2 to 0.4 wt % of nickel (Ni), and a balance of iron and impurities.
    Type: Grant
    Filed: September 11, 2014
    Date of Patent: February 20, 2018
    Assignee: Doosan Infracor Co., Ltd.
    Inventors: Choung Rae Lee, Sang Min An, Young Ji Shim, Seok Won Song, Dong Seob Shim
  • Patent number: 9856548
    Abstract: The invention relates to a hot-rolled steel sheet having a tensile strength of greater than 1200 MPa, an Re/Rm ratio of less than 0.75 and an elongation at break of greater than 10%, the composition of which contains, the contents being expressed by weight: 0.10%?C?0.25%; 1%?Mn?3%; Al?0.015%; Si?1.985%; Mo?0.30%; Cr?1.5%; S?0.015%; P?0.1%; Co?1.5%; B?0.005%; it being understood that 1%?Si+Al?2%; Cr+(3×Mo)?0.3%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the microstructure of the steel consisting of at least 75% bainite, residual austenite in an amount equal to or greater than 5% and martensite in an amount equal to or greater than 2%.
    Type: Grant
    Filed: February 14, 2007
    Date of Patent: January 2, 2018
    Assignee: ArcelorMittal France
    Inventors: Sebastien Allain, Audrey Couturier, Thierry Iung, Christine Colin
  • Patent number: 9611518
    Abstract: Provided is a hot-press molded article that can achieve a high level of balance between high strength and extension by region and has a region corresponding to an energy absorption site and a shock resistant site within a single molded article without applying a welding method by means of having first region having a metal structure containing both 80-97 area % of martensite and 3-20 area % of residual austenite, the remaining structure comprising no more than 5 area %, and a second region having a metal structure comprising 30-80 area % of ferrite, less than 30 area % (exclusive of 0 area %) of bainitic ferrite, no greater than 30 area % (exclusive of 0 area %) of martensite, and 3-20 area % of residual austenite.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: April 4, 2017
    Assignee: Kobe Steel, Ltd.
    Inventors: Junya Naitou, Toshio Murakami, Shushi Ikeda, Keisuke Okita
  • Patent number: 9522485
    Abstract: A mold material having a material hardness higher than 340 HB and a fine-grain structure. The mold material having a composition in weight percent that includes: C=0.25-0.35 Si=0.04-0.20 Mn=1.00-2.00 Cr=1.00-2.00 Ni=0.30-less than 0.90 Mo=0.30-0.80 V=less than/equal to 0.20 Al=0.01-0.03 N=0.0025-0.0150 S=less than 0.15 a remainder of Fe and impurities.
    Type: Grant
    Filed: March 29, 2013
    Date of Patent: December 20, 2016
    Assignee: BUDERUS EDELSTAHL GMBH
    Inventor: Peter Vetter
  • Patent number: 9308953
    Abstract: In a method of making a motor vehicle body structure, at least one region of a sheet metal plate of hardenable steel sheet is pierced using a blanking and/or cutting process. The at least one region of the sheet metal plate is preformed into a preform which is then hot formed in a hot forming tool and press hardened.
    Type: Grant
    Filed: October 24, 2012
    Date of Patent: April 12, 2016
    Assignee: BENTELER AUTOMOBILTECHNIK GMBH
    Inventor: Wilhelm Arns
  • Patent number: 9039962
    Abstract: A steel for an induction hardening including, by mass %, C: more than 0.75% to 1.20%, Si: 0.002 to 3.00%, Mn: 0.20 to 2.00%, S: 0.002 to 0.100%, Al: more than 0.050% to 3.00%, P: limited to 0.050% or less, N: limited to 0.0200% or less, O: limited to: 0.0030% or less, and the balance composing of iron and unavoidable impurities, wherein an Al content and a N content satisfy, by mass %, Al?(27/14)×N>0.050%.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: May 26, 2015
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Manabu Kubota, Toshiharu Aiso, Kei Miyanishi
  • Patent number: 9028626
    Abstract: A method of manufacturing a high-strength galvanized steel sheet includes hot-rolling a slab to form a steel sheet; during continuous annealing, heating the steel sheet to a temperature of 750° C. to 900° C. at an average heating rate of at least 10° C./s at a temperature of 500° C. to an A1 transformation point; holding that temperature for at least 10 seconds; cooling the steel sheet from 750° C. to a temperature of (Ms point—100° C.) to (Ms point—200° C.) at an average cooling rate of at least 10° C./s; reheating the steel sheet to a temperature of 350° C. to 600° C.; holding that temperature for 10 to 600 seconds; and galvanizing the steel sheet.
    Type: Grant
    Filed: March 25, 2013
    Date of Patent: May 12, 2015
    Assignee: JFE Steel Corporation
    Inventors: Tatsuya Nakagaito, Saiji Matsuoka, Shinjiro Kaneko, Yoshiyasu Kawasaki, Yoshitsugu Suzuki
  • Patent number: 8999078
    Abstract: A forging heat resistant steel of an embodiment contains in percent by mass C: 0.05-0.2, Si: 0.01-0.1, Mn: 0.01-0.15, Ni: 0.05-1, Cr: 8 or more and less than 10, Mo: 0.05-1, V: 0.05-0.3, Co: 1-5, W: 1-2.2, N: 0.01 or more and less than 0.015, Nb: 0.01-0.15, B: 0.003-0.03, and a remainder comprising Fe and unavoidable impurities.
    Type: Grant
    Filed: December 23, 2011
    Date of Patent: April 7, 2015
    Assignees: Kabushiki Kaisha Toshiba, The Japan Steel Works, Ltd.
    Inventors: Masayuki Yamada, Reki Takaku, Haruki Ohnishi, Kenichi Okuno, Kenichi Imai, Kazuhiro Miki, Tsukasa Azuma, Satoru Ohsaki
  • Patent number: 8992697
    Abstract: A high strength press-formed member includes a steel sheet constituting the member including a composition including by mass %, C: 0.12% to 0.69%, Si: 3.0% or less, Mn: 0.5% to 3.0%, P: 0.1% or less, S: 0.07% or less, Al: 3.0% or less, N: 0.010% or less, Si+Al: at least 0.
    Type: Grant
    Filed: February 28, 2011
    Date of Patent: March 31, 2015
    Assignee: JFE Steel Corporation
    Inventors: Hiroshi Matsuda, Yoshimasa Funakawa, Yasushi Tanaka
  • Patent number: 8980019
    Abstract: A steel rail includes: by mass %, higher than 0.85% to 1.20% of C; 0.05% to 2.00% of Si; 0.05% to 0.50% of Mn; 0.05% to 0.60% of Cr; P?0.0150%; and the balance consisting of Fe and inevitable impurities, wherein 97% or more of a head surface portion which is in a range from a surface of a head corner portion and a head top portion as a starting point to a depth of 10 mm has a pearlite structure, a Vickers hardness of the pearlite structure is Hv320 to 500, and a CMn/FMn value which is a value obtained by dividing CMn [at. %] that is a Mn concentration of a cementite phase in the pearlite structure by FMn [at. %] that is a Mn concentration of a ferrite phase is equal to or higher than 1.0 and equal to or less than 5.0.
    Type: Grant
    Filed: June 7, 2011
    Date of Patent: March 17, 2015
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Masaharu Ueda, Jun Takahashi, Akira Kobayashi, Takuya Tanahashi
  • Patent number: 8968496
    Abstract: In a press-hardening plant, a contact-cooling press (12) is provided between the furnace (11) and the press-hardening press (13). Preselected parts of the blank (18) are contact-cooled such that corresponding parts of the finished product are softer and display a lower yield point.
    Type: Grant
    Filed: February 17, 2011
    Date of Patent: March 3, 2015
    Assignee: Gestamp Hardtech AB
    Inventors: Jan Larsson, Paul Akerstrom, Daniel Berglund
  • Publication number: 20150047753
    Abstract: The invention relates to a method for producing a component from transformable steel by hot forming, in which a plate first is cut out of a strip or sheet as the pre-material, and is then heated to forming temperature and pre-formed, having an at least partially martensitic transformation structure after forming. Instead of a press mould hardening, the at least partially martensitic transformation structure is created in the pre-material, or in the plate to be formed, by austenitisation and quenching already before forming, and then the thus-conditioned plate is reheated after forming, while maintaining the at least partially martensitic transformation structure, to a temperature below the Ac1 transformation temperature, and formed at this temperature.
    Type: Application
    Filed: February 27, 2013
    Publication date: February 19, 2015
    Inventors: Friedrich Luther, Thomas Evertz, Stefan Muetze, Michael Braun
  • Patent number: 8945319
    Abstract: Provided is a manufacturing method of a hot-rolled steel sheet which enables manufacturing of a hot-rolled steel sheet having excellent surface properties and a fine structure. The manufacturing method of a hot-rolled steel sheet uses a heating device, descaling device, row of finishing mills, cooling device disposed in the row of finishing mills, and rapid cooling device disposed immediately after the row of finishing mills, and the operations of the heating device, cooling device and rapid cooling device are controlled, thereby controlling a temperature T1 of the material to be rolled on an entry side of the row of finishing mills, a temperature T2 of the material to be rolled on an entry side of a final stand in the row of finishing mills, and a temperature T3 of the material to be rolled on an exit side of the rapid cooling device.
    Type: Grant
    Filed: August 29, 2012
    Date of Patent: February 3, 2015
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Hisayoshi Tachibana, Shigemasa Nakagawa
  • Publication number: 20150027601
    Abstract: A method for producing partially hardened steel components in which a blank composed of a hardenable sheet steel is subjected to a temperature increase and shaped into a component; the component is transferred to a tool in which the heated component is cooled and thus quench hardened; during the heating of the blank or component in order to achieve the temperature increase to a temperature required for the hardening in regions that are to have a lower hardness and/or higher ductility, cooling elements are spaced apart from the surface by a small gap; the cooling element is dimensioned so that the thermal energy acting on the region that remains ductile flows through the component into the cooling element, characterized in that in order to space the cooling element apart from the component, micro-nubs or knobs are used, which are distributed over the area of the cooling element.
    Type: Application
    Filed: July 25, 2014
    Publication date: January 29, 2015
    Inventors: Andreas Sommer, Tobias Hägele, Reiner Kelsch, Dieter Hartmann
  • Patent number: 8940111
    Abstract: In a first step of the method of achieving TRIP microstructure in steels by deformation heat, steel feedstock is heated to a temperature below the temperature at which austenite begins to form in the steel in question, i.e. below AC1. In a next step, the feedstock is formed into a final product, using applied severe plastic deformation whereby deformation energy causes the temperature of the material to increase to the final temperature between AC1 and AC3, and whereupon the ferrite-pearlite microstructure transforms into austenite. In a third or last process step, the final product is cooled down from the final temperature to the temperature of the bainite nose of the material (B). The cooling is then interrupted and the material is held at the temperature of the bainite nose (B). Consequently, the TRIP microstructure forms. Finally, the product is cooled down to ambient temperature.
    Type: Grant
    Filed: September 28, 2012
    Date of Patent: January 27, 2015
    Assignee: Západo{hacek over (c)}eská Univerzita V Plzni
    Inventors: Bohuslav Ma{hacek over (s)}ek, Hana Jirková, Andrea Rone{hacek over (s)}ová, {hacek over (S)}t{hacek over (e)}pán Jení{hacek over (c)}ek, Ctibor {hacek over (S)}tádler
  • Patent number: 8926771
    Abstract: Process for manufacturing seamless precision steel tubes with improved isotropic toughness at low temperature for hydraulic cylinders comprising the following steps; —(i) providing a steel having a composition comprising 0.06-0.15% by weight of carbon, 0.30-2.5% by weight of Mn, and 0.10-0.
    Type: Grant
    Filed: June 29, 2006
    Date of Patent: January 6, 2015
    Assignee: Tenaris Connections Limited
    Inventors: Gianmario Agazzi, Emanuele Paravicini Bagliani, Andrea Poli
  • Patent number: 8920582
    Abstract: A steel material which is suitable for hot press working or hot three-dimensional bending and direct quench and which can be used to manufacture a high-strength formed article with sufficient quench hardening even by short time heating at a low temperature has a chemical composition comprising, in mass percent, C: 0.05-0.35%, Si: at most 0.5%, Mn: 0.5-2.5%, P: at most 0.03%, S: at most 0.01%, sol. Al: at most 0.1%, N: at most 0.01%, and optionally at least one element selected from the group consisting of B: 0.0001-0.005%, Ti: 0.01-0.1%, Cr: 0.18-0.5%, Nb: 0.03-0.1%, Ni: 0.18-1.0%, and Mo: 0.03-0.5% and has a steel structure in which the spheroidization ratio of carbides is 0.60-0.90.
    Type: Grant
    Filed: August 22, 2012
    Date of Patent: December 30, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Kazuo Hikita, Nobusato Kojima
  • Patent number: 8888934
    Abstract: In a method to produce formed steel parts a primary steel material is provided, which (in % by weight) comprises C: 0.02-0.6%, Mn: 0.5-2.0%, Al: 0.01-0.06%, Si: max. 0.4%, Cr: max. 1.2%, P: max. 0.035%, S: max. 0.035%, and optionally one or more of the elements of the “Ti, Cu, B, Mo, Ni, N” group, with the proviso that Ti: max. 0.05%, Cu: max. 0.01%, B: 0.0008-0.005%, Mo: max. 0.3%, Ni: max. 0.4%, N: max. 0.01%, and the remainder as iron and unavoidable impurities. The primary material is heated through at a heating temperature (TA) lying between the Ac1 and the Ac3 temperature, such that at best incomplete austenitising of the primary material takes place, is placed into a press-form tool and formed therein into the formed steel part. The formed steel part is then heated to a bainite forming temperature (TB), which is above the martensite starting temperature (MS), however below the pearlite transformation temperature of the steel.
    Type: Grant
    Filed: April 24, 2009
    Date of Patent: November 18, 2014
    Assignee: ThyssenKrupp Steel Europe AG
    Inventor: Jian Bian
  • Patent number: 8852367
    Abstract: A method of production of high-strength hollow bodies from multiphase martensitic steels includes a heating process, a forming process and a cooling process. A heating device heats hollow steel stock to the austenitic temperature of the material from which the stock is made. The stock is then converted by deformation in a forming device into a hollow body having the final shape. A cooling device thereafter cools the hollow body such that the material with the original austenite microstructure refined by deformation during the forming process cools to a temperature at which incomplete transformation of austenite to martensite occurs. The retained austenite stabilization is performed in an annealing device by diffusion-based carbon partitioning within the material from which the hollow body is made. The hollow body is cooled in a cooling device to ambient temperature after stabilization.
    Type: Grant
    Filed: February 1, 2012
    Date of Patent: October 7, 2014
    Assignee: Zapadoceska Univerzita v Plzni
    Inventors: Bohuslav Ma{hacek over (s)}ek, Hana Jirková, Pavel Hronek, Ctibor {hacek over (S)}tádler, Miroslav Urbánek
  • Publication number: 20140261918
    Abstract: Improved steel compositions and methods of making the same are provided. The present disclosure provides advantageous wear resistant steel. More particularly, the present disclosure provides high manganese (Mn) steel having enhanced wear resistance, and methods for fabricating high manganese steel compositions having enhanced wear resistance. The advantageous steel compositions/components of the present disclosure improve one or more of the following properties: wear resistance, ductility, crack resistance, erosion resistance, fatigue life, surface hardness, stress corrosion resistance, fatigue resistance, and/or environmental cracking resistance. In general, the present disclosure provides high manganese steels tailored to resist wear and/or erosion.
    Type: Application
    Filed: March 4, 2014
    Publication date: September 18, 2014
    Applicant: ExxonMobil Research and Engineering Company
    Inventors: HyunWoo Jin, Ning Ma, Raghavan Ayer, Russell Robert Mueller, Hak-Cheol Lee, Jong-Kyo Choi, In-Shik Suh
  • Patent number: 8828154
    Abstract: A steel sheet contains, in terms of percent by mass, C: 0.01 to 0.2%, Si: 2.0% or less, and Mn: 3.0% or less and has a martensite phase as dominant phase and ferrite with a grain size of 20 ?m or less as a second phase. The ferrite is contained in area ratio of 1% to 30% and the amount of solute carbon being 0.01 percent by mass of more. The steel sheet can provide a hot-rolled steel sheet suitable for automobile steel sheet, i.e., has excellent press workability and excellent strain aging property whereby the tensile strength significantly increases by heat treatment at about the same temperature as typical baking process after the press-working. Moreover, hardening of the ferrite phase improves the fatigue strength after the strain aging.
    Type: Grant
    Filed: March 29, 2006
    Date of Patent: September 9, 2014
    Assignee: JFE Steel Corporation
    Inventors: Toru Hoshi, Saiji Matsuoka
  • Patent number: 8815147
    Abstract: A cold die steel excellent in the characteristic of suppressing dimensional change, which has a chemical composition in mass %: C: 0.7% or more and less than 1.6%, Si: 0.5 to 3.0%, Mn: 0.1 to 3.0%, P: less than 0.05% including 0%, S: 0.01 to 0.12%, Cr: 7.0 to 13.0%, one or two elements selected from the group consisting of Mo and W: amounts satisfying the formula (Mo+(W/2))=0.5 to 1.7%, V: less than 0.7% including 0, Ni: 0.3 to 1.5%, Cu: 0.1 to 1.0% and Al: 0.1 to 0.7%. Preferably, the die steel satisfies the formula in mass %: Ni/Al=1 to 3.7. It is preferred that the die steel also satisfies the following formula in mass %: (Cr?4.2×C)=5 or less and (Cr?6.3×C)=1.4 or more and that it contains 0.3% or less of Nb.
    Type: Grant
    Filed: December 24, 2008
    Date of Patent: August 26, 2014
    Assignee: Hitachi Metals, Ltd.
    Inventors: Kunichika Kubota, Hideshi Nakatsu, Shugo Komatsubara
  • Patent number: 8784577
    Abstract: A high-tensile-strength hot-rolled steel sheet is provided having a composition which contains 0.02 to 0.08% C, 0.01 to 0.10% Nb, 0.001 to 0.05% Ti and Fe and unavoidable impurities as a balance, wherein the steel sheet contains C, Ti and Nb in such a manner that (Ti+(Nb/2))/C<4 is satisfied, and the steel sheet has a structure where a primary phase of the structure at a position 1 mm away from a surface in a sheet thickness direction is one selected from a group consisting of a ferrite phase, tempered martensite and a mixture structure of a ferrite phase and tempered martensite, a primary phase of the structure at a sheet thickness center position is formed of a ferrite phase, and a difference ?V between a structural fraction (volume %) of a secondary phase at the position 1 mm away from the surface in the sheet thickness direction and a structural fraction (volume %) of a secondary phase at the sheet thickness center position is 2% or less.
    Type: Grant
    Filed: January 29, 2010
    Date of Patent: July 22, 2014
    Assignee: JFE Steel Corporation
    Inventors: Chikara Kami, Hiroshi Nakata, Kinya Nakagawa
  • Patent number: 8778096
    Abstract: Provided is a low yield ratio, high strength and high toughness steel plate having excellent strain ageing resistance equivalent to API 5L X70 Grade or lower and a method for manufacturing the same. The steel plate has a metallographic microstructure that is a three-phase microstructure including bainite, M-A constituent, and quasi-polygonal ferrite, the area fraction of the bainite being 5% to 70%, the area fraction of the M-A constituent being 3% to 20%, the remainder being the quasi-polygonal ferrite, the equivalent circle diameter of the M-A constituent being 3.0 ?m or less. The steel plate has a yield ratio of 85% or less and a Charpy impact test absorbed energy of 200 J or more at ?30° C. before or after being subjected to strain ageing treatment at a temperature of 250° C. or lower for 30 minutes or less.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: July 15, 2014
    Assignee: JFE Steel Corporation
    Inventors: Junji Shimamura, Nobuyuki Ishikawa, Nobuo Shikanai
  • Patent number: 8778101
    Abstract: According to the method of production of a steel sheet pressed part with locally modified properties, the steel sheet blank is first heated in a device for heating to the austenitic temperature of the material. Next, the steel sheet blank is converted in a tool for deep drawing by deformation into a final drawn part. Subsequently, the final drawn part is cooled inside the tool for deep drawing. Various locations of the final drawn part are cooled to various temperatures and/or at various rates during the cooling process. Thereafter, the drawn part is placed in an annealing device, where retained austenite stabilization occurs by diffusion-based carbon partitioning within the material from which the drawn part is made. After stabilization, the final drawn part is removed from the annealing device and air cooled to ambient temperature.
    Type: Grant
    Filed: April 3, 2012
    Date of Patent: July 15, 2014
    Assignee: Zapadoceska Univerzita V Plzni
    Inventors: Bohuslav Maśek, Hana Jirková, Ludmila Kuĉerová, Andrea Rone{grave over (s)}ová, Stépàn Jeniĉek
  • Patent number: 8758528
    Abstract: The present invention provides a high-strength steel plate having excellent resistance to cutting crack, excellent Charpy absorbed energy, excellent DWTT properties, a low yield ratio, and a tensile strength of 900 MPa or more, a method of producing the steel plate, and a high-strength steel pipe using the steel plate. As solving means, a steel plate contains, by % by mass, 0.03 to 0.12% of C, 0.01 to 0.5% of Si, 1.5 to 3% of Mn, 0.01 to 0.08% of Al, 0.01 to 0.08% of Nb, 0.005 to 0.025% of Ti, 0.001 to 0.01% of N, and at least one component of 0.01 to 2% of Cu, 0.01 to 3% of Ni, 0.01 to 1% of Cr, 0.01 to 1% of Mo, and 0.01 to 0.1% of V; wherein the contents of Ca, O, and S satisfy the equation below; the microstructure includes ferrite and a second hard phase, the area fraction of ferrite being 10 to 50%; cementite in the second phase has an average grin size of 0.5 ?m or less; and the total amount of Nb and the like contained in carbides thereof present in steel is 10% or less of the total content in steel.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: June 24, 2014
    Assignee: JFE Steel Corporation
    Inventors: Junji Shimamura, Shigeru Endo, Mitsuhiro Okatsu
  • Patent number: 8747575
    Abstract: A martensitic stainless steel for inexpensive seamless pipe having 655 MPa yield strength, high toughness and excellent corrosion resistance in high CO2 environments, and a method for manufacturing thereof is provided. The steel comprises C: 0.005-0.05%, Si: 0.1-0.5%, Mn: 0.1-2.0%, P: ?0.05%, S: ?0.005%, Cr: 10.0-12.5%, Mo: 0.1-0.5%, Ni: 1.5-3.0%, N: ?0.02%, Al: 0.01-0.1%, by weight, while FI value defined by the formula [FI=Cr+Mo?Ni?30(C+N)] being 5.00 to 8.49, and balance of substantially Fe. The method comprises the steps of reheating the cooled steel at temperatures from 780° C. to 960° C., quenching the reheated steel, and then tempering the quenched steel at temperatures from 550° C. to 650° C.
    Type: Grant
    Filed: December 30, 2009
    Date of Patent: June 10, 2014
    Assignee: NKKTUBES
    Inventors: Shuji Hashizume, Yusuke Minami, Tatsuo Ono
  • Publication number: 20140144560
    Abstract: To establish a method for obtaining a hot-press-formed steel member, which exhibits high strength, high tensile elongation (ductility) and high bendability, thereby having excellent deformation characteristics at the time of collision crush (crashworthiness), and which is capable of ensuring excellent delayed fracture resistance. A method for producing a hot-press-formed steel member by heating a steel sheet, which has a chemical component composition containing 0.10% (% by mass, and hereinafter the same shall apply) to 0.30% (inclusive) of C, 1.0% to 2.5% (inclusive) of Si, 1.0% to 3.0% (inclusive) of Si and Al in total and 1.5% to 3.0% (inclusive) of Mn, with the balance consisting of iron and unavoidable impurities, and hot press forming the steel sheet one or more times.
    Type: Application
    Filed: July 18, 2012
    Publication date: May 29, 2014
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steet, Ltd.)
    Inventors: Takayuki Yamano, Jiro Iwaya, Noriyuki JIMBO, Tatsuya Asai, Naoki Mizuta
  • Patent number: 8734601
    Abstract: A method for hot rolling a metal strip or metal sheet, wherein 1.a) the slab or the strip or sheet is subjected in a first step to one or more reshaping actions in a hot rolling mill for producing a uniform, fine, recrystallised austenite structure and 2) the slab or the strip or sheet is then subjected in a second step to cooling for producing a fine-grain structure. The slab or the strip or sheet is subjected to heating between at least two roll stands of the hot rolling mill during performance of the step 1.a). The roll stands are arranged to follow one another in a rolling direction and in each of which the slab or the strip or sheet is subjected to reshaping. A heater for heating the rolling stock is arranged between at least two of the roll stands.
    Type: Grant
    Filed: December 2, 2010
    Date of Patent: May 27, 2014
    Assignee: SMS Siemag Aktiengesellschaft
    Inventors: Christian Klinkenberg, Christian Bilgen, Dieter Rosenthal, Christoph Klein
  • Patent number: 8715429
    Abstract: There is provided a rolled steel with excellent toughness, a drawn wire rod prepared by drawing the rolled steel, and a method for manufacturing the same, in which even if a heating step is omitted, the toughness of the steel can be improved by securing a degenerated pearlite structure in an internal structure of the rolled steel by controlling a content of Mn among components and cooling conditions, and then preventing C diffusion. The rolled steel according to the present invention includes C: 0.15˜0.30%, Si: 0.1˜0.2%, Mn: 1.8˜3.0%, P: 0.035% or less, S: 0.040% or less, the remainder Fe, and other inevitable impurites, as a percentage of weight, in which the microstucture of the rolled steel is composed of ferrite and pearlite including cementite with 150 nm or less of thickness.
    Type: Grant
    Filed: August 4, 2010
    Date of Patent: May 6, 2014
    Assignee: POSCO
    Inventors: You-Hwan Lee, Dong-Hyun Kim, Sang-Yoon Lee, Ha-Ni Kim, Yong-Sik Park
  • Patent number: 8715432
    Abstract: The present invention provides high temperature strength and fire-resistant steel superior in weld joint reheat embrittlement resistance and toughness which is produced using steel of a room temperature strength of the 400 to 600N/mm2 class containing as main ingredients C: 0.010% to less than 0.05%, Si: 0.01 to 0.50%, Mn: 0.80 to 2.00%, Cr: 0.50% to less than 2.00%, V: 0.03 to 0.30%, Nb: 0.01 to 0.10%, N: 0.001 to 0.010%, and Al: 0.005 to 0.10%, limiting the contents of Ni, Cu, Mo, and B, and satisfying the relationship of 4Cr[%]-5Mo[%]-10Ni[%]-2Cu[%]-Mn[%]>0.
    Type: Grant
    Filed: March 24, 2009
    Date of Patent: May 6, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Yasushi Hasegawa, Masaki Mizoguchi, Yoshiyuki Watanabe, Suguru Yoshida, Tadayoshi Okada
  • Patent number: 8696832
    Abstract: A high-strength hot-rolled steel sheet has a tensile strength (TS) of 540 to 780 MPa, only small variations in strength, and excellent uniformity in strength using a general-purpose Ti-containing steel sheet, which is inexpensive. The high-strength hot-rolled steel sheet includes, on a mass percent basis, 0.05%-0.12% C, 0.5% or less Si, 0.8%-1.8% Mn, 0.030% or less P, 0.01% or less S, 0.005%-0.1% Al, 0.01% or less N, 0.030%-0.080% Ti, and the balance being Fe and incidental impurities. The microstructure have a bainitic ferrite fraction of 70% or more, and the amount of Ti present in a precipitate having a size of less than 20 nm is 50% or more of the value of Ti* calculated using formula (1): Ti*=[Ti]?48/14×[N] (1) where [Ti] and [N] represent a Ti content (percent by mass) and a N content (percent by mass), respectively, of the steel sheet.
    Type: Grant
    Filed: February 4, 2009
    Date of Patent: April 15, 2014
    Assignee: JFE Steel Corporation
    Inventors: Shinjiro Kaneko, Kaneharu Okuda, Tetsuo Shimizu, Noriaki Moriyasu, Masahide Watabe
  • Patent number: 8685181
    Abstract: A carbon steel sheet having high formability due to a microscopic and uniform carbide distribution and having a good characteristic of final heat treatment, and a manufacturing method thereof. The carbon steel sheet having excellent formability includes, in wt %, C at 0.2-0.5%, Mn at 0.1-1.2%, Si at less than or equal to 0.4%, Cr at less than or equal to 0.5%, Al at 0.01-0.1%, S at less than or equal to 0.012%, Ti at less than or equal to 0.5×48/14×[N]% to 0.03% when the condition of B and N is not satisfied, B at 0.0005-0.0080%, N at less than or equal to 0.006%, Fe, and extra inevitable elements; an average size of carbide is less than or equal to 1 ?m; and an average grain size of ferrite is less than or equal to 5 ?m.
    Type: Grant
    Filed: May 15, 2012
    Date of Patent: April 1, 2014
    Assignee: Posco
    Inventors: Kyoo-Young Lee, Gyo-Sung Kim, Han-Chul Shin, Chang-Hoon Lee, Kee-Cheol Park, Jea-Chun Jeon
  • Publication number: 20140083574
    Abstract: Disclosed are heat-hardened steel with excellent crashworthiness and a method for manufacturing heat-hardenable parts using the same. The heat-hardened steel according to the invention comprises, based on wt %; C: 0.12-0.8%; Cr: 0.01-2%; Mo: 0.2% or less; B: 0.0005-0.08%; Ca: 0.01 or less; Sb: 1.0% or less; and Ti and/or Nb: 0.2%; and the reminder being Fe and inevitable impurities. In addition, the heat-treatment hardening steel satisfies anyone of following conditions i)-iv), wherein condition i) comprises Si: 0.5-3%; Mn: 1-10% and Al: 0.05-2%; condition ii) comprises Si: 1% or less; Mn: 0.5-5%; Al: 0.1-2.5%; and Ni: 0.01-8%; condition iii) comprises Si: 0.5-3%; Mn: 1-10%; Al: 0.1% or less; and Ni: 0.01-8%; and condition iv) comprises Si: 0.5-3%; Mn: 1-10%; Al: 0.1-2.5%; and Ni: 0.01-8%.
    Type: Application
    Filed: June 30, 2011
    Publication date: March 27, 2014
    Applicant: Hyundai Hysco Co.,Ltd.
    Inventors: Seung-Man Nam, Hee-Joong Im, Seung-Ha Lee, Dong-Eun Kim, Bo-Ryong Lee, Young-Jin Kim, Man-Been Man-Been
  • Publication number: 20140057130
    Abstract: A flat steel product which is provided for forming into a component by hot pressing and which has a base layer of steel on which is applied a Zn or a Zn alloy metallic protective coating for protecting against corrosion. On at least one of the free surfaces of the flat steel product, a separate cover layer is applied which contains an oxide, nitride, sulphide, carbide, hydrate or phosphate compound of a base metal. In addition, a method which allows the production of such a flat steel product, and a method which allows the production of a component from such a flat steel product.
    Type: Application
    Filed: March 5, 2012
    Publication date: February 27, 2014
    Applicant: THYSSENKRUPP STEEL EUROPE AG
    Inventors: Ken-Dominic Flechtner, Thorsten Koehler, Maria Koeyer, Manfred Meurer, Axel Schrooten
  • Patent number: 8656750
    Abstract: A hot forming die that includes a first die and a second die. The first die has a first die structure that is formed of a tool steel. The first die structure has a first die surface and a plurality of first cooling apertures. The first die surface has a complex shape. The first cooling apertures are spaced apart from the die surface by a first predetermined distance. The second die has a second die surface. The first and second die surfaces cooperate to form a die cavity. Related methods for forming a hot forming die and for hot forming a workpiece are also provided.
    Type: Grant
    Filed: June 12, 2012
    Date of Patent: February 25, 2014
    Assignee: Magna International Inc.
    Inventors: Frank A. Horton, Boris Shulkin, Bradford L. Hastilow, Jim Metz, James R. Judkins, Monty Hansen, Seetarama S. Kotagiri, Andreas G. Janssen
  • Patent number: 8652273
    Abstract: There are provided a steel for deep drawing, and a method for manufacturing the steel and a high pressure container. The steel for deep drawing includes, by weight: C: 0.25 to 0.40%, Si: 0.15 to 0.40%, Mn: 0.4 to 1.0%, Al: 0.001 to 0.05%, Cr: 0.8 to 1.2%, Mo: 0.15 to 0.8%, Ni: 1.0% or less, P: 0.015% or less, S: 0.015% or less, Ca: 0.0005 to 0.002%, Ti: 0.005 to 0.025%, B: 0.0005 to 0.0020% and the balance of Fe and inevitable impurities, wherein a microstructure of the steel has a triphase structure of ferrite, bainite and martensite. The steel for deep drawing may be useful to further improve the strength without the deterioration of the toughness by adding a trace of Ti and B, compared to the conventional steels having a strength of approximately 1100 MPa.
    Type: Grant
    Filed: September 12, 2008
    Date of Patent: February 18, 2014
    Assignee: Posco
    Inventors: Soon Taik Hong, Sung Ho Jang, Ki Hyun Bang
  • Patent number: 8636856
    Abstract: Embodiments of the present disclosure comprise carbon steels and methods of manufacture. In one embodiment, quenching and tempering procedure is performed in which a selected steel composition is formed and heat treated to yield a slightly tempered microstructure having a fine carbide distribution. In another embodiment, a double austenizing procedure is disclosed in which a selected steel composition is formed and subjected to heat treatment to refine the steel microstructure. In one embodiment, the heat treatment may comprise austenizing and quenching the formed steel composition a selected number of times (e.g., 2) prior to tempering. In another embodiment, the heat treatment may comprise subjecting the formed steel composition to austenizing, quenching, and tempering a selected number of times (e.g., 2). Steel products formed from embodiments of the steel composition in this manner (e.g., seamless tubular bars and pipes) will possess high yield strength, e.g.
    Type: Grant
    Filed: February 18, 2011
    Date of Patent: January 28, 2014
    Assignee: Siderca S.A.I.C.
    Inventors: Eduardo Altschuler, Teresa Perez, Edgardo Lopez, Constantino Espinosa, Gonzalo Gomez
  • Patent number: 8628630
    Abstract: A hot-pressed steel sheet member has a composition containing, by mass, C: 0.09% to 0.38%, Si: 0.05% to 2.0%, Mn: 0.5% to 3.0%, P: 0.05% or less, S: 0.05% or less, Al: 0.005% to 0.1%, N: 0.01% or less, Sb: 0.002% to 0.03%, and the balance being Fe and inevitable impurities, and having a tensile strength TS of 980 to 2,130 MPa.
    Type: Grant
    Filed: August 19, 2010
    Date of Patent: January 14, 2014
    Assignee: JFE Steel Corporation
    Inventors: Akio Kobayashi, Yoshimasa Funakawa, Kazuhiro Seto, Nobuyuki Kageyama, Tetsuo Yamamoto, Toru Hoshi, Takeshi Yokota
  • Publication number: 20130340899
    Abstract: The present invention has as its object the provision of steel sheet for hot stamping use which is excellent in part strength after hot stamping and delayed fracture resistance comprised of large C content high strength steel sheet in which effective hydrogen traps are formed in the steel material. The steel sheet of the present invention solves this problem by forming Fe—Mn-based composite oxides in the steel sheet and trapping hydrogen at the interfaces of the composite oxides and matrix steel and in the voids around the composite oxides. Specifically, it provides steel sheet for hot stamping use which is comprised of chemical ingredients which contain, by mass %, C: 0.05 to 0.40%, Si: 0.02% or less, Mn: 0.1 to 3%, S: 0.02% or less, P: 0.03% or less, Al: 0.005% or less, Ti: 0.01% or less, N: 0.01% or less, one or both of Cr and Mo in a total of 0.005 to 1%, and O: 0.003 to 0.03% and which have a balance of Fe and unavoidable impurities and which contains average diameter 0.
    Type: Application
    Filed: March 9, 2011
    Publication date: December 26, 2013
    Inventors: Kazuhisa Kusumi, Yuji Ogawa, Masayuki Abe, Hidekuni Murakami, Kengo Takeda, Jun Maki
  • Patent number: 8613819
    Abstract: The invention relates to a method for producing quenched components consisting of sheet steel, comprising the following steps: a) shaped parts are formed from sheet steel; b) the end of the shaped part is cut and the sheet steel is optionally punched or provided with a desired hole pattern prior to, during, or after the forming of the shaped part; c) at least some sections of the shaped part are subsequently heated to a temperature that permits the steel material to austenitize; and d) the component is then transferred to a quenching die, where it is subjected to a quenching process, during which the component is cooled and thus quenched by the contact of the quenching die with some sections of the component and the compression of said sections. The invention is characterized in that the component is supported by the quenching die in the vicinity of the positive radii and that some sections of said component are clamped in a secure manner without distortion in the vicinity of the cut edges.
    Type: Grant
    Filed: August 9, 2005
    Date of Patent: December 24, 2013
    Assignee: voestalpine Metal Forming GmbH
    Inventor: Robert Vehof
  • Publication number: 20130327453
    Abstract: A method for hot stamping an iron based component in which the component is heated to a temperature sufficient to transform the component into austenite. The heated component is then positioned in an open stamping die and the stamping die is closed to mechanically change the shape of the heated component to a desired end shape of the component. At least one opening is punched in the heated component and, thereafter, the component is quenched at a rate and to a temperature sufficient to transform the component into martensite.
    Type: Application
    Filed: June 12, 2012
    Publication date: December 12, 2013
    Applicant: Martinrea Industries, Inc.
    Inventors: Arpad Takacs, Di Yang, Roger Bianchi
  • Patent number: 8585835
    Abstract: A high-strength steel machined product giving excellent hardenability has a metal microstructure with excellent balance of strength and toughness and high stability of retained austenite. The product is composed of an ultra-high low-alloy TRIP steel having a metal microstructure which contains an appropriate quantity of two or more of Cr, Mo, and Ni, and an appropriate quantity of one or more of Nb, Ti, and V, and having an appropriate value of carbon equivalent; the metal microstructure has a mother-phase structure composed mainly of lathy bainitic ferrite with a small amount of granular bainitic ferrite and polygonal ferrite, and has a secondary-phase structure composed of fine retained austenite and martensite.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: November 19, 2013
    Assignees: Usui Kokusai Sangyo Kaisha Limited, Shinshu University
    Inventors: Koh-ichi Sugimoto, Sho-hei Sato, Teruhisa Takahashi, Goro Arai
  • Publication number: 20130292011
    Abstract: According to one aspect, provided is a high-strength steel sheet having superior toughness at cryogenic temperature, comprising, in weight percentage, 0.02 to 0.06% of C, 0.1 to 0.35% of Si, 1.0 to 1.6% of Mn, 0.02% or less (but not 0%) of Al, 0.7 to 2.0% of Ni, 0.4 to 0.9% of Cu, 0.003 to 0.015% of Ti, 0.003 to 0.02% of Nb, 0.01% or less of P, 0.005% or less of S, the remainder being Fe and unavoidable impurities, wherein the high-strength steel sheet satisfies the condition of [Mn]+5.4[Si]+26[Al]+32.8[Nb]<4.3 where [Mn], [Si], [Al], and [Nb] indicate contents of Mn, Si, Al, and Nb in weight percentage, respectively. The steel sheet secures toughness when used as structural steel materials for ships, offshore structures, or the like, or steel materials for tanks for storing and carrying liquefied gases, which are exposed to an extreme low temperature environment.
    Type: Application
    Filed: December 27, 2011
    Publication date: November 7, 2013
    Applicant: POSCO
    Inventors: Woo-Gyeom Kim, Sang-Ho Kim, Ki-Hyun Bang, In-Shik Suh