Chromium Containing, But Less Than 9 Percent Patents (Class 148/333)
  • Patent number: 11447844
    Abstract: A method for the fabrication of a hot rolled steel includes providing a liquid metal comprising a certain chemical composition; carrying out a vacuum or SiCa treatment, the chemical composition including, expressed by weight 0.0005%?Ca?0.005%, if a SiCA treatment is carried out; dissolving quantities of Ti and N in the liquid metal so as to satisfy (% [Ti])×(% [N])<6.10?4%2; casting the steel to obtain a cast semi-finished product; rolling the cast semi-finished product with an end-of-rolling temperature between 880° C. and 930° C., a reduction rate of the penultimate pass being less than 0.25, and a start-of-rolling temperature of the penultimate pass being less than 960° C. to obtain a hot-rolled product, then cooling the hot rolled product at a rate between 20 and 150° C./s to obtain a hot rolled steel sheet; and coiling the hot rolled product to obtain a hot rolled steel sheet.
    Type: Grant
    Filed: November 3, 2020
    Date of Patent: September 20, 2022
    Assignee: ArcelorMittal
    Inventors: Jean Marc Pipard, Astrid Perlade, Bastien Weber, Florence Pechenot, Aurelie Milani
  • Patent number: 11415599
    Abstract: A contact probe may include a Ni pipe that may include a coiled spring structure, and the Ni pipe 11 may contain 0.5 to 10 wt % of phosphorus (P). The contact probe may have improved durability, by reducing shrinkage, after probing performed in a high temperature environment.
    Type: Grant
    Filed: October 4, 2017
    Date of Patent: August 16, 2022
    Assignee: NIDEC READ CORPORATION
    Inventors: Masami Yamamoto, Norihiro Ota, Shigeki Sakai
  • Patent number: 11390930
    Abstract: A steel sheet and a manufacturing method therefor are provided. A steel sheet has a component composition and contains 6 to 80% of ferrite and 20 to 94% of a microstructure composed of one or two or more of upper bainite, fresh martensite, tempered martensite, lower bainite, and retained ?, and contains 7 to 20% of retained ?, where: an area ratio (S?UB) of retained ? having a particle width of 0.18 to 0.60 ?m, a particle length of 1.7 to 7.0 ?m, and an aspect ratio of 5 to 15 is 0.2 to 5%; and a total area ratio (S?Block) of fresh martensite having an equivalent circle diameter of 1.5 to 15 ?m and an aspect ratio of 3 or less and/or retained ? particles having an equivalent circle diameter of 1.5 to 15 ?m and an aspect ratio of 3 or less is 3% or less (including 0%).
    Type: Grant
    Filed: April 13, 2018
    Date of Patent: July 19, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Yoshihiko Ono, Junya Tobata, Hiroyuki Akimoto
  • Patent number: 11390936
    Abstract: There is provided a spring steel including predetermined chemical composition, in which ([Ti mass %]?3.43×[N mass %])/[S mass %]>4.0, and [Ni mass %]+[Cu mass %]<0.75 are satisfied, and an appearance frequency of MnS is less than 20% among inclusions having an equivalent circle diameter of 1 ?m or more which are observed at a ¼ position of a diameter from a surface.
    Type: Grant
    Filed: January 26, 2017
    Date of Patent: July 19, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Takahisa Suzuki, Suguru Yoshida, Yutaka Neishi
  • Patent number: 11365460
    Abstract: A high-carbon cold rolled steel sheet having a specified chemical composition, and a method for manufacturing the same. The method includes forming a hot rolled steel sheet, performing cooling at an average cooling rate of 30° C./s or more and 70° C./s or less through a temperature range of a finish rolling end temperature to 660° C., coiling a hot rolled steel sheet at a temperature of 500° C. or more and 660° C. or less, and, optionally, pickling the coiled hot rolled steel sheet, and then performing a first box-annealing of holding at an annealing temperature in a temperature range of 650 to 720° C., then performing cold rolling at a rolling reduction ratio of 20 to 50%, and then performing a second box-annealing of holding at an annealing temperature in a temperature range of 650 to 720° C.
    Type: Grant
    Filed: February 20, 2019
    Date of Patent: June 21, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Yuka Miyamoto, Yoichiro Matsui, Shogo Sato, Takeshi Yokota
  • Patent number: 11359267
    Abstract: Provided are a high-carbon hot-rolled steel sheet with excellent formability and hardenability and a method for manufacturing the same. The high-carbon hot-rolled steel sheet has a composition containing, on a mass basis, C: 0.10% to 0.33%, Si: 0.15% to 0.35%, Mn: 0.5% to 0.9%, P: 0.03% or less, S: 0.010% or less, sol. Al: 0.10% or less, N: 0.0065% or less, and Cr: 0.90% to 1.5%, the remainder being Fe and inevitable impurities, has a microstructure containing ferrite and cementite, a cementite density being 0.25 grains/?m2 or less, and has a hardness of 110 HV to 160 HV and a total elongation of 40% or more.
    Type: Grant
    Filed: February 13, 2018
    Date of Patent: June 14, 2022
    Assignee: JFE Steel Corporation
    Inventors: Yuka Miyamoto, Yasuhiro Sakurai, Takashi Kobayashi, Shunsuke Toyoda
  • Patent number: 11143257
    Abstract: A steel wire for a spring includes a steel wire that has Ca or Na adhered thereto in an amount of 0.2 g/m2 or less. The steel wire has an oxide film on a surface thereof, and the oxide film has a thickness of, for example, from 2.0 ?m to 20 ?m.
    Type: Grant
    Filed: January 24, 2017
    Date of Patent: October 12, 2021
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takafumi Uwano, Taketoshi Sasaki, Takao Yamazaki
  • Patent number: 11111566
    Abstract: The steel pipe of the present invention is a low alloy high strength seamless steel pipe for oil country tubular goods including a composition containing, in terms of mass %, C: 0.23 to 0.27%, Si: 0.01 to 0.35%, Mn: 0.45 to 0.70%, P: 0.010% or less, S: 0.001% or less, O: 0.0015% or less, Al: 0.015 to 0.080%, Cu: 0.02 to 0.09%, Cr: 0.8 to 1.5%, Mo: 0.5 to 1.0%, Nb: 0.02 to 0.05%, B: 0.0015 to 0.0030%, Ti: 0.005 to 0.020%, and N: 0.005% or less, and having a ratio of the Ti content to the N content (Ti/N) of 3.0 to 4.0, with the balance being Fe and inevitable impurities, the steel pipe having a ratio of a stress at a strain of 0.7% to a stress at a strain of 0.4% in a stress-strain curve of 1.02 or less and a yield strength of 655 MPa or more.
    Type: Grant
    Filed: August 22, 2018
    Date of Patent: September 7, 2021
    Assignee: JFE Steel Corporation
    Inventors: Mitsuhiro Okatsu, Masao Yuga, Hiroki Ota, Kazuki Fujimura
  • Patent number: 11091825
    Abstract: Provided is a prehardened steel material containing: 0.05?C?0.25 mass %, 0.01?Si?1.00 mass %, 0.40?Mn?1.80 mass %, 0.0002?S?0.3000 mass %, 0.30?Cu?1.80 mass %, 2.00?Ni?3.90 mass %, 0.05?Cr?3.20 mass %, 0.05?Mo?0.80 mass %, and 0.30?Al?1.50 mass %, with a balance being Fe and unavoidable impurities, in which the prehardened steel material has: a cross-sectional size of 350 mm or more in width and 350 mm or more in height, a hardness of 34 to 43 HRC, an average value of prior austenite grain size being 85 ?m or less, and an average value of impact value being 18 J/cm2 or higher.
    Type: Grant
    Filed: April 10, 2018
    Date of Patent: August 17, 2021
    Assignee: DAIDO STEEL CO., LTD.
    Inventor: Masamichi Kawano
  • Patent number: 11015232
    Abstract: A seamless steel tube with high strength and toughness, comprising the following chemical elements by mass: 0.1-0.25% of C, 0.1-0.5% of Si, 0.01-0.1% of Al, 0.6-2% of Mn, the balance of Fe and other unavoidable impurities, wherein C+Mn/6?0.35. Also provided is a method for preparing a seamless steel tube.
    Type: Grant
    Filed: September 21, 2016
    Date of Patent: May 25, 2021
    Assignee: BAOSHAN IRON & STEEL CO., LTD.
    Inventors: Yaoheng Liu, Zhonghua Zhang
  • Patent number: 10995396
    Abstract: A rail according to an aspect of the present invention is manufactured by melting steel using an electric furnace, satisfies a predetermined range as a chemical composition and particularly includes Pb: 0.0003% to 0.0020%, 95 area % or more of a region from an outer surface of a head portion to a depth of 20 mm is a pearlite structure, and a hardness in the region from the outer surface of the head portion to the depth of 20 mm is in a range of Hv 300 to Hv 500.
    Type: Grant
    Filed: May 19, 2017
    Date of Patent: May 4, 2021
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Masaharu Ueda, Teruhisa Miyazaki
  • Patent number: 10995383
    Abstract: A method for producing a high strength coated steel sheet having a yield strength YS of at least 800 MPa, a tensile strength TS of >1180 MPa, a total elongation >14% and a hole expansion ratio HER >30%. The steel contains in weight %: 0.13%?C?0.22%, 1.2%?Si?1.8%, 1.8%?Mn?2.2%, 0.10%?Mo?0.20%, Nb?0.05%, Al?0.5%, the remainder being Fe and unavoidable impurities. The sheet is annealed at a temperature TA higher than Ac3 but less than 1000° C. for more than 30 s, then quenched by cooling temperature QT between 325° C. and 375° C., at a cooling speed sufficient to obtain a structure consisting of austenite and at least 60% of martensite, the austenite content being such that the final structure can contain between 3% and 15% of residual austenite and between 85 and 97% of the sum of martensite and bainite, without ferrite, then heated to a partitioning temperature PT between 430° C. and 480° C.
    Type: Grant
    Filed: July 3, 2015
    Date of Patent: May 4, 2021
    Assignee: ARCELORMITTAL
    Inventors: Dongwei Fan, Hyun Jo Jun, Rashmi Ranjan Mohanty
  • Patent number: 10822677
    Abstract: A forged component having a chemical composition including, by mass %, C: 0.30 to 0.45%, Si: 0.05 to 0.35%, Mn: 0.50 to 0.90%, P: 0.030 to 0.070%, S: 0.040 to 0.070%, Cr: 0.01 to 0.50%, Al: 0.001 to 0.050%, V: 0.25 to 0.35%, Ca: 0 to 0.0100%, N: 0.0150% or less, and the balance being Fe and unavoidable impurities, and satisfying formula 1. Metal structure is a ferrite pearlite structure, and a ferrite area ratio is 30% or more. Vickers hardness is in the range of 320 to 380 HV. 0.2% yield strength is 800 MPa or more. A Charpy V-notch impact value is in the range of 7 to 15 J/cm2.
    Type: Grant
    Filed: March 18, 2014
    Date of Patent: November 3, 2020
    Assignees: AICHI STEEL CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Takeyuki Uenishi, Susumu Owaki, Hisanori Koma, Tomoyasu Kitano, Kazuhiro Tanahashi, Nobuyuki Shinohara
  • Patent number: 10774412
    Abstract: A hot-dip galvanized cold-rolled steel sheet has a tensile strength of 750 MPa or higher, a composition consisting, in mass percent, C: more than 0.10% and less than 0.25%, Si: more than 0.50% and less than 2.0%, Mn: more than 1.50% and 3.0% or less, and optionally containing one or more types of Ti, Nb, V, Cr, Mo, B, Ca, Mg, REM, and Bi, P: less than 0.050%, S: 0.010% or less, sol. Al: 0.50% or less, and N: 0.010% or less, and a main phase as a low-temperature transformation product and a second phase as retained austenite. The retained austenite volume fraction is more than 4.0% and less than 25.0% of the whole structure, and has an average grain size of less than 0.80 ?m. A number density of retained austenite grains having a grain size of 1.2 ?m or more is 3.0×10?2/?m2 or less.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: September 15, 2020
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Norio Imai, Masayuki Wakita, Takuya Nishio, Jun Haga, Kengo Hata, Yasuaki Tanaka, Mitsuru Yoshida, Hiroshi Takebayashi, Suguhiro Fukushima, Toshiro Tomida
  • Patent number: 10494690
    Abstract: A high strength and toughness seamless steel tube for an automobile airbag, comprising the following elements, by wt %: C: 0.05-0.15%; Si: 0.1-0.45%; Mn: 1.0-1.9%; Ni: 0.1-0.6%; Cr: 0.05-1.0%; Mo: 0.05-0.2%; Cu: 0.05-0.50%; Al: 0.015-0.060%; Nb: 0.02-0.1%; V: 0.02-0.15%; and the balance being Fe and other inevitable impurities. A method for manufacturing the seamless steel tube comprises the steps: (1) heating a tube blank and then soaking; (2) hot piercing, reducing the diameter and the wall thickness of the tube blank with a stretch reducer and then cooling naturally; (3) annealing, pickling, phosphating and saponifying; (4) cold working to obtain a finished product size; and (5) carrying out stress relief annealing treatment.
    Type: Grant
    Filed: January 14, 2015
    Date of Patent: December 3, 2019
    Assignee: Boashan Iron & Steel Co., Ltd.
    Inventors: Guoli Zhai, Qingchao Tian, Qijiang Wang, Cailing Liu
  • Patent number: 10358708
    Abstract: A steel plate has a chemical composition containing, by mass %, C: 0.03% or more and 0.08% or less, Si: 0.01% or more and 1.0% or less, Mn: 1.2% or more and 3.0% or less, P: 0.015% or less, S: 0.005% or less, Al: 0.08% or less, Nb: 0.005% or more and 0.07% or less, Ti: 0.005% or more and 0.025% or less, N: 0.010% or less, O: 0.005% or less and the balance being Fe and inevitable impurities, a structure being a dual-phase structure consisting of a bainite phase and island martensite, wherein the area fraction of the island martensite is 3% to 15%, the equivalent circle diameter of the island martensite is 3.0 ?m or less, and the remainder of the structure is a bainite phase.
    Type: Grant
    Filed: March 29, 2013
    Date of Patent: July 23, 2019
    Assignee: JFE Steel Corporation
    Inventors: Junji Shimamura, Kimihiro Nishimura
  • Patent number: 10174399
    Abstract: A steel wire rod includes required amounts of chemical components and a remainder including Fe and impurities; in which the area ratio of pearlite in a cross section perpendicular to a longitudinal direction is 95% or more and a remainder includes a non-pearlite structure which includes one or more of a bainite, a degenerate pearlite, a proeutectoid ferrite and a proeutectoid cementite; the average block size of the pearlite is 15 ?m to 35 ?m and the area ratio of the pearlite having a block size of 50 ?m or more is 20% or less; and the area ratio of a region where a lamellar spacing of the pearlite is 150 nm or less is 20% or less in a region within a depth from a surface of the steel wire rod of 1 mm or less.
    Type: Grant
    Filed: June 23, 2014
    Date of Patent: January 8, 2019
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Makoto Okonogi, Daisuke Hirakami
  • Patent number: 10125405
    Abstract: A method thermally treats hot rails to obtain a desired microstructure having enhanced mechanical properties. The method includes an active cooling phase where the rail is fast cooled from an austenite temperature and subsequently soft cooled, to maintain a target transformation temperature between defined values. The cooling treatment is performed by a plurality of cooling modules. Each of the cooling modules has a plurality of devices spraying a cooling medium onto the rail. The method is characterized in that during the active cooling phase, each cooling device is driven to control the cooling rate of the rail such that the amount of transformed austenite within the rail is not lower than 50% on the rail surface and not lower than 20% at a rail head core.
    Type: Grant
    Filed: June 7, 2013
    Date of Patent: November 13, 2018
    Assignee: PRIMETALS TECHNOLOGIES ITALY S.R.L.
    Inventors: Alberto Gioachino Lainati, Luigi Langellotto, Andrea Mazzarano, Federico Pegorin, Alessio Saccocci, Augusto Sciuccati
  • Patent number: 10125412
    Abstract: A composition includes tungsten (W); at least one element selected form the group of elements consisting of boron (B), beryllium (Be) and silicon (Si); and at least one element selected from the group of elements consisting of titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), hafnium (Hf), tantalum (Ta), rhenium (Re), osmium (Os), iridium (Ir), lithium (Li) and aluminum (Al). The composition satisfies the formula W1-xMxXy wherein X is one of B, Be and Si; M is at least one of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Hf, Ta, Re, Os, Ir, Li and Al; x is at least 0.001 and less than 0.999; and y is at least 4.0. A tool is made from or coated with this composition.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: November 13, 2018
    Assignee: The Regents of the University of California
    Inventors: Richard B. Kaner, Sarah H. Tolbert, Reza Mohammadi, Andrew T. Lech, Miao Xie
  • Patent number: 9957582
    Abstract: A cold-rolled sheet is provided. The cold-rolled sheet includes a steel substrate with a carbon content C0 between 0.07% and 0.5%, expressed by weight, and a metal pre-coating on at least the two principal faces of the steel substrate. The substrate has a decarburized area on the surface of each of the two principal faces. The depth p50% of the decarburized area is between 6 and 30 micrometers, and p50% is the depth at which the carbon content is equal to 50% of the content C0. The sheet does not contain a layer of iron oxide between the substrate and the metal pre-coating.
    Type: Grant
    Filed: May 31, 2017
    Date of Patent: May 1, 2018
    Assignee: ArcelorMittal
    Inventors: Juan David Puerta Velasquez, Jonas Staudte, Pascal Drillet
  • Patent number: 9869009
    Abstract: The present invention relates to a wrought, quenched and tempered, fine-grained, with deep hardenability, high strength and low alloy steel having a sum of the alloying elements: nickel, molybdenum, tungsten, vanadium, titanium, and niobium in weight percent 1.0% to 1.60%. The air melted and hot forged steel of the present invention has hardness of HRC 55, an ultimate tensile strength of 300 ksi, a yield strength of 257 ksi, a total elongation of 9%, a reduction of area of 32%, and Charpy v-notch impact toughness energy of 15 ft-lb after normalizing, gas quenching, and tempering at 450° F.
    Type: Grant
    Filed: November 14, 2014
    Date of Patent: January 16, 2018
    Inventor: Gregory Vartanov
  • Patent number: 9738945
    Abstract: A forging process is conducted in a temperature range of 350-600° C. on at least a portion that is required to have a fatigue strength in an intermediate forged product having a ferrite and pearlite texture obtained by conducting a hot forging on a steel in which N is not greater than an amount at which N is unavoidably dissolved as a solid, thereby improving strength of the portion that is required to have a fatigue strength. With this, there is provided a forged product having a good strength and a low price.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: August 22, 2017
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Jun Yoshida, Daisuke Kaneko, Noriyuki Iwata
  • Patent number: 9692473
    Abstract: Aspects of this disclosure relate to compensating for an offset in a receiver. In one embodiment, the receiver comprises a mixer, a feedback amplifier, and an offset correction circuit. The offset correction circuit can generate an indication of an offset in a differential input to the feedback amplifier and apply an offset compensation signal at an offset compensation node. The offset compensation node can be in a signal path of the feedback amplifier. Such offset compensation can reduce or eliminate leakage from a local oscillator at an input port of the mixer and/or at an antenna port of the receiver.
    Type: Grant
    Filed: May 11, 2015
    Date of Patent: June 27, 2017
    Assignee: ANALOG DEVICES, INC.
    Inventors: Kevin Glenn Gard, Robert C. Glenn
  • Patent number: 9677150
    Abstract: A high strength hot dip galvanized steel strip including, in mass percent, of the following elements: 0.10-0.18% C, 1.90-2.50% Mn, 0.30-0.50% Si, 0.50-0.70% Al, 0.10-0.50% Cr, 0.001-0.10% P, 0.01-0.05% Nb, max 0.004% Ca, max 0.05% S, max 0.007% N, and optionally at least one of the following elements: 0.005-0.50% Ti, 0.005-0.50% V, 0.005-0.50% Mo, 0.005-0.50% Ni, 0.005-0.50% Cu, max 0.005% B, the balance Fe and inevitable impurities, wherein 0.80%<Al+Si<1.05% and Mn+Cr>2.10%. This steel offers improved formability at a high strength, has a good weldability and surface quality together with a good produce-ability and coat-ability.
    Type: Grant
    Filed: October 28, 2014
    Date of Patent: June 13, 2017
    Assignee: TATA STEEL IJMUIDEN B.V.
    Inventors: Bernard Leo Ennis, David Neal Hanlon
  • Patent number: 9669482
    Abstract: Assembled submarine hull steel components, each steel component having a chemical composition consisting of, in weight percent: 0.030%?C<0.080% 0.040%?Si?0.13% 0.1%?Mn?1.4% 2%?Ni?4% Cr?0.3% 0.30%?Mo+W/2+3(V+Nb/2+Ta/4)?0.89% 0.15%?Mo?0.89% V+Nb/2+Ta/4?0.004% Nb?0.004% Cu?0.45% Al?0.1% Ti?0.04% N?0.0300% impurities resulting from the production operation, said impurities including B?0.0005%, P+S?0.015%, the balance being iron, the chemical composition complying with the condition: 410?540×C0.25+245[Mo+W/2+3(V+Nb/2+Ta/4)]0.30?460.
    Type: Grant
    Filed: March 1, 2016
    Date of Patent: June 6, 2017
    Assignee: INDUSTEEL FRANCE
    Inventors: Jean Beguinot, Cedric Chauvy
  • Patent number: 9540704
    Abstract: A method for producing a high fatigue life quenched/tempered steel pipe comprises a quenching treatment of keeping an unquenched starting steel pipe having a composition that comprises, % by mass, C: 0.1 to 0.4%, Si: 0.5 to 1.5%, Mn: 0.3 to 2%, P: at most 0.02%, S: at most 0.01%, Cr: 0.1 to 2%, Ti: 0.01 to 0.1%, Nb: 0.01 to 0.1%, Al: at most 0.1%, B: 0.0005 to 0.01%, and N: at most 0.01%, with a balance of Fe and inevitable impurities, at 900 to 1100° C. for 10 to 60 seconds and then rapidly cooling it. The cooled pipe is subjected to a tempering treatment of keeping the pipe at 280 to 380° C. for 10 to 60 minutes.
    Type: Grant
    Filed: March 24, 2014
    Date of Patent: January 10, 2017
    Assignee: NISSHIN STEEL CO., LTD.
    Inventors: Masaru Fujihara, Tsunetoshi Suzaki
  • Patent number: 9523139
    Abstract: A high-strength cold-rolled steel sheet excellent in ductility, work hardenability, and stretch flangeability, and having tensile strength of 780 MPa or more includes: a chemical composition containing, in mass percent, C: more than 0.020% to less than 0.30%, Si: more than 0.10% to 3.00% or less, Mn: more than 1.00% to 3.50% or less; and metallurgical structure whose main phase is a low-temperature transformation product, and whose secondary phase contains retained austenite. The retained austenite has a volume fraction relative to overall structure of more than 4.0% to less than 25.0% and an average grain size of less than 0.80 ?m, and of the retained austenite, the number density of retained austenite grains whose grain size is 1.2 ?m or more is 3.0×10?2 grains/?m2 or less.
    Type: Grant
    Filed: June 27, 2012
    Date of Patent: December 20, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Jun Haga, Takuya Nishio, Masayuki Wakita, Yasuaki Tanaka, Norio Imai, Toshiro Tomida
  • Patent number: 9341223
    Abstract: A spring with superior fatigue resistance is provided by decreasing the material cost while simplifying the production process. Disclosed is a spring including: a composition consisting of, by mass %, 0.5 to 0.7% of C, 1.0 to 2.0% of Si, 0.1 to 1.0% of Mn, 0.1 to 1.0% of Cr, not more than 0.035% of P, not more than 0.035% of S, and the balance of Fe and impurities; a structure including not less than 95% of tempered martensitic structure; a compressive residual stress layer formed to a depth of 0.35 mm to D/4, in which D (mm) is a diameter; the compressive residual stress layer having maximum compressive residual stress of 800 to 2000 MPa; a center portion with Vickers hardness of 550 to 700 HV; and a high hardness layer with greater hardness than the center portion.
    Type: Grant
    Filed: March 1, 2012
    Date of Patent: May 17, 2016
    Assignee: NHK SPRING CO., LTD.
    Inventors: Takeshi Suzuki, Yoshiki Ono, Shimpei Kurokawa
  • Patent number: 9222156
    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: October 31, 2013
    Date of Patent: December 29, 2015
    Assignee: Siderca S.A.I.C.
    Inventors: Eduardo Altschuler, Teresa Perez, Edgardo Lopez, Constantino Espinosa, Gonzalo Gomez
  • Patent number: 9194033
    Abstract: A chemical composition includes, in mass percent, C: 0.30 to 0.55%, Si: 0.05 to 1.0%, Mn: 0.05 to 0.9%, P: 0.001 to 0.030%, S: 0.005 to 0.12%, Cr: 0.05 to 2.0%, Al: 0.005 to 0.05%, N: 0.0050 to 0.0200%, and the balance being Fe and unavoidable impurities, an amount of N in solid solution being not less than 0.0020%, wherein the contents of Mn and S satisfy relationships expressed by the following expressions: 2.6?Mn/S<15??(1) and Mn+6S<1.2??(2).
    Type: Grant
    Filed: March 27, 2013
    Date of Patent: November 24, 2015
    Assignee: AICHI STEEL CORPORATION
    Inventors: Komei Makino, Hiroyuki Mizuno
  • Patent number: 9188252
    Abstract: Embodiments of the present disclosure comprise carbon steels and methods of manufacture. In one 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, at least about 175 ksi (about 1200 MPa) while maintaining good toughness.
    Type: Grant
    Filed: March 6, 2013
    Date of Patent: November 17, 2015
    Assignee: Siderca S.A.I.C.
    Inventors: Eduardo Altschuler, Teresa Perez, Edgardo Lopez, Constantino Espinosa, Gonzalo Gomez
  • Patent number: 9157132
    Abstract: The high-strength galvanized steel sheet having excellent formability has a component composition containing, on the basis of mass percent, 0.05 to 0.2% C, 0.5 to 2.5% Si, 1.5 to 3.0% Mn, 0.001 to 0.05% P, 0.0001 to 0.01% S, 0.001 to 0.1% Al, and 0.0005 to 0.01% N, the balance being Fe and incidental impurities; and the steel sheet has a microstructure including a ferritic phase and a martensitic phase including a tempered-martensitic phase, the ferritic phase having an area fraction of 30% or more relative to an entirety of the microstructure, the martensitic phase having an area fraction of 30 to 50% relative to the entirety of the microstructure, and the tempered-martensitic phase having an area fraction of 70% or more relative to an entirety of the martensitic phase.
    Type: Grant
    Filed: February 19, 2010
    Date of Patent: October 13, 2015
    Assignee: JFE Steel Corporation
    Inventors: Shinjiro Kaneko, Yoshiyasu Kawasaki, Tatsuya Nakagaito, Saiji Matsuoka
  • Patent number: 9121079
    Abstract: On a cross section with a sheet width direction of a high-strength hot-rolled steel sheet set as a normal line, with regard to an inclusion having a major diameter of 3.0 ?m or more, a maximum of a major diameter/minor diameter ratio expressed by (a major diameter of the inclusion)/(a minor diameter of the inclusion) is 8.0 or less, and a sum total of a rolling direction length per 1 mm2 cross section of a predetermined inclusion group composed of plural inclusions each having a major diameter of 3.0 ?m or more and a predetermined extended inclusion having a length in a rolling direction of 30 ?m or more is 0.25 mm or less. The plural inclusions composing the predetermined inclusion group congregate in both the rolling direction and a direction perpendicular to the rolling direction 50 ?m or less apart from each other. The predetermined extended inclusion is spaced over 50 ?m apart from all the inclusions each having a major diameter of 3.
    Type: Grant
    Filed: March 9, 2011
    Date of Patent: September 1, 2015
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Yuzo Takahashi, Junji Haji, Osamu Kawano
  • Patent number: 9097306
    Abstract: Provided are: a steel wire rod material for a high-strength spring, which does not undergo the increase in deformation resistance arising from the increase in hardness and can exhibit good wire-drawing processability and the like even when a heat treatment, which deteriorates productivity, is eliminated or a simplified and rapid heat treatment is employed instead; a useful method for producing the steel wire rod material for a high-strength spring; a high-strength spring produced using the steel wire rod material for a high-strength spring as a material; and others. This steel wire rod material for a high-strength spring is a steel wire rod material that has been hot-rolled already, and has a texture having a specified chemical composition and mainly composed of pearlite, wherein the average value (Pave) of the pearlite nodule size numbers and the standard deviation (P?) of the pearlite nodule size numbers fulfill the following formulae (1) and (2), respectively: 9.5?Pave?12.0;??(1) and 0.2?P??0.7??(2).
    Type: Grant
    Filed: August 30, 2011
    Date of Patent: August 4, 2015
    Assignee: Kobe Steel, Ltd.
    Inventors: Tomonobu Ishida, Nao Yoshihara, Shuhei Kitamura
  • Patent number: 9080223
    Abstract: A steel tube for an airbag which has a low alloy cost and a strength of at least 1000 MPa and vTrs100 of ?80° C. or below and a process for its manufacture which can minimize the number of times that softening annealing treatment is performed in a cold drawing step are provided. Stable properties are obtained even when quench hardening is carried out by high frequency induction heating on a large scale. The steel tube has a steel composition which comprises, in mass percent, C: 0.05-0.20%, Si: 0.10-0.50%, Mn: 0.10-1.00%, P: at most 0.025%, S: at most 0.005%, Al: 0.005-0.10%, Ca: 0.0005-0.0050%, Nb: 0.005-0.050%, Ti: 0.005-0.050%, Cu: 0.01-0.50%, Ni: 0.01-0.50%, Cr: 0.01-0.50%, B: 0.0005-0.0050%, N: 0.002-0.010%, and a remainder of Fe and unavoidable impurities.
    Type: Grant
    Filed: April 4, 2012
    Date of Patent: July 14, 2015
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Yuji Arai, Takashi Takano, Takuma Kawamoto
  • Publication number: 20150144231
    Abstract: In a steel sheet having a specific chemical composition and having a microstructure including ferrite that is a soft first phase by 20-50% in terms of the area ratio, the remainder being tempered martensite and/or tempered bainite that is a hard second phase, the microstructure of steel of a surface layer section of the steel sheet from the surface to the depth of 100 ?m and a center section of t/4-3t/4 (t is the sheet thickness) is controlled.
    Type: Application
    Filed: May 29, 2013
    Publication date: May 28, 2015
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Tomokazu Masuda, Katsura Kajihara, Toshio Murakami, Masaaki Miura, Muneaki Ikeda
  • Patent number: 9039847
    Abstract: A multiphase steel sheet has a steel composition containing, in percent by mass, more than 0.015% to less than 0.100% of carbon, less than 0.40% of silicon, 1.0% to 1.9% of manganese, more than 0.015% to 0.05% of phosphorus, 0.03% or less of sulfur, 0.01% to 0.3% of soluble aluminum, 0.005% or less of nitrogen, less than 0.30% of chromium, 0.0050% or less of boron, less than 0.15% of molybdenum, 0.4% or less of vanadium, 0.02% or less of titanium, wherein [Mneq] is 2.0 to 2.8, the balance being iron and incidental impurities.
    Type: Grant
    Filed: July 27, 2010
    Date of Patent: May 26, 2015
    Assignee: JFE Steel Corporation
    Inventors: Yoshihiko Ono, Kenji Takahashi, Kaneharu Okuda, Shoichiro Taira, Michitaka Sakurai, Yusuke Fushiwaki
  • Publication number: 20150114524
    Abstract: In a high strength cold-rolled steel plate having a specific chemical composition, a soft first phase (ferrite) has an area ratio of 20-50%, the remainder being a hard second phase (tempered martensite and/or tempered bainite), among all the ferrite grains, ferrite grains that have an average grain diameter of 10-25 ?m account for a total area ratio of 80% or more, the number of the cementite grains that have an equivalent circle diameter of 0.3 ?m or more is more than 0.15 piece and 1.0 piece or less per 1 ?m2 of ferrite, and the tensile strength is 980 MPa or more.
    Type: Application
    Filed: May 24, 2013
    Publication date: April 30, 2015
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Tomokazu Masuda, Katsura Kajihara, Toshio Murakami, Masaaki Miura, Muneaki Ikeda
  • Publication number: 20150111065
    Abstract: Polycrystalline material comprising a plurality of nano-grains of a crystalline phase of an iron group element and a plurality of crystalline grains of material including carbon (C) or nitrogen (N); each nano-grain having a mean size less than 10 nanometres.
    Type: Application
    Filed: May 24, 2013
    Publication date: April 23, 2015
    Inventors: Igor Yurievich Konyashin, Bernd Heinrich Ries, Frank Friedrich Lachmann
  • Publication number: 20150110667
    Abstract: A high-strength and high-ductility steel sheet having a composition including, by weight, 1.0 to 1.4% C, 5.0 to 9.0% Mn, 2.0 to 8.0% Cr and the balance Fe, and unavoidable impurities. The steel sheet has an austenite structure formed at room temperature, and stacking fault energy is effectively controlled by the addition of Cr and N2. Mechanical twins are formed during the plastic deformation of the steel, thereby leading to high levels of work hardening, tensile strength and workability.
    Type: Application
    Filed: October 21, 2014
    Publication date: April 23, 2015
    Inventors: Young-Kook LEE, Yeon-Seung JUNG, Singon KANG, Jeogho HAN, Dongjoon MIN
  • Patent number: 9011614
    Abstract: A high-strength galvanized steel sheet has excellent mechanical properties such as a TS of 1200 MPa or more, an El of 13% or more, and a hole expansion ratio of 50% or more and a method for manufacturing the same. A high-strength galvanized steel sheet excellent in formability contains 0.05% to 0.5% C, 0.01% to 2.5% Si, 0.5% to 3.5% Mn, 0.003% to 0.100% P, 0.02% or less S, and 0.010% to 0.5% Al on a mass basis, the remainder being Fe and unavoidable impurities, and has a microstructure which contains 0% to 10% ferrite, 0% to 10% martensite, and 60% to 95% tempered martensite on an area basis as determined by structure observation and which further contains 5% to 20% retained austenite as determined by X-ray diffractometry.
    Type: Grant
    Filed: January 28, 2009
    Date of Patent: April 21, 2015
    Assignee: JFE Steel Corporation
    Inventors: Tatsuya Nakagaito, Saiji Matsuoka, Yoshitsugu Suzuki, Yuki Toji
  • Publication number: 20150090370
    Abstract: A steel plate has a chemical composition containing, by mass %, C: 0.03% or more and 0.08% or less, Si: 0.01% or more and 1.0% or less, Mn: 1.2% or more and 3.0% or less, P: 0.015% or less, S: 0.005% or less, Al: 0.08% or less, Nb: 0.005% or more and 0.07% or less, Ti: 0.005% or more and 0.025% or less, N: 0.010% or less, O: 0.005% or less and the balance being Fe and inevitable impurities, a structure being a dual-phase structure consisting of a bainite phase and island martensite, wherein the area fraction of the island martensite is 3% to 15%, the equivalent circle diameter of the island martensite is 3.0 ?m or less, and the remainder of the structure is a bainite phase.
    Type: Application
    Filed: March 29, 2013
    Publication date: April 2, 2015
    Applicant: JFE Steel Corporation
    Inventors: Junji Shimamura, Kimihiro Nishimura
  • 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
  • Publication number: 20150086808
    Abstract: A high-strength cold-rolled steel sheet has a specific chemical composition and has a steel microstructure meeting conditions: a total content of bainitic ferrite (BF) and tempered martensite (TM) is 65% (in area percent, hereinafter the same for steel microstructure) or more; a fresh martensite (M) content is 3% to 18%; a retained austenite content is 5% or more; and a polygonal ferrite (F) content is 5% or less. The steel sheet has a specific average KAM<1.00° of 0.50° or more and has a tensile strength of 980 MPa or more. The high-strength cold-rolled steel sheet excels in formability and shape fixability.
    Type: Application
    Filed: March 6, 2013
    Publication date: March 26, 2015
    Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (Kobe Steel, Ltd.)
    Inventors: Kouji Kasuya, Yuichi Futamura, Yukihiro Utsumi
  • Publication number: 20150075680
    Abstract: A steel sheet suitable as a starting material for a vehicle impact absorbing member with high absorption of impact energy and resistance to cracking contains, by mass %, C: 0.08-0.30%, Mn: 1.5-3.5%; Si+Al: 0.50-3.0%, P: 0.10% or less, S: at most 0.010%, and N: at most 0.010%, and optionally, one or more types selected from Cr: at most 0.5%, Mo: at most 0.5%, B: at most 0.010%, Ti: less than 0.04%, Nb: less than 0.030%, V: less than 0.5%, Ca: at most 0.010%, Mg: at most 0.010%, REM: at most 0.050%, and Bi: at most 0.050%. The microstructure contains, by area %, bainite: more than 50%, martensite: 3-30%, and retained austenite: 3-15%, the remainder comprising ferrite having an average grain diameter of less than 5 mm. The product of uniform elongation and hole expansion ratio is at least 300%2 and 5% effective flow stress is at least 900 MPa.
    Type: Application
    Filed: April 8, 2013
    Publication date: March 19, 2015
    Inventors: Yasuaki Tanaka, Kaori Kawano, Masahito Tasaka, Yoshiaki Nakazawa, Takuya Nishio, Masayuki Wakita, Jun Haga, Toshiro Tomida
  • Publication number: 20150075682
    Abstract: The present invention provides a high tensile strength steel plate having a chemical composition containing, in percent by mass, 0.03% to 0.12% of C, 0.01% to 0.30% of Si, 0.5% to 1.95% of Mn, 0.008% or less of P, 0.005% or less of S, 0.015% to 0.06% of Al, 0.011% to 0.05% of Nb, 0.005% to 0.02% of Ti, 0.001% to 0.006% of N, 0.0005% to 0.003% of Ca, optionally, one or two or more of Cr, Mo, V, Cu, and Ni, in which Ceq is 0.44 or less, Ti/N is 1.5 to 3.5, and parameter formulas composed of specific elements for controlling the sulfide morphology and the degree of center segregation in the steel are satisfied, and the balance being Fe and incidental impurities, in which the hardness of the center segregation area of the steel sheet is further specified.
    Type: Application
    Filed: March 1, 2012
    Publication date: March 19, 2015
    Applicant: JFE Steel Corporation
    Inventors: Masao Yuga, Shigeki Kitsuya, Yusuke Terazawa, Minoru Suwa, Kenji Hayashi
  • 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: 8980022
    Abstract: This case hardening steel has a chemical composition including, by mass %: C: 0.1 to 0.6%; Si: 0.02 to 1.5%; Mn: 0.3 to 1.8%; P: 0.025% or less; S: 0.001 to 0.15%; Al: over 0.05 to 1.0%; Ti: 0.05 to 0.2%; N: 0.01% or less; and O: 0.0025% or less, and further including, by mass %, one or more of Cr: 0.4 to 2.0%, Mo: 0.02 to 1.5%, Ni: 0.1 to 3.5%, V: 0.02 to 0.5%, and B: 0.0002 to 0.005%, and the balance consisting of iron and unavoidable impurities.
    Type: Grant
    Filed: January 13, 2010
    Date of Patent: March 17, 2015
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Kei Miyanishi, Masayuki Hashimura, Shuuji Kozawa, Manabu Kubota, Tatsuro Ochi
  • Patent number: 8974610
    Abstract: A high-strength welded steel pipe is obtained by welding a seam weld portion of a steel plate that are formed in a pipe shape. In the high-strength welded steel pipe, a base metal of the steel plate includes, by mass %, C: 0.010% to 0.080%, Si: 0.01% to 0.50%, Mn: 0.50% to 2.00%, S: 0.0001% to 0.0050%, Ti: 0.003% to 0.030%, Mo: 0.05% to 1.00%, B: 0.0003% to 0.0100%, O: 0.0001% to 0.0080%, N: 0.006% to 0.0118%, P: limited to 0.050% or less, Al: limited to 0.008% or less, and the balance of Fe and inevitable impurities, Ceq is 0.30 to 0.53, Pcm is 0.10 to 0.20, [N]?[Ti]/3.4 is less than 0.003, the average grain size of the prior ? grains in heat affected zones in the steel plate is 250 ?m or less, and the prior ? grains include bainite and intragranular bainite.
    Type: Grant
    Filed: February 4, 2011
    Date of Patent: March 10, 2015
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Taishi Fujishiro, Takuya Hara, Yoshio Terada, Shinya Sakamoto, Hitoshi Asahi
  • Publication number: 20150059912
    Abstract: A steel plate has a chemical composition containing, by mass %, C: 0.03% or more and 0.08% or less, Si: 0.01% or more and 1.0% or less, Mn: 1.2% or more and 3.0% or less, P: 0.015% or less, S: 0.005% or less, Al: 0.08% or less, Nb: 0.005% or more and 0.07% or less, Ti: 0.005% or more and 0.025% or less, N: 0.010% or less, O: 0.005% or less and the balance being Fe and inevitable impurities, a metallographic structure including a bainite phase and island martensite, and a polygonal ferrite in surface portions within 5 mm from the upper and lower surfaces, wherein the area fraction of the island martensite is 3% to 15%, the equivalent circle diameter of the island martensite is 3.0 ?m or less, the area fraction of the polygonal ferrite in the surface portions is 10% to less than 80%.
    Type: Application
    Filed: March 29, 2013
    Publication date: March 5, 2015
    Inventors: Junji Shimamura, Kimihiro Nishimura