Age Or Precipitation Hardened Or Strengthed Patents (Class 148/328)
  • Patent number: 10501830
    Abstract: Provided is a high-strength cold-rolled steel sheet having excellent ductility and stretch-flangeability as well as weldability in a range in which a tensile strength is 980 MPa or higher and a 0.2% yield strength is 700 MPa or higher. In the high-strength cold-rolled steel sheet of the present invention, the chemical composition is adjusted as appropriate, and the area ratio of below-mentioned metal structures at a position of ¼ sheet thickness in the steel sheet satisfies following requirements: tempered martensite: 30 area % or more, bainite: 15 area % to 70 area %, total of tempered martensite and bainite: 90 area % or more, ferrite: 0 area % to 5 area %, and retained austenite: 0 area % to 4 area %. The high-strength cold-rolled steel sheet has excellent ductility, stretch-flangeability, and weldability, and has a tensile strength of 980 MPa or higher and a 0.2% yield strength of 700 MPa or higher.
    Type: Grant
    Filed: March 19, 2015
    Date of Patent: December 10, 2019
    Assignee: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Michitaka Tsunezawa, Michiharu Nakaya
  • Patent number: 10465260
    Abstract: This disclosure is directed at methods for mechanical property improvement in a metallic alloy that has undergone one or more mechanical property losses as a consequence of forming an edge, such as in the formation of an internal hole or an external edge. Methods are disclosed that provide the ability to improve mechanical properties of metallic alloys that have been formed with one or more edges placed in the metallic alloy by a variety of methods which may otherwise serve as a limiting factor for industrial applications.
    Type: Grant
    Filed: February 21, 2017
    Date of Patent: November 5, 2019
    Assignee: The NanoSteel Company, Inc.
    Inventors: Daniel James Branagan, Andrew E. Frerichs, Brian E. Meacham, Grant G. Justice, Andrew T. Ball, Jason K. Walleser, Kurtis Clark, Logan J. Tew, Scott T. Anderson, Scott Larish, Sheng Cheng, Taylor L. Giddens, Alla V. Sergueeva
  • Patent number: 10415108
    Abstract: The present invention relates to the steel alloy for railway components and the process of manufacturing it, said alloy comprising, in weight percentage, from 0.21 to 0.27 carbon, from 0.80 to 1.20 manganese, from 0.35 to 0.60 silicon, up to 0.02 phosphorus, up to 0.02 sulfur, from 0.55 to 0.65 chromium, from 0.45 to 0.55 molybdenum, from 1.75 to 2.05 nickel and from 0.005 to 0.030 titanium, conferring, with its composition, desirable mechanical properties, hardenability and corrosion resistance for application on railway components.
    Type: Grant
    Filed: January 13, 2017
    Date of Patent: September 17, 2019
    Assignee: Amsted Maxion Fundição e Equipamentos Ferroviários S.A.
    Inventor: Carlos Marcelo Belchior
  • Patent number: 10350676
    Abstract: A spring steel includes a predetermined chemical composition and a composite inclusion having a maximum diameter of 2 ?m or more that TiN is adhered to an inclusion containing REM, O and Al, in which the number of the composite inclusion is 0.004 pieces/mm2 to 10 pieces/mm2, the maximum diameter of the composite inclusion is 40 ?m or less, the sum of the number density of an alumina cluster having the maximum diameter of 10 ?m or more, MnS having the maximum diameter of 10 ?m or more and TiN having the maximum diameter of 1 ?m to 10 pieces/mm2.
    Type: Grant
    Filed: April 23, 2013
    Date of Patent: July 16, 2019
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Masafumi Miyazaki, Hideaki Yamamura, Masayuki Hashimura, Takashi Fujita
  • Patent number: 10280492
    Abstract: A steel alloy is disclosed that provides a unique combination of strength, toughness, and fatigue life. The steel alloy has the following composition in weight percent: C about 0.15 to about 0.30 Mn about 1.7 to about 2.3 Si about 0.7 to about 1.1 Cr about 1.85 to about 2.35 Ni about 0.5 to about 0.9 Mo+½W about 0.1 to about 0.3 Cu about 0.3 to about 0.7 V+ 5/9×Nb about 0.2 to about 0.5. The balance of the alloy is iron, usual impurities, and residual amounts of other elements added during melting for deoxidizing and/or desulfurizing the alloy. A hardened and tempered steel article made from the alloy is also disclosed.
    Type: Grant
    Filed: September 28, 2016
    Date of Patent: May 7, 2019
    Assignee: CRS HOLDINGS, INC.
    Inventor: Paul M. Novotny
  • Patent number: 10240224
    Abstract: An alloy with tailored hardenability includes carbon, silicon, manganese, nickel, molybdenum, chromium, vanadium, and cobalt. A time and temperature transformation diagram of the alloy has a bainite nose and a ferrite nose that occur at approximately the same time at approximately 4 seconds at temperatures of about 750 K and 950 K, respectively.
    Type: Grant
    Filed: August 12, 2016
    Date of Patent: March 26, 2019
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Charles M. Enloe, Jianfeng Wang, Curt D. Horvath, Jatinder P. Singh
  • Patent number: 10099268
    Abstract: Method for producing an extrusion die having a functional surface for metal extrusion material, comprising the following steps: providing a die support body, depositing a weldable substance containing cobalt and/or nickel onto a subsection of the die support body by means of an effective bonding application process to produce an inseparable deposition layer, machining the deposition layer in a chipping and/or material removal process to form the functional surface of the extrusion die, and carrying out a CVD coating process with a reaction gas at least on the functional surface.
    Type: Grant
    Filed: June 10, 2014
    Date of Patent: October 16, 2018
    Assignee: WEFA Singen GmbH
    Inventors: Oliver Maier, Joachim Maier
  • Patent number: 9970072
    Abstract: A high-strength spring steel wire is provided which secures excellent hydrogen embrittlement resistance even when the adding amount of alloy elements is suppressed, and has 80 area % or more of tempered martensite and 1,900 MPa or more of the tensile strength, in which a predetermined chemical composition is satisfied, with C and Si satisfying the relation of the expression (1) below, with prior austenite grain size number being No. 10 or more, and with the hydrogen absorption amount being 14.0 ppm or more. 0.73%?[C]+[Si]/8?0.90%??(1) where [C] and [Si] express the content (mass %) of C and Si respectively.
    Type: Grant
    Filed: December 2, 2013
    Date of Patent: May 15, 2018
    Assignee: Kobe Steel, Ltd.
    Inventors: Atsuhiko Takeda, Nao Yoshihara
  • Patent number: 9963940
    Abstract: A method of forming an earth-boring tool includes introducing metal into a die, rotating the die to generate centrifugal forces on the metal, and cooling the metal in the rotating die. A rotary drill bit may include a unitary, centrifugally cast bit body including an integral shank, at least one blade, and at least one cutting element on the blade. A rotary drill bit or a roller cone may include a first centrifugally cast material and a second centrifugally cast material. Another rotary drill bit includes a bit body comprising a maraging steel alloy. A method of forming a rotary drill bit may include disposing cutting elements on a rotary drill bit comprising maraging steel and aging the rotary drill bit to form at least one intermetallic precipitate phase. Methods of repairing a rotary drill bit include annealing and aging at least a portion of a rotary drill bit.
    Type: Grant
    Filed: March 31, 2015
    Date of Patent: May 8, 2018
    Assignee: Baker Hughes Incorporated
    Inventors: Xiaomin Chris Cheng, Eric C. Sullivan, Tu Tien Trinh
  • Patent number: 9745639
    Abstract: The invention relates to a steel sheet having a tensile strength of 1180 MPa or more, which excels in workability and cold brittleness resistance. The high-strength steel sheet contains 0.10% to 0.30% of C, 1.40% to 3.0% of Si, 0.5% to 3.0% of Mn, 0.1% or less of P, 0.05% or less of S, 0.005% to 0.20% of Al, 0.01% or less of N, 0.01% or less of O, as well as Fe and inevitable impurities. The steel sheet has: (i) a ferrite volume fraction of 5% to 35% and a bainitic ferrite and/or tempered martensite volume fraction of 60% or more; (ii) a MA constituent volume fraction of 6% or less (excluding 0%); and (iii) a retained austenite volume fraction of 5% or more.
    Type: Grant
    Filed: June 5, 2012
    Date of Patent: August 29, 2017
    Assignee: Kobe Steel, Ltd.
    Inventors: Sae Mizuta, Yuichi Futamura, Yukihiro Utsumi
  • Patent number: 9689050
    Abstract: A rolled steel sheet or blank is provided, the composition of which comprises the elements listed below in percent by weight: C?0.1%; 0.5%?Mn?7%; 0.5%?Si?3.5%; 0.5%<Ti?2%; 2%<Ni?7%; Al?0.10%; Cr?2%; Cu?2%; Co?2%; Mo?2%; S?0.005%; P?0.03%; Nb?0.1%; V?0.1%; B<0.005%; N?0.008%, and the silicon and titanium contents are such that: Si + Ti ? 2.5 ? % , Ti Si ? 0.3 the remainder of the composition consisting of iron and unavoidable impurities resulting from processing. A method for the fabrication of a part for a land motor vehicle from the sheet or blank by hot stamping is also provided. The microstructure of the part consisting essentially of martensite and intermetallic precipitates of type Fe2TiSi with an area percentage between 1 and 5% intermetallic precipitates.
    Type: Grant
    Filed: September 6, 2011
    Date of Patent: June 27, 2017
    Assignee: ARCELORMITTAL INVESTIGACIÓN Y DESARROLLO S.L.
    Inventors: Olivier Bouaziz, David Barbier, Coralie Jung
  • Patent number: 9523404
    Abstract: The present invention provides a spring steel, which is finally formed into a spring, by making use of, at a maximum, the temper softening resistance effect due to alloying elements while suppressing the formation of hard inclusions of SiO2 and the generation of decarburization, which may cause deterioration of fatigue characteristics of the spring. The spring steel is characterized by comprising, in % by mass, C: 0.50 to 0.70%, Si: 1.00 to 5.00%, Mn: 0.30 to 2.00%, P: 0.0002 to 0.0500%, S: 0.0002 to 0.0500%, Cr: 0.10 to 3.50%, Al: 0.0005 to 0.0500%, and N: 0.0020 to 0.0100%, with the balance being Fe and inevitable impurities, wherein the H-value defined by the following equation (a) is 160 or more, and the C-value defined by the following equation (b) is 3.25 or less: H=33.6[C]+10.0[Si]+5.95[Mn]+11.1[Cr]+90.0??(a), and C=[Si]/[Mn]??(b).
    Type: Grant
    Filed: August 15, 2012
    Date of Patent: December 20, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Shinya Teramoto, Manabu Kubota
  • Patent number: 9410231
    Abstract: A steel sheet, including: as chemical components, by mass %, 0.05% to 0.35% of C; 0.05% to 2.0% of Si; 0.8% to 3.0% of Mn; 0.01% to 2.0% of Al; equal to or less than 0.1% of P; equal to or less than 0.05% of S; equal to or less than 0.01% of N; and the balance including iron and inevitable impurities, wherein the steel sheet comprises 50% or more of a ferrite phase, a bainite phase, and a tempered martensite phase, 3% or more of a retained austenite phase, and 50% or more of the crystal grains of the retained austenite phase satisfy Expression 1, wherein a carbon concentration at a position of center of gravity is Cgc and a carbon concentration at a grain boundary is Cgb.
    Type: Grant
    Filed: January 31, 2011
    Date of Patent: August 9, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Riki Okamoto, Natsuko Sugiura, Kohichi Sano, Chisato Wakabayashi, Naoki Yoshinaga, Kaoru Kawasaki
  • Patent number: 9127336
    Abstract: Provided is a hot-working steel excellent in machinability and impact value comprising, in mass %, C: 0.06 to 0.85%, Si: 0.01 to 1.5%, Mn: 0.05 to 2.0%, P: 0.005 to 0.2%, S: 0.001 to 0.35%, and Al: 0.06 to 1.0% and N: 0.016% or less, in contents satisfying Al×N×105?96, and a balance of Fe and unavoidable impurities, total volume of AlN precipitates of a circle-equivalent diameter exceeding 200 nm accounting for 20% or less of total volume of all AlN precipitates.
    Type: Grant
    Filed: April 17, 2008
    Date of Patent: September 8, 2015
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kei Miyanishi, Masayuki Hashimura, Atsushi Mizuno
  • Patent number: 9067260
    Abstract: The invention relates to a steel plate, the chemical composition of which comprises, the contents being expressed by weight: 0.010%?C?0.20%, 0.06%?Mn?3%, Si?1.5%, 0.005%?Al?1.5%, S?0.030%, P?0.040%, 2.5%?Ti?7.2%, (0.45×Ti)?0.35%?B?(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni?1%, Mo?1%, Cr?3%, Nb?0.1%, V?0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.
    Type: Grant
    Filed: June 25, 2010
    Date of Patent: June 30, 2015
    Assignee: ArcelorMittal France
    Inventors: Frederic Bonnet, Olivier Bouaziz, Laure Cala
  • Publication number: 20150147589
    Abstract: A rolled steel sheet or blank is provided, the composition of which comprises the elements listed below in per cent by weight: C?0.1%; 0.5%?Mn?7%; 0.5%?Si?3.5%; 0.5%<Ti?2%; 2%<Ni?7%; Al?0.10%; Cr?2%; Cu?2%; Co?2%; Mo?2%; S?0.005%; P?0.03%; Nb?0.1%; V?0.1%; B<0.005%; N?0.008%, and the silicon and titanium contents are such that: Si + Ti ? 2.5 ? % , Ti Si ? 0.3 the remainder of the composition consisting of iron and unavoidable impurities resulting from processing. A method for the fabrication of a part for a land motor vehicle from the sheet or blank by hot stamping is also provided. The microstructure of the part consisting essentially of martensite and intermetallic precipitates of type Fe2TiSi with an area percentage between 1 and 5% intermetallic precipitates.
    Type: Application
    Filed: September 6, 2011
    Publication date: May 28, 2015
    Applicant: Arcelormittal Investigacion Y Desarrollo, S.L.
    Inventors: Olivier Bouaziz, David Barbier, Coralie Jung
  • 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: 9034119
    Abstract: A component composition contains, by % by mass, 0.0016 to 0.01% of C, 0.05 to 0.60% of Mn, and 0.020 to 0.080% of Nb so that the C and Nb contents satisfy the expression, 0.4?(Nb/C)×(12/93)?2.5. In addition, the amount of Nb-based precipitates is 20 to 500 ppm by mass, the average grain diameter of the Nb-based precipitates is 10 to 100 nm, and the average crystal grain diameter of ferrite is 6 to 10 ?m. Nb is added to ultra-low-carbon steel used as a base, and the amount and grain diameter of the Nb-based precipitates are controlled to optimize the pinning effect. Grain refinement of ferrite is achieved by specifying the Mn amount, thereby achieving softening and excellent resistance to surface roughness of steel.
    Type: Grant
    Filed: March 25, 2010
    Date of Patent: May 19, 2015
    Assignee: JFE Steel Corporation
    Inventors: Yusuke Nakagawa, Masaki Tada, Katsumi Kojima, Hiroki Iwasa
  • 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
  • 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
  • Publication number: 20150068647
    Abstract: A hot worked matrix steel consisting of (in weight-%) 0.60-0.85 C, 0.05-0.5 Si, ?0.5 (Si+Al), 0.1-2.0 Mn, 4.5-5.5 Cr, 1.5-2.6 Mo, ?1.0 W, 1.5-2.6 (Mo+W/2), 0.42-0.65 V, ?0.1 Nb, ?0.1 Ti, ?0.1 Zr, ?2.0 Co, ?2.0 Ni, ?0.003 S, optionally, up to 30 ppm B, balance iron and unavoidable impurities. The steel after hardening and tempering at 520-600° C. (2×2 h) has a hardness of 57-63 HRC and an un-notched impact energy in the transverse direction of 20-100 J. The steel consists of tempered martensite. The steel contains 1.04 vol. % or less of primary precipitated vanadium carbides. The steel is void of primary carbides other than primary precipitated vanadium carbides.
    Type: Application
    Filed: November 17, 2014
    Publication date: March 12, 2015
    Applicant: UDDEHOLMS AB
    Inventors: Börje JOHANSSON, Odd SANDBERG
  • Publication number: 20150059935
    Abstract: The present invention relates to high strength cold rolled steel sheet suitable for applications in automobiles, construction materials and the like, specifically high strength steel excellent in formability. In particular, the invention relates to cold rolled steel sheets having a tensile strength of at least 780 MPa.
    Type: Application
    Filed: April 2, 2013
    Publication date: March 5, 2015
    Applicant: VOESTALPINE STAHL GMBH
    Inventors: Thomas Hebesberger, Daniel Krizan, Stefan Paul, Andreas Pichler
  • Publication number: 20150053315
    Abstract: Provided are: a boron-added high strength steel for bolt excellent in delayed fracture resistance even having a tensile strength of 1100 MPa or more without addition of large amounts of expensive alloy elements such as Cr and Mo: and a high strength bolt made from the boron-added high strength steel for bolt. The high strength steel for bolt contains C of 0.23% to less than 0.40%, Si of 0.23% to 1.50%, Mn of 0.30% to 1.45%, P of 0.03% or less (excluding 0%), S of 0.03% or less (excluding 0%), Cr of 0.05% to 1.5%, V of 0.02% to 0.30%, Ti of 0.02% to 0.1%, B of 0.0003% to 0.0050%, Al of 0.01% to 0.10%, and N of 0.002% to 0.010%, with the remainder being iron and inevitable impurities. The steel has a ratio ([Si]/[C]) of the Si content [Si] to the C content [C] of 1.0 or more and has a ferrite-pearlite mixed microstructure.
    Type: Application
    Filed: February 5, 2013
    Publication date: February 26, 2015
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Yosuke Matsumoto, Atsushi Inada, Masamichi Chiba
  • Publication number: 20150056468
    Abstract: The high strength steel sheet has a chemical composition including 0.08% to 0.20% of C, 0.3% or less of Si, 0.1% to 3.0% of Mn, 0.10% or less of P, 0.030% or less of S, 0.10% or less of Al, 0.010% or less of N, 0.20% to 0.80% of V, and the remainder composed of Fe and incidental impurities on a percent by mass basis, and a microstructure which includes 95% or more of ferrite phase on an area percentage basis, in which fine precipitates are dispersed having a distribution in such a way that the number density of precipitates having a particle size of less than 10 nm is 1.0×105/?m3 or more and the standard deviation of natural logarithm values of precipitate particle sizes with respect to precipitates having a particle size of less than 10 nm is 1.5 or less.
    Type: Application
    Filed: April 18, 2013
    Publication date: February 26, 2015
    Inventors: Taro Kizu, Yoshimasa Funakawa, Hidekazu Ookubo, Tokunori Kanemura, Masato Shigemi, Shoji Kasai, Shinji Yamazaki, Yusuke Yasufuku
  • Publication number: 20150038380
    Abstract: This gear has a predetermined chemical composition and has, in a surface-layer part, a texture of tempered martensite and/or tempered bainite and a steel material texture in which retained austenite exists in 1-10% by area percentage and in which a carbide is deposited in at least 5% by area percentage, and the nitrogen content at a depth of 20 ?m below the surface is 2.0-6.0%. Thus, a gear that achieves even better seizing resistance in a power transmission part subjected to high rotation and high slippage and using a low-kinematic-viscosity lubricating oil is provided.
    Type: Application
    Filed: March 29, 2013
    Publication date: February 5, 2015
    Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO(KOBE STEEL, LTD.)
    Inventors: Sayaka Nagamatsu, Yosuke Shindo
  • Publication number: 20150034218
    Abstract: The present invention relates to high strength cold rolled steel sheet suitable for applications in automobiles, construction materials and the like, specifically high strength steel excellent in formability. In particular, the invention relates to cold rolled steel sheets having a tensile strength of at least 980 MPa and a method for producing such steel sheet.
    Type: Application
    Filed: April 2, 2013
    Publication date: February 5, 2015
    Inventors: Daniel Krizan, Stefan Paul, Andreas Pichler, Michiharu Nakaya
  • Publication number: 20150030882
    Abstract: The invention relates to a steel plate, the chemical composition of which comprises, the contents being expressed by weight: 0.010%?C?0.20%, 0.06%?Mn?3%, Si?1.5%, 0.005%?Al?1.5%, S?0.030%, P?0.040%, 2.5%?Ti?7.2%, (0.45×Ti)?0.35%?B?(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni?1%, Mo?1%, Cr?3%, Nb?0.1%, V?0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.
    Type: Application
    Filed: October 14, 2014
    Publication date: January 29, 2015
    Inventors: Frederic BONNET, Olivier BOUAZIZ, Jean-Claude CHEVALLOT
  • Publication number: 20150013856
    Abstract: In the present invention, a press-formed product is manufactured by heating a steel sheet for hot pressing use to a temperature of 900° C. or above and 1,100° C. or below, the steel sheet for hot pressing use having a predetermined chemical component composition, some of Ti-containing precipitates contained in the steel sheet, each of which having an equivalent circle diameter of 30 nm or less, having an average equivalent circle diameter of 6 nm or less, and the precipitated Ti amount and the total Ti amount in the steel fulfilling the relationship represented by formula (1) shown below, thereafter starting press-forming, and holding at the bottom dead point and cooling to a temperature lower than the martensite transformation starting temperature Ms while securing the average cooling rate of 20° C./s or more within a tool. Precipitated Ti amount(mass %)?3.4[N]<0.5×[total Ti amount (mass %)?3.4[N]]??(1) (In the formula (1), [N] represents the content (mass %) of N in the steel.
    Type: Application
    Filed: February 28, 2013
    Publication date: January 15, 2015
    Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (Kobe Steel, Ltd.)
    Inventors: Toshio Murakami, Hideo Hata, Junya Naitou, Keisuke Okita, Shushi Ikeda
  • Publication number: 20150007911
    Abstract: A method of the present invention includes the steps of heating a steel sheet for hot pressing use to a temperature of Ac3 transformation point or above and 950° C. or below, the steel sheet for hot pressing use containing a predetermined chemical component composition, some of Ti-containing precipitates contained in the steel sheet, each of which having an equivalent circle diameter of 30 nm or less, having an average equivalent circle diameter of 3 nm or more, and the precipitated Ti amount and the total Ti amount in the steel fulfilling the relationship represented by formula (1) shown below, thereafter starting press forming, and being held at the bottom dead point and being cooled to a temperature lower than martensite transformation starting temperature Ms while securing the average cooling rate of 20° C./s or more within a tool. Precipitated Ti amount (mass %)?3.4[N]?0.5×[total Ti amount (mass %)?3.4[N]]??(1) (In the formula (1), [N] represents the content (mass %) of N in the steel.
    Type: Application
    Filed: March 1, 2013
    Publication date: January 8, 2015
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Toshio Murakami, Hideo Hata, Junya Naitou, Keisuke Okita, Shushi Ikeda
  • Patent number: 8926767
    Abstract: The present invention provides a steel part for machine structural use whose fatigue strength and toughness are improved and a manufacturing method thereof. A steel part made of a steel containing, in mass %, C: 0.05 to 0.20%, Si: 0.10 to 1.00%, Mn: 0.75 to 3.00%, P: 0.001 to 0.050%, S: 0.001 to 0.200%, V: exceeding 0.25 to 0.50%, Cr: 0.01 to 1.00%, Al: 0.001 to 0.500%, and N: 0.0080 to 0.0200%, and a balance being composed of Fe and inevitable impurities, in which a steel structure contains a bainite structure having an area ratio of 95% or more, a bainite lath width is 5 ?m or less, V carbide having an average grain diameter of not less than 4 nm nor more than 7 nm dispersedly exists in the bainite structure, and an area ratio of V carbide in the bainite structure is 0.18% or more.
    Type: Grant
    Filed: May 25, 2012
    Date of Patent: January 6, 2015
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Shinya Teramoto, Hiromasa Takada, Manabu Kubota
  • Patent number: 8926766
    Abstract: Provided is a low yield ratio, high strength and high uniform elongation steel plate having excellent strain ageing resistance equivalent to API 5L X70 Grade or lower and a method for manufacturing the same. In particular, the steel plate contains 0.06% to 0.12% C, 0.01% to 1.0% Si, 1.2% to 3.0% Mn, 0.015% or less P, 0.005% or less S, 0.08% or less Al, 0.005% to 0.07% Nb, 0.005% to 0.025% Ti, 0.010% or less N, and 0.005% or less O on a mass basis, the remainder being Fe and unavoidable impurities. The low yield ratio, high strength and high uniform elongation steel plate has a metallographic microstructure that is a two-phase microstructure consisting of bainite and M-A constituent, the area fraction of the M-A constituent being 3% to 20%, the equivalent circle diameter of the M-A constituent being 3.0 ?m or less.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: January 6, 2015
    Assignee: JFE Steel Corporation
    Inventors: Junji Shimamura, Nobuyuki Ishikawa, Nobuo Shikanai
  • Publication number: 20150000797
    Abstract: The invention relates to a cold-rolled flat steel product which, despite high strength values, has a high level of deformability characterised by a high elongation at break and a good hole expansion ratio A. For this purpose the flat steel product is produced from a steel that is composed of (in % by weight) C: 0.12-0.19%, Mn: 1.5-2.5%, Si: >0.60-1.0%, Al: ?0.1%, Cr: 0.2-0.6%, Ti: 0.05-0.15% with the remainder being iron and unavoidable impurities caused by the production process, and which comprises a perlite- and bainite-free structure having 4-20% by vol. martensite, 2-15% by vol. residual austenite, remainder ferrite, an elongation at break A80 of at least 15%, a tensile strength Rm of at least 880 MPa, a yield strength ReL of at least 550 MPa and a hole expansion ratio ?M of more than 6%. The invention also relates to a method which easily enables production of a flat steel product according to the invention.
    Type: Application
    Filed: July 10, 2013
    Publication date: January 1, 2015
    Applicant: ThyssenKrupp Steel Europe AG
    Inventors: Roland Sebald, Dorothea Mattissen, Sigrun Ebest, Stefan Follner
  • Patent number: 8916008
    Abstract: The present invention provides a steel part for machine structural use whose fatigue strength and toughness are improved and a manufacturing method thereof. A steel part made of a steel containing, in mass %, C: 0.05 to 0.20%, Si: 0.10 to 1.00%, Mn: 0.75 to 3.00%, P: 0.001 to 0.050%, S: 0.001 to 0.200%, V: 0.05 to 0.20%, Cr: 0.01 to 1.00%, Al: 0.001 to 0.500%, and N: 0.0080 to 0.0200%, and a balance being composed of Fe and inevitable impurities, in which a steel structure contains a bainite structure having an area ratio of 95% or more, a bainite lath width is 5 ?m or less, V carbide having an average grain diameter of not less than 4 nm nor more than 7 nm dispersedly exists in the bainite structure, and an area ratio of V carbide in the bainite structure is 0.18% or more.
    Type: Grant
    Filed: May 25, 2012
    Date of Patent: December 23, 2014
    Assignee: Nippon Steel and Sumitomo Metal Corporation
    Inventors: Shinya Teramoto, Hiromasa Takada, Manabu Kubota
  • Publication number: 20140363694
    Abstract: A low density high strength steel sheet including 0.15% to 0.25% C, 2.5% to 4% Mn, 0.02% or less P, 0.015% or less S, 6% to 9% Al and 0.01% or less N, the balance being iron and inevitable impurities, wherein 1.7·(Mn—Al)+52.7·C is at least 3 and at most 4.5. A method of producing the low density and high strength steel sheet.
    Type: Application
    Filed: February 21, 2012
    Publication date: December 11, 2014
    Applicant: TATA STEEL NEDERLAND TECHNOLOGY BV
    Inventors: Cheng Liu, Radhakanta Rana
  • Patent number: 8900381
    Abstract: Disclosed is a spring steel which contains, by mass, 1.2% or less C; 0.1% to 2% Mn; 0.2% to 3% Si; 0.0003% to 0.005% Al; to 8 ppm Li; 30 ppm or less (excluding 0 ppm) Ca; and 10 ppm or less (excluding 0 ppm) Mg. The steel contains oxide inclusions satisfying the following conditions (1) to (3) in a number of 1×10?4 or more per square millimeter: (1) containing a total of 80 percent by mass or more of Al2O3 and SiO2 based on the inclusion composition excluding Li2O; (2) having a ratio by mass of Al2O3 to SiO2 of from 1:4 to 2:3; and (3) containing lithium (Li). The spring steel gives a spring that exhibits superior fatigue properties without strict control of the average composition of inclusions.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: December 2, 2014
    Assignee: Kobe Steel, Ltd.
    Inventors: Tomoko Sugimura, Koichi Sakamoto, Atsuhiko Yoshida, Kei Masumoto
  • Patent number: 8894778
    Abstract: The present invention relates to a mechanical part, which is obtained by: processing a steel into a shape of a part, the steel having an alloy composition containing, by weight percent, C: 0.10 to 0.30%, Si: 0.50 to 3.00%, Mn: 0.30 to 3.00%, P: 0.030% or less, S: 0.030% or less, Cu: 0.01 to 1.00%, Ni: 0.01 to 3.00%, Cr: 0.20 to 1.00%, Al: 0.20% or less, N: 0.05% or less, and the remainder of Fe and inevitable impurities, and the alloy composition satisfying the following condition: [Si %]+[Ni %]+[Cu %]?[Cr %]>0.50, in which [Si %], [Ni %], [Cu %] and [Cr %] represent the concentration of Si, the concentration of Ni, the concentration of Cu and the concentration of Cr in the alloy composition, respectively; subjecting the steel to a carburizing treatment in a vacuum, followed by gradually cooling the steel; and subsequently subjecting the steel to a high-frequency hardening to thereby harden a surface of the steel.
    Type: Grant
    Filed: April 8, 2008
    Date of Patent: November 25, 2014
    Assignees: Daido Tokushuko Kabushiki Kaisha, Aisin Aw Co., Ltd.
    Inventors: Toshiyuki Morita, Kouji Ohbayashi, Masaki Kuwabara, Taro Matsukawa, Yutaka Eto, Kohki Mizuno
  • Patent number: 8888933
    Abstract: This high-strength steel sheet includes: in terms of percent by mass, 0.03 to 0.10% of C; 0.01 to 1.5% of Si; 1.0 to 2.5% of Mn; 0.1% or less of P; 0.02% or less of S; 0.01 to 1.2% of Al; 0.06 to 0.15% of Ti; and 0.01% or less of N; and contains as the balance, iron and inevitable impurities, wherein a tensile strength is in a range of 590 MPa or more, and a ratio between the tensile strength and a yield strength is in a range of 0.80 or more, a microstructure includes bainite at an area ratio of 40% or more and the balance being either one or both of ferrite and martensite, a density of Ti(C,N) precipitates having sizes of 10 nm or smaller is in a range of 1010 precipitates/mm3 or more, and a ratio (Hvs/Hvc) of a hardness (Hvs) at a depth of 20 ?m from a surface to a hardness (Hvc) at a center of a sheet thickness is in a range of 0.85 or more.
    Type: Grant
    Filed: May 26, 2010
    Date of Patent: November 18, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Kunio Hayashi, Toshimasa Tomokiyo, Nobuhiro Fujita, Naoki Matsutani, Koichi Goto
  • Patent number: 8864922
    Abstract: A method for manufacturing a precipitation hardening cold-rolled steel sheet with an excellent yield ratio. The method may include the steps of hot rolling a steel slab with finish rolling at a temperature of Ar3 transformation point or more to form a hot-rolled steel sheet, coiling the hot-rolled steel sheet at a temperature of 550-600 ° C., cold rolling the hot-rolled steel sheet at a reduction ratio of 50% or more; and recovery-recrystallization annealing the cold-rolled steel sheet at a line speed of 150-200 mpm and at a temperature of 780-820° C. in a continuous annealing furnace. The recovery-recrystallization annealing may provide a recrystallization ratio of 65-75%. The steel slab includes, by weight %: C: 0.07-0.10%, Mn: 1.41-1.70%, P: 0.05-0.07%, S: 0.005% or less, N: 0.005% or less, acid-soluble Al: 0.10-0.15%, Nb: 0.06-0.09%, B: 0.0008-0.0012%, Sb: 0.02-0.06%, and the balance comprising Fe and other unavoidable impurities.
    Type: Grant
    Filed: March 1, 2013
    Date of Patent: October 21, 2014
    Assignee: POSCO
    Inventor: Sang-Ho Han
  • Patent number: 8821652
    Abstract: Steel for induction hardening wherein coarsening of austenite crystal grains can be prevented even at a high temperature of over 1100° C. such as which occurs at projecting parts of steel parts at the time of induction hardening, the steel for induction hardening characterized by containing, by mass %, C: 0.35 to 0.6%, Si: 0.01 to 1%, Mn: 0.2 to 1.8%, S: 0.001 to 0.15%, Al: 0.001 to 1%, Ti: 0.05 to 0.2%, and Nb: 0.001 to 0.04%, restricting N: 0.0060% or less, P: 0.025% or less, and O: 0.0025% or less, satisfying Nb/Ti?0.015, and having a balance of iron and unavoidable impurities.
    Type: Grant
    Filed: October 7, 2010
    Date of Patent: September 2, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Shuji Kozawa, Manabu Kubota
  • Patent number: 8815024
    Abstract: The present invention provides steel plate or steel pipe with small occurrence of the Bauschinger effect and methods of production of the same, particularly steel pipe used for steel pipe for oil wells or line pipe with a small drop in the compression strength in the circumferential direction due to the Bauschinger effect when expanded and methods of production of the same, that is steel plate or steel pipe with small occurrence of the Bauschinger effect characterized by having a dual-phase structure substantially comprising a ferrite structure and fine martensite which is dispersed in the ferrite structure. Further, this steel plate or steel pipe contains, by mass %, C: 0.03 to 0.30%, Si: 0.01 to 0.8%, Mn: 0.3 to 2.5%, P: 0.03% or less, S: 0.01% or less, Al: 0.001 to 0.01%, and N: 0.01% or less and a balance of iron and unavoidable impurities.
    Type: Grant
    Filed: February 15, 2005
    Date of Patent: August 26, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Hitoshi Asahi, Eiji Tsuru
  • Patent number: 8815025
    Abstract: A high strength steel, including about 0.05 to about 0.25% of C, less than about 0.5% of Si, about 0.5 to about 3.0% of Mn, not more than about 0.06% of P, not more than about 0.01% of S, about 0.50 to about 3.0% of Sol. Al, not more than about 0.02% of N, about 0.1 to about 0.8% of Mo, about 0.02 to about 0.40% of Ti, and the balance of iron and unavoidable impurities, wherein the steel has a structure formed of at least three phases including a bainite phase, and a retained austenite phase in addition to a ferrite phase having a composite carbide containing Ti and Mo dispersed and precipitated therein, wherein the total volume of the ferrite phase and the bainite phase is not smaller than 80%, the volume of the bainite phase is about 5% to about 60%, and the volume of the retained austenite phase is about 3 to about 20%.
    Type: Grant
    Filed: November 3, 2006
    Date of Patent: August 26, 2014
    Assignees: JFE Steel Corporation, ThyssenKrupp Steel AG
    Inventors: Takeshi Yokota, Akio Kobayashi, Kazuhiro Seto, Yoshihiro Hosoya, Thomas Heller, Brigitte Hammer, Rolf Bode, Günter Stich
  • Patent number: 8801872
    Abstract: A case hardened gear steel having enhanced core fracture toughness includes by weight percent about 16.3Co, 7.5Ni, 3.5Cr, 1.75Mo, 0.2W, 0.11C, 0.03Ti, and 0.02V and the balance Fe, characterized as a predominantly lath martensitic microstructure essentially free of topologically close-packed (TCP) phases and carburized to include fine M2C carbides to provide a case hardness of at least about 62 HRC and a core toughness of at least about 50 ksi?in.
    Type: Grant
    Filed: August 20, 2008
    Date of Patent: August 12, 2014
    Assignee: QuesTek Innovations, LLC
    Inventors: James A. Wright, Jason Sebastian
  • Publication number: 20140212324
    Abstract: Provided by the present invention are a fine crystallite high-function metal alloy member, a method for manufacturing the same, and a business development method thereof, in which a crystallite of a metal alloy including a high-purity metal alloy whose crystal lattice is a face-centered cubic lattice, a body-centered cubic lattice, or a close-packed hexagonal lattice is made fine with the size in the level of nanometers (10?9 m to 10?6 m) and micrometers (10?6 m to 10?3 m), and the form thereof is adjusted, thereby remedying drawbacks thereof and enhancing various characteristics without losing superior characteristics owned by the alloy.
    Type: Application
    Filed: April 10, 2012
    Publication date: July 31, 2014
    Applicant: THREE-O CO., LTD.
    Inventor: Kazuo Ogasa
  • 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: 8778261
    Abstract: The present invention provides a steel material for automobile chassis parts, having high fatigue characteristics, without a heat treatment, and superior shapeability, and a method of production of such automobile chassis parts. The surface of the steel has a high hardness and the center has a low hardness, providing the superior characteristics. With an annealing step of the invention, it is possible to relieve internal stress and further improve fatigue characteristics.
    Type: Grant
    Filed: November 21, 2011
    Date of Patent: July 15, 2014
    Assignees: Nippon Steel & Sumitomo Metal Corporation, Toyota Jidosha Kabushiki Kaisha
    Inventors: Hideyuki Nakamura, Isao Anai, Yasushi Yamamoto, Takaaki Fukushi, Izuru Yamamoto, Masaaki Kondo, Satoru Shimazu
  • Patent number: 8747576
    Abstract: This high-carbon pearlitic steel rail having excellent ductility, includes: in terms of percent by mass, C: more than 0.85% to 1.40%; Si: 0.10% to 2.00%; Mn: 0.10% to 2.00%; Ti: 0.001% to 0.01%; V: 0.005% to 0.20%; and N: less than 0.0040%, with the balance being Fe and inevitable impurities, wherein contents of Ti and V fulfill the following formula (1), and a rail head portion has a pearlite structure.
    Type: Grant
    Filed: April 14, 2010
    Date of Patent: June 10, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Teruhisa Miyazaki, Masaharu Ueda, Suguru Yoshida
  • Publication number: 20140150934
    Abstract: The present invention relates to a wire rod used in bolts for automobile engines, for example, and more specifically to a wire rod having an improved resistance to hydrogen delayed fracture, to a manufacturing method for same, to a bolt using same and a method for manufacturing the bolt. Provided are a high strength wire rod having a superior resistance to hydrogen delayed fracture and a method for manufacturing same, a high strength bolt using the wire rod and a method for manufacturing same, wherein. the wire rod comprises, 0.3-0.7 wt % C, 0.05-2.0 wt % Si, 0.7-1.5 wt % Mn, 0.01-0.1 wt % Ni, and 30-70 ppm La, and the remainder thereof is comprised by Fe and inevitable impurities.
    Type: Application
    Filed: May 14, 2012
    Publication date: June 5, 2014
    Applicant: POSCO
    Inventors: You-Hwan Lee, Dong-Hyun Kim, Geun-Soo Ryu
  • Publication number: 20140150930
    Abstract: The present invention relates to a hot press forming steel plate made of a composition comprising: 0.3-1.0 wt % of C; 0.0-4.0 wt % of Mn; 1.0-2.0 wt % of Si; 0.01-2.0 wt % of Al; 0.015 wt % or less of S; 0.01 wt % or less of N; and the remainder being Fe and unavoidable impurities. Further, the present. invention relates to a method for manufacturing the hot press forming steel plate, characterized by comprising the steps of: heating, to between 1100 and 1300° C., a steel slab having the composition; performing hot rolling finishing between. an Ar3 transformation point and 950° C.; and performing winding between MS and 720° C. Further, the present invention. relates to a hot press formed member characterized by having the composition, and having a dual phase microstructure made of bainite and residual austenite.
    Type: Application
    Filed: July 15, 2011
    Publication date: June 5, 2014
    Inventors: Kyoo-Young Lee, Jin-Keun Oh, Jong-Sang Kim, Tae-Kyo Han
  • Patent number: 8721807
    Abstract: A method of making a hypereutectoid, head-hardened steel rail is provided that includes a step of head hardening a steel rail having a composition containing 0.86-1.00 wt % carbon, 0.40-0.75 wt % manganese, 0.40-1.00 wt % silicon, 0.05-0.15 wt % vanadium, 0.015-0.030 wt % titanium, and sufficient nitrogen to react with the titanium to form titanium nitride. Head hardening is conducted at a cooling rate that, if plotted on a graph with xy-coordinates with the x-axis representing cooling time in seconds, and the y-axis representing temperature in Celsius of the surface of the head of the steel rail, is maintained in a region between an upper cooling rate boundary plot defined by an upper line connecting xy-coordinates (0 s, 775° C.), (20 s, 670° C.), and (110 s, 550° C.) and a lower cooling rate boundary plot defined by a lower line connecting xy-coordinates (0 s, 750° C.), (20 s, 610° C.), and (110 s, 500° C.).
    Type: Grant
    Filed: August 13, 2012
    Date of Patent: May 13, 2014
    Assignee: Arcelormittal Investigacion Y Desarrollo, S.L.
    Inventors: Bruce L. Bramfitt, Fred B. Fletcher, John A. Davis, Jr.
  • Publication number: 20140113159
    Abstract: When contents of Ti, V, Zr, Nb, and C (mass %) are represented as [Ti], [V], [Zr], [Nb], and [C] respectively, a value of a parameter Q represented by “Q=([Ti]/48+[V]/51+[Zr]/91+[Nb]/93)/([C]/12)” is not less than 0.9 nor more than 1.1. A matrix of a metal structure is a ferrite phase, and the metal structure does not include a non-recrystallized structure. An average grain size of ferrite grains constituting the ferrite phase is not less than 10 ?m nor more than 200 ?m. A precipitate containing at least one selected from the group consisting of Ti, V, Zr, and Nb exists with a density of 10 ?m?3 or more in the ferrite grain. An average grain size of the precipitate is not less than 0.002 ?m nor more than 0.2 ?m.
    Type: Application
    Filed: August 16, 2012
    Publication date: April 24, 2014
    Inventors: Masahiro Fujikura, Yoshiyuki Ushigami, Tesshu Murakawa, Shinichi Kanao, Makoto Atake, Takeru Ichie, Kojiro Hori, Shinichi Matsui