With Working Patents (Class 148/624)
  • Patent number: 9840750
    Abstract: A medium carbon steel sheet for cold working that has a hardness of 500 HV to 900 HV when subjected to high-frequency quenching and a quick cooling to a room temperature is carried out. The medium carbon steel sheet includes, by mass %, C: 0.30 to 0.60%, Si: 0.06 to 0.30%, Mn: 0.3 to 2.0%, P: 0.03% or less, S: 0.0075% or less, Al: 0.005 to 0.10%, N: 0.001 to 0.01%, and Cr: 0.001 to 0.10%, the balance composed of Fe and inevitable impurities. An average diameter d of a carbide is 0.6 ?m or less, a spheroidizing ratio p of the carbide is equal to or more than 70% and less than 90%, and the average diameter d (?m) of the carbide and the spheroidizing ratio p % of the carbide satisfy the expression d?0.04×p?2.6.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: December 12, 2017
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kengo Takeda, Masayuki Abe, Yasushi Tsukano, Takashi Aramaki, Shinichi Yamaguchi
  • Patent number: 9631250
    Abstract: A steel sheet has a microstructure including ferrite phase: 40% to 60%, bainite phase: 10% to 30%, tempered martensite phase: 20% to 40%, and retained austenite phase: 5% to 20% by volume fraction, and satisfying a condition that a ratio of tempered martensite phase having major axis length ?5 ?m to a total volume fraction of the tempered martensite phase is 80% to 100%.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: April 25, 2017
    Assignee: JFE Steel Corporation
    Inventors: Hidetaka Kawabe, Takeshi Yokota, Reiko Sugihara, Shigeyuki Aizawa, Kazuki Nakazato
  • Patent number: 9410222
    Abstract: A method for forming and treating a steel article of a high strength and ductile alloy. The method includes the steps of providing a starting steel composition for the steel article, preheating the composition, heating the starting material to a peak temperature range in less than forty seconds, holding the heated steel composition at the peak temperature range for between two and sixty seconds, quenching the heated steel composition from the peak temperature range to below 177° C. (350° F.) at a temperature rate reduction of 200 to 3000 ° C./sec (360 and 5400° F./sec), removing residual quench media from the surface of the quenched steel composition, tempering the quenched steel composition at a temperature of 100 to 704° C. (212 to 1300° F.); and air cooling the tempered steel composition to less than 100° C. (212° F.) to form a steel having desired mechanical properties.
    Type: Grant
    Filed: August 15, 2014
    Date of Patent: August 9, 2016
    Assignee: Buffalo Armory LLC
    Inventors: John Batiste, Richard Clare, Jack Heinz, Brent Nicholson, Pete Zdjelar
  • Patent number: 9410220
    Abstract: A method for forming and treating a steel article of a high strength and high ductility alloy particularly suited for use as armor plate. The method includes the steps of providing a starting material for the steel article, heating the starting material to a peak temperature range in less than ten seconds, holding the heated steel composition at the peak temperature range for between two and six seconds, quenching the heated steel composition from the peak temperature range to below 100° C. (212° F.) at a temperature rate reduction of 400 and 3000° C./sec (752 and 5432° F./sec), removing residual quench media from the surface of the quenched steel composition, tempering the quenched steel composition at a temperature of 100 to 260° C. (212 to 500° F.); and air cooling the tempered steel composition to less than 100° C. (212° F.) to form a steel having desired mechanical properties.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: August 9, 2016
    Assignee: Buffalo Armory LLC
    Inventors: John Batiste, Todd Zyra, Brent Nicholson, Jim Sloan, Brad Cooper, John Sparling, Mark Turek, Mike Haselkorn
  • Patent number: 9303295
    Abstract: Disclosed embodiments include fuel assemblies, fuel element, cladding material, methods of making a fuel element, and methods of using same.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: April 5, 2016
    Assignee: TERRAPOWER, LLC
    Inventors: Micah Hackett, Ronald Klueh
  • 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
  • Publication number: 20150090372
    Abstract: This disclosure deals with a class of metal alloys with advanced property combinations applicable to metallic sheet production. More specifically, the present application identifies the formation of metal alloys of relatively high strength and ductility and the use of one or more cycles of elevated temperature treatment and cold deformation to produce metallic sheet at reduced thickness with relatively high strength and ductility.
    Type: Application
    Filed: October 2, 2014
    Publication date: April 2, 2015
    Inventors: Daniel James BRANAGAN, Grant G. JUSTICE, Andrew T. BALL, Jason K. WALLESER, Brian E. MEACHAM, Kurtis CLARK, Longzhou MA, Igor YAKUBTSOV, Scott Larish, Sheng CHENG, Taylor L. GIDDENS, Andrew E. FRERICHS, Alla V. SERGUEEVA
  • 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
  • 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: 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
  • Patent number: 8894781
    Abstract: A method for forming and treating a steel article of a high strength and high ductility alloy particularly suited for use as armor plate. The method includes the steps of providing a starting material for the steel article, heating the starting material to a peak temperature range in less than ten seconds, holding the heated steel composition at the peak temperature range for between two and six seconds, quenching the heated steel composition from the peak temperature range to below 100° C. (212° F.) at a temperature rate reduction of 400 and 3000° C./sec (752 and 5432° F./sec), removing residual quench media from the surface of the quenched steel composition, tempering the quenched steel composition at a temperature of 100 to 260° C. (212 to 500° F.); and air cooling the tempered steel composition to less than 100° C. (212° F.) to form a steel having desired mechanical properties.
    Type: Grant
    Filed: July 24, 2013
    Date of Patent: November 25, 2014
    Assignee: Buffalo Armory LLC
    Inventors: John Batiste, Todd Zyra, Brent Nicholson, Jim Sloan, Brad Cooper, John Sparling, Mark Turek, Mike Haselkorn
  • Publication number: 20140232385
    Abstract: A semi-hard magnetic material that is formed with equal to or more than 5.0% but less than 13.0% of Ni by mass, equal to or more than 0.5% but equal to or less than 4.0% of Mn by mass, more than 0% but equal to or less than 3.0% of Al by mass, more than 0% but equal to or less than 1.0% of Ti by mass and a remainder of Fe and an impurity, that has a coercivity of 1000 to 2400 A/m and that has a residual magnetic flux density of 1.3 T or more. A method of manufacturing the above semi-hard magnetic material wherein the material is a thin plate having a thickness of 0.030 to 0.30 mm and, after a cold rolling, performing an aging treatment on the thin plate at a temperature of 520° C. to 680° C.
    Type: Application
    Filed: August 17, 2012
    Publication date: August 21, 2014
    Applicant: HITACHI METALS, LTD.
    Inventors: Masaru Fujiyoshi, Shin-ichiro Yokoyama
  • Publication number: 20140182749
    Abstract: Disclosed embodiments include fuel assemblies, fuel element, cladding material, methods of making a fuel element, and methods of using same.
    Type: Application
    Filed: March 11, 2013
    Publication date: July 3, 2014
    Inventors: Micah Hackett, Ronald Klueh
  • 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
  • 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
  • Patent number: 8702879
    Abstract: A method of producing a martensitic steel including a content of other metals such that it can be hardened by intermetallic compound and carbide precipitation, with an Al content of between 0.4% and 3%. The heat shaping temperature of a last heat shaping pass of the steel is lower than the solubility temperature of aluminum nitrides in the steel, and a treatment temperature for each potential heat treatment after the last heat shaping pass is lower than the solid-state solubility temperature of the aluminum nitrides in the steel.
    Type: Grant
    Filed: July 2, 2010
    Date of Patent: April 22, 2014
    Assignees: SNECMA, Aubert & Duval
    Inventors: Laurent Ferrer, Philippe Heritier
  • Publication number: 20130186527
    Abstract: The microstructure of a low alloy steel workpiece for cold forming may be beneficially modified by heating the workpiece to a temperature just above its austenite transformation temperature (Ac3 temperature). The steel workpiece is then cooled just below its Ac3 temperature to promote ferrite formation on and between the austenite grains. Heating and cooling, above and below the Ac3 temperature, is repeated a determined number of times to refine the austenite grains before the workpiece is quenched below its martensite transformation temperature to form a mixture of martensite with increased retained austenite. The workpiece may be further heated in its martensite region to increase the proportion of retained austenite before quenching the steel workpiece to an ambient temperature. The formability of the workpiece is improved, as is the strength of its formed shape.
    Type: Application
    Filed: January 20, 2012
    Publication date: July 25, 2013
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventor: John R. Bradley
  • Publication number: 20130186529
    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 0.20 to 0.25%, 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: Application
    Filed: May 25, 2012
    Publication date: July 25, 2013
    Applicant: NIPPON STEEL AND SUMITOMO METAL CORPORATION
    Inventors: Shinya Teramoto, Hiromasa Takada, Manabu Kubota, Yoichi Taniguchi, Junichi Nakatsuka, Kazuhiro Fujimura, Satoshi Koganemaru
  • Publication number: 20130186528
    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: Application
    Filed: May 25, 2012
    Publication date: July 25, 2013
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Shinya Teramoto, Hiromasa Takada, Manabu Kubota
  • Publication number: 20130167986
    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: Application
    Filed: May 25, 2012
    Publication date: July 4, 2013
    Applicant: NIPPON STEEL AND SUMITOMO METAL CORPORATION
    Inventors: Shinya Teramoto, Hiromasa Takada, Manabu Kubota
  • Publication number: 20130058773
    Abstract: A method of manufacturing a material for a rotary machine component, by performing at least a solution treatment on a material made of a duplex stainless steel, wherein, in the solution treatment, the material is heated to a temperature in a range of 950 to 1100° C. and is thereafter cooled to 700° C. at an average cooling rate of equal to or greater than 20° C./min.
    Type: Application
    Filed: May 12, 2011
    Publication date: March 7, 2013
    Inventors: Shugo Iwasaki, Yoshikazu Yamada, Shinichiro Tokuyama, Tatsuya Osawa, Seiichi Yarimizu
  • Publication number: 20120180911
    Abstract: The present invention is premised upon a method of piercing a hole through a plate member by removing at least 10% of the hole offal material prior to piercing the hole. In the case of high strength steel plating (e.g. armor plating), the step of annealing before punching may be included, as well as the step of hardening the steel after the punching operation.
    Type: Application
    Filed: October 3, 2008
    Publication date: July 19, 2012
    Inventors: Mark Bartolomucci, James M. Kuriluk
  • Publication number: 20120018063
    Abstract: Cold worked, machined, and carburized quenched case-hardened steel prevented from formation of coarse grains, that is, case-hardened steel superior in cold workability, machinability, and fatigue characteristics after carburized quenching characterized by limiting, by mass %, S: 0.001 to 0.15%, Ti: 0.05 to 0.2%, Al: 0.04% or less, and N: 0.0050% or less, containing other specific ingredients in specific ranges, furthermore containing one or more of Mg: 0.003% or less, Zr: 0.01% or less, and Ca: 0.005% or less, limiting the amount of precipitation of AlN to 0.01% or less, and having a density d (/mm2) of sulfides with a equivalent circle diameter of over 20 ?m and an aspect ratio of over 3 and a content of S [S] (mass %) satisfying d?1700[S]+20.
    Type: Application
    Filed: October 14, 2009
    Publication date: January 26, 2012
    Inventors: Masayuki Hashimura, Kei Miyanishi, Shuji Kozawa, Manabu Kubota, Tatsuro Ochi
  • Publication number: 20110226386
    Abstract: A steel characterized in that its composition is percentages by weight: C=0.18-0.30% Co=1.5-4% Cr=2-5% Al=1-2% Mo+W/2=1-4% V=traces-0.3% Nb=traces-0.1% B=traces-30 ppm Ni=11-16% where Ni?7+3.5 Al Si=traces-1.0% Mn=traces-4.0% Ca=traces-20 ppm Rare earths=traces-100 ppm if N?10 ppm, Ti+Zr/2=traces-100 ppm where Ti+Zr/2?10 N if 10 ppm<N?20 ppm, Ti+Zr/2=traces-150 ppm O=traces-50 ppm N=traces-20 ppm S=traces-20 ppm Cu=traces-1% P=traces-200 ppm the remainder being iron and inevitable impurities resulting from the smelting. A process for manufacturing a part from this steel, and part thus obtained.
    Type: Application
    Filed: July 8, 2009
    Publication date: September 22, 2011
    Inventor: François Roch
  • Publication number: 20110186190
    Abstract: A thermal mechanical treatment method includes hot working a precipitation hardening martensitic stainless steel, quenching the stainless steel, and aging the stainless steel. According to certain embodiments, the thermal mechanical treatment does not include solution heat treating the stainless steel prior to aging or cryogenically cooling the stainless steel. An article includes a precipitation hardening martensitic stainless steel having a process history that includes hot working the stainless steel, quenching the stainless steel, and aging the stainless steel. According to certain embodiments, the process history does not include solution heat treating the stainless steel prior to aging or cryogenically cooling the stainless steel.
    Type: Application
    Filed: March 15, 2011
    Publication date: August 4, 2011
    Applicant: ATI Properties, Inc.
    Inventors: Wei-Di Cao, Erin T. McDevitt
  • Publication number: 20110132503
    Abstract: Disclosed herein is a method for reducing edge serration defects in a thin slab, including: reheating a thin slab having an alloy composition including carbon (C), niobium (Nb), aluminum (Al), iron (Fe) and inevitable impurities to uniformalize the thin slab into an austenite structure; controlling precipitates that occur in the reheated thin slab by controlling an temperature of the thin slab discharged from a heat-treatment furnace at a temperature at which niobium carbide (NbC) start to precipitate; and hot-rolling the thin slab. The method is advantageous in that the temperature of a thin slab discharged from a heat-treatment furnace is controlled, so that the edge serration defects in the thin slab can be reduced, thereby improving the productivity of the thin slab.
    Type: Application
    Filed: February 15, 2011
    Publication date: June 9, 2011
    Applicant: HYUNDAI STEEL COMPANY
    Inventors: Sukhyun YOO, Hongkil MOON, Jinsoo JANG
  • Publication number: 20110042625
    Abstract: A main object thereof is to provide a non-oriented electrical steel sheet being excellent in surface characteristics and having both excellent mechanical characteristics and magnetic characteristics necessary for a rotor of rotating machines such as motors and generators which rotate at a high speed, and a method for producing the same. To achieve the object, the present invention provides a non-oriented electrical steel sheet comprising in % by mass: 0.06% or less of C; 3.5% or less of Si; from 0.05% or more to 3.0% or less of Mn; 2.5% or less of Al; 0.30% or less of P; 0.04% or less of S; 0.02% or less of N; at least one element selected from the group consisting of Nb, Ti, Zr and V in the predetermined range; and a balance consisting of Fe and impurities; and having a recrystallized fraction being less than 90%.
    Type: Application
    Filed: November 2, 2010
    Publication date: February 24, 2011
    Applicant: SUMITOMO METAL INDUSTRIES, LTD.
    Inventors: Ichirou Tanaka, Hiroshi Fujimura, Hirokatsu Nitomi, Hiroyoshi Yashiki, Kouji Nishida, Hiroki Takamaru
  • Publication number: 20110030854
    Abstract: A high strength steel sheet has a tensile strength of 900 MPa or higher that can achieve both high strength and good formability and a composition including, on a mass basis, C: 0.1% or more and 0.3% or less; Si: 2.0% or less; Mn: 0.5% or more and 3.0% or less; P: 0.1% or less; S: 0.07% or less; Al: 1.0% or less; and N: 0.008% or less, with the balance Fe and incidental impurities. The steel sheet microstructure includes, on an area ratio basis, 5% or more and 80% or less of ferrite, 15% or more of autotempered martensite, 10% or less of bainite, 5% or less of retained austenite, and 40% or less of as-quenched martensite; the mean hardness of the autotempered martensite is HV?700; and the mean number of precipitated iron-based carbide grains each having a size of 5 nm or more and 0.5 ?m or less and included in the autotempered martensite is 5×104 or more per 1 mm2.
    Type: Application
    Filed: January 29, 2009
    Publication date: February 10, 2011
    Applicant: JFE STEEL CORPORATION
    Inventors: Hiroshi Matsuda, Reiko Mizuno, Yoshimasa Funakawa, Yasushi Tanaka, Tatsuya Nakagaito, Saiji Matsuoka
  • Patent number: 7838075
    Abstract: A method for strengthening a surface of a metal member. The method includes the following steps in the sequence set forth: (a) coating the surface of the metal member with a carbon-based film having a thickness of not smaller than 0.2 ?m; and (b) repeatedly applying a pressing force onto the surface of the film-coated metal member in a condition of maintaining a contact pressure of not lower than 2.5 GPa at the surface of the film-coated metal member.
    Type: Grant
    Filed: July 5, 2006
    Date of Patent: November 23, 2010
    Assignee: JATCO Ltd
    Inventors: Masao Kumagai, Yoshio Jimbo, Fumiya Yakabe
  • Patent number: 7799148
    Abstract: Iron-carbon-manganese austenitic steel sheet, the chemical composition of which comprises, the contents being expressed by weight: 0.45%?C?0.75%; 15%?Mn?26%; Si?3%; Al?0.050%; S?0.030%; P?0.080%; N?0.1%; at least one metal element chosen from vanadium, titanium, niobium, chromium and molybdenum, where 0.050%?V?0.50%; 0.040%?Ti?0.50; 0.070%?Nb?0.50%; 0.070%?Cr?2%; 0.14%?Mo?2%; and, optionally, one or more elements chosen from 0.0005%?B?0.003%; Ni?1%; Cu?5%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the amounts of said at least one metal element in the form of precipitated carbides, nitrides or carbonitrides being: 0.030%?Vp?0.150%; 0.030%?Tip?0.130%; 0.040%?Nbp?0.220%; 0.070%?Crp?0.6%; 0.14%?Mop?0.44%.
    Type: Grant
    Filed: January 10, 2006
    Date of Patent: September 21, 2010
    Assignee: Arcelor France
    Inventors: Colin Scott, Philippe Cugy, Maurita Roscini, Anne Dez, Dominique Cornette
  • Patent number: 7740722
    Abstract: A steel for use in high strength pinion shaft which is not refined and used by applying high frequency hardening, with less occurrence of peeling during hobbing, having high surface hardness, impact value and torsional strength after high frequency hardening, and with less heat treatment strains during high frequency hardening, containing, on the mass % basis; C: 0.45-0.55%, Si: 0.10-0.50%, Mn: 0.50-1.20%, P: 0.025% or less, S: 0.025% or less, Mo: 0.15-0.25%, B: 0.0005-0.005%, Ti: 0.005-0.10%, and N: 0.015% or less, satisfying: 0.80?Ceq 0.95 and f value?1.0, and the balance of Fe and inevitable impurities, as well as a manufacturing method thereof.
    Type: Grant
    Filed: January 23, 2004
    Date of Patent: June 22, 2010
    Assignee: JTEKT Corporation
    Inventors: Katsunori Takada, Koichiro Inoue, Katsushi Goto, Atsuhiko Ohta, Tomoyuki Takei
  • Publication number: 20100132855
    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: Application
    Filed: March 24, 2009
    Publication date: June 3, 2010
    Inventors: Yasushi Hasegawa, Masaki Mizoguchi, Yoshiyuki Watanabe, Suguru Yoshida, Tadayoshi Okada
  • Publication number: 20100116380
    Abstract: The invention relates to a method for producing strips (1) of steel, preferably of silicon steel, in particular of grain-oriented silicon steel or of multiphase steel in which a slab (3) is initially cast in a casting machine (2), wherein this is then rolled in at least one roll train (4, 5) to form strip (1) and wherein before and/or after the at least one roll train (4, 5), the slab is heated in at least one furnace (6, 7).
    Type: Application
    Filed: July 21, 2008
    Publication date: May 13, 2010
    Inventors: Juergen Seidel, Joachim Ohlert
  • Patent number: 7695824
    Abstract: A reinforced member which is made from a steel product having a strain aging characteristic and has a closed section at a cross section perpendicular to an axis of the reinforced member. The reinforced member includes a reinforced area which is produced by press-forming the steel product so as to generate a compression strain in the press-formed steel product due to the application of a compression stress to the steel product along the direction from a surface of the steel product to an inside of the steel product, and by giving a strain aging treatment to the press-formed member.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: April 13, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Fumihiko Gejima, Hiroshi Sakurai, Masaki Kuno
  • Publication number: 20100084058
    Abstract: The invention produces a grain-oriented electrical steel sheet having a primary recrystallization structure in which Goss-oriented crystal grains and crystal grains having a coincidence orientation relationship to the Goss orientation are aligned in the rolling direction. It is characterized heating a slab containing, in mass %, C: 0.025 to 0.10%, Si: 2.5 to 4.5%, Mn: 0.03 to 0.55%, and Al: 0.007 to 0.040% to 1,100 to 1,450° C.
    Type: Application
    Filed: April 22, 2008
    Publication date: April 8, 2010
    Inventors: Takao Mukai, Shinya Hayashi, Atsushi Tanaka, Hiroyuki Mimura, Hisataka Uto
  • Patent number: 7678208
    Abstract: In the press hardening process when a blank is formed and cooled in cooled tools (30,31), the tools are used as a fixture during the hardening. The tools have alternately contact surfaces (33,34) and clearances (35) in a certain area against the formed product (20-24) and the contact surfaces have an area that is less than 20% of the area. As a result, this area will be a soft zone (11) of the final product and the zone will have good dimensional accuracy.
    Type: Grant
    Filed: October 4, 2005
    Date of Patent: March 16, 2010
    Assignee: Gestamp Hardtech AB
    Inventor: Hans Bodin
  • Publication number: 20100037994
    Abstract: A method of processing a workpiece of maraging steel includes receiving a workpiece of maraging steel that has been subjected to thermomechanical processing at an austenite solutionizing temperature and then directly aging the workpiece of maraging steel at an aging temperature to form precipitates within a microstructure of the workpiece of maraging steel, without any intervening heat treatments between the thermomechanical processing and the direct aging.
    Type: Application
    Filed: August 14, 2008
    Publication date: February 18, 2010
    Inventor: Gopal Das
  • Publication number: 20100018615
    Abstract: A thermal mechanical treatment method includes hot working a precipitation hardening martensitic stainless steel, quenching the stainless steel, and aging the stainless steel. According to certain embodiments, the thermal mechanical treatment does not include solution heat treating the stainless steel prior to aging or cryogenically cooling the stainless steel. An article includes a precipitation hardening martensitic stainless steel having a process history that includes hot working the stainless steel, quenching the stainless steel, and aging the stainless steel. According to certain embodiments, the process history does not include solution heat treating the stainless steel prior to aging or cryogenically cooling the stainless steel.
    Type: Application
    Filed: July 28, 2008
    Publication date: January 28, 2010
    Applicant: ATI Properties, Inc.
    Inventors: Wei-Di Cao, Erin T. McDevitt
  • Publication number: 20090314395
    Abstract: The present invention provides high strength thin-gauge steel sheet with excellent elongation and hole expandability having a tensile strength of 500 MPa or more and a method of production of high strength thin-gauge steel sheet with excellent elongation and hole expandability enabling production of this on an industrial scale, that is, high strength thin-gauge steel sheet comprised of, by mass %, C: 0.03 to 0.25%, Si: 0.4 to 2.0%, Mn: 0.8 to 3.1%, P?0.02%, S?0.02%, Al?2.0%, N?0.01%, and a balance of Fe and unavoidable impurities and having a microstructure comprised of ferrite with an area fraction of 10 to 85% and residual austenite with a volume fraction of 1 to 10%, an area fraction of 10% to 60% of tempered martensite, and a balance of bainite.
    Type: Application
    Filed: August 27, 2009
    Publication date: December 24, 2009
    Applicant: Nippon Steel Corporation
    Inventors: Toshiki Nonaka, Hirokazu Taniguchi, Koichi Goto
  • Publication number: 20090300902
    Abstract: A cold-rolled steel sheet that is suitable for battery cases and has low anisotropy is composed of, by mass %, C: ?0.0030%, Si: ?0.02%, Mn: 0.15 to 0.19%, P: ?0.020%, S: ?0.015%, N: ?0.0040%, Al: 0.020 to 0.070%, Nb: 1.00?Nb/C (atomic equivalent ratio)?5.0, B: 1 ppm?B-(11/14)N?15 ppm (in the expression, B and N denote the contents of the respective elements), and the balance: being Fe and inevitable impurities, and has a planar anisotropy ?r of the r-value in the range of ?0.10??r?0.10. In a process for producing the steel sheet, the cold rolling is performed at a rolling ratio of 70 to 87%, and then annealing is performed on a continuous annealing line at an annealing temperature of from the recrystallization temperature to 830° C.
    Type: Application
    Filed: December 20, 2006
    Publication date: December 10, 2009
    Applicant: JFE Steel Corporation
    Inventors: Nobuko Mineji, Reiko Sugihara, Tadashi Inoue
  • Publication number: 20090301613
    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: Application
    Filed: April 6, 2009
    Publication date: December 10, 2009
    Inventors: Jayoung Koo, 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
  • Publication number: 20090242085
    Abstract: A dual phase steel sheet with good bake-hardening properties is provided. The steel sheet is characterized in containing (in terms of percent by mass) C: no less than 0.06% and less than 0.25%; Si+Al: 0.5 to 3%; Mn: 0.5 to 3%; P: no more than 0.15%; and S: no more than 0.02%; and also meeting the following condition (in terms of space factor) that retained austenite is at least 3%, bainite is at least 30%, and ferrite is no more than 50%, and further characterized in differing in stress larger than 50 MPa before and after application of 2% pre-strain and ensuing heat treatment for paint baking at 170° C. for 20 minutes. The steel sheet has well-balanced strength and workability, exhibits good bake-hardening properties at the time of paint baking, and offers good resistance to natural aging.
    Type: Application
    Filed: June 3, 2009
    Publication date: October 1, 2009
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd)
    Inventors: Shushi IKEDA, Koichi Makii, Hiroshi Akamizu
  • Publication number: 20090202383
    Abstract: A main object thereof is to provide a non-oriented electrical steel sheet being excellent in surface characteristics and having both excellent mechanical characteristics and magnetic characteristics necessary for a rotor of rotating machines such as motors and generators which rotate at a high speed, and a method for producing the same. To achieve the object, the present invention provides a non-oriented electrical steel sheet comprising in % by mass: 0.06% or less of C; 3.5% or less of Si; from 0.05% or more to 3.0% or less of Mn; 2.5% or less of Al; 0.30% or less of P; 0.04% or less of S; 0.02% or less of N; at least one element selected from the group consisting of Nb, Ti, Zr and Vin the predetermined range; and a balance consisting of Fe and impurities; and having a recrystallized fraction being less than 90%.
    Type: Application
    Filed: December 6, 2005
    Publication date: August 13, 2009
    Inventors: Ichirou Tanaka, Hiroshi Fujimura, Hirokatsu Nitomi, Hiroyoshi Yashiki, Kouji Nishida, Hiroki Takamaru
  • Publication number: 20090178739
    Abstract: It is an object of the present invention to provide a ferromagnetic Fe-based alloy having a large reversible strain obtained by application and removal of a magnetic field gradient. The Fe-based alloy contains one or two or more types selected from Al: 0.01 to 11%, Si: 0.01 to 7% and Cr: 0.01 to 26%, or Al: 0.01 to 11%, Si: 0.01 to 7%, Cr: 0.01 to 26% and Ni: 35 to 50%. A twin crystal interface is introduced by working the Fe-based alloy at a working rate: 10% or more. An area ratio of the twin crystal interface to a crystal grain boundary is 0.2 or more. One or two or more types of Ti: 0.01 to 5%, V: 0.01 to 10%, Mn: 0.01 to 5%, Co: 0.01 to 30%, Ni: 0.01 to 10%, Cu: 0.01 to 5%, Zr: 0.01 to 5%, Nb: 0.01 to 5%, Mo: 0.01 to 5%, Hf: 0.01 to 5%, Ta: 0.01 to 5%, W: 0.01 to 5%, B: 0.001 to 1%, C: 0.001 to 1%, P: 0.001 to 1% and S: 0.001 to 1% may be added to the Fe-based alloy if needed.
    Type: Application
    Filed: February 20, 2009
    Publication date: July 16, 2009
    Applicant: JAPAN SCIENCE AND TECHNOLOGY AGENCY
    Inventors: Kiyohito Ishida, Ryosuke Kainuma, Katunari Oikawa, Yuji Sutou, Toshihiro Omori, Keisuke Ando
  • Publication number: 20090065106
    Abstract: The present invention provides an ultra soft high carbon hot-rolled steel sheet. The ultra soft high carbon hot-rolled steel sheet contains 0.2% to 0.7% of C, 0.01% to 1.0% of Si, 0.1% to 1.0% of Mn, 0.03% or less of P, 0.035% or less of S, 0.08% or less of Al, 0.01% or less of N, and the balance being Fe and incidental impurities and further contains 0.0010% to 0.0050% of B and 0.05% to 0.30% of Cr in some cases. In the texture of the steel sheet, an average ferrite grain diameter is 20 ?m or more, a volume ratio of ferrite grains having a grain diameter of 10 ?m or more is 80% or more, and an average carbide grain diameter is in the range of 0.10 to less than 2.0 ?m. In addition, the steel sheet is manufactured by the steps, after rough rolling, performing finish rolling at a reduction ratio of 10% or more and at a finish temperature of (Ar3?20° C.) or more in a final pass, then performing first cooling within 2 seconds after the finish rolling to a cooling stop temperature of 600° C.
    Type: Application
    Filed: September 19, 2006
    Publication date: March 12, 2009
    Inventors: Hideyuki Kimura, Takeshi Fujita, Nobuyuki Nakamura, Satoshi Ueoka, Naoya Aoki, Kenichi Mitsuzuka
  • Publication number: 20090020196
    Abstract: A cold rolled steel sheet, and a method of manufacturing the same, designed to have aging resistance and excellent formability suitable for use in automobile bodies, electronic appliances, and the like. The cold rolled steel sheet comprises in weight %: 0.003% or less of C, 0.003˜0.03% of S, 0.01˜0.1% of Al, 0.02% or less of N, 0.2% or less of P, at least one of 0.03˜0.2% of Mn and 0.005˜0.2% of Cu, and a balance of Fe and other unavoidable impurities. When the steel sheet comprises one of Mn and Cu, the composition of Mn, Cu, and S satisfies at least one relationship: 0.58*Mn/S?10 and 1?0.5*Cu/S?10, and when the steel sheet comprises both Mn and Cu, the composition of Mn, Cu, and S satisfies the relationship: Mn+Cu?0.3 and 2?0.5*(Mn+Cu)/S?20. Participates of MnS, CuS, and (Mn, Cu)S in the steel sheet have an average size of 0.2 ?m or less.
    Type: Application
    Filed: November 10, 2004
    Publication date: January 22, 2009
    Applicant: POSCO
    Inventors: Jeong-Bong Yoon, Won-Ho Son, Ki-Bong Kang, Noi-Ha Cho, Ki-Duck Park
  • Publication number: 20080308194
    Abstract: The subject of the invention is a process for manufacturing a part made of steel having a multiphase microstructure, said microstructure comprising ferrite and being homogeneous in each of the regions of said part, which process comprises the steps consisting in: cutting a blank from a strip of steel, the composition of which is typical of that of steels having a multiphase microstructure; said blank is heated so as to reach a soak temperature Ts above Ac1 but below Ac3 and held at this soak temperature Ts for a soak time ts adjusted so that the steel, after the blank has been heated, has an austenite content equal to or greater than 25% by area; said heated blank is transferred into a forming tool so as to hot-form said part; and said part is cooled within the tool at a cooling rate V such that the microstructure of the steel, after the part has been cooled, is a multiphase microstructure, said microstructure comprising ferrite and being homogeneous in each of the regions of said part.
    Type: Application
    Filed: September 18, 2006
    Publication date: December 18, 2008
    Applicant: ArcelorMittal France
    Inventors: Jacques Corquillet, Jacques Devroc, Jean-Louis Hochard, Jean-Pierre Laurent, Antoine Moulin, Nathalie Romanowski
  • Publication number: 20080302453
    Abstract: A shaped steel, such as H-shaped steel, excellent in fire resistance, where a flange portion has 50% or more of a ratio of strength, 80% or less of yield ratio, and 100 J or more of impact strength of Charpy impact test at 0° C., wherein the ratio of strength=(proof stress of 0.2% at 600° C.)/(yield strength at room temperature), and a producing method thereof are provided. The shaped steel comprises in mass percent (%): C: 0.03-0.15; Mo: 0.1-0.6; V?0.35; and N: 0.002-0.012, and the balance being iron and residual impurities, wherein (x) a mol fraction of precipitate of alloy carbides and alloy carbonitrides at 600° C. is 0.3% or more, and (y) the ratio of the mol fraction of precipitate of alloy carbides and alloy carbonitrides at 300° C. to the mol fraction of precipitate of alloy carbides and alloy carbonitrides at 600° C. is 2.0 or less.
    Type: Application
    Filed: July 26, 2005
    Publication date: December 11, 2008
    Inventors: Suguru Yoshida, Kazuhiko Eda, Hiroshi Kita
  • Publication number: 20080256772
    Abstract: A method of manufacturing forks for lift trucks comprises the steps of: providing a straight metal bar designed to make the fork, heating the bar at a segment thereof where the fork knee is to be formed, bending the bar at the heated segment in order to form the knee by carrying out bending in a closed-die press provided with containment walls that, when bending has been completed, enclose the knee so as to define the surface contours of the latter.
    Type: Application
    Filed: April 8, 2008
    Publication date: October 23, 2008
    Inventor: Emilio Bolzoni
  • Publication number: 20080251166
    Abstract: Disclosed herein is a precipitation hardening cold-rolled steel sheet and method for manufacturing the same, which can be used for structural components such as seat rails and the like of a vehicle body. The steel sheet comprises, by weight %, C: 0.07˜0.1%, Mn: 1.4˜1.7%, P: 0.05˜0.07%, S: 0.005% or less, acid-soluble Al: 0.1˜0.15%, Nb: 0.06˜0.09%, B: 0.0008˜0.0012%, Sb: 0.02˜0.06%, and the balance of Fe and other unavoidable impurities. The steel sheet has a yield strength of 750 MPa or more and a yield ratio of 85% or more, and is free from surface defects due to a very low degree of oxide enrichment on the surface thereof.
    Type: Application
    Filed: September 28, 2006
    Publication date: October 16, 2008
    Applicant: POSCO
    Inventor: Sang-Ho Han