With Working Patents (Class 148/608)
  • Patent number: 10000832
    Abstract: Provided is duplex stainless steel having high strength, SCC resistance and SSC resistance excellent in a high-temperature chloride environment, and capable of suppressing precipitation of a ? phase. The duplex stainless steel of the present embodiment includes, in mass %, of: C: at most 0.03%; Si: 0.2 to 1%; Mn: more than 5.0% to at most 10%; P: at most 0.040%; S: at most 0.010%; Ni: 4.5 to 8%; sol. Al: at most 0.040%; N: more than 0.2% to at most 0.4%; Cr: 24 to 29%; Mo: 0.5 to less than 1.5%; Cu: 1.5 to 3.5%; W: 0.05 to 0.2%; the balance being Fe and impurities, wherein the duplex stainless steel satisfies Formula (1): Cr+8Ni+Cu+Mo+W/2?65 . . . (1), where a symbol of each element in Formula (1) represents a content of the element (in mass %).
    Type: Grant
    Filed: August 28, 2012
    Date of Patent: June 19, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hideki Takabe, Hisashi Amaya, Kazuhiro Ogawa
  • Patent number: 9938598
    Abstract: The present invention provides a low-alloy high-purity ferritic stainless steel sheet provided with improved oxidation resistance and high-temperature strength by utilizing Sn addition in trace amounts without relying on excessive alloying of Al and Si which reduces fabricability and weldability or addition of rare elements such as Nb, Mo, W, and rare earths, and a process for producing the same. The high-purity ferritic stainless steel sheet includes C: 0.001 to 0.03%, Si: 0.01 to 2%, Mn: 0.01 to 1.5%, P: 0.005 to 0.05%, S: 0.0001 to 0.01%, Cr: 16 to 30%, N: 0.001 to 0.03%, Al: 0.05 to 3%, and Sn: 0.01 to 1% (% by mass), with the remainder being Fe and unavoidable impurities. A stainless steel slab having such steel components is heated, wherein an extraction temperature is 1100 to 1250° C., and a winding temperature after hot rolling is 650° C. or lower. A hot-rolled sheet is annealed at 900 to 1050° C., and cooled at 10° C./sec or less over a temperature range of 550 to 850° C.
    Type: Grant
    Filed: January 23, 2012
    Date of Patent: April 10, 2018
    Assignee: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Masaharu Hatano, Eiichiro Ishimaru, Akihiko Takahashi
  • Publication number: 20150101714
    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: December 18, 2014
    Publication date: April 16, 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: 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
  • Patent number: 8980018
    Abstract: Ferritic stainless steel sheet for an exhaust part which has little deterioration in strength even if undergoing long term heat history and is low in cost, excellent in heat resistance and workability characterized by containing, characterized by containing, by mass %, C: less than 0.010%, N: 0.020% or less, Si: over 0.1% to 2.0%, Mn: 2.0% or less, Cr: 12.0 to 25.0%, Cu: over 0.9 to 2%, Ti: 0.05 to 0.3%, Nb: 0.001 to 0.1%, Al: 1.0% or less, and B: 0.0003 to 0.003%, having a Cu/(Ti+Nb) of 5 or more, and having a balance of Fe and unavoidable impurities.
    Type: Grant
    Filed: March 25, 2011
    Date of Patent: March 17, 2015
    Assignee: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Junichi Hamada, Shinichi Teraoka, Yoshiharu Inoue, Norihiro Kanno
  • Publication number: 20150013820
    Abstract: Provided is a method of rolling/drawing a nickel-free high-nitrogen stainless steel material, the method including: an intermediate annealing process S11 in which a nickel-free high-nitrogen stainless steel material made of a fine grain structure having a maximum crystal grain size of 30 ?m or less is annealed at a temperature of 900° C. or higher and 1000° C. or lower and then is air-cooled to room temperature; a rolling/drawing process S12 in which the nickel-free high-nitrogen stainless steel material is extended while being thinned or being reduced in diameter; and a final solution treatment process S13 in which the nickel-free high-nitrogen stainless steel material is heated to a temperature of 1200° C. or higher and 1400° C. or lower and then is air-cooled to room temperature.
    Type: Application
    Filed: November 30, 2012
    Publication date: January 15, 2015
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Tetsushi Taguchi, Yasuyuki Katada
  • Publication number: 20140209220
    Abstract: It is an object of the present invention to provide a metal diaphragm capable of achieving a higher strength, excellent corrosion resistance, and a smooth surface condition, and a pressure sensor including the diaphragm. The diaphragm according to the present invention includes a two-phase stainless steel having a composition of 24 to 26 mass % Cr, 2.5 to 3.5 mass % Mo, 5.5 to 7.5 mass % Ni, 0.03 mass % or less C, 0.08 to 0.3 mass % N, and the balance Fe and inevitable impurities, and having a 0.2% proof stress of 1300 MPa or higher.
    Type: Application
    Filed: January 23, 2014
    Publication date: July 31, 2014
    Applicant: Seiko Instruments Inc.
    Inventors: Takuma OTOMO, Keita NAITO, Ryo SUGAWARA, Tomoo KOBAYASHI
  • Patent number: 8747575
    Abstract: A martensitic stainless steel for inexpensive seamless pipe having 655 MPa yield strength, high toughness and excellent corrosion resistance in high CO2 environments, and a method for manufacturing thereof is provided. The steel comprises C: 0.005-0.05%, Si: 0.1-0.5%, Mn: 0.1-2.0%, P: ?0.05%, S: ?0.005%, Cr: 10.0-12.5%, Mo: 0.1-0.5%, Ni: 1.5-3.0%, N: ?0.02%, Al: 0.01-0.1%, by weight, while FI value defined by the formula [FI=Cr+Mo?Ni?30(C+N)] being 5.00 to 8.49, and balance of substantially Fe. The method comprises the steps of reheating the cooled steel at temperatures from 780° C. to 960° C., quenching the reheated steel, and then tempering the quenched steel at temperatures from 550° C. to 650° C.
    Type: Grant
    Filed: December 30, 2009
    Date of Patent: June 10, 2014
    Assignee: NKKTUBES
    Inventors: Shuji Hashizume, Yusuke Minami, Tatsuo Ono
  • Publication number: 20140137994
    Abstract: Austenitic stainless steel having high temperature strength and excellent nitric acid corrosion resistance is provided. The austenitic stainless steel according to the present embodiment including, in mass percent, C: at most 0.050%, Si: 0.01 to 1.00%, Mn: 1.75 to 2.50%, P: at most 0.050%, S: at most 0.0100%, Ni: 20.00 to 24.00%, Cr: 23.00 to 27.00%, Mo: 1.80 to 3.20%, and N: 0.110 to 0.180%, the balance being Fe and impurities, a grain size number of crystal grains based on JIS G0551 (2005) is at least 6.0, and an area fraction of a ? phase is at most 0.1%.
    Type: Application
    Filed: June 20, 2012
    Publication date: May 22, 2014
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventor: Masaki Ueyama
  • Patent number: 8506729
    Abstract: An austenitic stainless steel hot-rolled steel material can be provided which has sea-water resistance and strength superior to conventional steel. Low-temperature toughness can be maintained, which is preferable in a structural member of speedy craft. The steel material can include an austenitic stainless steel hot-rolled steel material which excels in the properties of corrosion resistance, proof stress, and low-temperature toughness. In such austenitic stainless steel hot-rolling steel material, e.g., PI [=Cr+3.3(Mo+0.5W)+16N] ranges from 35 to 40, ? cal [=2.9 (Cr+0.3Si+Mo+0.5W)?2.6 (Ni+0.3Mn+0.25Cu+35C+20N)?18] ranges from ?6 to +2, and a 0.2% proof stress at room temperature is not less than 550 MPa, Charpy impact value measured using a V-notch test piece at ?40° C. is not less than 100 J/cm2, and the pitting potential measured in a deaerated aqueous solution of 10% NaCl at 50° C. (Vc?100) is not less than 500 mV (as it relates to saturated Ag/AgCl).
    Type: Grant
    Filed: January 13, 2012
    Date of Patent: August 13, 2013
    Assignee: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Yuusuke Oikawa, Shinji Tsuge, Shigeo Fukumoto, Kazuhiro Suetsugu, Ryo Matsuhashi, Hiroshige Inoue
  • Patent number: 8440029
    Abstract: A stainless steel having good conductivity and ductility for use in a fuel cell separator is provided. In particular, the stainless steel has a composition of, in terms of % by mass, C: 0.01% or less, Si: 1.0% or less, Mn: 1.0% or less, S: 0.01% or less, P: 0.05% or less, Al: 0.20% or less, N: 0.02% or less, Cr: 20 to 40%, Mo: 4.0% or less, and at least one selected from Nb, Ti, and Zr: 0.05 to 0.60% in total, the balance being Fe and unavoidable impurities. At least one precipitate having an equivalent circle diameter of 0.1 ?m or more is present per 100 ?m2, a ratio of a thickness t (?m) to a maximum diameter Dmax (?m) of the precipitates satisfies formula (1) below 20?t/Dmax??(1) and the thickness is 200 ?m or less.
    Type: Grant
    Filed: July 26, 2010
    Date of Patent: May 14, 2013
    Assignee: JFE Steel Corporation
    Inventors: Shinsuke Ide, Atsutaka Honda, Shin Ishikawa, Takumi Ujiro
  • Patent number: 8323428
    Abstract: Dispersion strengthened aluminum base alloys are shaped into metal parts by high strain rate forging compacts or extruded billets composed thereof. The number of process steps required to produce the forged part are decreased and strength and toughness of the parts are increased. The dispersion strengthened alloy may have the formula Albal,Fea,SibXc, wherein X is at least one element selected from Mn, V, Cr, Mo, W, Nb, and Ta, “a” ranges from 2.0 to 7.5 weight-%, “b” ranges from 0.5 to 3.0 weight-%, “c” ranges from 0.05 to 3.5 weight-%, and the balance is aluminum plus incidental impurities. Alternatively, the dispersion strengthened alloy may be described by the formula Albal,Fea,SibVdXc, wherein X is at least one element selected from Mn, Mo, W, Cr, Ta, Zr, Ce, Er, Sc, Nd, Yb, and Y, “a” ranges from 2.0 to 7.5 weight-%, “b” ranges from 0.5 to 3.0 weight-%, “d” ranges from 0.05 to 3.5 weight-%, “c” ranges from 0.02 to 1.50 weight-%, and the balance is aluminum plus incidental impurities.
    Type: Grant
    Filed: September 8, 2006
    Date of Patent: December 4, 2012
    Assignee: Honeywell International Inc.
    Inventors: Paul Chipko, Derek Raybould
  • Patent number: 8313592
    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: Grant
    Filed: March 15, 2011
    Date of Patent: November 20, 2012
    Assignee: ATI Properties, Inc.
    Inventors: Wei-Di Cao, Erin T. McDevitt
  • Patent number: 8303733
    Abstract: This stainless steel sheet includes, in terms of mass %, C: 0.001 to 0.1%, N: 0.01 to 0.15%, Si: 0.01 to 2%, Mn: 0.1 to 10%, P: 0.05% or less, S: 0.01% or less, Ni: 0.5 to 5%, Cr: 10 to 25%, and Cu: 0.5 to 5%, with a remainder being Fe and unavoidable impurities, and contains a ferrite phase as a main phase and 10% or more of an austenite phase, wherein a work-hardening rate in a strain range of up to 30% is 1000 MPa or more which is measured by a static tensile testing and a difference between static and dynamic stresses which occur when 10% of deformation is caused is 150 MPa or more. This method for producing a stainless steel includes annealing a cold-rolled steel sheet under conditions where a holding temperature is set to be in a range of 950 to 1150° C. and a cooling rate until 400° C. is set to be in a range of 3° C./sec or higher.
    Type: Grant
    Filed: January 22, 2009
    Date of Patent: November 6, 2012
    Assignee: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Junichi Hamada, Haruhiko Kajimura, Eiichiro Ishimaru
  • Patent number: 8273191
    Abstract: Provided is a high-strength stainless steel material having less deterioration in mechanical strength and improved workability, particularly bending workability compared with conventional steel materials. The high-strength stainless steel material of the present invention has a specific composition, has a metal microstructure composed of two phases, that is a ferrite phase and a martensite phase, has a ?max of from 50 to 85, the ?max being represented by the following equation (1): ?max=420Wc+470WN+23WNi+7WMn?11.5WCr?11.5WSi+189??(1) wherein, Wc, WN, WNi, WMn, WCr, and WSi; represent contents (unit: mass %) of C, N, Ni, Mn, Cr, and Si relative to the total mass of the stainless steel material, respectively; and has a difference of 300 HV or less in hardness between the ferrite phase and the martensite phase.
    Type: Grant
    Filed: February 2, 2009
    Date of Patent: September 25, 2012
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Naoki Hirakawa, Hiroshi Fujimoto, Satoshi Suzuki
  • Patent number: 8262815
    Abstract: The present invention provides high purity ferrite stainless steel able to reduce deterioration in surface conditions due to pitting corrosion or rusting or other corrosion to an extent no different from SUS304 or better without inviting a drop in manufacturability or workability and without relying on the addition of rare elements, and a method of production of the same, that is, ferritic stainless steel containing, by mass %, C: 0.01% or less, Si: 0.01 to 0.20%, Mn: 0.01 to 0.30%, P: 0.04% or less, S: 0.01% or less, Cr: 13 to 22%, N: 0.001 to 0.020%, Ti: 0.05 to 0.35%, Al: 0.005 to 0.050%, Sn: 0.001 to 1%, and a balance of Fe and unavoidable impurities to which Sn is added to modify the passive film and improve the corrosion resistance. To improve the effect of modification of the passive film by the addition of Sn, after the final annealing, the steel is held in the 200 to 700° C. temperature range for 1 minute or more.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: September 11, 2012
    Assignee: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Masaharu Hatano, Akihiko Takahashi
  • Publication number: 20120190321
    Abstract: A nonmagnetic stainless steel which has a higher electrical resistivity than existing nonmagnetic alloys, a production process for producing the stainless steel, and a radio wave receiver. The receiver has a main case and rear cover constituted of a nonmagnetic stainless steel having an electrical resistivity as high as more than 100 ??·cm and consisting of C: not more than 0.1%, Si: 4.0-7.5%, Mn: not more than 2.0%, Ni: 25.5-30.0%, Cr: 15.0-20.0%, Mo: 0.1-3.0%, Cu: 0-2.0%, in mass % and the balance Fe and impurities. Even if some variable magnetic flux generated by a coil of an antenna runs through the main case and the rear cover, the receiving efficiency of the antenna can be prevented from being reduced by eddy current loss and a sufficient radio receiving sensitivity can be obtained. This nonmagnetic stainless steel is produced by hot and/or cold plastic working and subsequent solution treating conducted at 1,000-1,180° C.
    Type: Application
    Filed: July 29, 2010
    Publication date: July 26, 2012
    Applicants: HITACHI METALS, LTD., CASIO COMPUTER CO., LTD.
    Inventors: Junichi Sato, Toshihiro Uehara, Kenji Yokoyama
  • Publication number: 20120145285
    Abstract: The invention relates to a method for producing a component, made of an iron-chromium alloy that precipitates Laves phases and/or particles containing Fe and/or particles containing Cr and/or particles containing Si and/or carbides, by subjecting a semi-finished product made of the alloy to a thermomechanical treatment, wherein in a first step, the alloy is solution heat treated at temperatures?the solution heat treatment temperature and is subsequently quenched in stationary protective gas or air, moving (blown) protective gas or air, or water. In a second step, a mechanical forming of the semi-finished product in a range from 0.05 to 99% is performed, and in a subsequent step, Laves phases Fe2(M, Si) or Fe7(M, Si)6 and/or particles containing Fe and/or particles containing Cr and/or particles containing Si and/or carbides are precipitated in a specific and finely distributed manner in that the component produced from the formed semi-finished product is brought to an application temperature between 550° C.
    Type: Application
    Filed: August 18, 2010
    Publication date: June 14, 2012
    Applicant: THYSSENKRUPP VDM GMBH
    Inventors: Heike Hattendorf, Osman Ibas
  • Patent number: 8177929
    Abstract: A metal gasket formed from a suitable iron-nickel chromium alloy includes at least one embossment that exhibits essentially full functional recovery at temperatures exceeding 1000° F. and including in the range of 1100° F. to 1600° F. or more and which is made from sheet material that is work hardened and strengthened by cold rolling, or a combination of cold rolling and precipitation hardening, without any post embossment heat treating that would act to further harden the material. Suitable iron-nickel-chromium alloys include those comprising, by weight, greater than 18% nickel; greater than 14% chrome and 0.1-10% of at least one element selected from the group consisting of Mo, Ti, V, Al, Co, Nb, Ta and Cu, with the balance being substantially Fe, wherein the gasket sheet alloy has a deformed microstructure.
    Type: Grant
    Filed: March 18, 2010
    Date of Patent: May 15, 2012
    Assignee: Federal-Mogul World Wide, Inc.
    Inventor: Thomas Zurfluh
  • Patent number: 8097098
    Abstract: The invention concerns martensitic stainless steel, characterized in that its composition in weight percentages is as follows: 9%=Cr=13%; 1.5%=Mo=3%; 8%=Ni=14%; 1%=Al=2%; 0.5%=Ti=1.5% with AI+Ti=2.25%; traces=Co=2%; traces=W=1% with Mo+(W/2)=3%; traces=P=0.02%; traces=S=0.0050%; traces=N=0.0060%; traces=C=0.025%; traces=Cu=0.5%; traces=Mn=3%; traces=Si=0.25%; traces=O=0.0050%; and is such that: Ms (° C.)=1302 42 Cr 63 Ni 30 Mo+20AI-15W-33Mn-28Si-30Cu-13Co+10 Ti=50Cr eq/Ni eq=1.05 with Cr eq (%)=Cr+2Si+Mo+1.5 Ti+5.5 AI+0.6W Ni eq (%)=2Ni+0.5 Mn+3O C+25 N+Co+0.3 Cu. The invention also concerns a method for making a mechanical part using said steel, and the resulting part.
    Type: Grant
    Filed: June 26, 2006
    Date of Patent: January 17, 2012
    Assignee: Aubert & Duval
    Inventor: Jacques Montagnon
  • Patent number: 8043446
    Abstract: A high manganese duplex stainless steel with excellent hot workability, comprising (in weight %): less than 0.1% of C; 0.05-2.2% of Si; 2.1-7.8% of Mn; 20-29% of Cr; 3.0-9.5% of Ni; 0.08-0.5% of N; less than 5.0% of Mo and 1.2-8% of W, alone or composite; the balance Fe and inevitable impurities; and a method for manufacturing the duplex stainless steel, comprising the steps of: solution heating the duplex stainless steel composition at a temperature of 1,050 to 1,250° C., hot working at a starting temperature of 1,130 to 1,280° C. and then ending at a temperature greater than 1,000° C., and then cooling within the temperature range from 1,000 to 700° C. at a cooling rate of more than 3° C./min. The duplex stainless steel exhibits a reduction in area of more than 50% at 1,050° C., and possesses a yield strength of more than 400 MPa, and a corrosion rate of less than 0.36 mm/year, after solution heating.
    Type: Grant
    Filed: April 26, 2002
    Date of Patent: October 25, 2011
    Assignee: Research Institute of Industrial Science and Technology
    Inventors: Jae-Young Jung, Bong-Year Ma
  • Patent number: 7967927
    Abstract: A nanocarbide precipitation strengthened ultrahigh-strength, corrosion resistant, structural steel possesses a combination of strength and corrosion resistance comprising in combination, by weight, about: 0.1 to 0.3% carbon (C), 8 to 17% cobalt (Co), 0 to 10% nickel (Ni), 6 to 12% chromium (Cr), less than 1% silicon (Si), less than 0.5% manganese (Mn), and less than 0.15% copper (Cu), with additives selected from the group comprising about: less than 3% molybdenum (Mo), less than 0.3% niobium (Nb), less than 0.8% vanadium (V), less than 0.2% tantalum (Ta), less than 3% tungsten (W), and combinations thereof, with additional additives selected from the group comprising about: less than 0.2% titanium (Ti), less than 0.2% lanthanum (La) or other rare earth elements, less than 0.15% zirconium (Zr), less than 0.005% boron (B), and combinations thereof, impurities of less than about: 0.02% sulfur (S), 0.012% phosphorus (P), 0.015% oxygen (O) and 0.
    Type: Grant
    Filed: January 9, 2007
    Date of Patent: June 28, 2011
    Assignee: QuesTek Innovations, LLC
    Inventors: Charles J. Kuehmann, Gregory B. Olson, Herng-Jeng Jou
  • Patent number: 7947136
    Abstract: An austenitic, substantially ferrite-free steel alloy and a process for producing components therefrom. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.
    Type: Grant
    Filed: March 16, 2010
    Date of Patent: May 24, 2011
    Assignees: Boehler Edelstahl GmbH & Co KG, Schoeller-Bleckmann Oilfield Technology GmbH
    Inventors: Gabriele Saller, Herbert Aigner, Josef Bernauer, Raimund Huber
  • Patent number: 7931758
    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: Grant
    Filed: July 28, 2008
    Date of Patent: April 26, 2011
    Assignee: ATI Properties, Inc.
    Inventors: Wei-Di Cao, Erin T. McDevitt
  • Patent number: 7905967
    Abstract: The occurrence of delayed fracture which is found in a hot worked martensitic stainless steel is prevented by subjecting the steel, after hot working and prior to heat treatment for hardening by quenching from a temperature of at least Ac1 point of the steel, to preliminary softening heat treatment under such conditions that the softening parameter P defined below is at least 15,400 and the softening temperature T is lower than the Ac1 point: P(softening parameter):P=T(20+log t) T: softening temperature [K] t: duration of softening treatment [Hr]. The present invention is particularly effective for a martensitic stainless steel having a steel composition in which the amount of effective dissolved C and N (=[C*+10N*]) where C* and N* are calculated by the following formulas is larger than 0.45: C*=C?[12{(Cr/52)×(6/23)}/10, and N*=N?[14{(V/51)+(Nb/93)}/10]?[14{(Ti/48)+(B/11)+(Al/27)}/10].
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: March 15, 2011
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventor: Nobuyuki Mori
  • Patent number: 7806993
    Abstract: The present invention provides a ferritic stainless steel that has excellent strength at high temperature, oxidation resistance at high temperature, and salt corrosion resistance at high temperature and that can be used under high temperatures exceeding 900° C., and a method of producing the same. Specifically, the composition thereof is adjusted, on a % by mass basis, so as to include C: 0.02% or less; Si: 2.0% or less; Mn: 2.0% or less; Cr: from 12.0 to 40.0%; Mo: from 1.0 to 5.0%; W: more than 2.0% and 5.0% or less; wherein the total content of Mo and W: (Mo+W)?4.3%, Nb: from 5 (C+N) to 1.0%, N: 0.02% or less, and Fe and inevitable impurities as residual.
    Type: Grant
    Filed: June 2, 2003
    Date of Patent: October 5, 2010
    Assignee: JFE Steel Corporation
    Inventors: Atsushi Miyazaki, Kenji Takao, Osamu Furukimi
  • Publication number: 20100180990
    Abstract: The present invention relates to an impact beam for use in a vehicle. More specifically, the invention relates to an impact beam comprising precipitation hardenable stainless steel, and a method of producing such a beam. The precipitation hardenable stainless steel has a composition, all in percent by weight, of: C max 0.07 Si max 1.2 Mn max 0.7 Cr 10-14 Mo max 1.5 Ni 7-12 Cu max 2.6 Ti 0.6-2.0 (Nb+Ta) max 0.7 balance Fe and normally occurring impurities. An impact beam comprising precipitation hardenable stainless steel, according to the invention, provides improved impact absorbing properties per unit of weight, and can be formed by conventional hot forming techniques.
    Type: Application
    Filed: May 29, 2008
    Publication date: July 22, 2010
    Applicant: SANDVIK INTELLECTUAL PROPERTY AB
    Inventor: Carl-Johan Irander
  • Patent number: 7758707
    Abstract: The invention relates to a martensitic stainless steel to be used for making a razor, surgical and similar blades or other cutting tools, which steel contains 0.40 to 0.55 wt % carbon, 0.8 to 1.5 wt % silicon, 0.7 to 0.85 wt % manganese, 13.0 to 14.0 wt % chromium, 1.0 to 1.5 wt % molybdenum and 0.2 to 0.4 wt % nickel, 0.02 to 0.04 wt % nitrogen, the balance of the steel being iron and inevitable impurities. The invention also relates to a method of manufacturing the said steel.
    Type: Grant
    Filed: June 16, 2006
    Date of Patent: July 20, 2010
    Assignee: Outokumpu Oyj
    Inventor: Chris Millward
  • Publication number: 20100170597
    Abstract: A metal gasket formed from a suitable iron-nickel chromium alloy includes at least one embossment that exhibits essentially full functional recovery at temperatures exceeding 1000° F. and including in the range of 1100° F. to 1600° F. or more and which is made from sheet material that is work hardened and strengthened by cold rolling, or a combination of cold rolling and precipitation hardening, without any post embossment heat treating that would act to further harden the material. Suitable iron-nickel-chromium alloys include those comprising, by weight, greater than 18% nickel; greater than 14% chrome and 0.1-10% of at least one element selected from the group consisting of Mo, Ti, V, Al, Co, Nb, Ta and Cu, with the balance being substantially Fe, wherein the gasket sheet alloy has a deformed microstructure.
    Type: Application
    Filed: March 18, 2010
    Publication date: July 8, 2010
    Inventor: Thomas Zurfluh
  • Publication number: 20100170596
    Abstract: An austenitic, substantially ferrite-free steel alloy and a process for producing components therefrom. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.
    Type: Application
    Filed: March 16, 2010
    Publication date: July 8, 2010
    Applicants: Boehler Edelstahl GmbH & Co KG, Schoeller-Bleckmann Oilfield Technology GmbH
    Inventors: Gabriele Saller, Herbert Aigner, Josef Bernauer, Raimund Huber
  • Publication number: 20100116382
    Abstract: An austenitic stainless steel excellent in intergranular corrosion resistance and stress corrosion cracking resistance, comprising: C: 0.005 wt % or less; Si: 0.5 wt % or less; Mn: 0.5 wt % or less; P: 0.005 wt % or less; S: 0.005 wt % or less; Ni: 15.0 to 40.0 wt %, Cr: 20.0 to 30.0 wt %, N: 0.01 wt % or less; O: 0.01 wt % or less; and the balance of Fe and inevitable impurities, wherein the content of B included in the inevitable impurities is 3 wt ppm or less.
    Type: Application
    Filed: April 24, 2008
    Publication date: May 13, 2010
    Applicants: Japan Atomic Energy Agency, Kobelco Research Institute, Inc., Kabushiki Kaisha Kobe Seiko Sho
    Inventors: Kiyoshi Kiuchi, Ikuo Ioka, Chiaki Kato, Nobutoshi Maruyama, Ichiro Tsukatani, Makoto Tanabe, Jumpei Nakayama
  • Patent number: 7708841
    Abstract: An austenitic, substantially ferrite-free steel alloy and a process for producing components therefrom. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.
    Type: Grant
    Filed: December 2, 2004
    Date of Patent: May 4, 2010
    Assignees: Boehler Edelstahl GmbH & Co KG, Schoeller-Bleckmann Oilfield Technology GmbH
    Inventors: Gabriele Saller, Herbert Aigner, Josef Bernauer, Raimund Huber
  • 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: 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
  • Patent number: 7531053
    Abstract: An inexpensive metallic material for interconnects of solid-oxide fuel cells, a fuel cell using the metallic material, and a method for producing the metallic material having excellent oxidation resistance and spalling resistance of an oxide layer, high electrical conductivity, and a small difference in thermal expansion from an electrolyte. Specifically, 0.20 percent by mass or less of C, 0.02 to 1.0 percent by mass of Si, 2.0 percent by mass or less of Mn, 10 to 40 percent by mass of Cr, 0.03 to 5.0 percent by mass of Mo, 0.1 to 3.0 percent by mass of Nb, and at least one element selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Zr, and Hf in a total of 1.0 percent by mass or less are added so as to satisfy 0.1?Mo/Nb?30, for decreasing the growth rate of the oxide layer and improving the spalling resistance.
    Type: Grant
    Filed: August 7, 2003
    Date of Patent: May 12, 2009
    Assignee: JFE Steel Corporation
    Inventors: Shinsuki Ide, Shin Ishikawa, Kenji Takao, Osamu Furukimi, Kunio Fukuda, Atsushi Miyazaki
  • Patent number: 7494551
    Abstract: A Ti-containing ferritic stainless steel sheet and a manufacturing method thereof include stainless steels being formed while a refining load is decreased and having a low yield strength which exhibits superior workability. The Ti-containing ferritic stainless steel sheet contains on mass percent basis: 0.01% or less of C; 0.5% or less of Si; 0.3% or less of Mn; 0.01% to 0.04% of P; 0.01% or less of S; 8% to 30% of Cr; 1.0% or less of Al; 0.05% to 0.5% of Ti; 0.04% or less of N, 8?Ti/(C+N)?30 being satisfied; and the balance being substantially Fe and incidental impurities, wherein a grain size number of ferrite grain is 6.0 or more, and an average diameter Dp of precipitation diameters, each being [(a long axis length of a Ti base precipitate+a short axis length thereof)/2], of the Ti base precipitates in the steel sheet is in the range of from 0.05 ?m to 1.0 ?m.
    Type: Grant
    Filed: June 16, 2003
    Date of Patent: February 24, 2009
    Assignee: JFE Steel Corporation
    Inventors: Yoshihiro Yazawa, Osamu Furukimi, Yasushi Kato
  • Patent number: 7475478
    Abstract: A method for making structural automotive components and the like includes providing a blank of air hardenable martensitic stainless steel in the annealed condition. The steel blank has a thickness in the range of 0.5-5.0 mm., and is formed utilizing stamping, forging, pressing, or roller forming techniques or the like into the form of an automotive structural member. The automotive structural member is then hardened by application of heat, preferably to between 950° C. and 1100° C. for standard martensitic stainless steels. Thereafter, the automotive structural member is preferably cooled at a rate greater than 25° C. per minute to achieve a Rockwell C hardness of at least 39. The automotive structural member may undergo additional heat treating processes including high temperature or low temperature tempering processes which may incorporate electro-coating.
    Type: Grant
    Filed: September 11, 2006
    Date of Patent: January 13, 2009
    Assignee: KVA, Inc.
    Inventors: Edward J. McCrink, Danny Codd
  • Patent number: 7470336
    Abstract: A martensitic alloy in which the ASTM grain size number is at least 5, including (wt. %) up to about 0.5% C, at least about 5% Cr, at least about 0.5% Ni, up to about 15% Co, up to about 8% Cu, up to about 8% Mn, up to about 4% Si, up to about 6% (Mo+W), up to about 1.5% Ti, up to about 3% V, up to about 0.5% Al, and at least about 40% Fe.
    Type: Grant
    Filed: October 5, 2007
    Date of Patent: December 30, 2008
    Assignee: Advanced Steel Technology LLC
    Inventor: Robert F. Buck
  • Publication number: 20080308198
    Abstract: There are provided an austenitic stainless steel having high stress corrosion crack resistance, characterized by containing, in percent by weight, 0.030% or less C, 0.1% or less Si, 2.0% or less Mn, 0.03% or less P, 0.002% or less S, 11 to 26% Ni, 17 to 30% Cr, 3% or less Mo, and 0.01% or less N, the balance substantially being Fe and unavoidable impurities; a manufacturing method for an austenitic stainless steel, characterized in that a billet consisting of the said austenitic stainless steel is subjected to solution heat treatment at a temperature of 1000 to 1150° C.; and a pipe and a in-furnace structure for a nuclear reactor to which the said austenitic stainless steel is applied.
    Type: Application
    Filed: January 13, 2005
    Publication date: December 18, 2008
    Applicants: MITSUBISHI HEAVY INDUSTRIES, LTD., THE TOKYO ELECTRIC POWER COMPANY, INC.
    Inventors: Yasuhiro Sakaguchi, Toshihiko Iwamura, Hiroshi Kanasaki, Hidehito Mimaki, Masaki Taneike, Shunichi Suzuki, Kenrou Takamori, Suguru Ooki, Naoki Anahara, Naoki Hiranuma, Toshio Yonezawa
  • Patent number: 7429302
    Abstract: A structural hot-rolled or cold-rolled stainless steel sheet having improved intergranular corrosion resistance and toughness at the welding heat affected zone and further having low strength and high elongation. The composition of the steel sheet contains less than about 0.008 mass percent of C; about 1.0 mass percent or less of Si; about 1.5 mass percent or less of Mn; about 11 to about 15 mass percent of Cr; more than about 1.0 mass percent and about 2.5 mass percent or less of Ni; less than about 0.10 mass percent of Al; about 0.009 mass percent or less of N; about 0.04 mass percent or less of P; about 0.01 mass percent or less of S; and the balance being Fe and incidental impurities. These contents satisfy the expressions: (Cr)+1.2×(Ni)?15.0; (Ni)+0.5×(Mn)+30×(C)?3.0; (C)+(N)?0.015; and (Cr)?(Mn)?1.7×(Ni)?27×(C)?100×(N)?9.0.
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: September 30, 2008
    Assignee: JFE Steel Corporation
    Inventors: Junichiro Hirasawa, Takumi Ujiro, Osamu Furukimi
  • Patent number: 7399372
    Abstract: A metallic bellows, composed of precipitation hardening stainless steel, includes ridge portions and valley portions formed alternately and continuously, an average grain size of 10 to 15 ?m, and compressive residual stress of not less than 500 MPa provided to at least surfaces of the ridge portions and the valleys by surface working.
    Type: Grant
    Filed: November 1, 2004
    Date of Patent: July 15, 2008
    Assignee: NHK Spring Co., Ltd.
    Inventor: Hideki Okada
  • Publication number: 20080110534
    Abstract: A nickel alloy having an excellent corrosion resistance (hereinafter referred to as “nickel alloy”) used for pipes, structural materials and structural members, such as bolts or the like, in a nuclear power plant or in a chemical plant, and a manufacturing method for the same are provided. In the nickel alloy according to the present invention, an excellent corrosion resistance, in particular an excellent resistance against the IGSCC, is obtained by specifying the low angle boundary rate of 4% or more in the grain boundaries, along with the restriction of the chemical composition in the alloy, thereby making it possible to provide a nickel alloy which is most suitably used for pipes, structural materials and structural members, such as bolts or the like. Accordingly, the nickel alloy according to the present invention is widely applicable to structural members used in a nuclear station or in a chemical plant.
    Type: Application
    Filed: October 17, 2007
    Publication date: May 15, 2008
    Inventor: Manabu Kanzaki
  • Patent number: 7294212
    Abstract: Material for stainless steel sheets is heated to a temperature within a range of 850 to 1250° C. and cooled at a rate 1° C./s or faster, the material including 0.02% by mass or less of C, 1.0% by mass or less of Si, 2.0% by mass or less of Mn, 0.04% by mass or less of P, 0.01% by mass or less of S, 0.1% by mass or less of Al, 11% by mass or more but less than 17% by mass of Cr, 0.5% by mass or more but, less than 3.0% by mass of Ni, and 0.02% by mass or less of N, so as to satisfy specific relationships between the compositions.
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: November 13, 2007
    Assignee: JFE Steel Corporation
    Inventors: Junichiro Hirasawa, Takumi Ujiro, Osamu Furukimi
  • Patent number: 7070663
    Abstract: A ferritic or martensitic stainless steel has the structure that Cu-enriched particles with concentration of C not less than 0.1 mass % or concentration of Sn and/or In not less than 10 mass % were dispersed in a matrix. Precipitation and dispersion of Cu-enriched particles is realized by aging the stainless steel at 500–900° C. for 1 hour or longer on any stage after a hot-rolling step until a forming step to a final product. The ferritic stainless steel contains 0.01–1.0% C, Si up to 1.0%, Mn up to 1.0%, 15–30% Cr, Ni up to 6.0% and 0.5–6.0% Cu. The martensitic stainless steel contains 0.01–0.5% C, Si up to 1.0%, Mn up to 1.0%, 10–15% Cr, Ni up to 6.0% and 0.5–6.0% Cu. Since Cu-enriched particles are dispersed for improvement of machinability instead of addition of S, Pb, Bi or Se, the stainless steel is machined to an objective shape without any harmful influence on workability, corrosion-resistance and the environment.
    Type: Grant
    Filed: November 14, 2003
    Date of Patent: July 4, 2006
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Satoshi Suzuki, Hideki Tanaka, Naoto Hiramatsu
  • Patent number: 6893727
    Abstract: This invention relates to a stainless steel gasket having markedly improved strength and fatigue properties due to precipitation strengthening. Its composition comprises C: at most 0.03%, Si: at most 1.0%, Mn: at most 2%, Cr: 16.0%-18.0%, Ni: 6.0%-8.0%, N: at most 0.25%, if necessary Nb: at most 0.30%, and a remainder of Fe and unavoidable impurities. After cold rolling, final annealing is carried out, and after a structure is formed of recrystallized grains with an average grain diameter of at most 5 ?m having an area ratio of 50-100% and an unrecrystallized portion having an area ratio of 0-50%, a metal gasket is formed by steps including temper rolling with a reduction of at least 30% to make the area ratio of a strain induced martensite phase at least 40%, and forming and heat treatment at 200-350° C.
    Type: Grant
    Filed: October 24, 2003
    Date of Patent: May 17, 2005
    Assignees: Sumitomo Metal Industries, Ltd., Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Kazuhiko Adachi, Seishi Ishiyama, Kenichi Goshokubo, Takashi Katsurai
  • Patent number: 6893608
    Abstract: Maraging steel with improved machinability, good weldability, and high corrosion resistance, a process for the heat treatment of such a steel, as well as its use. According to the invention this steel contains (in % by weight) 0.02-0.075% carbon; 0.1-0.6% silicon; 0.5-0.9% manganese; 0.08-0.25% sulfur; maximum 0.04%; phosphorus; 12.4-15.2% chromium; 0.05-1.0% molybdenum; 0.2-1.8% nickel; maximum 0.15% vanadium; 0.1-0.45% copper; maximum 0.03% aluminum; 0.02-0.08% nitrogen; as well as optionally one or more additional alloying elements up to maximum 2.0%, residual iron, and impurities caused in manufacturing, and a ferrite percentage in the structure of less than 28% by volume.
    Type: Grant
    Filed: February 13, 2002
    Date of Patent: May 17, 2005
    Assignee: Boehler Edelstahl GmbH
    Inventors: Klaus Sammt, Johann Sammer, Gerhard Lichtenegger
  • Patent number: 6884388
    Abstract: A martensitic stainless steel sheet which is hard to be softened by tempering caused by heating during the use of a disk brake, can maintain the predetermined hardness, and has excellent punching workability, bending workability before quenching, and a particularly small shear drop, and in which a predetermined hardness after quenching is constantly achieved, in a low carbon martensitic stainless steel sheet used only after quenching. Specifically, the sheet contains, on the basis of mass percent, 0.030% to 0.100% C; 0.50% or less of Si; 1.00% to 2.50% Mn; more than 10.00% to 15.00% Cr; at least one selected from the group consisting of 0.01% to 0.50% Ti, 0.01% to 0.50% V, 0.01% to 1.00% Nb, and 0.01% to 1.00% Zr; N in an amount defined by the following expression, N: 0.005% to (Ti+V)×14/50+(Nb+Zr)×14/90; and the balance being Fe and incidental impurities.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: April 26, 2005
    Assignee: JFE Steel Corporation
    Inventors: Yoshihiro Ozaki, Toshimitsu Nagaya, Atsushi Miyazaki, Susumu Satoh, Mineo Muraki, Setsuo Kakihara, Toshihiro Kasamo
  • Patent number: 6855213
    Abstract: A ferritic non-ridging stainless steel and process therefor. A chromium alloyed steel melt containing sufficient titanium and nitrogen but a controlled amount of aluminum is cast into an ingot or continuously cast into a strip or a slab having an as-cast fine equiaxed grain structure substantially free of columnar grains. The as-cast steel contains 0.08% C, at least about 8% Cr, up to 1.50% Mn, <0.020% Al, ?0.05% N, ?1.5% Si, <2.0% Ni, Ti?0.10%, the ratio of (Ti×N)/Al?0.14, all percentages by weight, the balance Fe and residual elements. Preferably, the titanium is controlled so that (Ti/48)/[(C/12)+(N/14)]>1.5. A hot processed sheet may be formed from a continuously cast slab without grinding the surfaces of the slab. The hot processed sheet may be descaled, cold reduced to a final thickness and recrystallization annealed. Annealing the hot processed sheet prior to cold reduction is not required to obtain an annealed sheet essentially free of ridging and having high formability.
    Type: Grant
    Filed: September 15, 1998
    Date of Patent: February 15, 2005
    Assignee: Armco Inc.
    Inventors: Eizo Yoshitake, Alan R. McKague
  • Patent number: 6841014
    Abstract: A method for manufacturing a striking plate of a golf club head includes the steps of soft heat-treating a flat metal blank to increase its malleability, stamping out a striking plate with an integral wall and a bend portion from the flat metal blank, precise machining the striking plate, and age hardening the striking plate to precipitation harden it and improve its mechanical properties after it has been joined to a main body of the golf club head.
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: January 11, 2005
    Assignee: Fu Sheng Industrial Co., Ltd.
    Inventors: Chun-Yung Huang, Chan-Tung Chen
  • Patent number: 6811622
    Abstract: The invention relates to semifinished and finished products made from special corrosion-resistant precipitation-hardened austenitic steel containing a large amount of intersticially dissolved nitrogen, comprising substantially smooth surfaces. The invention also relates to a method for producing corresponding semifinished and finished items. The aim of the invention is to produce semifinished and finished item and to provide an economical method for the production thereof, combining both solidity and resistance to corrosion. This is achieved by precipitation-hardening areas of the steel material.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: November 2, 2004
    Inventors: Heinrich Friederich, Reinhard Schmoock