Tube Patents (Class 148/909)
  • Patent number: 11215356
    Abstract: An Ni-based alloy pipe for nuclear power has a chemical composition consisting of, in mass percent: C: 0.015 to 0.030%, Si: 0.10 to 0.50%, Mn: 0.10 to 0.50%, P: 0.040% or less, S: 0.015% or less, Cu: 0.01 to 0.20%, Ni: 50.0 to 65.0%, Cr: 19.0 to 35.0%, Mo: 0 to 0.40%, Co: 0.040% or less, Al: 0.30% or less, N: 0.010 to 0.080%, Ti: 0.020 to 0.180%, Zr: 0.010% or less, and Nb: 0.060% or less, the balance: Fe and impurities, and satisfying [(N?Ti×14/48)×d3?4000] in relation to an average grain diameter, wherein a standard deviation of grain diameters is 20 ?m or less, and a hardness of insides of grains is 180 HV or more.
    Type: Grant
    Filed: June 7, 2018
    Date of Patent: January 4, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Kiyoko Takeda, Hirokazu Okada, Osamu Miyahara
  • Patent number: 9005520
    Abstract: The invention concerns steels having excellent resistance over time, in a corrosive atmosphere due to oxidizing environments such as, for example, fumes or water vapor, under high pressure and/or temperature. The invention concerns a steel composition for special applications, said composition containing, by weight, about 1.8 to 11% of chromium (and preferably between about 2.3 and 10% of chromium), less than 1% of silicon, and between 0.20 and 0.45% of manganese. It has been found that it is possible to adjust the contents of the composition based on a predetermined model, selected to obtain substantially optimal properties with respect to corrosion in specific conditions of high temperature performances. Said model can involve as additive of as residue at least one element selected among molybdenum, tungsten, cobalt, and nickel.
    Type: Grant
    Filed: June 7, 2007
    Date of Patent: April 14, 2015
    Assignees: V & M France
    Inventors: Jean Leyer, Bruno Vandenberghe, Viviane Lepingle, Ghislain Louis, Annie Fouquet, Catheline Petelot, Emilie Petelot, Adeline Petelot
  • Patent number: 8974610
    Abstract: A high-strength welded steel pipe is obtained by welding a seam weld portion of a steel plate that are formed in a pipe shape. In the high-strength welded steel pipe, a base metal of the steel plate includes, by mass %, C: 0.010% to 0.080%, Si: 0.01% to 0.50%, Mn: 0.50% to 2.00%, S: 0.0001% to 0.0050%, Ti: 0.003% to 0.030%, Mo: 0.05% to 1.00%, B: 0.0003% to 0.0100%, O: 0.0001% to 0.0080%, N: 0.006% to 0.0118%, P: limited to 0.050% or less, Al: limited to 0.008% or less, and the balance of Fe and inevitable impurities, Ceq is 0.30 to 0.53, Pcm is 0.10 to 0.20, [N]?[Ti]/3.4 is less than 0.003, the average grain size of the prior ? grains in heat affected zones in the steel plate is 250 ?m or less, and the prior ? grains include bainite and intragranular bainite.
    Type: Grant
    Filed: February 4, 2011
    Date of Patent: March 10, 2015
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Taishi Fujishiro, Takuya Hara, Yoshio Terada, Shinya Sakamoto, Hitoshi Asahi
  • Patent number: 8876987
    Abstract: A high strength pressed member has excellent ductility and stretch flangeability and tensile strength of 780-1400 MPa, with a predetermined steel composition and steel microstructure relative to the entire microstructure of steel sheet, where area ratio of martensite 5-70%, area ratio of retained austenite 5-40%, area ratio of bainitic ferrite in upper bainite 5% or more, and total thereof is 40% or more, 25% or more of martensite is tempered martensite, polygonal ferrite area ratio is above 10% and below 50% to the entire microstructure of steel sheet, and average grain size is 8 ?m or less, average diameter of a group of polygonal ferrite grains is 15 ?m or less, the group of polygonal ferrite grains represented by a group of ferrite grains of adjacent polygonal ferrite grains, and average carbon content in retained austenite is 0.70 mass % or more and tensile strength is 780 MPa or more.
    Type: Grant
    Filed: October 2, 2012
    Date of Patent: November 4, 2014
    Assignee: JFE Steel Corporation
    Inventors: Hiroshi Matsuda, Yoshimasa Funakawa, Kaneharu Okuda, Kazuhiro Seto
  • Patent number: 8871039
    Abstract: The present invention provides a thick welded steel pipe excellent in low temperature toughness in which contents of Mn and Mo satisfy (Expression 1) below, Pcm obtained by (Expression 2) below is 0.16 to 0.19, and a metal structure of a base material steel plate consists of ferrite being 30 to 95% in an area ratio and a low temperature transformation structure, and in a metal structure of a coarse-grained HAZ, an area ratio of grain boundary ferrite is 1.5% or more, the total area ratio of the grain boundary ferrite and intragranular ferrite is not less than 11% nor more than 90%, an area ratio of MA is 10% or less, and its balance is composed of bainite. 1.2325?(0.85×[Mn]?[Mo])?1.5215??(Expression 1) and Pcm=[C]+[Si]/30+([Mn]+[Cu]+[Cr])/20+[Ni]/60+[Mo]/15+[V]/10??(Expression 2).
    Type: Grant
    Filed: September 13, 2011
    Date of Patent: October 28, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Yasuhiro Shinohara, Takuya Hara, Naoki Doi, Eiichi Yamashita
  • Patent number: 8852362
    Abstract: There is provided an austenitic stainless steel pipe excellent in steam oxidation resistance. The austenitic stainless steel pipe excellent in steam oxidation resistance contains, by mass percent, 14 to 28% of Cr and 6 to 30% of Ni, and is configured so that a region satisfying the following Formula exists in a metal structure at a depth of 5 to 20 ?m from the inner surface of the steel pipe: (?/?)×?/?×100?0.3 where the meanings of symbols in the above Formula are as follows: ?: sum total of the number of pixels of digital image in region in which orientation difference of adjacent crystals detected by electron backscattering pattern is 5 to 50 degrees ?: the number of total pixels of digital image in region of measurement using electron backscattering pattern ?: analysis pitch width of electron backscattering pattern (?m) ?: grain boundary width (?m).
    Type: Grant
    Filed: June 1, 2012
    Date of Patent: October 7, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Yoshitaka Nishiyama, Mitsuru Yoshizawa, Masahiro Seto, Katsuki Tanaka
  • Patent number: 8821653
    Abstract: Embodiments of the present disclosure comprise carbon steels and methods of manufacturing thick walled pipes (wall thickness greater than or equal to about 35 mm) there from. In one embodiment, a steel composition is processed that yields an average prior austenite grain size greater than about 15 or 20 ?m and smaller than about 100 ?m. Using this composition, a quenching sequence is provided that yields a microstructure of greater than or equal to about 50% by volume, and less than or equal to about 50% by volume, lower bainite, without substantial ferrite, upper bainite, or granular bainite. After quenching, pipes may be tempered. The quenched and tempered pipes may exhibit yield strengths greater than about 450 MPa (65 ksi) or 485 (70 ksi). Mechanical property measurements find the quenched and tempered pipes suitable for 450 MPa grade and 485 MPa grade, and resistance to sulfide stress corrosion cracking.
    Type: Grant
    Filed: February 6, 2012
    Date of Patent: September 2, 2014
    Assignee: Dalmine S.p.A.
    Inventors: Ettore Anelli, Mariano Armengol, Paolo Novelli, Federico Tintori
  • Patent number: 8685182
    Abstract: This high-strength steel pipe includes, by mass %, C: 0.02% to 0.09%, Mn: 0.4% to 2.5%, Cr: 0.1% to 1.0%, Ti: 0.005% to 0.03%, Nb: 0.005% to 0.3%, and a balance consisting of Fe and inevitable impurities, in which Si, Al, P, S, and N are limited to 0.6% or less, 0.1% or less, 0.02% or less, 0.005% or less, 0.008% or less, respectively, the bainite transformation index BT is 650° C. or less, and the microstructure thereof is a single bainite microstructure including first bainite and second bainite, the first bainite being a gathered microstructure of bainitic ferrite including no carbide, and the second bainite being a mixed microstructure of bainitic ferrite including no carbide and cementite between the bainitic ferrites.
    Type: Grant
    Filed: June 10, 2010
    Date of Patent: April 1, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Kensuke Nagai, Yasuhiro Shinohara, Shinya Sakamoto, Takuya Hara, Hitoshi Asahi
  • Patent number: 8608872
    Abstract: The problem to be solved is the provision of a high-strength stainless steel pipe having a sufficient corrosion resistance in a high-temperature carbonic acid gas environment and having an excellent sulfide stress cracking resistance at normal temperature. A high-strength stainless steel pipe consist of, by mass %, C: 0.05% or less, Si: 1.0% or less, P: 0.05% or less, S: less than 0.002%, Cr: more than 16% and 18% or less, Mo: more than 2% and 3% or less, Cu: 1% to 3.5%, Ni: 3% or more and less than 5%, Al: 0.001% to 0.1% and O: 0.01% or less, Mn: 1% or less and N: 0.05% or less, and Mn and N in the above ranges satisfy formula (1), and the balance being Fe and impurities; and the metal micro-structure of the stainless steel pipe mainly includes a martensitic phase and comprises 10 to 40% of a ferritic phase by volume fraction and 10% or less of a retained ?-phase by volume fraction. [Mn]×([N]?0.0045)?0.
    Type: Grant
    Filed: April 8, 2011
    Date of Patent: December 17, 2013
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Kunio Kondo, Hisashi Amaya, Hideki Takabe, Taro Ohe
  • Patent number: 8608871
    Abstract: There is provided a high-strength steel tube having excellent chemical conversion treatability and excellent formability and a method for manufacturing the high-strength steel tube. More specifically, in processing a mother steel sheet containing, on the basis of mass percent, 0.05% or more C, more than 0.7% Si, and 0.8% or more Mn into a pipe shape, the sum total of absolute circumferential surface strains each applied in individual process steps of the processing is 5% or more as nominal strain. A welded steel tube thus manufactured using a steel sheet even containing more than 0.7% Si can have excellent chemical conversion treatability without mechanical grinding or chemical pickling treatment.
    Type: Grant
    Filed: October 7, 2009
    Date of Patent: December 17, 2013
    Assignees: JFE Steel Corporation, Honda Motor Co., Ltd.
    Inventors: Yasuhide Ishiguro, Akio Sato, Yasuhisa Shimizu
  • Patent number: 8585835
    Abstract: A high-strength steel machined product giving excellent hardenability has a metal microstructure with excellent balance of strength and toughness and high stability of retained austenite. The product is composed of an ultra-high low-alloy TRIP steel having a metal microstructure which contains an appropriate quantity of two or more of Cr, Mo, and Ni, and an appropriate quantity of one or more of Nb, Ti, and V, and having an appropriate value of carbon equivalent; the metal microstructure has a mother-phase structure composed mainly of lathy bainitic ferrite with a small amount of granular bainitic ferrite and polygonal ferrite, and has a secondary-phase structure composed of fine retained austenite and martensite.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: November 19, 2013
    Assignees: Usui Kokusai Sangyo Kaisha Limited, Shinshu University
    Inventors: Koh-ichi Sugimoto, Sho-hei Sato, Teruhisa Takahashi, Goro Arai
  • Patent number: 8496763
    Abstract: A seamless steel tube for an airbag accumulator which can be manufactured by heat treatment of normalizing without quenching and tempering and which has a tensile strength of at least 850 MPa and resistance to bursting at ?20° C. has a stee; composition comprising, in mass %, C: 0.08-0.20%, Si: 0.1-1.0%, Mn: 0.6-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Mo: 0.05-1.0%, Al: 0.002-0.10%, at least one of Ca: 0.0003-0.01%, Mg: 0.0003-0.01%, and REM (rare earth metals): 0.0003-0.01%, at least one of Ti: 0.002-0.1% and Nb: 0.002-0.1%, with Ceq which is defined by the following Equation (1) being in the range of 0.45-0.63, with the metallurgical structure being a mixed structure of ferrite+bainite: Ceq=C+Si/24+Mn/6+(Cr+Mo)/5+(Ni+Cu)/15??(1) wherein the symbol for each element in Equation (1) indicates the number expressing the mass percent of the element.
    Type: Grant
    Filed: April 24, 2009
    Date of Patent: July 30, 2013
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Yuji Arai, Takashi Takano
  • Patent number: 8414715
    Abstract: Embodiments of the present disclosure comprise carbon steels and methods of manufacture. In one embodiment, a double austenizing procedure is disclosed in which a selected steel composition is formed and subjected to heat treatment to refine the steel microstructure. In one embodiment, the heat treatment may comprise austenizing and quenching the formed steel composition a selected number of times (e.g., 2) prior to tempering. In another embodiment, the heat treatment may comprise subjecting the formed steel composition to austenizing, quenching, and tempering a selected number of times (e.g., 2). Steel products formed from embodiments of the steel composition in this manner (e.g., seamless tubular bars and pipes) will possess high yield strength, at least about 175 ksi (about 1200 MPa) while maintaining good toughness.
    Type: Grant
    Filed: February 18, 2011
    Date of Patent: April 9, 2013
    Assignee: Siderca S.A.I.C.
    Inventors: Eduardo Altschuler, Teresa Perez, Edgardo Lopez, Constantino Espinosa, Gonzalo Gomez
  • Patent number: 8333851
    Abstract: A method for producing a two-phase stainless steel pipe, which comprises: preparing a two-phase stainless steel material consisting of, by mass %, C: 0.03% or less, Si: 1% or less, Mn: 0.1 to 2%, Cr: 20 to 35%, Ni: 3 to 10%, Mo: 0 to 4%, W: 0.5 to 6%, Cu: 0 to 3% and N: more than 0.175 and up to 0.35%, and the balance being Fe and impurities; forming a material pipe by subjecting to a hot working: and performing a cold drawing, where the cold drawing is characterized in being performed under the conditions that the working ratio Rd, in terms of the reduction of area, in the final cold drawing step is within a range from 5 to 35%, and the following formula (1) is satisfied: Rd(%)?(MYS?55)/17.2?{1.2×Cr+3.0×(Mo+0.5×W)}??(1).
    Type: Grant
    Filed: July 8, 2008
    Date of Patent: December 18, 2012
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventor: Hitoshi Suwabe
  • Patent number: 8328960
    Abstract: A high strength bainitic steel and a process for producing seamless pipes for OCTG applications are described. In particular, the advantages ensuing to the steel of the invention are the improvement in strength-toughness over tempered martensitic steels, and a simplified thermal treatment. Quenching is not necessary and by avoiding the quenching treatment the microstructure results far more homogeneous, which allows thick walled tubes to be produced. For the same steel composition, in comparison to conventional tempered martensitic structures, a better combination of strength and toughness can be achieved, in particular by tempering as rolled carbide-free bainitic structures.
    Type: Grant
    Filed: November 19, 2007
    Date of Patent: December 11, 2012
    Assignee: Tenaris Connections Limited
    Inventors: Gonzalo Roberto Gomez, Teresa Estela Pérez, Harsad Kumar Dharamshi Hansraj Bhadeshia
  • Patent number: 8328957
    Abstract: In an electric resistance welded steel pipe with excellent weld toughness for a line pipe, the area fraction of minute defects each having a maximum length of less than 50 ?m in a projection plane of an electric resistance welded seam is in the range of 0.000006 to 0.026, and the absorbed energy at ?40° C. measured by a method for an impact test of metallic materials is 315 J or more.
    Type: Grant
    Filed: May 18, 2007
    Date of Patent: December 11, 2012
    Assignee: JFE Steel Corporation
    Inventors: Hiroyasu Yokoyama, Kazuhito Kenmochi, Takatoshi Okabe, Yukinori Iizuka
  • Patent number: 8317946
    Abstract: A seamless steel pipe of a low-alloy steel consisting, by mass %, of C: 0.10 to 0.20%, Si: 0.05 to 1.0%, Mn: 0.05 to 1.2%, Ni: 0.02 to 1.5%, Cr: 0.50 to 1.50%, Mo: 0.50 to 1.50%, Nb: 0.002 to 0.10%, Al: 0.005 to 0.10%, and either or both of Ti: 0.003 to 0.050% and V: 0.01 to 0.20%, the balance being Fe and impurities, the impurities containing 0.025% or less of P, 0.005% or less of S, 0.007% or less of N, and less than 0.0003% of B, wherein the tensile strength is 950 MPa or more and the yield strength is 850 MPa or more, and the Charpy absorbed energy at ?40° C. is 60 J or more. This seamless steel pipe may further contain one or more of Cu: 0.02 to 1.0%, Ca: 0.0005 to 0.0050%, and Mg: 0.0005 to 0.0050%. The present invention also provides a method for manufacturing the above-described seamless steel pipe.
    Type: Grant
    Filed: April 20, 2011
    Date of Patent: November 27, 2012
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Yuji Arai, Takashi Takano
  • Patent number: 8293037
    Abstract: A method for producing a duplex stainless steel pipe having a minimum yield strength of 758.3 to 965.2 MPa, comprises first hot working and optionally solution heat treating a duplex stainless steel material pipe having a chemical composition consisting, by mass %, of C: 0.03% or less, Si: 1% or less, Mn: 0.1 to 4%, Cr: 20 to 35%, Ni: 3 to 10%, Mo: 0 to 6%, W: 0 to 6%, Cu: 0 to 3% and N: 0.15 to 0.60%, the balance being Fe and impurities. The pipe is then cold rolled under conditions that the working ratio Rd, in terms of the reduction of area, in the final cold rolling step falls within a range from 10 to 80%, and formula (1) is satisfied: Rd=exp[{In(MYS)?In(14.5×Cr+48.3×Mo+20.7×W+6.9×N)}/0.195]??(1) wherein Rd is a reduction in area %, MYS is the targeted yield strength (MPa), and Cr, Mo, W and N are in mass %.
    Type: Grant
    Filed: July 18, 2011
    Date of Patent: October 23, 2012
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Hitoshi Suwabe, Toshihide Ono
  • Patent number: 8252129
    Abstract: The invention relates to a method for transforming steel blanks. The invention in particular relates to a method for transforming a steel blank comprising kneading in order to obtain very good mechanical properties. The obtained products may notably be used for forming a pressure device component.
    Type: Grant
    Filed: August 2, 2007
    Date of Patent: August 28, 2012
    Assignee: Aubert & Duval
    Inventors: Gérald Gay, Bruno Gaillard-Allemand, Dominique Thierree
  • Patent number: 8147623
    Abstract: To provide a steel pipe as a fuel injection pipe with high material strength, high internal pressure limit free from fatigue failure, prolonged fatigue life, and high reliability. A steel pipe as a fuel injection pipe of 500 N/mm2 or higher tensile strength comprising, by mass, C: 0.12 to 0.27%, Si: 0.05 to 0.40%, and Mn: 0.8 to 2.0%, and the balance being Fe and impurities, the contents of Ca, P, and S in the impurities being Ca: 0.001% or less, P: 0.02% or less, and S: 0.01% or less, respectively, characterized in that the maximum diameter of nonmetallic inclusions present in at least in a region extending from the inner surface of the steel pipe to a depth of 20 ?m is 20 ?m or less. Further, this steel pipe may contain, in place of a portion of Fe, at least one selected from among Cr: 1% or less, Mo: 1% or less, Ti: 0.04% or less, Nb: 0.04% or less, and V: 0.1% or less.
    Type: Grant
    Filed: October 2, 2008
    Date of Patent: April 3, 2012
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Kikuo Asada, Osamu Endo, Katsunori Nagao, Keisuke Hitoshio
  • Patent number: 8070890
    Abstract: The present invention provides an induction-hardened hollow driving shaft that comprises, as a raw material, a steel pipe that contains, by mass %, 0.30 to 0.47% C, 0.5% or less Si, 0.3 to 2.0% Mn, 0.018% or less P, 0.015% or less S, 0.15 to 1.0% Cr, 0.001 to 0.05% Al, 0.005 to 0.05% Ti, 0.004% or less Ca, 0.01% or less N, 0.0005 to 0.005% B and 0.0050% or less O (oxygen) and the balance Fe and impurities and of which Beff defined by an equation (a) or (b) below is 0.0001 or more, wherein a prior austenite grain size number (JIS G0551) after the hardening is 9 or more. Here, in the case of Neff=N?14×Ti/47.9?0, Beff=B?10.8×(N?14×Ti/47.9)/14 . . . (a), and, in other cases, Beff=B . . . (b). According to the present invention, a hollow driving shaft that is simultaneously provided with excellent cold workability, hardenability, toughness and torsional fatigue strength and can exert stable fatigue lifetime can be obtained and can be widely utilized.
    Type: Grant
    Filed: December 30, 2008
    Date of Patent: December 6, 2011
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Kunio Kondo, Kouichi Kuroda
  • Patent number: 8071020
    Abstract: A high strength Cr—Ni alloy material excellent in hot workability and stress corrosion cracking resistance, and seamless pipe for oil well application which consists of, by mass percent, C: 0.05% or less, Si: 0.05 to 1.0%, Mn: 0.01% or more and less than 3.0%, P: 0.05% or less, S: 0.005% or less, Cu: 0.01 to 4%, Ni: 25% or more and less than 35%, Cr: 20 to 30%, Mo: 0.01% or more and less than 4.0%, N: 0.10 to 0.30%, Al: 0.03 to 0.30%, O (oxygen): 0.01% or less, and REM (rare earth metal): 0.01 to 0.20% with the balance being Fe and impurities, and also satisfies the conditions in the following formula (1). N×P/REM?0.40??formula (1) where P, N, and REM in the formula (1) respectively denote the contents (mass %) of P, N, and REM. The high strength Cr—Ni alloy material may further contain one or more types of W, Ti, Nb, Zr, V, Ca, and Mg, instead of part of Fe.
    Type: Grant
    Filed: June 16, 2009
    Date of Patent: December 6, 2011
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Yohei Otome, Masaaki Igarashi, Hisashi Amaya, Hirokazu Okada
  • Patent number: 8034198
    Abstract: The present invention relates to an austenitic stainless steel tube for boiler, used for superheater or reheater in thermal power plant, giving excellent resistance to high temperature steam oxidation, in particular to an austenitic stainless steel tube containing 16 to 20% Cr by weight, and being cold-worked at the inner surface of the tube. The Cr concentration in the vicinity of the inner surface of the steel tube is 14% by weight or larger, and the hardness at 100 ?m depth from the inner surface of the steel tube is 1.5 times or larger the average hardness of the mother material or is HV 300 or larger.
    Type: Grant
    Filed: August 23, 2006
    Date of Patent: October 11, 2011
    Assignee: NKK Tubes
    Inventors: Yusuke Minami, Hitoshi Iijima, Motohisa Yoshida, Toshihiko Fukui, Tatsuo Ono
  • Patent number: 7985372
    Abstract: A ferritic stainless steel sheet for use in raw material pipes for forming bellows pipes has excellent formability. More specifically, the ferritic stainless steel sheet contains 10 % to 25 % by mass of Cr and has a yield stress in the range of 300 to 450 MPa and the product of the yield stress and the uniform elongation properties of at least 5200 (MPa·%). Preferably, the ferritic stainless steel sheet for use in raw material pipes for forming bellows pipes has an average crystal grain size D of 35 ?m or less or a surface roughness of 0.40 ?m or less as determined by Ra.
    Type: Grant
    Filed: May 29, 2006
    Date of Patent: July 26, 2011
    Assignee: JFE Steel Corporation
    Inventors: Yoshihiro Ozaki, Yasushi Kato, Takaaki Iguchi
  • Patent number: 7959745
    Abstract: A high-strength steel pipe having a strength of API X65 grade or higher consisting essentially of, by mass %, 0.02 to 0.08% of C, 0.01 to 0.5% of Si, 0.5 to 1.8% of Mn, 0.01% or less of P, 0.002% or less of S, 0.01 to 0.7% of Al, 0.005 to 0.04% of Ti, 0.05 to 0.50% Mo, at least one element selected from 0.005 to 0.05% of Nb and 0.005 to 0.10% of V, and the balance being Fe, in which the volume percentage of the ferritic phase is 90% or higher, and complex carbides containing Ti, Mo, and at least one element selected from the group consisting of Nb and V are precipitated in the ferritic phase. The high-strength steel pipe has excellent HIC resistance and good toughness of a heat-affected zone, and can be manufactured stably at a low cost.
    Type: Grant
    Filed: May 15, 2006
    Date of Patent: June 14, 2011
    Assignee: JFE Steel Corporation
    Inventors: Nobuyuki Ishikawa, Toyohisa Shinmiya, Shigeru Endo, Minoru Suwa
  • Patent number: 7931757
    Abstract: A thick-walled seamless steel pipe for line pipe which has a high strength and improved toughness and corrosion resistance in spite of the thick wall and which is suitable for use as a riser and flow line has a chemical composition comprising, in mass percent, C: 0.02-0.08%, Si: at most 0.5%, Mn: 1.5-3.0%, Al: 0.001-0.10%, Mo: greater than 0.4%-1.2%, N: 0.002-0.015%, at least one of Ca and REM in a total amount of 0.0002-0.007%, and a remainder of Fe and impurities, with the impurities having the content of P: at most 0.05%, S: at most 0.005%, and O: at most 0.005%, the chemical composition satisfying the inequality: 0.8?[Mn]×[Mo]?2.6, wherein [Mn] and [Mo] are the numbers equivalent to the contents of Mn and Mo, respectively, in mass percent.
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: April 26, 2011
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Kunio Kondo, Yuji Arai, Nobuyuki Hisamune
  • Patent number: 7862666
    Abstract: A highly corrosion resistant high strength stainless steel pipe for linepipe, having a composition containing about 0.001 to about 0.015% C, about 0.01 to about 0.5% Si, about 0.1 to about 1.8% Mn, about 0.03% or less P, about 0.005% or less S, about 15 to about 18% Cr, about 0.5% or more and less than about 5.5% Ni, about 0.5 to about 3.5% Mo, about 0.02 to about 0.2% V, about 0.001 to about 0.015% N, and about 0.006% or less O, by mass, so as to satisfy (Cr+0.65 Ni +0.6Mo+0.55Cu?20C?18.5), (Cr+Mo+0.3Si?43.5C?0.4Mn?Ni?0.3Cu?9 N?11.5) and (C+N?0.025). Preferably quenching and tempering treatment is applied to the pipe. The composition may further contain about 0.002 to about 0.05% Al, and may further contain one or more of Nb, Ti, Zr, B, and W, and/or Cu and Ca. The microstructure preferably contains martensite, ferrite, and residual ?.
    Type: Grant
    Filed: October 22, 2004
    Date of Patent: January 4, 2011
    Assignee: JFE Steel Corporation
    Inventors: Mitsuo Kimura, Takanori Tamari, Yoshio Yamazaki, Ryosuke Mochizuki
  • Patent number: 7799149
    Abstract: An oil country tubular good for expansion according to the invention is expanded in a well. The oil country tubular good for expansion has a composition containing, in percentage by mass, 0.05% to 0.08% C, at most 0.50% Si, 0.80% to 1.30% Mn, at most 0.030% P, at most 0.020% S, 0.08% to 0.50% Cr, at most 0.01% N, 0.005% to 0.06% Al, at most 0.05% Ti, at most 0.50% Cu, and at most 0.50% Ni, and the balance consisting of Fe and impurities, and a structure having a ferrite ratio of at least 80%. The oil country tubular good for expansion has a yield strength in the range from 276 MPa to 379 MPa and a uniform elongation of at least 16%. Therefore, the oil country tubular good according to the invention has a high pipe expansion characteristic.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: September 21, 2010
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Taro Ohe, Keiichi Nakamura, Hideki Takabe, Toshiharu Abe, Tomoki Mori, Masakatsu Ueda
  • Patent number: 7780800
    Abstract: A bent pipe corresponding to at least API X100 grade and having a base metal with high strength and toughness and a weld metal with high toughness is provided. A steel plate prepared by cooling after hot rolling at a cooling rate at the central portion in the plate thickness direction of at most 5° C. per second at 700-500° C. is formed into a bend mother pipe, which is then heated to 900-1100° C. and subjected to bending, then it is cooled to a temperature of at most 300° C. at a cooling rate in the central portion of the thickness direction of at least 5° C. per second at 700-500° C., after which it is tempered at 300-500° C.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: August 24, 2010
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Nobuaki Takahashi, Akio Yamamoto, Masahiko Hamada
  • Patent number: 7776160
    Abstract: An apparatus (10) includes a low-carbon steel tube (24). The low-carbon steel tube (24) yields plastically more than about 5% before fracturing at temperatures down to about ?40° C. when stress is applied to the low-carbon steel tube sufficient to cause the low carbon steel tube to so yield.
    Type: Grant
    Filed: December 3, 2003
    Date of Patent: August 17, 2010
    Assignees: TRW Automotive U.S. LLC, Sumitomo Metal Industries Ltd.
    Inventor: Eric C. Erike
  • Patent number: 7767037
    Abstract: A stainless steel pipe for use in oil wells which has a high strength having a YS of 654 MPa or more and superior corrosion resistance even in a severe corrosive environment in which CO2 and are present and the temperature is high, such as up to 230° C. The pipe contains on a mass percent basis: 0.005% to 0.05% of C; 0.05% to 0.5% of Si; 0.2% to 1.8% of Mn; 0.03% or less of P; 0.005% or less of S; 15.5% to 18% of Cr; 1.5% to 5% of Ni; 1% to 3.5% of Mo; 0.02% to 0.2% of V; 0.01% to 0.15% of N; 0.006% or less of 0; and the balance being Fe and unavoidable impurities, in which Cr+0.65Ni+0.6Mo+0.55Cu?20C?19.5 and Cr+Mo+0.3Si?43.5C?0.4Mn?Ni?0.3Cu?9N?11.5 are satisfied (where Cr, Ni, Mo, Cu, C, Si, Mn, and N represent the respective contents on a mass percent basis).
    Type: Grant
    Filed: August 11, 2004
    Date of Patent: August 3, 2010
    Assignee: JFE Steel Corporation
    Inventors: Mitsuo Kimura, Takanori Tamari, Yoshio Yamazaki, Ryosuke Mochizuki
  • Patent number: 7749339
    Abstract: An airbag inflator bottle member comprising a tubular body having a reduced-diameter portion at an end portion for fitting an initiator or the like thereto in which the reduced-diameter portion has a good low temperature toughness comparable to that of the portion which is not reduced in diameter is manufactured by the following method. A steel tube having a composition comprising C: 0.05-0.20%, Si: 0.1-1.0%, Mn: 0.10-2.0%, Cr: 0.05-2.0%, sol. Al: at most 0.10%, Ca: 0.0003-0.01%, optionally one or more elements selected from Cu: at most 1.0%, Ni: at most 1.5%, Mo: at most 1.0%, V: at most 0.2%, Nb: at most 0.1%, and Ti: at most 0.1%, and a remainder of Fe and impurities in which P: at most 0.025% and S: at most 0.010% is subjected to cold working, then it is cut to a predetermined length, and the cut steel tube is subjected to reducing in at least one end portion thereof and then to quenching and tempering.
    Type: Grant
    Filed: April 5, 2007
    Date of Patent: July 6, 2010
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventor: Takashi Takano
  • Patent number: 7601231
    Abstract: A high-strength steel pipe excellent in weldability on site and a method for producing the steel pipe by improving the reliability of the low temperature toughness of a steel are provided. For example, the steel pipe includes elements to enhance hardenability for furthering high-strengthening and also improving toughness at a weld heat affected zone subjected to double or more layer welding. In the method, the steel is made to consist of a structure composed of bainite and/or martensite by containing prescribed amounts of C, Si, Mn, P, S, Ni, Mo, Nb, Ti, Al and N, and, as occasion demands, one or more of B, V, Cu, Cr, Ca, REM, and Mg, and regulating C, Si, Mn, Cr, Ni, Cu, V and Mo. Such elements enhancing hardenability, by a specific relational expression. The diameter of prior austenite grains may be regulated in a prescribed range.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: October 13, 2009
    Assignee: Nippon Steel Corporation
    Inventors: Takuya Hara, Hitoshi Asahi
  • Patent number: 7485197
    Abstract: In a martensitic stainless steel tube according to the present invention, the content is determined by each of elements C, Si, Mn and Cr, and the bubble content ratio is further prescribed in accordance with the scale thickness on the outer surface of the steel tube, so that defects can be detected with high precision in the non-destructive inspection, such as ultrasonic test or the like. This allows the non-destructive inspection to be carried out with high efficiency. Moreover, there is another advantage that the weather resistance can be enhanced. The steel tube according to the present invention and the manufacturing method thereof can be suitably used in all of the technical fields in which a martensitic stainless steel tube having equal chemical composition is treated.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: February 3, 2009
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventor: Mutsumi Tanida
  • Patent number: 7459033
    Abstract: The present invention provides a method of production of oil country tubular goods having a small drop in collapse pressure after expansion and having a collapse pressure recovering by low temperature ageing at about 100° C. and oil country tubular goods obtained by this method of production. This method of production comprises hot rolling a steel slab having amounts of addition of C, Mn, P, S, Nb, Ti, Al, and N in specific ranges and having a balance of iron and unavoidable impurities and shaping the steel strip coiled at a temperature of not more than 300° C. as it is into a tube. Alternatively, it comprises heating steel pipe having amounts of addition of C, Mn, P, S, Nb, Ti, Al, and N in specific ranges and having a balance of iron and unavoidable impurities to a temperature of the Ac3 [° C.] to 1150° C., then cooling it in a range of 400 to 800° C. at a rate of 5 to 50° C./second.
    Type: Grant
    Filed: June 12, 2003
    Date of Patent: December 2, 2008
    Assignee: Nippon Steel Corporation
    Inventors: Hitoshi Asahi, Eiji Tsuru
  • Patent number: 7402215
    Abstract: Deformed wire for a submarine optical fiber cable used for the pressure-proof layer of the submarine optical cable and having a high strength, that is, having a tensile strength of 1800 MPa or more, is provided, which deformed wire for reinforcing submarine optical fiber cable is characterized by including, by wt %, C: more than 0.65% to 1.1%, Ceq=C+1/4Si+1/5Mn+4/13Cr satisfying 0.80%?Ceq?1.80%, having a number of shear bands cutting across an L-section center axial line of 20/mm per unit length of the center axis, having an angle formed by the center axis and shear bands in the range of 10 to 90°, having a tensile strength of 1800 MPa or more, having a sectional area forming an approximately fan shape, a plurality of the approximately fan shapes being combined to form a circular hollow cross-section for accommodating optical fibers, having at its surface a pebbled surface comprised of relief shapes of depths of 0.2 to 5 ?m, and having a weld at least at one location in the longitudinal direction.
    Type: Grant
    Filed: January 14, 2003
    Date of Patent: July 22, 2008
    Assignees: Nippon Steel Corporation, Namitei Co., Ltd., OCC Corporation
    Inventors: Shoichi Ohashi, Hitoshi Demachi, Masatsugu Murao, Michiyasu Honda
  • Patent number: 7393420
    Abstract: Steel tubes for bearing element parts according to the present invention, wherein the specific compositions are limited and an accumulation intensity of {211} face along with an impact property at ambient temperature in the longitudinal direction of steel tube are specified, can be provided as a source material for bearing element parts, which have excellent machinability and fatigue life in rolling contact, being incorporated without adding a free-cutting element specifically nor without reducing productivity since the spheroidizing for the same annealing duration with that of conventional spheroidizing treatment can be applied. Accordingly, by applying a manufacturing method or a cutting-machining method according to the present invention, bearing element parts such as races, rollers and shafts can be produced with less cost and efficiently.
    Type: Grant
    Filed: July 29, 2005
    Date of Patent: July 1, 2008
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Yoshihiro Daito, Takashi Nakashima
  • Patent number: 7320178
    Abstract: A standoff for a cold plate and a cold plate using the standoff are characterized by a coil pack consisting of a plurality of individual fluid conveying tubes formed into a coil pack having a desired configuration and held in place by a plurality of retaining wires. The standoffs are slidably attached to the retaining wires and each comprises an elongate body that is triangular in cross-section, has a bottom end, an apex end opposite from the bottom end and a longitudinal bore toward the bottom end and through which a retaining wire extends. The standoffs are made of aluminum and are of sufficient size to maintain their structural integrity during a casting process in which the coil pack is placed in a mold and molten aluminum is poured around the coil pack.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: January 22, 2008
    Assignee: IMI Cornelius Inc.
    Inventors: Matthew J. Kirby, Jose L. Rodriguez, Miguel Angel Herrera Bucio
  • Patent number: 7252721
    Abstract: A power transmission shaft having an improved strength and ensuring a stable torsion fatigue strength. The power transmission shaft has coupling members respectively provided on the opposite ends of an pipe part made of a steel material. The steel material includes 0.30-0.45% by weight of C, 0.05-0.35% by weight of Si, 1.0-2.0% by weight of Mn, 0.05% by weight or less of Al, 0.01% by weight or less of S, and the remainder (iron Fe and unavoidable impurities). The pipe part has an electro-unite portion that extends in the axial direction. The electro-unite portion and neighborhood thereof are hardened so as to have a Rockwell hardness HRC of 45 or more. Also, another power transmission shaft has coupling members integrally formed on opposite ends thereof. In addition, the shaft is formed from a steel element tube by a plastic working.
    Type: Grant
    Filed: May 24, 2002
    Date of Patent: August 7, 2007
    Assignee: NTN Corporation
    Inventors: Kazuya Wakita, Katsuyuki Ikei, Hisaaki Kura
  • Patent number: 7048810
    Abstract: A method for processing a hot formed, high-tensile-strength steel having an ultimate tensile strength (UTS) of at least about 730 MPa (105 ksi) and excellent toughness to retain essentially all the strength and toughness is provided. This processing is needed for the fabrication of high strength fittings that are used in the construction of linepipe for transport of natural gas, crude oil, as well as other applications. Furthermore, the hot formed high strength steel may be weldable with a Pcm of less than or equal to 0.35.
    Type: Grant
    Filed: September 24, 2002
    Date of Patent: May 23, 2006
    Assignee: ExxonMobil Upstream Research Company
    Inventors: Clifford W. Petersen, Jayoung Koo, Narasimha-Rao V. Bangaru, Michael J. Luton
  • Patent number: 6936119
    Abstract: The invention is directed to a method and a device for producing metal, non-rotationally symmetric rings with a constant wall thickness along their circumference, particularly cam rings, starting from a hot-rolled pipe from which individual portions are severed, mechanically machined and subsequently hardened and tempered. Ring blanks of equal width are severed from the pipe and are mechanically machined on all sides, and the non-rotationally symmetric shape is produced by cold forming, the pipe or the severed ring blank having a structure suitable for cold forming.
    Type: Grant
    Filed: July 11, 2001
    Date of Patent: August 30, 2005
    Assignee: Mannesmannrohren-Werke AG
    Inventors: Wilfried Förster, Joachim Schlegel, Dieter Wamser, Roland Stephan
  • Patent number: 6866725
    Abstract: The present invention is a high strength steel pipe excellent in formability in hydroforming and similar forming methods, characterized by: containing, in mass, C of 0.0005 to 0.30%, Si of 0.001 to 2.0%, Mn of 0.01 to 3.0% and appropriate amounts of other elements if necessary, with the balance consisting of Fe and unavoidable impurities; and an average for the ratios of the X-ray strength in the orientation component group of {110}<110> to {111}<110> to random X-ray diffraction strength on a plane at the wall thickness center being 2.0 or more and/or a ratio of the X-ray strength in the orientation component of {110}<110> to random X-ray diffraction strength on the plane at the wall thickness center being 3.0 or more.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: March 15, 2005
    Assignee: Nippon Steel Corporation
    Inventors: Nobuhiro Fujita, Naoki Yoshinaga, Manabu Takahashi, Hitoshi Asahi, Yasuhiro Shinohara, Yasushi Hasegawa
  • Patent number: 6793745
    Abstract: The invention relates to a high-strength, age-hardenable, corrosion-resistant maraging type spring steel, which is essentially comprised of 6.0 to 9.0 wt. % of Ni, 11.0 to 15.0 wt. % of Cr, 0.1 to 0.3 wt. % of Ti, 0.2 to 0.3 wt. % of Be and of a remainder consisting of Fe, whose martensite temperature Ms≧130° C. and which has a ferrite content cferrite of less than 3%.
    Type: Grant
    Filed: September 16, 2002
    Date of Patent: September 21, 2004
    Assignee: Vacuumschmelze GmbH & Co. KG
    Inventors: Hartwin Weber, Waldemar Doering, Gernot Hausch
  • Patent number: 6736910
    Abstract: The invention provides a high-carbon steel pipe having superior cold workability and induction hardenability, and a method of producing the steel pipe. The method comprises the steps of heating or soaking a base steel pipe having a composition containing C: 0.3 to 0.8%, Si: not more than 2%, and Mn: not more than 3%, and then carrying out reducing rolling on the base steel pipe at least in the temperature range of (Ac1, transformation point −50° C.) to Ac1, transformation point with an accumulated reduction in diameter of not less than 30%. A structure in which the grain size of cementite is not greater than 1.0 &mgr;m is obtained, thus resulting in improved cold workability and induction hardenability.
    Type: Grant
    Filed: January 29, 2002
    Date of Patent: May 18, 2004
    Assignee: JFE Steel Corporation
    Inventors: Takaaki Toyooka, Yoshikazu Kawabata, Akira Yorifuji, Masanori Nishimori, Motoaki Itadani, Takatoshi Okabe, Masatoshi Aratani, Yasue Koyama
  • Patent number: 6632296
    Abstract: The present invention provides a steel pipe excellent in formability during hydraulic forming and the like and a method to produce the same, and more specifically: a steel pipe excellent in formability having an r-value of 1.4 or larger in the axial direction of the steel pipe, and the property that the average of the ratios of the X-ray intensity in the orientation component group of {110}<110> to {332}<110> on the plane at the center of the steel pipe wall thickness to the random X-ray intensity is 3.5 or larger, and/or the ratio of the X-ray intensity in the orientation component of {110}<110> on the plane at the center of the steel pipe wall thickness to the random X-ray intensity is 5.
    Type: Grant
    Filed: February 6, 2002
    Date of Patent: October 14, 2003
    Assignee: Nippon Steel Corporation
    Inventors: Naoki Yoshinaga, Nobuhiro Fujita, Manabu Takahashi, Yasuhiro Shinohara, Tohru Yoshida, Natsuko Sugiura
  • Patent number: 6517643
    Abstract: A steel pipe is provided which is excellent in resistance to outer surface stress corrosion cracking (SCC) when used for a pipeline without impairing the fundamental requirement for the steel as a pipeline. The steel pipe has a surface adjusted to have a mean line roughness Ra of up to 7 &mgr;m and a maximum height Rmax of up to 50 &mgr;m. The surface is adjusted by sand blasting to have this roughness.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: February 11, 2003
    Assignees: Nippon Steel Corporation, Kabushiki Kaisha Kobe Seiko Sho, NKK Corporation, Kawasaki Steel Corporation, Sumitomo Metals Industries, Ltd.
    Inventors: Hitoshi Asahi, Shigeo Okano, Takahiro Kushida, Yasuyoshi Yamane, Hideaki Fukai
  • Patent number: 6506121
    Abstract: A cage having a plurality of pockets, and a pair of end faces of each pocket formed in the cage that oppose each other in a circumferential direction of the cage are formed by surfaces cut after hardening and their surface hardness is reduced to a value lower than the surface hardness of a pair of side faces of each pocket that oppose each other in an axial direction of the cage to impart toughness to the bridge portions defined between the pockets and thus to increase the strength of the cage.
    Type: Grant
    Filed: November 29, 2000
    Date of Patent: January 14, 2003
    Assignee: NTN Corporation
    Inventors: Masazumi Kobayashi, Masayuki Tanio, Takao Maeda, Takuya Katou
  • Patent number: 6440234
    Abstract: A martensitic stainless steel product having a chromium content of 9 to 15% by weight and a surface from which mill scales generated during production are removed by a shot blasting. The surface satisfies that, when a color image of the surface taken with 640×480 pixels is analyzed on blue color and a histogram of the pixel numbers and the tones divided into 0 to 255 classes is obtained, a relationship between the maximum frequency Yp and the tone value Xp at which Yp is counted satisfies an inequality, 800Xp−Yp−27000>0. This steel product is superior in weatherability under atmospheric environments, and also superior in sulfide stress cracking resistance under environments containing hydro-sulfide.
    Type: Grant
    Filed: December 3, 1999
    Date of Patent: August 27, 2002
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Hisashi Amaya, Toshiro Anraku, Yasuyoshi Hidaka
  • Patent number: 6406564
    Abstract: This invention provides a boiler steel pipe that exhibits a high creep rupture strength on a high-temperature high-pressure side and is excellent in electric weldability, and an electric welded boiler steel pipe having fewer defects at an electric welded portion. The boiler steel contains, in terms of wt %, C: 0.01 to 0.20%, Si: 0.01 to 1.0% and Mn: 0.10 to 2.0%, contains further Cr: 0.5 to 3.5%, and limits p≦0.030%, S≦0.010% and 0≦0.20%, wherein a weight ratio of (Si %)/(Mn %) or (Si %)/(Mn %+Cr %) is from 0.005 to 1.5, the balance Fe and unavoidable impurities, and the melting point of the mixed oxide of SiO2 and MnO, or SiO2, MnO and Cr2O3, is not higher than 1,600° C. The oxide that would otherwise result in the defects of the electric welded portion is molten and squeezed out as slag components.
    Type: Grant
    Filed: August 10, 2000
    Date of Patent: June 18, 2002
    Assignee: Nippon Steel Corporation
    Inventors: Taro Muraki, Yasushi Hasegawa, Junichi Okamoto
  • Patent number: 6379821
    Abstract: This invention relates to a large-diameter, thick-wall martensitic stainless steel welded pipe. For this welded pipe, the size of the raised weld bead portion on the inside surface is restricted to be small based on a conditional formula derived by considering the bead width and height and the yield strength of the base metal and of the weld metal. As a result, the base metal portion and pipe inside surface seam portion of this welded pipe are superior in corrosion resistance, in particular stress corrosion cracking resistance (SCC resistance). The sulfide stress corrosion resistance (sour gas resistance) and carbon dioxide corrosion resistance can be further improved by selecting the chemical compositions. This welded pipe is very well suited for use as a pipe for a pipeline for conveying a crude oil and a natural gas with no dehydration treatment, which is highly corrosive to metals.
    Type: Grant
    Filed: April 2, 2001
    Date of Patent: April 30, 2002
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Takahiro Kushida, Tomohiko Omura, Kunio Kondo, Kazuhiro Ogawa, Masahiko Hamada