With Working Patents (Class 148/593)
  • Patent number: 6652680
    Abstract: The method for producing tubes for heavy guns employs a heat-treatable steel, consisting in wt.-% of 0.20 to 0.50% carbon, max. 1.0% silicon, max. 1.0% manganese, max. 0.03% phosphorus, max. 0.03% sulfur, max. 0.1% aluminum, max. 4% nickel, max. 2% chromium, max. 1% molybdenum, max. 0.5% vanadium, and the remainder of iron and the customary impurities. Forgings of open-smelted cast ingots are pre-worked on a lathe on the outside. The solid blanks obtained in this way are hardened and tempered, only subsequently drilled and then finished.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: November 25, 2003
    Assignees: Edelstahlwerke Buderus AG, Rheinmetall W & M GmbH
    Inventors: Walter Grimm, Wolfgang Arrenbrecht
  • Publication number: 20030178111
    Abstract: A steel material and a steel pipe made by using the same are provided which are to be used in severe oil well environments. Such a highly tough oil well steel pipe can be produced by rolling the base material, quenching the rolling product from the austenite region and tempering the same so that the relationship between the content of Mo [Mo] in the carbides precipitated at austenite grain boundaries and the austenite grain size (according to ASTM E 112) can be defined by the formula (a) given below. In this manner, steel pipes suited for use even under oil well environments becoming more and more severe can be produced while satisfying the requirements that the cost should be rationalized, the productivity improved and energy saved.
    Type: Application
    Filed: April 22, 2003
    Publication date: September 25, 2003
    Inventors: Shigeru Nakamura, Kaori Kawano, Tomohiko Omura, Toshiharu Abe
  • Publication number: 20030180174
    Abstract: The present invention provides a high-strength steel pipe 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 0.07% 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 ferritic phase is 90% or higher, and complex carbides containing Ti, Mo, and at least one element selected from Nb and V are precipitated in the ferritic phase. The high-strength steel pipe in accordance with the present invention has excellent HIC resistance and good toughness of heat-affected zone, and can be manufactured stably at a low cost.
    Type: Application
    Filed: March 10, 2003
    Publication date: September 25, 2003
    Applicant: JFE STEEL CORPORATION
    Inventors: Nobuyuki Ishikawa, Toyohisa Shinmiya, Shigeru Endo, Minoru Suwa
  • Publication number: 20030164210
    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: Application
    Filed: January 13, 2003
    Publication date: September 4, 2003
    Inventors: Wilfried Forster, Joachim Schlegel, Dieter Wamser, Roland Stephan
  • Patent number: 6610154
    Abstract: A surface treatment process for enhancing the resistance to intergranular corrosion and intergranular cracking of components fabricated from austenitic Ni—Fe—Cr based alloys comprising the application of surface deformation to the component, to a depth in the range of 0.01 mm to 0.5 mm, for example by high intensity shot peening below the recrystallization temperature, followed by recrystallization heat treatment, preferably at solutionizing temperatures. The surface deformation and annealing process can be repeated to further optimize the microstructure of the near-surface region. Following the final heat treatment, the process optionally comprises the application of further surface deformation (work) of reduced intensity, yielding a worked depth of between 0.005 mm to 0.01 mm, to impart residual compression in the near surface region to further enhance cracking resistance.
    Type: Grant
    Filed: November 27, 2001
    Date of Patent: August 26, 2003
    Assignee: Integran Technologies Inc.
    Inventors: David L. Limoges, Gino Palumbo, Peter K. Lin
  • Publication number: 20030155052
    Abstract: In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of: 1 C: 0.05-0.20%, Si: 0.1-1.0%, Mn: 0.20-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Al: at most 0.
    Type: Application
    Filed: November 27, 2002
    Publication date: August 21, 2003
    Inventors: Kunio Kondo, Miyuki Yamamoto, Takashi Takano, Kenichi Beppu, Susumu Hirano, Keisuke Hitoshio, Hidetoshi Kurata
  • Publication number: 20030116238
    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: Application
    Filed: August 27, 2002
    Publication date: June 26, 2003
    Inventors: Nobuhiro Fujita, Naoki Yoshinaga, Manabu Takahashi, Hitoshi Asahi, Yasuhiro Shinohara, Yasushi Hasegawa
  • Patent number: 6564689
    Abstract: Blank for a gun barrel, consisting of a steel bar, which bar, in one or more hot working steps, has been repeatedly wrung about its own longitudinal axis.
    Type: Grant
    Filed: August 21, 2001
    Date of Patent: May 20, 2003
    Assignee: Damasteel Aktiebolag
    Inventor: Per Billgren
  • Patent number: 6547894
    Abstract: A method of making a stabilizer bar from a tubular blank to which a mixture of an adhesive and powdered metal is applied to the inside surface of opposite ends of the tube. The adhesive is cured and then the fuseweld powder is placed in an oven to melt the fuseweld powder. The ends are swagged to shape flat tubes ends that are trimmed and pierced to form a fastener eyelet in each end. The stabilizer bar is then heated for hot working to form the bends along the length of the bar. After forming to shape, the stabilizer bar is quenched and annealed.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: April 15, 2003
    Inventor: James B. Smith
  • Publication number: 20030066580
    Abstract: A method of producing a high-strength high-toughness martensitic stainless steel seamless pipe which includes heating a martensitic stainless steel raw material to an austenitic range and subjecting the raw material to piercing and elongating to form an original pipe. The original pipe is cooled to form a structure substantially composed of martensite in the original pipe. The original pipe is reheated to a temperature in the dual-phase range between the Ac1 transformation point and the Ac3 transformation point, and is subjected to finishing rolling at an initial rolling temperature T (° C.) between the Ac1 transformation point and the Ac3 transformation point. The original pipe is then cooled to form a processed pipe. The processed pipe is tempered at a temperature below the Ac1 transformation point. The reduction in area R in the finishing rolling step may be in the range of 10% to 90%, and the initial rolling temperature T and the reduction in area R may satisfy the relationship 800≦T−0.
    Type: Application
    Filed: August 23, 2002
    Publication date: April 10, 2003
    Applicant: KAWASAKI STEEL CORPORATION
    Inventors: Yukio Miyata, Mitsuo Kimura, Takaaki Toyooka
  • Patent number: 6540848
    Abstract: A high-strength, high-toughness seamless steel pipe used for a line pipe contains 0.03 to 0.06% of C, 0.05 to 0.15% of Si, 1.6 to 2.0% of Mn, 0.010 to 0.10% of Al, 0.3 to 0.7% of Ni, 0.10 to 0.40% of Mo, 0.01 to 0.06% of V, 0.003 to 0.03% of Nb, 0.003 to 0.020% of Ti, and 0.0010 to 0.0100% of N, the relationships Mo+5V≧0.4% and 2Nb−V≦0% being satisfied, and the balance being Fe and incidental impurities. Consequently, it is possible to provide the high-strength, high-toughness seamless steel pipe used for a line pipe in which grade X80 strength and toughness are stably ensured, and the target strength can be easily attained regardless of the size.
    Type: Grant
    Filed: August 29, 2001
    Date of Patent: April 1, 2003
    Assignee: Kawasaki Steel Corporation
    Inventors: Yukio Miyata, Mitsuo Kimura, Takaaki Toyooka, Noritsugu Itakura
  • Publication number: 20030051782
    Abstract: A steel tube having a composition which contains: 0.05 to 0.30% of C; 1.8 to 4.0% of Mn; Si; and Al is subjected to a diameter-reducing rolling process in which the total diameter-reduction rate is no less than 20% and the temperature at which the diameter-reducing rolling process is finished is no higher than 800 ° C., whereby a structure constituted of martensite and/or bainite or further of ferrite is obtained as a transformation product from the deformed &ggr;. As a result, a steel tube having tensile strength of 1000 MPa or more and excellent three-point-bending property can be obtained. The composition of the steel tube of the present invention may further include at least one type of element selected from the group consisting of Cu, Ni, Cr and Mo, or at least one type of element selected from the group consisting of Nb, V, Ti and B, or at least of one type selected from the group consisting of REM and Ca.
    Type: Application
    Filed: August 26, 2002
    Publication date: March 20, 2003
    Inventors: Takaaki Toyooka, Masanori Nishimori, Yoshikazu Kawabata, Akira Yorifuji, Motoaki Itadani, Takatoshi Okabe, Masatoshi Aratani
  • Publication number: 20020174921
    Abstract: A vehicle structural beam, such as a door intrusion beam, which possesses an elongate tubular beam part which at opposite ends is provided with mounting flanges for securement to a vehicle frame. The elongate tubular beam part and the flanges provided at opposite ends are defined by an integral, one-piece, monolithic steel structure which has been initially roll-formed from an elongate flat metal sheet to define the closed tubular structure of the tubular beam part, and which has been subjected to heating and quenching so that the elongate tubular beam part is of relatively high strength steel throughout its entire length, whereas the integrally and monolithically joined end flanges remain as lower strength steel which has been significantly unaffected by the heat treatment and quenching so as to permit appropriate shaping thereof and ease of welding to the vehicle frame.
    Type: Application
    Filed: July 22, 2002
    Publication date: November 28, 2002
    Inventors: Frank G. McNulty, Gerald Hackstock, Jeffrey L. Bladow
  • Publication number: 20020170637
    Abstract: A high-strength, high-toughness seamless steel pipe used for a line pipe contains 0.03 to 0.06% of C, 0.05 to 0.15% of Si, 1.6 to 2.0% of Mn, 0.010 to 0.10% of Al, 0.3 to 0.7% of Ni, 0.10 to 0.40% of Mo, 0.01 to 0.06% of V, 0.003 to 0.03% of Nb, 0.003 to 0.020% of Ti, and 0.0010 to 0.0100% of N, the relationships Mo+5V≧0.4% and 2Nb−V≦0% being satisfied, and the balance being Fe and incidental impurities. Consequently, it is possible to provide the high-strength, high-toughness seamless steel pipe used for a line pipe in which grade X80 strength and toughness are stably ensured, and the target strength can be easily attained regardless of the size.
    Type: Application
    Filed: August 29, 2001
    Publication date: November 21, 2002
    Inventors: Yukio Miyata, Mitsuo Kimura, Takaaki Toyooka, Noritsugu Itakura
  • Patent number: 6475307
    Abstract: A composition and method for the manufacture of products of a precipitation hardenable martensitic stainless steel, the composition of which comprises at least 0.5% by weight of Cr and at least 0.5% by weight of Mo wherein the sum of Cr, Ni and Fe exceeds 50%. The method steps include smelting the material into a casting, hot extrusion followed by a number of cold deforming steps so as to obtain at least 50% martensite and finally an ageing treatment at 425-525° C. to obtain precipitation of quasicrystalline particles. Such material can be used in vehicle components where demands for corrosion resistance, high strength and good toughness are to be satisfied.
    Type: Grant
    Filed: November 16, 2000
    Date of Patent: November 5, 2002
    Assignee: Sandvik AB
    Inventors: Anna-Lena Nyström, Anna Hultin Stigenberg
  • Publication number: 20020153070
    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: Application
    Filed: January 29, 2002
    Publication date: October 24, 2002
    Inventors: Takaaki Toyooka, Yoshikazu Kawabata, Akira Yorifuji, Masanori Nishimori, Motoaki Itadani, Takatoshi Okabe, Masatoshi Aratani, Yasue Koyama
  • Patent number: 6454884
    Abstract: A vehicle structural beam, such as a door intrusion beam, which possesses an elongate tubular beam part which at opposite ends is provided with mounting flanges for securement to a vehicle frame. The elongate tubular beam part and the flanges provided at opposite ends are defined by an integral, one-piece, monolithic steel structure which has been initially roll-formed from an elongate flat metal sheet to define the closed tubular structure of the tubular beam part, and which has been subjected to heating and quenching so that the elongate tubular beam part is of relatively high strength steel throughout its entire length, whereas the integrally and monolithically joined end flanges remain as lower strength steel which has been significantly unaffected by the heat treatment and quenching so as to permit appropriate shaping thereof and ease of welding to the vehicle frame.
    Type: Grant
    Filed: February 6, 2001
    Date of Patent: September 24, 2002
    Assignee: Pullman Industries, Inc.
    Inventors: Frank G. McNulty, Gerald Hackstock, Jeffrey L. Bladow
  • Patent number: 6419768
    Abstract: A method for producing an autogenous welded tubular metal article having a substantially uniform grain size, including the weld-affected area thereof. This is achieved by applying to the metal article a series of cold reduction and annealing operations that in combination render the grain size of the weld-affected area uniform with respect to the remainder of the cross-section of the article, and particular the visual appearance of the cross-section.
    Type: Grant
    Filed: January 29, 2001
    Date of Patent: July 16, 2002
    Assignee: Crucible Materials Corp.
    Inventor: John C. Tverberg
  • Patent number: 6344097
    Abstract: A surface treatment process for enhancing the intergranular corrosion and intergranular cracking resistance of components fabricated from austenitic Ni—Fe—Cr based alloys comprised of the application of surface cold work to a depth in the range of 0.01 mm to 0.5 mm, for example by high intensity shot peening, followed by recrystallization heat treatment preferably at solutionizing temperatures (>900 C.). The surface cold work and annealing process can be repeated to further optimize the microstructure of the near-surface region. Following the final heat treatment, the process can optionally comprise the application of surface cold work of reduced intensity, yielding a cold worked depth of 0.005 mm to 0.01 mm, in order further enhance resistance to cracking by rendering the near surface in residual compression.
    Type: Grant
    Filed: May 26, 2000
    Date of Patent: February 5, 2002
    Assignee: Integran Technologies Inc.
    Inventors: David L. Limoges, Gino Palumbo, Peter K. Lin
  • Publication number: 20020011284
    Abstract: The invention relates to a process for producing seamless line pipes within the quality grade range X 52 to X 90, with a stable yield strength up to a temperature of use of 200° C., and with an essentially constant stress-strain characteristic, by hot-rolling a pipe blank made from a steel which contains the following alloying elements (% by weight): 1 C 0.06-0.18% Si max. 0.40% Mn 0.80-1.40% P max. 0.025% S max. 0.010% Al 0.010-0.060% Mo max. 0.50% V max. 0.10% Nb max. 0.10% N max. 0.015% W >0.30-1.
    Type: Application
    Filed: July 15, 1999
    Publication date: January 31, 2002
    Inventors: INGO VON HAGEN, MARKUS RING, GERD HEINZ, BERNHARD KOSCHLIG, KURT NIEDERHOFF
  • Patent number: 6331216
    Abstract: The steel pipe has a structure composed mainly of ferrite or ferrite plus pearlite or ferrite plus cementite. The steel pipe is characterized by grain size not greater than 3 &mgr;m, preferably not greater than 1 &mgr;m, elongation greater than 20%, tensile strength (TS:MPa) and elongation (E1:%) whose product is greater than 10000, and percent ductile fracture greater than 95%, preferably 100%, measured by Charpy impact test on an actual pipe at −100° C. The structure is characterized by C: 0.005-0.03%, Si: 0.01-3.0%, Mn: 0.01-2.0%, and Al: 0.001-0.10% on a weight basis, and is composed of ferrite or ferrite and a secondary phase, with ferrite grains being not greater than 3 &mgr;m and the secondary phase having an areal ratio not more than 30%. A steel pipe stock having the above-mentioned composition is heated at a temperature of (Ac1+50° C.) to 400° C. and subsequently reduced at a rolling temperature of (Ac1+50° C.) to 400° C.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: December 18, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Takaaki Toyooka, Akira Yorifuji, Masanori Nishimori, Motoaki Itadani, Yuji Hashimoto, Takatoshi Okabe, Nobuki Tanaka, Taro Kanayama, Osamu Furukimi, Masahiko Morita, Takaaki Hira, Saiji Matsuoka
  • Patent number: 6290788
    Abstract: A process for producing precision steel tubes includes cold forming tube blanks, in particular in a plurality of forming steps, with or without an internal tool. In this process, a tube blank made from interstitial free IF steel is used as the starting material.
    Type: Grant
    Filed: February 8, 1999
    Date of Patent: September 18, 2001
    Assignee: Mannesmann AG
    Inventors: Ronald Claus, Jürgen Wiete, Rüdiger Hahn, Stefan Meimeth
  • Patent number: 6290789
    Abstract: A steel pipe containing fine ferrite crystal grains, which has excellent toughness and ductility and good ductility-strength balance as well as superior collision impact resistance, and a method for producing the same are provided. A steel pipe containing super-fine crystal grains can be produced by heating a base steel pipe having ferrite grains with an average crystal diameter of di (&mgr;m), in which C, Si, Mn and Al are limited within proper ranges, and if necessary, Cu, Ni, Cr and Mo, or Nb, Ti, V, B, etc. are further added, at not higher than the Ac3 transformation point, and applying reducing at an average rolling temperature of &thgr;m (°C.) and a total reduction ration Tred (%) within s temperature range of from 400 to Ac3 transformation point, with di, &thgr;m and Tred being in a relation satisfying a prescribed equation.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: September 18, 2001
    Assignee: Kawasaki Steel Corporation
    Inventors: Takaaki Toyooka, Akira Yorifuji, Masanori Nishimori, Motoaki Itadani, Yuji Hashimoto, Takatoshi Okabe, Taro Kanayama, Masahiko Morita, Saiji Matsuoka, Nobuki Tanaka, Osamu Furukimi, Takaaki Hira
  • Patent number: 6270596
    Abstract: Disclosed is a process for producing a shaft having improved strength without sacrificing machinability and cold workability. The process for producing a high strength shaft comprises the steps of: rolling or forging an alloy at a heating temperature of Ac3 to 105° C. with a reduction in area of not less than 30%, the alloy comprising by weight carbon: 0.47 to 0.55%, silicon: 0.03 to 0.15%, manganese: 0.20 to 0.50%, molybdenum: 0.08 to 0.30%, sulfur: 0.005 to 0.035%, boron: 0.0005 to 0.005%, titanium: 0.05 to 0.20%, nitrogen: not more than 0.01%, aluminum: 0.005 to 0.05%, and manganese+molybdenum: 0.45 to 0.70% with the balance consisting of iron and unavoidable impurities, thereby producing a steel product having a hardness after rolling or forging of 85 to 97 HRB; and induction hardening the steel product to obtain a shaft, as shown in FIG. 1, having a hardening depth ratio (distance from the surface to a position of 500 HV/radius of component) of not less than 0.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: August 7, 2001
    Assignees: Sanyo Special Steel., Ltd., Honda Motor Co., Ltd.
    Inventors: Makoto Iguchi, Motohiro Nishikawa, Masayoshi Saga
  • Publication number: 20010004809
    Abstract: A bucket tooth capable of preventing a bolt from being loosened during operation is provided. In order to allow the bucket tooth to generate a resilient return force after attachment, a warp is caused by resilient deformation so that a face on the bucket lip side becomes a concave face. As another means, a spot facing portion is formed around a bolt hole into which a fastening bolt is inserted, on the side facing the bucket lip.
    Type: Application
    Filed: November 29, 2000
    Publication date: June 28, 2001
    Applicant: Komatsu, Ltd.
    Inventors: Masaharu Amano, Kazuhide Okawa
  • Patent number: 6190472
    Abstract: A method for soft annealing of high carbon steel, characterized by taking objects to be soft annealed directly from a hot forming step and cooling to below Al−20° C.; heating the objects to Al+20° C. or above, and then cooling the objects down to beneath the Al temperature of the steel quickly as in air, which step is performed at least once; heating the objects to Al+20° C. or above, cooling the objects down to about 740° C., and then cooling the objects down to about 690° C. at a cooling rate of 3.5° C./min. or lower; and finally cooling the objects down to ambient temperature.
    Type: Grant
    Filed: March 16, 1999
    Date of Patent: February 20, 2001
    Assignee: Ovako Steel AB
    Inventors: Thore Lund, Staffan Larsson, Patrik Ölund
  • Patent number: 6159311
    Abstract: A martensitic stainless steel pipe comprises, on the weight basis, C: 0.005 to 0.2%, Si: 1% or below, Mn: 0.1 to 5%, Cr: 7 to 15%, and Ni: 0 to 8%, wherein a wall thickness t (mm) and contents of C and Cr satisfy the relationship represented by the following equation (1).t(mm).ltoreq.exp{5.21-18.1C(%)-0.0407Cr(%)} (1)The steel pipe can be made by employing water quenching as a quenching method.
    Type: Grant
    Filed: January 7, 2000
    Date of Patent: December 12, 2000
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Hisashi Amaya, Masakatsu Ueda, Kunio Kondo
  • Patent number: 6126897
    Abstract: A carburizing steel having the following chemical composition:C: 0.1 to 0.25%,Si: 0.2 to 0.4%,Mn: 0.3 to 0.9%,P: 0.02% or less,S: 0.001 to 0.15%,Cr: 0.5 to 0.9%,Mo: 0.15 to 1%,Al: 0.01 to 0.1%,B: 0.0005 to 0.009%,N: less than 0.006%, andthe balance of Fe and incidental impurities, wherein % is on a weight basis. Also disclosed are a method for the manufacture of the carburizing steel, parts of constant velocity universal joints for drive shafts made of the carburizing steel, as well as a method for the manufacture of such parts. The carburizing steel may further contain Ni: 0.3-4.0%, and one or more elements selected from the group consisting of Ti, Nb, V and Zr: 0.01-0.3% for each. The parts of constant velocity universal joints for drive shafts are manufactured using the carburizing steel of the present invention as a material. When they are carburized and quenched, they exhibit a surface hardness (Hv) of 650-800, core hardness (Hv) of 250-450, and carburized case depth of 0.2-1.2 mm.
    Type: Grant
    Filed: August 21, 1998
    Date of Patent: October 3, 2000
    Assignees: Sumitomo Metal Industries, Ltd., NTN Corporation
    Inventors: Kenji Aihara, Yasuhide Fujioka, Kazuhiko Yoshida, Tatsuhiro Goto, Akira Wakita
  • Patent number: 6103027
    Abstract: A process for forming a cylindrical pipe from a welded metal pipe stock by roll extruding and annealing whereby the weldment microstructure forming the seam is essentially reformed to provide a recrystallized grain structure which is substantially homogeneous with the parent material of the pipe stock.
    Type: Grant
    Filed: November 12, 1997
    Date of Patent: August 15, 2000
    Assignee: Kaiser Aerospace & Electronics Corp.
    Inventors: Louis F. Glasier, Jr., Michael J. Dosdourian
  • Patent number: 6060180
    Abstract: The present invention provides a highly corrosion-resistant alloy used as a boiler tube in equipment the energy source of which is obtained by burning fossil fuel or waste, a steel tube for which the alloy is used, and a process for producing the steel tube. The alloy comprises up to 0.05% of C, 1.0 to 2.6% of Si, 0.02 to 1.0% of Mn, 20.0 to 28.0% of Cr, 18.0 to 30.0% of Ni, up to 4.0% of Mo, up to 0.05% of Al, 0.05 to 0.30% of N and the balance Fe and unavoidable impurities. Furthermore, the present invention also provides a multilayer steel tube having the alloy as a liner material and a standardized boiler tube as a base layer material, and a process for producing the multilayer steel tube.
    Type: Grant
    Filed: November 2, 1997
    Date of Patent: May 9, 2000
    Assignee: Nippon Steel Corporation
    Inventors: Tetsuo Ishitsuka, Koichi Nose
  • Patent number: 6024808
    Abstract: A method of manufacturing a seamless steel pipe having excellent properties with high productivity in on-line processing, and an apparatus in which includes casting and heat treatment unit on-line. In the method the following steps (1) to (6) are successively performed. (1) A round billet is produced by continuous casting machine 1. (2) The billet is cooled to a temperature not higher than a Ar.sub.1 point, then heated and soaked in a furnace 3. (3) The billet is pierced by a piercer 5 at a strain rate of not higher than 200/sec and made into a hollow shell. (4) The hollow shell is elongated and finish rolled to make into a seamless steel pipe at an average strain rate of not lower than 0.01/sec and with a reduction ratio of not lower than 40%, and finishing the rolling at a temperature from 800.degree. C. to 1050.degree. C. (5) The seamless steel pipe is cooled to a temperature not higher than the Ar.sub.3 point at a cooling rate of not lower than 80.degree. C./min.
    Type: Grant
    Filed: April 1, 1998
    Date of Patent: February 15, 2000
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Kunio Kondo, Yasutaka Okada, Seiji Tanimoto
  • Patent number: 5958158
    Abstract: The invention relates to a process for producing hot-worked elongated products, such as bars or tubes, from high-alloy or hypereutectoid steel in which a feedstock is heated to a deformation temperature and undergoes at least one deformation step. Following the at least one deformation step, the deformed feedstock is either cooled or heated at a specific temperature to achieve a uniform temperature distribution throughout the length and thickness of the deformed feedstock. Next the deformed feedstock is reheated to a temperature below the deformation temperature. The reheated feedstock is continuously rolled in a multi-stand reducing mill to its final size and then cooled by ambient air.
    Type: Grant
    Filed: November 10, 1997
    Date of Patent: September 28, 1999
    Assignee: Mannesmann Aktiengesellschaft
    Inventors: Heinz Kron, Karlheinz Kutzenberger, Gunther Manig, Gustav Zouhar
  • Patent number: 5951794
    Abstract: Methods for making an aluminum drive shaft for automobiles or trucks or other drive shaft applications from aluminum alloy tube and methods for making drive shafts. The method includes providing an aluminum tube member is joined to drive shaft end members. The method includes the steps of (a) providing a 6000 series type alloy; (b) extruding the alloy within about 500.degree. to 800.degree. F. into a hollow elongate tube; (c) drawing the tube to a reduction of at least 15% in metal cross-sectional area; (d) solution heat treating the alloy at a temperature of at least about 990.degree. F. and then quenching; and (e) reducing the diameter of the tube and increasing the tube wall thickness to provide a relatively short tube length of reduced diameter, a transition section and thicker wall thickness at one or both ends of a drive shaft suitable length of said tube. The transition section has a non-linear wall. In a preferred embodiment, the transition section has central circumferential stiffener section.
    Type: Grant
    Filed: October 1, 1997
    Date of Patent: September 14, 1999
    Assignee: Aluminum Company of America
    Inventor: John A. Dickson, Jr.
  • Patent number: 5938865
    Abstract: A process for producing a seamless steel pipe wherein pipe manufacturing steps and the heat treatment steps are carried out in one production line. The properties of the pipe are comparative or superior to those of the pipe manufactured in the conventional reheating, quenching and tempering process. The process is characterized by using the billet of a low alloy steel containing C: 0.15-0.50%, Cr: 0.1-1.5%, Mo: 0.1-1.5%, Al: 0.005-0.50%, Ti: 0.005-0.50% and Nb: 0.003-0.50%, and comprising the following steps (1) to (5).(1) hot rolling with 40% or more of cross sectional reduction ratio,(2) finishing the hot rolling in a temperature range of 800-1100.degree. C.,(3) putting the manufactured steel pipe promptly in a complementary heating apparatus after the finish rolling, and complementarily heating at the temperature and time satisfying the following formula (a).
    Type: Grant
    Filed: February 5, 1998
    Date of Patent: August 17, 1999
    Assignee: Sumitomo Metal Industries, LTC.
    Inventors: Kunio Kondo, Takahiro Kushida, Hajime Osako, Hideki Takabe
  • Patent number: 5873960
    Abstract: The manufacturing method of the present invention comprises steps (1) through (8) which are sequentially arranged, and the steps or equipment from the production of billets to end products are connected in the same single continuous manufacturing line:(1) a step of producing a round billet by continuous casting,(2) a step of cooling the billet to a temperature not higher than an A.sub.r1 transformation temperature,(3) a step of heating the billet to a temperature which allows piercing of the billet,(4) a step of piercing, at a strain rate of not higher than 200/sec, the billet to obtain a hollow shell,(5) a step to form a steel pipe by elongating and finish rolling the hollow shell using a continuous elongating mill and a finish rolling mill which are directly connected to each other, at a predetermined average strain rate, a predetermined reduction ratio, and at a predetermined finishing temperature,(6) a step of recrystallizing the steel pipe at a temperature of not lower than an Ar.sub.
    Type: Grant
    Filed: March 26, 1997
    Date of Patent: February 23, 1999
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Kunio Kondo, Yasutaka Okada, Seiji Tanimoto
  • Patent number: 5853507
    Abstract: A method for treating heat exchanger tubing to be expanded by fluidic or electromagnetic expansion. The tubing treatment reduces the increased material hardness of the tubing in areas where cold work has been imparted thereon. By reducing these areas which have increased material hardness, the tubing will have a substantially similar tube yield along its entire length and can therefore be expanded to substantially the same cross-sectional area throughout by either fluidic or electromagnetic expansion. After forming the cold work regions, the regions are annealed with a heat source, such as through flame or induction heating, and are gradually cooled to avoid the effects of quenching.
    Type: Grant
    Filed: December 11, 1996
    Date of Patent: December 29, 1998
    Assignee: Carrier Corporation
    Inventors: Amer F. Ali, Kenneth P. Gray, Daniel P. Gaffaney
  • Patent number: 5849116
    Abstract: A steel material and a steel pipe each exhibiting an excellent corrosion resistance in an environment containing a wet carbon dioxide and a small amount of hydrogen sulfide are produced at low cost and with high productivity, a steel slab which contains, in wt %, 0.01 to 0.6% of Si, 0.02 to 1.8% of Mn, 7.5 to 14.0% of Cr, 1.5 to 4.0% of Cu and 0.005 to 0.1% of Al, which reduces C to not more than 0.02%, N to not more than 0.02%, P to not more than 0.025% and S to not more than 0.01%, and whose balance consists of Fe and unavoidable impurities, is heated to a temperature of 1,100.degree. to 1,300.degree. C., hot rolling is finished at a rolling finish temperature of not less than 800.degree. C. and a cumulative rolling reduction quantity at a temperature not more than 1,050.degree. C. is at least 65%, and cooling is carried out at a cooling rate of less than 0.02.degree. C./sec to at least 500.degree. C. so as to substantially convert the metallic structure to ferrite.
    Type: Grant
    Filed: January 15, 1997
    Date of Patent: December 15, 1998
    Assignee: Nippon Steel Corporation
    Inventors: Akihiro Miyasaka, Masaaki Obata, Takashi Motoyoshi
  • Patent number: 5820703
    Abstract: A steel pipe having excellent corrosion resistance in an environment containing wet carbon dioxide and a small amount of hydrogen sulfide and having also excellent weldability is produced at a low production cost and with high productivity. The production method comprises heating to a temperature of 1,050.degree. to 1,300.degree. C. a slab containing, in terms of wt %, 0.01 to less than 1.2% of Si, 0.02 to 3.0% of Mn, 7.5 to 14.0% of Cr and 0.005 to 0.5% of Al, reduced C, N, P and S contents, at least one of Cu, Ni, Co, Mo and W, a balance of Fe and unavoidable impurities, and having an MC value of at least 0, finishing hot rolling within an austenite monophase temperature range, coiling the steel sheet as a hot coil having a sheet thickness of 3.0 to 25.4 mm, cooling the coil at a cooling rate of at least 0.01.degree. C./sec to at least 500.degree. C. to convert the steel sheet to a steel substantially consisting of martensite, reheating the steel to a temperature of 550.degree. C. to not more than an A.sub.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: October 13, 1998
    Assignee: Nippon Steel Corporation
    Inventors: Yasushi Suzuki, Masaaki Obata, Akihiro Miyasaka
  • Patent number: 5817193
    Abstract: In the fabrication of components from a face centered cubic alloy, wherein the alloy is cold worked and annealed, the cold working is carried out in a number of separate steps, each step being followed by an annealing step. The resultant product has a grain size not exceeding 30 microns, a "special" grain boundary fraction not less than 60%, and major crystallographic texture intensities all being less than twice that of random values. The product has a greatly enhanced resistance to intergranular degradation and stress corrosion cracking, and possesses highly isotropic bulk properties.
    Type: Grant
    Filed: January 17, 1997
    Date of Patent: October 6, 1998
    Inventor: Gino Palumbo
  • Patent number: 5730812
    Abstract: A method is disclosed for manufacturing ejector sleeves from tubular stock. In particular, the method includes the following steps or operations: (a) cutting the tube stock to length, (b) enlarging a portion of the inside diameter of the sleeve to provide a clearance diameter, (c) rough-sizing a close-fitting inner diameter, (d) optionally semi-finishing the outside diameter of the sleeve, (e) hardening and straightening the sleeve, (f) final sizing of the outside diameter while maintaining concentricity with the inside diameters, (g) finishing the end face of the sleeve adjacent the close-fitting diameter, (h) final sizing of the close-fitting inner diameter while maintaining concentricity with the outside diameter, (i) forming a head on the sleeve by heating and forging to a predetermined size, (j) optional annealing and refinishing of the head for purposes of hardness or dimensional modification, or improving surface finish.
    Type: Grant
    Filed: May 19, 1997
    Date of Patent: March 24, 1998
    Assignee: D-M-E Company
    Inventor: David E. Lawrence
  • Patent number: 5545270
    Abstract: A high strength steel composition comprising ferrite and martensite/banite phases, the ferrite phase having primarily vanadium and mobium carbide or carbonitride precipitates, is prepared by a first rolling above the austenite recrystallization temperature; a second rolling below the anstenite recrystallization temperature; a third rolling between the Ar.sub.3 and Ar.sub.1 transformation points, and water cooling to below about 400.degree. C.
    Type: Grant
    Filed: December 6, 1994
    Date of Patent: August 13, 1996
    Assignee: Exxon Research and Engineering Company
    Inventors: Jayoung Koo, Michael J. Luton
  • Patent number: 5478523
    Abstract: A machinable, graphitic steel is disclosed having a composition in weight % of about 1.0 to 1.5 total C; 1.0 to Si; 0.3 to 1.0 Mn; up to 2.0 Ni; up to 0.5 Cr; up to 0.5 Mo; up to 0.1 S; up to 0.5 Al; balance Fe and incidental impurities. The steel is hot worked and cooled to precipitate a controlled amount of graphite for improved machinability and to achieve a controlled amount of matrix carbon for enhanced physical properties. A matrix carbon content of between about 0.2 to 0.8 weight % is desired. The steel may be further heat treated to yield further variations in the microstructure and physical properties.
    Type: Grant
    Filed: January 24, 1994
    Date of Patent: December 26, 1995
    Assignee: The Timken Company
    Inventors: James A. Brusso, George T. Matthews
  • Patent number: 5188680
    Abstract: A method of making a tooth point and product wherein a tubular blank of alloy steel is heated, shaped at one end to provide a box section and shaped at the other end to provide a blade made up of two layers of steel forged together.
    Type: Grant
    Filed: November 15, 1990
    Date of Patent: February 23, 1993
    Assignee: ESCO Corporation
    Inventors: Frederick C. Hahn, Andrew H. Ulven, James W. Huiras
  • Patent number: 5186769
    Abstract: A method for producing seamless steel tubes suitable for use as grades of casing and line pipe having yield strengths in excess of 70,000 psi, without being heat treated. Such steels are made of an alloy comprising, by weight, about 0.10% to 0.18% carbon, about 0.10% to 2.0% manganese, about 0.10% to 0.16% vanadium, about 0.008% to 0.012% titanium and about 150 parts per million to 220 parts per million nitrogen, the balance comprising iron and incidental impurities. The subject method comprises the steps of alloying a steel of the aforesaid chemical composition, forming the steel into a billet of steel, reheating the billet in a reheating furnace, passing the billet through a piercing mill to form a steel shell, elongating the steel shell within a mandrel mill, and reducing the diameter of the elongated shell in a stretch reducing mill. Strains are applied to the shell in the stretch reducing mill below the T.sub.nr of the steel and above the A.sub.r3 to provoke dynamic recrystallization.
    Type: Grant
    Filed: July 28, 1991
    Date of Patent: February 16, 1993
    Assignee: The Algoma Steel Corporation, Limited
    Inventors: Patrick J. Hunt, John J. Jonas, Stephen Yue, George E. Ruddle, Lakshman N. Pussegoda