Abstract: A blank with a closed profile is made of hardenable sheet steel and is hydroformed when hot. The tool is cooled and the blank is heated to a hardening temperature and formed so fast that it will not have time to harden before it contacts the tool and becomes rapidly cooled by the tool and by the liquid fluid so that it hardens. In this simple way, a product of high strength steel can be achieved which has a closed profile and complicated form. The product can be, for example, a bow-formed bumper.
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.
Abstract: An ultra-high strength, weldable, low alloy steel with excellent cryogenic temperature toughness in the base plate and in the heat affected zone (HAZ) when welded, having a tensile strength greater than about 830 MPa (120 ksi) and a microstructure comprising (i) predominantly fine-grained lower bainite, fine-grained lath martensite, fine granular bainite (FGB), or mixtures thereof, and (ii) up to about 10 vol % retained austenite, is prepared by heating a steel slab comprising iron and specified weight percentages of some or all of the additives carbon, manganese, nickel, nitrogen, copper, chromium, molybdenum, silicon, niobium, vanadium, titanium, aluminum, and boron; reducing the slab to form plate in one or more passes in a temperature range in which austenite recrystallizes; finish rolling the plate in one or more passes in a temperature range below the austenite recrystallization temperature and above the Ar3 transformation temperature; quenching the finish rolled plate to a suitable Quench Stop Temperat
Type:
Grant
Filed:
December 19, 1998
Date of Patent:
July 3, 2001
Assignee:
ExxonMobile Upstream Research Company
Inventors:
Jayoung Koo, Narasimha-Rao V. Bangaru, Glen A. Vaughn, Raghavan Ayer
Abstract: A method for fabricating a homogeneous wire of inter-metallic alloy comprising the steps of providing a base-metal wire bundle comprising a metal, an alloy or a combination thereof; working the wire bundle through at least one die to obtain a desired dimension and to form a precursor wire; and, controllably heating the precursor wire such that a portion of the wire will become liquid while simultaneously maintaining its desired shape, whereby substantial homogenization of the wire occurs in the liquid state and additional homogenization occurs in the solid state resulting in a homogenous alloy product.
Abstract: A hot rolled steel sheet with improved formability and producing method therefor, which can be easily produced with general hot strip mills, having less anisotropy of mechanical properties and final ferrite grain diameter of less than 2 &mgr;m that could not be achieved by the prior art. The hot rolled steel sheet comprises a ferrite phase as a primary phase, and has an average ferrite grain diameter of less than 2 &mgr;m, with the ferrite grains having an aspect ratio of less than 1.5. The hot rolled steel sheet is obtained by carried out a reduction process under a dynamic recrystallization conditions through reduction passes of not less than 5 stands in the hot finish rolling.
Abstract: This invention provides a ferritic heat-resistant steel that can improve HAZ softening resistance, can omit heat-treatment after welding and can reduce the construction cost of a power generation plant. This ferritic heat-resistant steel contains C: 0.01 to 0.06%, Si: 0.02 to 0.80%, Mn: 0.20 to 1.50%, Cr: 0.50 to 3.00%, Mo: 0.01 to 1.50%, W: 0.01 to 3.50%, V: 0.02 to 1.00%, Nb: 0.01 to 0.50%, N: 0.001 to 0.06%, B: 0.0003 to 0.008%, Ti: 0.001 to 0.5%, Zr: 0.001 to 0.5%, or containing one of Cu: 0.1 to 2.0%, Ni: 0.1 to 2.0% and Co: 0.1 to 2.0% either individually or in combination, and limiting P to not greater than 0.030%, S to not greater than 0.010% and O to not greater than 0.020%, wherein a weight ratio of TiN and BN in the steel is controlled to 1 to 100 in terms of a value (TiN+ZrN %)/(BN %), and a mean grain diameter of BN is not greater than 1 .mu.m.
Abstract: An ultra-high strength, weldable, low alloy, triple phase steel with excellent cryogenic temperature toughness in the base plate and in the heat affected zone (HAZ) when welded, having a tensile strength greater than about 830 MPa (120 ksi) and a microstructure comprising a ferrite phase, a second phase of predominantly lath martensite and lower bainite, and a retained austenite phase, is prepared by heating a steel slab comprising iron and specified weight percentages of some or all of the additives carbon, manganese, nickel, nitrogen, copper, chromium, molybdenum, silicon, niobium, vanadium, titanium, aluminum, and boron; reducing the slab to form plate in one or more passes in a temperature range in which austenite recrystallizes; further reducing the plate in one or more passes in a temperature range below the austenite recrystallization temperature and above the Ar.sub.3 transformation temperature; finish rolling the plate between the Ar.sub.3 transformation temperature and the Ar.sub.
Type:
Grant
Filed:
December 19, 1998
Date of Patent:
December 12, 2000
Assignee:
ExxonMobil Upstream Research Company
Inventors:
Jayoung Koo, Narasimha-Rao V. Bangaru, Raghavan Ayer, Glen A. Vaughn
Abstract: An ultra-high strength, weldable, low alloy, dual phase steel with excellent cryogenic temperature toughness in the base plate and in the heat affected zone (HAZ) when welded, having a tensile strength greater than 830 MPa (120 ksi) and a microstructure comprising a ferrite phase and a second phase of predominantly lath martensite and lower bainite, is prepared by heating a steel slab comprising iron and specified weight percentages of some or all of the additives carbon, manganese, nickel, nitrogen, copper, chromium, molybdenum, silicon, niobium, vanadium, titanium, aluminum, and boron; reducing the slab to form plate in one or more passes in a temperature range in which austenite recrystallizes; further reducing the plate in one or more passes in a temperature range below the austenite recrystallization temperature and above the Ar.sub.3 transformation temperature; finish rolling the plate between the Ar.sub.3 transformation temperature and the Ar.sub.
Abstract: This invention relates to the working of a metallic strip. More particularly, the invention relates to a method of working a length of metallic strip by heat treating under tensile force, to a length of metallic strip and to an apparatus for use in working a length of metallic strip.
Type:
Grant
Filed:
August 14, 1998
Date of Patent:
May 16, 2000
Assignee:
Trico Products Corporation
Inventors:
Oliver F. R. A. Damm, Warwick John Green, Lillian Hristov Ivanchev, Walter Luigi Trevisan
Abstract: Steel, steel wire, and a process for forming a drawn wire, especially tire-reinforcing wire of diameter smaller than 0.4 mm, by drawing a steel of the following composition by weight: 0.005%.ltoreq.carbon.ltoreq.0.050%; 0.005%.ltoreq.nitrogen.ltoreq.0.050%; 0.1%.ltoreq.silicon.ltoreq.2.0%; 0.1%.ltoreq.manganese.ltoreq.5%; 5%.ltoreq.nickel.ltoreq.12%; 10%.ltoreq.chromium.ltoreq.20%; 0.01%.ltoreq.copper.ltoreq.4%; 0.01%.ltoreq.molybdenum.ltoreq.3%,the base wire being subjected to:drawing to a cumulative deformation ratio .epsilon. of larger than 2 and smaller than 4,an intermediate annealing treatment at above 700.degree. C.final drawing to a cumulative deformation ratio .epsilon. of smaller than 4.5 and larger than 3.
Type:
Grant
Filed:
April 29, 1999
Date of Patent:
April 11, 2000
Assignees:
Ugine-Savoie Imphy, Sprint Metal - Societe de Production Internationale de Trefiles
Abstract: This process makes it possible to manufacture articles of any shape by stamping, in which articles the matrix of the alloy has to have a coarse-grained structure. According to the invention, a partial hot-forming operation is carried out by stamping a blank made of an oxide-dispersion-strengthened alloy, especially a nickel-based alloy, having an initial ultrafine-grained structure, in order to form a shaped component, this shaped component is subjected to a secondary recrystallization heat treatment so as to develop an abnormal grain growth, and then a new hot-forming operation is carried out by stamping in order to give the recrystallized shaped component the final shape of the article.
Abstract: Steel with ultrafine grains is produced by altering the transformation from one which normally proceeds with grain boundary nucleation followed by intragranular nucleation at deformation bands and other defects, to one which induces a substantially instantaneous transformation homogeneously over the austenite grain. This is favoured by a reduction or minimisation of grain boundary nucleation, (for example by enlargement of the austenite grain size), prior to or during the transformation. In an embodiment, a partially cooled austenite phase steel is deformed in a single pass at a temperature in the range of 700-950.degree. C. to obtain ferrite grain size of 5 .mu.m or less.
Type:
Grant
Filed:
June 25, 1997
Date of Patent:
February 22, 2000
Assignee:
The Broken Hill Proprietary Company Limited
Inventors:
Peter Damian Hodgson, Mark Richard Hickson, Russell Keith Gibbs
Abstract: A steel for machine structural use, essentially having the following chemical composition:C: 0.45-0.60 wt %,Si: 0.50-2.00 wt %,Mn: 0.10-0.30 (0.30 not inclusive) wt %,P: 0.01-0.10 wt %,S: 0.01-0.20 wt %,V: 0.08-0.15 wt %, andN: 0.0020-0.0050 (0.0050 not inclusive) wt %. The remainder is Fe and impurities inevitably included. The inner structure of the steel is a ferrite-pearlite structure.
Type:
Grant
Filed:
November 18, 1998
Date of Patent:
November 30, 1999
Assignee:
Isuzu Motors Limited and Nippon Steel Corporation
Abstract: A method of manufacturing a thick steel product of high strength and high toughness having excellent weldability with minimal variation of material properties, comprises heating a steel raw material to the temperature of Ac.sub.3 to 1350.degree. C., hot rolling and then cooling at the cooling rate of 10.degree. C./sec. or less. The steel raw material has the following composition:C: 0.001-0.25 wt %;Mn: 1.0-3.0 wt %;Ti: 0.005-0.20 wt %;Nb: 0.005-0.20 wt %;B: 0.0003-0.0050 wt %; andAl: 0.01-0.100 wt %balance substantially Fe and incidental impurities. The composition has a transformation start temperature (Bs) of 670.degree. C. or less. Since the steel product obtained by the method has no variation in physical properties regardless of variation in cooling rate, it is possible to supply steel products of high strength and high toughness which have uniform microstructure and properties along their thickness direction and are excellent in weldability.
Abstract: In the present invention, a steel product having a specified composition comprising by weight C: 0.02 to 0.25%, Si: 0.01 to 2.0%, Mn: 0.30 to 1.5%, Al: 0.003 to 0.10%, Nb: 0.005 to 0.10%, and Mo: 0.05 to 1.00% with the balance consisting of Fe and unavoidable impurities is used to prepare a steel plate having a thickness of 3 to 100 mm (the upper limits of the Nb and Mo contents each being 0.025% particularly for a plate thickness of 3 to 25 mm), and the ratio of the yield stress of the steel plate at a temperature T, .sigma..sub.yT, to the yield stress of the steel plate at room temperature, .sigma..sub.y, over the temperature range of room temperature to 600.degree. C. is brought to a value falling within the following range:1.00-1.083.times.10.sup.-3 T<(.sigma..sub.yT /.sigma..sub.y)<1.16-5.101.times.10.sup.-4 T.Further, the constituents of a welding material are specified to bring the .gamma..sub.3 transformation temperature to below 620.degree. C.
Abstract: High strength steel structural members and a method of making same are disclosed by providing high-strength steel material having a specific chemical composition and preferably a tensile strength of at least about 120,000 psi and a yield strength of at least about 90,000 psi and hot rolling the steel material to provide the structural member of desired geometric configuration.
Abstract: A aluminum alloy in the form of bulk includes an aluminum matrix and carbon particles having an average particle size of 100 nm or less and dispersed in the aluminum matrix in an amount of 1 to 40 atomic % with respect to the total atoms constituting the aluminum alloy. The aluminum alloy is produced by preparing a raw material comprising aluminum and carbon as components and forming an aluminum alloy by inserting the raw material into a cavity formed by a set of dies and applying repeatedly plastic deformation to the raw material while maintaining the temperature of the raw material in the range of from 100 to 400.degree. C.
Abstract: The present invention is concerned about high toughness and high strength untempered steel having the mechanical properties equivalent to or better than those of tempered steel and processing method thereof, more particularly, the high toughness and high strength untempered steel having the tensile strength higher than 90 kgf/mm.sup.2 with the impact toughness higher than 5 kgf-m/cm.sup.2 in the KS 3 specimen, and processing method thereof.
Abstract: A clutch diaphragm comprises a peripheral Belleville ring portion and a central portion having a central aperture and comprising a set of radial fingers separated by slots, each of which extends from a blind end which is close to the peripheral portion to an inner end which is open into the central aperture, the latter being common to all of the slots.In a method of making this diaphragm, a flat blank is heat treated and is then soaked and hot formed to give the diaphragm a first diaphragm angle. It is then tempered in a tempering oven. The diaphragm is then transferred from the tempering oven to a stabilizing press, in which the conicity of the diaphragm is reversed while it is still hot from the tempering oven, so that instead of the first angle it now has an inversion angle.
Abstract: High strength steel structural members and method of making are disclosed by providing a blank of high-strength steel material having a tensile strength of at least about 120,000 psi and a yield strength of at least about 90,000 psi and warm forming the blank to provide the member of desired geometric configuration while substantially maintaining or increasing the strength properties of the blank.
Abstract: Process and apparatus are provided for selective heating a portion of a workpiece to achieve improved ausforming and isoforming processes when the workpiece is plastically deformed by mechanical working above the M.sub.s temperature. The process and apparatus includes a preheating step where a larger portion of the workpiece is preheated to less than the austenitic critical temperature while the final heating step conducted at a temperature higher than the austenitic critical temperature heats a smaller portion of the workpiece which is subsequently subjected to plastic deformation.
Abstract: A thermomechanical method for improving the fatigue characteristics of a metallic material (for example carbon steel and low alloy steel) takes advantage of the materials' plastic flow characteristics to improve external and internal surface conditions. The material is heated to a temperature in the range of about 0.3 to 0.45 its homologous temperature, e.g., from about 200 degrees C to about the Young's Modulus Transition Temperature of said material. While the temperature of the material is in this range, force is applied to the material to produce in at least the region of said material to be treated a tensile stress level greater than the yield point of said material at the temperature, and thereby to produce limited plastic elongation in the region. The material is then cooled under stress, the stress being maintained above the instantaneous yield point of the material during at least part of the cooling process. As a result of this process, the shape of existing stress raisers (e.g.
Abstract: The strength of interstitial free steels is increased by up to 100% and the ductile to brittle transition temperature is decreased by up to 100.degree. C. by warm finish rolling in the single phase ferrite region below A.sub.rl to effect ferrite dynamic recrystallization of the steel microstructure to a ferrite structure of grain size having a grain size of up to 5 .mu.m, and especially an ultra fine grain size of 1 to 2 .mu.m; the method may be employed in various hot working methods including strip and rod mills, planetary hot rolling and extrusion.
Type:
Grant
Filed:
February 8, 1991
Date of Patent:
April 6, 1993
Assignee:
McGill University
Inventors:
Abbas Najah-Zadeh, John J. Jonas, Stephen Yue