Nine Percent Or More Chromium(cr) (e.g., Stainless Steel, Etc.) Patents (Class 148/597)
  • Patent number: 10157687
    Abstract: Disclosed embodiments include fuel assemblies, fuel element, cladding material, methods of making a fuel element, and methods of using same.
    Type: Grant
    Filed: February 9, 2017
    Date of Patent: December 18, 2018
    Assignee: TerraPower, LLC
    Inventors: Micah J. Hackett, Ronald L. Klueh
  • Patent number: 9979256
    Abstract: A rotary electric machine may include a rotor that includes a laminated core arranged on a rotor shaft, wherein the rotor has at least one end-winding cover that encloses the laminated core in the axial direction of the rotor shaft, the end-winding cover has at least one inner face facing the laminated core, and a balancing ring is concentrically arranged around the rotor shaft on the inner face of the end-winding cover.
    Type: Grant
    Filed: February 26, 2013
    Date of Patent: May 22, 2018
    Inventor: Michael Bulatow
  • Publication number: 20150027598
    Abstract: A hardenable chromium-nickel steel, comprising 0.005 to 0.12% carbon, 9 to 17% chromium, 5 to 12% nickel, at most 3% cobalt, 0.5 to 4% molybdenum, 0.25 to 1.0% silicon, 0.5% to 3.0% manganese, 1 to 3% titanium, 0.25 to 1% vanadium, 0.05 to 0.5% niobium, 0.001 to 0.30% nitrogen, at most 0.5% tantalum, 0.001 to 0.030% sulfur, 0.2 to 2.0% copper, at most 0.5% tungsten, at most 1.5% aluminum, 0.0001 to 0.01% boron, and at most 0.035% phosphorus, remainder iron including impurities resulting from smelting, is suitable in particular as a material for producing wire by drawing in the 3-phase region of ?-martensite, ?-martensite, and austenite, in conjunction with a heat treatment. The wire can be used for components for instrument construction, surgical needles, valve pins, and dental braces.
    Type: Application
    Filed: June 28, 2011
    Publication date: January 29, 2015
    Inventors: Stefan Seng, Gisbert Klossulitzka, Osakar Pacher, Günter Schnabel
  • Patent number: 8840735
    Abstract: Fatigue damage resistant metal or metal alloy wires have a submicron-scale or nanograin microstructure that demonstrates improved fatigue damage resistance properties, and methods for manufacturing such wires. The present method may be used to form a wire having a nanograin microstructure characterized by a mean grain size that is 500 nm or less, in which the wire demonstrates improved fatigue damage resistance. Wire manufactured in accordance with the present process may show improvement in one or more other material properties, such as ultimate strength, unloading plateau strength, permanent set, ductility, and recoverable strain, for example. Wire manufactured in accordance with the present process is suitable for use in a medical device, or other high end application.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: September 23, 2014
    Assignee: Fort Wayne Metals Research Products Corp
    Inventor: Jeremy E. Schaffer
  • Publication number: 20140041768
    Abstract: Provided is a method for fabricating a stepped forged material that can realize a uniform microscopic structure in both the large diameter flange portion and the small diameter shaft portion. This method for fabricating a stepped forged material comprises the following steps: a step for obtaining a primary forged material in which an austenite stainless steel billet is heated to 1000-1080° C., and, without any further heating, the material is forged by means of reciprocal forging into a round rod having along the entire length thereof a forging ratio of 1.5 or greater; a step for obtaining a secondary forged material, that forms the large diameter flange portion and the small diameter shaft portion, in which without reheating, the small diameter shaft portion is formed by means of reciprocal forging at a temperature where the surface temperature of the primary forged material never falls more than 200° C.
    Type: Application
    Filed: April 24, 2012
    Publication date: February 13, 2014
    Applicant: HITACHI METALS, LTD.
    Inventors: Shinya Nagao, Etsuo Fujita
  • Patent number: 8075991
    Abstract: A stainless steel material for a fuel cell, used for a fuel cell or a cartridge for the fuel cell, having a magnetic permeability of 1.000 to 2.500, and forming a layer having a value of chromium atomic %/iron atomic % of not less than 3.0 in the most surface thereof, and/or the layer of thickness of not less than 12 nm calculated as SiO2 having an oxygen atomic % of not less than 20%. Even when brought into contact with the content solution exhibiting acidity of the fuel cell, the stainless steel material reliably suppresses the elution of metal ions thereof.
    Type: Grant
    Filed: August 9, 2007
    Date of Patent: December 13, 2011
    Assignee: Toyo Seikan Kaisha, Ltd.
    Inventors: Kouki Kinouchi, Wataru Kurokawa, Shouzou Shintani, Kinuyo Shintani, legal representative, Daisuke Imoda, Kenji Yoshihiro, You Yamamori
  • Publication number: 20110253269
    Abstract: In an antibacterial stainless steel wire and its manufacturing method, a wire drawing process, a cold working process, or a solution treatment integrated with an ageing treatment are used for making a precipitation of copper into an independent phase and in a granular form uniformly distributed in a stainless steel substrate, such that the stainless steel wire has an antibacterial effect.
    Type: Application
    Filed: April 14, 2010
    Publication date: October 20, 2011
    Applicant: YUEN NENG CO., LTD.
    Inventor: Tzu-Hsia Wei
  • Patent number: 7926180
    Abstract: A method for making gas and liquid storage tanks such as automotive fuel tanks includes providing two or more blanks of air hardenable martensitic stainless steel in the annealed condition. The steel blanks have a thickness in the range of 0.5-5.0 mm., and are formed utilizing stamping, forging, pressing, or roller forming techniques or the like into the form of a tank shell components. The shell components are hardened and assembled into a storage tank. The shell components are hardened by application of heat, preferably to between 950° C. and 1100° C. for standard air hardenable martensitic stainless steels. Thereafter, the automotive fuel tank is preferably cooled at a rate greater than 25° C. per minute to achieve a Rockwell C hardness of at least 39. The automotive fuel tank may undergo additional heat treating processes including high temperature or low temperature tempering processes which may incorporate electro-coating.
    Type: Grant
    Filed: October 4, 2006
    Date of Patent: April 19, 2011
    Inventors: Edward J. McCrink, Danny Codd
  • Patent number: 7625455
    Abstract: A method of heat treating stainless steel in the form of blanks, piping, tubing, strip, or wire-like material, after rolling the material, and in a heat treatment furnace at a temperature higher than about 900° C. The material is subjected to a preheating stage and a final heating stage, wherein in the preheating stage flames from burners are directed toward the surface of the material to impinge on the surface. Burners situated in the preheating stage are supplied with a fuel that burns with the aid of an oxidizing gas that contains gaseous oxygen. The material is held in the preheating stage long enough to obtain at least some degree of oxidation on the surface of the material, and the material is heated further in a following, final heating stage by burners situated in a furnace and that are supplied with a fuel and an oxidizing gas.
    Type: Grant
    Filed: February 17, 2003
    Date of Patent: December 1, 2009
    Assignee: Linde AG
    Inventors: Carl-Lennart Axelsson, Tomas Ekman, Ola Ritzén
  • Publication number: 20090044884
    Abstract: Treatment process for stainless steel bars, in particular a solution quenching, to be performed directly in-line downstream of the rolling mill which makes it possible to obtain a material devoid of intergranular corrosion and with microstructural characteristics suitable for subsequent uses. Advantageously, said process also makes it possible to improve the productivity of the entire rolling plant. The treatment is suitable to be performed on austenitic, ferritic, or austeno-ferritic stainless steel bars, Al—Cu alloy bars, Nickel alloy bars, and all other alloys requiring rapid cooling in order to prevent undesired phase precipitations. Prevention of intergranular corrosion obtained with the treatment process of the invention makes it possible to prevent problems, and relative costs, during surface treatment of the bars and those that could occur in final use.
    Type: Application
    Filed: October 21, 2005
    Publication date: February 19, 2009
    Inventors: Francesco Toschi, Rolando Paolone
  • Patent number: 7475478
    Abstract: A method for making structural automotive components and the like includes providing a blank of air hardenable martensitic stainless steel in the annealed condition. The steel blank has a thickness in the range of 0.5-5.0 mm., and is formed utilizing stamping, forging, pressing, or roller forming techniques or the like into the form of an automotive structural member. The automotive structural member is then hardened by application of heat, preferably to between 950° C. and 1100° C. for standard martensitic stainless steels. Thereafter, the automotive structural member is preferably cooled at a rate greater than 25° C. per minute to achieve a Rockwell C hardness of at least 39. The automotive structural member may undergo additional heat treating processes including high temperature or low temperature tempering processes which may incorporate electro-coating.
    Type: Grant
    Filed: September 11, 2006
    Date of Patent: January 13, 2009
    Assignee: KVA, Inc.
    Inventors: Edward J. McCrink, Danny Codd
  • Patent number: 7166174
    Abstract: The invention relates to stainless steel fibers obtained by bundled drawing of stainless steel wires embedded in a matrix material. The composition of the stainless steel fibers comprises iron and the following components expressed in percent by weight: C £ 0.05%, Mn £ 5%, Si £ 2%, 8 £ Ni £ 12%, 15% £ Cr £ 20%, Mo £ 3%, Cu £ 4%, N £ 0.05%, S £ 0.03% and P £ 0.05%. The invention further relates to a method of manufacturing stainless steel fibers.
    Type: Grant
    Filed: July 2, 2002
    Date of Patent: January 23, 2007
    Assignee: NV Bekaert SA
    Inventors: Stefaan De Bondt, Jaak Decrop
  • Patent number: 7119329
    Abstract: In a mass spectrometer, an ion of a sample gas is produced in an ion source by colliding the gas with an electron beam, and is introduced into a magnetic field or an electric field. The ion is separated based on the mass number, and the sample is analyzed from a mass spectrum. The ion source has an electrode made of stainless steel, which is baked at a temperature in a range from 200° C. to 700° C. in an air atmosphere.
    Type: Grant
    Filed: May 26, 2005
    Date of Patent: October 10, 2006
    Assignee: Shimadzu Corporation
    Inventors: Manabu Shimomura, Hiroto Itoi
  • Patent number: 6896747
    Abstract: Austenitic alloy for high-temperature strength with improved pourability and manufacturing, of which the composition comprises, in weight-%: 0.010%<carbon<0.04% 0%<nitrogen<0.01% silicon<2% 16%<nickel<19.9% manganese<8% 18.1%<chromium<21% 1.8%<titanium<3% molybdenum<3% copper<3% aluminum<1.5% boron<0.01% vanadium<2% sulfur<0.2% phosphorous<0.04% and possibly up to 0.5% of at least one element chosen from among yttrium, cerium, lanthanum and other rare earths, the remainder being iron and impurities resulting from manufacturing or deoxidizing, the said composition also satisfying the two following relationships: in relationship to the solidification mode: remainder a=eq. Nia?0.5×eq. Cra<3.60 where eq. Cra=Cr+0.7×Si+0.2×Mn+1.37×Mo+3×Ti+6×Al+4×V, and where eq. Nia=Ni+22×C+0.5×Cu, in relationship to the rate of residual ferrite: remainder b=eq. Nib?2×eq. Crb>?41 where eq. Crb=Cr+0.7×Si+1.37×Mo+3×Ti+6×Al+4×V, and where eq. Nib=Ni+22×C+0.5×Cu+0.
    Type: Grant
    Filed: November 1, 2002
    Date of Patent: May 24, 2005
    Assignee: Usinor
    Inventors: Jean-Michel Hauser, Christophe Bourgin
  • Patent number: 6780261
    Abstract: A metallurgical process for producing a metallic implantable medical device, such as a stent, in a condition wherein the metallic alloy of the device has improved mechanical properties. The starting material is formed into an oversized tube which is drawn to finished outer diameter. The drawing process cold works the tube to produce a material having a high dislocation density and a yield strength that is above approximately 125 ksi. Next, the drawn tube is heat treated at a temperature of approximately one-half the absolute melting temperature of the alloy. The heat treatment causes dislocations to rearrange, forming sub-grains and re-crystallization of the grain structure. Upon cooling, a material is obtained having a yield strength between approximately 45-70 ksi and an elongation exceeding 40 percent. The material also has good resistance to fatigue fracture due to the fine grains and sub-grains that are established during the heat treatment.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: August 24, 2004
    Assignee: SciMed Life Systems, Inc.
    Inventor: Thomas Trozera
  • Publication number: 20040045645
    Abstract: Medical devices, medical device components, and methods of making the same. For example, one embodiment provides a method of shaping a reinforcing member through annealing. Another exemplary embodiment includes a method of making a medical device that includes such a shaped reinforcement member incorporated therein. Yet another exemplary embodiment provides a medical device including such a shaped reinforcing member therein.
    Type: Application
    Filed: September 10, 2002
    Publication date: March 11, 2004
    Inventor: Pu Zhou
  • Patent number: 6699603
    Abstract: A stainless steel with a passive state fluorinated film formed thereon, which is easy to construct and does not produce particles even when it is welded, and a device using the same. The stainless steel does not cause leakage even when said film is formed on a sealing surface of a joint and a valve seat surface. The stainless steel is characterized in that at least a part of the surface coated with a passive state fluorinated film not thicker than 190Å consisting of a metal fluoride as a main component.
    Type: Grant
    Filed: December 26, 2001
    Date of Patent: March 2, 2004
    Assignee: Stella Chemifa Kabushiki Kaisha
    Inventors: Tadahiro Ohmi, Hirohisa Kikuyama, Masayuki Miyashita, Hiroto Izumi, Takanobu Kujime
  • Patent number: 6440579
    Abstract: Process for producing a drawn wire, in particular a wire for reinforcing tires, having a diameter of less than 0.3 mm by drawing a base wire rod having a diameter of greater than 5 mm or a predrawn base wire made of steel with the following composition by weight: carbon≦40×10−3% nitrogen≦40×10−3%, the carbon and nitrogen satisfying the relationship C+N≦50×10−3%, 0.2%≦silicon≦1.0%, 0.2%≦manganese≦5%, 9%≦nickel≦12%, 15%≦chromium≦20%, 1.5%≦copper≦4%, sulfur≦10×10−3%, phosphorus<0.050%, 40×10−4%≦total oxygen≦120×10−4%, 0.1×10−4%≦aluminum≦20×10−4%, magnesium≦5×10−4%, 0.
    Type: Grant
    Filed: February 18, 1998
    Date of Patent: August 27, 2002
    Assignees: Ugine Savoie Societe de Production Internationale de Trefiles, Sprint Metal
    Inventors: Jean-Michel Hauser, Joël Marandel, Etienne Havette
  • Patent number: 6383316
    Abstract: Through electro slag refining of a bloom of a stainless, precipitation hardenable stainless steel of 17-7 PH type, the fatigue resistance of springs made of cold drawn wires of said material is increased substantially. This depends on the fact that large slag inclusions, which can initiate fatigue failures, are eliminated at the ESR remelting, while longer zones containing concentrations of small slag inclusions are substantially reduced. The material is particularly suitable for springs in injection pumps for Diesel engines.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: May 7, 2002
    Assignee: Haldex Garphyttan Aktiebolag
    Inventor: Claes-Henrik Engström
  • Patent number: 6374477
    Abstract: After heat treatment for hardening the outer peripheral surface of the input shaft 15 is enforced, a straightening operation for straightening the bent portions of the input shaft 15 caused by the heat treatment is carried out prior to formation of the through holes 17, 17. After then, the input shaft 15 is machined using electric sparks to thereby form the through holes 17, 17 in the input shaft 15. In the present working method, there is eliminated the possibility that, during the straightening operation, stresses can concentrate in the through holes 17, 17 portions of the input shaft 15, thereby being able to attain the above object.
    Type: Grant
    Filed: August 4, 2000
    Date of Patent: April 23, 2002
    Assignee: NSK, Ltd.
    Inventors: Hideki Hashitani, Masami Tanaka
  • Patent number: 6106639
    Abstract: Stainless steel wire of diameter smaller than 2 mm and with a tensile strength greater than 2100 MPa, consisting of a steel whose chemical composition includes, by weight: 0%.ltoreq.C.ltoreq.0.03%, 0%.ltoreq.Mn.ltoreq.2%, 0%.ltoreq.Si.ltoreq.0.5%, 8%.ltoreq.Ni.ltoreq.9%, 17%.ltoreq.Cr.ltoreq.18%, 0%.ltoreq.Mo.ltoreq.0.4%, 3%.ltoreq.Cu.ltoreq.3.5%, 0%.ltoreq.N.ltoreq.0.03%, S.ltoreq.0.01%, P.ltoreq.0.04%, the remainder being iron and impurities resulting from the production. Process of manufacture of the wire and uses.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: August 22, 2000
    Assignees: Sprint Metal Societe de Production Internationale de Trefiles, Imphy S.A., Ugine Savoie
    Inventors: Joel Marandel, Jean-Michel Hauser
  • Patent number: 6048416
    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 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
    Inventors: Jean-Michel Hauser, Joel Marandel
  • Patent number: 5833771
    Abstract: A stainless steel wire for reinforcing the crown (1) of tires (100), comping at least 0.02% and at most 0.2% carbon, at least 6% and at most 10% nickel, at least 16% and at most 20% chromium, the content of molybdenum of the steel being zero or at most equal to 5%, the total of the nickel, chromium and molybdenum being at least 23% and at most 28.5%, all these percentages being % by weight;the structure of the steel comprises at least 50% by volume martensite and it is without austenite or comprises less than 50% by volume thereof.Assemblies (620), reinforcement plies (62) and tires (100) comprising this wire.Process for preparing this wire.
    Type: Grant
    Filed: April 11, 1997
    Date of Patent: November 10, 1998
    Assignee: Compagnie Generale Des Etablissements Michelin-Michelin & Cie
    Inventors: Jean-Claude Arnaud, Patrick Corsi, Eric Depraetere, Christian Lamoureux
  • Patent number: 5716466
    Abstract: Disclosed is a stainless steel wire made of a two-phase stainless steel having austenite and ferrite, which is used as a PC tension member and wire rope both for dynamic and static use. The stainless steel wire contains 0.01-0.10 wt % of C, 0.1-1.0 wt % of Si, 0.30-1.50% of Mn, 0.010-0.040 wt % of P, 0.001-0.030 wt % of S, 18.0-30.0 wt % of Cr, 3.0-8.0 wt % of Ni, 0.1-3.0 wt % of Mo, and 0.10-0.45 wt % of N, the balance being essentially Fe and inevitable impurities, wherein the volume ratio of the ferrite to the sum of the austenite and the ferrite is specified to be in the range from 20.0 to 80.0%. Upon drawing, the drawing draft is in the range from 40 to 97%, the mean slenderness ratio (M.sub.R value) is in the range from 4 to 20, and the aging temperature is in the range from to C.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: February 10, 1998
    Assignee: Shinko Kosen Kogyo Kabushiki Kaisha
    Inventors: Yukio Yamaoka, Suchun Fang, Kishio Tamai
  • Patent number: 5672218
    Abstract: Method of straightening a metal bar in which the metal bar is straightened by transporting the metal bar between a pair of rollers at a first straightening pressure. An outer layer portion of the metal bar is then removed in order to provide the metal bar with a reduced diameter and a substantially round cross-section. The metal bar is then again straightened by transporting the metal bar between a pair of rollers at a second straightening pressure. Subsequent to such straightening step, the metal bar desirably is heat treated under stress relieving conditions.
    Type: Grant
    Filed: June 24, 1996
    Date of Patent: September 30, 1997
    Assignee: Slater Steels Corporation
    Inventor: Jon S. Schumacher
  • Patent number: 5578149
    Abstract: The present invention is directed to an expandable stent for use in blood vessels. The length of the stent after expansion is substantially the same as the stent length before expansion. The stent is annealed at high temperatures to permit stent deformation at relatively low pressures to conform to the blood vessel shape and diameter.
    Type: Grant
    Filed: May 31, 1995
    Date of Patent: November 26, 1996
    Assignee: Global Therapeutics, Inc.
    Inventors: Ivan De Scheerder, Joseph B. Horn
  • Patent number: 5462615
    Abstract: Disclosed is a process for producing seamless steel pipes or flat products (strip or sheet) for pipes or vessels which are intended for the conveyance, transport or processing of gaseous or liquid hydrocarbons containing CO.sub.2 and water and possibly small proportions of H.sub.2 S and are resistant to stress crack corrosion and have good welding properties at the same time and a 0.2-percent elongation limit of at least 450 N/mm.sup.2. The process uses a nickel-containing steel of the following composition (percent by weight): min. 0.015% C, 0.15-0.50% Si, max. 2.00% Mn, max. 0.020% P, max. 0.003% S, 12.0-13.8% Cr, 0.002-0.02% N, 0.01-0.05% Nb, remainder iron and usual impurities. It is presently suggested that the nickel content is limited to a maximum of 0.25%, the manganese content amounts to at least 1.0%, the carbon content is limited to 0.035%, and 0.01 to 1.2% molybdenum is contained as additional alloying component.
    Type: Grant
    Filed: July 25, 1994
    Date of Patent: October 31, 1995
    Assignee: Mannesmann Aktiengesellschaft
    Inventors: Ingo Von Hagen, Rolf Popperling, Hubertus Schlerkmann, Ulrike Zeislmair
  • Patent number: 5433798
    Abstract: High strength martensitic stainless steel having high rusting resistance which comprises, by weight, 0.13 to 0.20% of C, 0.5 or less of Si, 2.0% or less of Mn, 1.0 to 2.5% of Ni, 12.0 to 16.0% of Cr, 1.3 to 3.5% of Mo, 0.06 to 0.13% of N, if necessary, 0.001 to 0.010% of B, or 0.05 to 1.0% of Ti, 0.05 to 1.0% of Nb, which satisfies 16 to 21% of ARI value for a rusting resistance index (Formula (1)), less than 0% of DI value for a .delta.-ferrite content index (Formula (2)), less than 0% of MI value for martensite content index (Formula (3)), less than 260% of W.sub.1 or W.sub.2 value for a cold workability index (Formulas (4) or (5)), with the balance comprising substantially Fe and inevitable impurities, said steel being characterized in that the martensite structure or the tempered martensite structure is contained, in which a Cr carbide of 0.2 .mu.
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: July 18, 1995
    Assignee: Nippon Steel Corporation
    Inventors: Koji Takano, Mizuo Sakakibara, Satoshi Araki, Takayoshi Matsui, Wataru Murata, Koichi Yoshimura
  • Patent number: 5352406
    Abstract: A properly balanced chemical composition and the choice of a heat treatment (annealing and quenching) under controlled conditions allow to obtain uperduplex stainless steel manufactures which, in the hot-worked form, are excellent in resistance to corrosion and have unit tensile yield strength at room temperature of 90 ksi min.
    Type: Grant
    Filed: April 23, 1993
    Date of Patent: October 4, 1994
    Assignees: Centro Sviluppo Materiali S.p.A., Dalmine S.p.A.
    Inventors: Massimo Barteri, Ivan Nembrini
  • Patent number: 5228932
    Abstract: An Fe-Cr-Al alloy having excellent oxidation resistance and high temperature brittleness resistance comprises:Cr: 10 to 28 wt. %,Al: 1 to 10 wt. %, andB : 0.0003 to 0.010 wt. %,andLa: 0.01 to 0.20 wt. % andZr: 0.01 to 1.0 wt. %,while within the scope of Equation (1)0.1.ltoreq.[wt. % of Zr]/[wt. % of La].ltoreq.20 (1)and wherein elements of impurities are limited as follows:C: 0.05 wt. % or less,N: 0.02 wt. % or less,Si: 0.5 wt. % or less,Mn: 1.0 wt. % or lessTi: less than 0.05 wt. %and the balance consisting of Fe and incidental impurities.
    Type: Grant
    Filed: May 27, 1992
    Date of Patent: July 20, 1993
    Assignee: Kawasaki Steel Corporation
    Inventors: Hiroshi Shimizu, Sadao Hasuno