With Working Patents (Class 148/608)
  • Patent number: 6841014
    Abstract: A method for manufacturing a striking plate of a golf club head includes the steps of soft heat-treating a flat metal blank to increase its malleability, stamping out a striking plate with an integral wall and a bend portion from the flat metal blank, precise machining the striking plate, and age hardening the striking plate to precipitation harden it and improve its mechanical properties after it has been joined to a main body of the golf club head.
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: January 11, 2005
    Assignee: Fu Sheng Industrial Co., Ltd.
    Inventors: Chun-Yung Huang, Chan-Tung Chen
  • Patent number: 6811622
    Abstract: The invention relates to semifinished and finished products made from special corrosion-resistant precipitation-hardened austenitic steel containing a large amount of intersticially dissolved nitrogen, comprising substantially smooth surfaces. The invention also relates to a method for producing corresponding semifinished and finished items. The aim of the invention is to produce semifinished and finished item and to provide an economical method for the production thereof, combining both solidity and resistance to corrosion. This is achieved by precipitation-hardening areas of the steel material.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: November 2, 2004
    Inventors: Heinrich Friederich, Reinhard Schmoock
  • Patent number: 6793744
    Abstract: The present invention relates to a martensitic stainless steel that can be used in manufacturing articles such as a shaft or an impeller which require high mechanical strength and corrosion resistance and provides a martensitic stainless steel comprising less than 0.06 wt. % C, less than 2.5 wt. % Si, less than 2.5 wt. % Mn, 1.0-6.0 wt. % Ni, 10.0-19.0 wt. % Cr, 0.5-6.0 wt. % W, less than 3.5 wt. % Mo, less than 0.5 wt. % Nb, less than 0.5 wt. % V, less than 3.0 wt. % Cu, 0.05-0.25 wt. % N, and the remainder being Fe and minor impurities.
    Type: Grant
    Filed: November 15, 2000
    Date of Patent: September 21, 2004
    Assignee: Research Institute of Industrial Science & Technology
    Inventor: Jae-Young Jung
  • 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: 20040144453
    Abstract: A method for manufacturing a striking plate of a golf club head includes the steps of soft heat-treating a flat metal blank to increase its malleability, stamping out a striking plate with an integral wall and a bend portion from the flat metal blank, precise machining the striking plate, and age hardening the striking plate to precipitation harden it and improve its mechanical properties after it has been joined to a main body of the golf club head.
    Type: Application
    Filed: March 6, 2003
    Publication date: July 29, 2004
    Applicant: Fu Sheng Industrial Co., Ltd.
    Inventors: Chun-Yung Huang, Chan-Tung Chen
  • Patent number: 6764555
    Abstract: A high-strength austenitic stainless steel strip exhibiting excellent flatness with Vickers hardness of 400 or more has the composition comprising: C up to 0.20 mass %, Si up to 4.0 mass %, Mn up to 5.0 mass %, 4.0-12.0 mass % Ni, 12.0-20.0 mass % Cr, Mo up to 5.0 mass %, N up to 0.15 mass % and the balance being Fe except inevitable impurities having a value Md(N) in a range of 0-125 defined by the formula Md(N)=580-520C-2Si-16Mn-16Cr-23Ni-26Cu-300N-10Mo. The material has a dual-phase structure of austenite and martensite involving a reverse-transformed austenite at a ratio of 3 vol. % or more. The material is manufactured by solution-heating a steel strip having the above composition, cold-rolling the steel strip to generate a deformation-induced martensite, and then re-heating at 500-700° C. to induce a phase reversion from martensite to at least 3 vol. % austenite. The reversion effectively flattens the steel strip.
    Type: Grant
    Filed: December 3, 2001
    Date of Patent: July 20, 2004
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Naoto Hiramatsu, Kouki Tomimura, Hiroshi Fujimoto, Kenichi Morimoto
  • Publication number: 20040096351
    Abstract: A ferritic or martensitic stainless steel has the structure that Cu-enriched particles with concentration of C not less than 0.1 mass % or concentration of Sn and/or In not less than 10 mass % were dispersed in a matrix. Precipitation and dispersion of Cu-enriched particles is realized by aging the stainless steel at 500-900° C. for 1 hour or longer on any stage after a hot-rolling step until a forming step to a final product. The ferritic stainless steel contains 0.01-1.0% C, Si up to 1.0%, Mn up to 1.0%, 15-30% Cr, Ni up to 6.0% and 0.5-6.0% Cu. The martensitic stainless steel contains 0.01-0.5% C, Si up to 1.0%, Mn up to 1.0%, 10-15% Cr, Ni up to 6.0% and 0.5-6.0% Cu. Since Cu-enriched particles are dispersed for improvement of machinability instead of addition of S, Pb, Bi or Se, the stainless steel is machined to an objective shape without any harmful influence on workability, corrosion-resistance and the environment.
    Type: Application
    Filed: November 14, 2003
    Publication date: May 20, 2004
    Applicant: Nisshin Steel Co., Ltd.
    Inventors: Satoshi Suzuki, Hideki Tanaka, Naoto Hiramatsu
  • Patent number: 6719855
    Abstract: The present invention provides an Fe—Cr—Al-based alloy for catalyst carriers and a foil thereof having a thickness of 40 &mgr;m or less, the alloy and the foil improved in the oxidation resistance at high temperatures and having excellent deformation resistance. Specifically, the present invention provides an Fe—Cr—Al-based alloy foil and a manufacturing method thereof, comprising 16.0 to 25.0 mass % of Cr, 1 to 8 mass % of Al, La, Zr, and the balance being Fe and incidental impurities. The contents by mass % of La and Zr meet the following ranges when the foil thickness thereof is t &mgr;m: 1.4/t≦La≦6.0/t  (1) 0.6/t≦Zr≦4.0/t  (2) The Fe—Cr—Al-based alloy foil may further comprises Hf and the balance being Fe and incidental impurities, wherein the contents by mass % of La, Zr, and Hf meet the following ranges: 1.4/t≦La≦6.0/t  (1) 0.4/t≦Zr≦2.0/t  (3) 0.5/t≦Hf≦2.0/t  (4).
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: April 13, 2004
    Assignee: JFE Steel Corporation
    Inventors: Kunio Fukuda, Susumu Satoh, Kazuhide Ishii, Takeshi Fujihira, Akira Kawaharada
  • Publication number: 20040050463
    Abstract: A high manganese duplex stainless steel with excellent hot workability, comprising (in weight %): less than 0.1% of C; 0.05-2.2% of Si; 2.1-7.8% of Mn; 20-29% of Cr; 3.0-9.5% of Ni; 0.08-0.5% of N; less than 5.0% of Mo and 1.2-8% of W, alone or composite; the balance Fe and inevitable impurities; and a method for manufacturing the duplex stainless steel, comprising the steps of: solution heating the duplex stainless steel composition at a temperature of 1,050 to 1,250° C., hot working at a starting temperature of 1,130 to 1,280° C. and then ending at a temperature greater than 1,000° C., and then cooling within the temperature range from 1,000 to 700° C. at a cooling rate of more than 3° C./min. The duplex stainless steel exhibits a reduction in area of more than 50% at 1,050° C., and possesses a yield strength of more than 400 MPa, and a corrosion rate of less than 0.36 mm/year, after solution heating.
    Type: Application
    Filed: March 31, 2003
    Publication date: March 18, 2004
    Inventors: Jae-Young Jung, Bong-Year Ma
  • Patent number: 6613166
    Abstract: The proposed brake disk consists of steel of a composition of 0.1 to 0.4% of carbon, up to 1.0% of silicon, up to 2.0% of manganese, up to 0.02% of sulfur, 11 to 16% of chromium, up to 1.0% of nickel and 0.5 to 1.5% of molybdenum, the remainder being iron and production-related impurities.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: September 2, 2003
    Assignee: Edelstahl Werke Buderus AG
    Inventor: Walter Grimm
  • Publication number: 20030136482
    Abstract: A material for the manufacture of parts and tools for use at elevated temperature, comprising an iron-based alloy comprising C, Si, Mn, Cr, Ni and N in certain concentrations and being cold formed to a hardness of at least 230 HB, a process for the manufacture of the material and a hot working tool comprising the material. This abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.
    Type: Application
    Filed: January 22, 2003
    Publication date: July 24, 2003
    Applicant: Bohler Edelstahl Gmbh & Co KG
    Inventors: Gottfried Mayerbock, Johann Sammer, Gabriele Saller
  • Patent number: 6576068
    Abstract: A method for producing a stainless steel with improved corrosion resistance includes homogenizing at least a portion of an article of a stainless steel including chromium, nickel, and molybdenum and having a PREN of at least 50, as calculated by the equation: PREN=Cr+(3.3×Mo)+(30×N), where Cr is weight percent chromium, Mo is weight percent molybdenum, and N is weight percent nitrogen in the steel. In one form of the method, at least a portion of the article is remelted to homogenize the portion. In another form of the method, the article is annealed under conditions sufficient to homogenize at least a surface region of the article. The method of the invention enhances corrosion resistance of the stainless steel as reflected by the steel's critical crevice corrosion temperature.
    Type: Grant
    Filed: April 24, 2001
    Date of Patent: June 10, 2003
    Assignee: ATI Properties, Inc.
    Inventors: John F. Grubb, James D. Fritz
  • Patent number: 6546771
    Abstract: The invention relates to a method for the manufacturing of strips of stainless steel, comprising cold rolling of a strip which in a foregoing process has been manufactured through casting a melt to form a cast strip and/or has been hot rolled. The cold rolling is performed in a rolling mill line (B), which comprises, in the initial part of the line, at least two initial cold rolling mills (11-13) in series, after said initial cold rolling mills at least one annealing furnace (18) and at least one pickling section (26, 27), and in a terminating part of the line, at least one more cold rolling mill (32). The patent specification discloses various modes of operation, including passing the strip once or twice through the line.
    Type: Grant
    Filed: July 10, 2001
    Date of Patent: April 15, 2003
    Assignee: Avestapolarit AB
    Inventor: Sten Ljungars
  • Patent number: 6478900
    Abstract: An improved method of forging a precipitation hardening type stainless steel. The method comprises the steps of soaking the precipitation hardening type stainless steel at a temperature of austenitizing range, cooling the steel to a temperature in the range of 200-700° C., preferably 400-600° C., and subjecting the steel to forging at the temperature in this range. Conventional lubricants and die cooling oils can be used without being deteriorated due to high temperature. It is preferable to forcibly cool the soaked steel to adjust the temperature of the steel at which it is forged. The forged steel is then age hardened to exhibit inherent hardness.
    Type: Grant
    Filed: July 1, 1996
    Date of Patent: November 12, 2002
    Assignee: Diado Tokushuko Kabushiki Kaisha
    Inventors: Sachihiro Isogawa, Masamichi Kawano, Katsuyoshi Sakoda
  • 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
  • Patent number: 6440236
    Abstract: An ultra-high strength metastable austenitic stainless steel exhibiting a tensile strength of not less than 2200 N/mm2 has a chemical composition comprising, in mass %, not more than 0.15 % of C, more than 1.0 to 6.0 % of Si, not more than 5.0 % of Mn, 4.0-10.0 % of Ni, 12.0-18.0 % of Cr, not more than 3.5 % of Cu, not more than 5.0 % of Mo, not more than 0.02 % of N, 0.1-0.5 % of Ti, optionally one or both of not more than 0.5 % of V and not more than 0.5 % of Nb, and the balance of Fe and unavoidable impurities, satisfies Si+Mo≧3.5 %, has a value of Md(N) defined by the equation Md(N)=580-520C-2Si-16Mn-16Cr-23Ni-300N-26Cu-10Mo of 20-140, exhibits a cold worked multiphase texture composed of 50-95 vol % of martensite phase and the remainder substantially of austenite phase, and has Mo-system precipitates and Ti-system precipitates distributed in the martensite phase.
    Type: Grant
    Filed: November 2, 2000
    Date of Patent: August 27, 2002
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Naoto Hiramatsu, Kouki Tomimura
  • Publication number: 20020102178
    Abstract: A high-strength austenitic stainless steel strip excellent in flatness of shape with Vickers hardness of 400 or more is newly proposed, which has the composition consisting of C up to 0.20 mass %, Si up to 4.0 mass %, Mn up to 5.0 mass %, 4.0-12.0 mass % Ni, 12.0-20.0 mass % Cr, Mo up to 5.0 mass %, N up to 0.15 mass % and the balance being Fe except inevitable impurities under the condition that a value Md(N) defined by the formula (1) is in a range of 0-125. It has a dual-phase structure of austenite and martensite involving reverse-transformed austenite at a ratio of 3 vol. % or more. It is manufactured by solution-heating a steel strip having the composition, cold-rolling the steel strip to generate deformation-induced martensite, and then re-heating at 500-700° C. to induce reversion. The reversion effectively flattens a shape of the steel strip.
    Type: Application
    Filed: December 3, 2001
    Publication date: August 1, 2002
    Applicant: Nisshin Steel Co., Ltd.
    Inventors: Naoto Hiramatsu, Kouki Tomimura, Hiroshi Fujimoto, Kenichi Morimoto
  • Patent number: 6406570
    Abstract: An elastic component for a precision measuring instrument is made from an austenitic metal alloy containing less than two percent ferrite, less than two percent martensite, and more than eleven percent chromium. The crystalline texture has a nano-structure with blocked dislocations. The manufacturing process includes cold hardening followed by thermal aging between 200° C. and 700° C. The benefits are low anelasticity, freedom from creep and hysteresis, resistance to corrosion, and a low magnetic permeability. Examples are load cells used in analytical, motion-guiding mechanisms, coupling elements and pivoting elements.
    Type: Grant
    Filed: August 7, 2000
    Date of Patent: June 18, 2002
    Assignee: Mettler-Toledo, GmbH
    Inventor: Jean-Maurice Tellenbach
  • Patent number: 6245163
    Abstract: An austenitic stainless steel having resistance to neutron-irradiation-induced deterioration obtained by subjecting a stainless steel consisting of not more than 0.08% by weight of C, not more than 2.0% by weight of Mn, not more than 1.5% by weight of Si, not more than 0.045% by weight of P, not more than 0.030% by weight of S, 8.0 to 22.0% of by weight Ni, 16.0 to 26.0% of by weight Cr and the balance as Fe; to thermal solid solution treatment at a temperature of 1,000° C. to 1,180° C. and then subjecting the so-treated steel to aging treatment at a temperature in the range of 600° C. to 750° C.
    Type: Grant
    Filed: April 19, 1999
    Date of Patent: June 12, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Toshio Yonezawa, Toshihiko Iwamura, Koji Fujimoto
  • Patent number: 6129795
    Abstract: A method is provided for improving the microstructure of nickel and iron-based precipitation strengthened superalloys used in high temperature applications by increasing the frequency of "special", low-.SIGMA. CSL grain boundaries to levels in excess of 50%. Processing entails applying specific thermomechanical processing sequences to precipitation hardenable alloys comprising a series of cold deformation and recrystallization-annealing steps performed within specific limits of deformation, temperature, and annealing time. Materials produced by this process exhibit significantly improved resistance to high temperature degradation (eg. creep, hot corrosion, etc.), enhanced weldability, and high cycle fatigue resistance.
    Type: Grant
    Filed: August 3, 1998
    Date of Patent: October 10, 2000
    Assignee: Integran Technologies Inc.
    Inventors: Edward M. Lehockey, Gino Palumbo, Peter Keng-Yu Lin, David L. Limoges
  • Patent number: 6106638
    Abstract: The subject of the invention is a process for manufacturing ferritic stainless steel strip, in which a strip of a ferritic stainless steel, of the type containing at most 0.12% of carbon, at most 1% of manganese, at most 1% of silicon, at most 0.040% of phosphorus, at most 0.030% of sulfur and between 16 and 18% of chromium, is solidified, directly from liquid metal, between two close-together, internally-cooled, counterrotating rolls with horizontal axes, wherein said strip is then cooled or left to cool so as to avoid making it remain within the austenite to ferrite and carbides transformation range, wherein said strip is coiled at a temperature of between 600.degree. C. and the martensitic transformation temperature Ms, wherein the coiled strip is left to cool at a maximum rate of 300.degree. C./h down to a temperature of between 200.degree. C. and ambient temperature and wherein said strip then undergoes box annealing.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: August 22, 2000
    Assignee: Usinor
    Inventors: Philippe Paradis, Philippe Martin
  • 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: 6099668
    Abstract: A method for producing an exhaust valve is described, comprising subjecting a raw material of a specified heat resisting alloy to solid solution treatment; forming a head portion of the exhaust valve from the solution treated raw material through cold working or warm working; joining a stem portion made of martensitic heat resisting steel to said head portion of the exhaust valve; and subjecting the head portion and the stem portion joined with each other to aging treatment.
    Type: Grant
    Filed: July 13, 1998
    Date of Patent: August 8, 2000
    Assignee: Daido Tokushuko Kabushiki Kaisha
    Inventors: Shigeki Ueta, Toshiharu Noda, Michio Okabe
  • Patent number: 6045633
    Abstract: A manufacturing mold base for plastic injection molds is formed from a martensitic stainless steel alloy comprising: about 0.03%-0.06% by weight C, about 1.0%-1.6% by weight Mn, about 0.01%-0.03% by weight P, about 0.06%-0.3% by weight S, about 0.25%-1.0% by weight Si, about 12.0%-14.0% by weight Cr, about 0.5%-1.3% by weight Cu, about 0.01%-0.1% by weight V, about 0.02%-0.08% by weight N, with the balance being Fe with trace amounts of ordinarily present elements.
    Type: Grant
    Filed: May 14, 1998
    Date of Patent: April 4, 2000
    Assignee: EDRO Engineering, Inc.
    Inventors: Eric D. Henn, Robert J. Friedrich, Michael A. Guscott
  • Patent number: 5986205
    Abstract: The stainless steel sheet useful as a substrate for non-single crystalline semiconductor solar cells has minute ripples with undulations along a rolling direction, and its surface roughness is controlled in the range of R.sub.z 0.3-1.4 .mu.m and R.sub.max 0.5-1.7 .mu.m. It is manufactured by finish cold rolling a stainless steel strip with a reduction ratio of at least 20% at a rolling speed of at least 400 m/min. using work rolls polished with abrasives of gage #100-#400 at a final pass, annealing the rolled strip in an open-air atmosphere and then electrolytically pickling the annealed strip in a nitric acid solution. Since minute ripples with undulations are formed on the surface of the stainless steel sheet, an energy conversion efficiency is increased by acceleration of scattering and multiple reflection of incident light rays projected into a non-single crystalline semiconductor layer.
    Type: Grant
    Filed: September 4, 1997
    Date of Patent: November 16, 1999
    Assignees: Nisshin Steel Co., Ltd., Canon Kabushiki Kaisha
    Inventors: Hisashi Matsune, Yasushi Nishimura, Takuji Okiyama, Masafumi Sano
  • Patent number: 5976275
    Abstract: The present invention aims at providing structural materials having a resistance to degradation by neutron irradiation, causing no SCC in an environment of light-water reactors even after subjecting the materials to neutron irradiation of approximately at least 1.times.10.sup.22 n/cm.sup.2 (E>1 MeV), and having thermal expansion coefficients approximately similar to that of structural materials. The high nickel austenitic stainless steels of the present invention having a resistance to degradation by neutron irradiation can be produced by subjecting stainless steels having compositions (by weight %) of 0.005 to 0.08% of carbon, at most 0.3% of Mn, at most 0.2% of (Si+P+S), 25 to 40% of Ni, 25 to 40% of Cr, at most 3% of Mo or at most 5% of (Mo+W), at most 0.3% of Nb+Ta, at most 0.3% of Ti, at most 0.001% of B and the balance of Fe to a solution-annealing treatment at a temperature of 1000 to 1150.degree. C.
    Type: Grant
    Filed: June 5, 1997
    Date of Patent: November 2, 1999
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Toshio Yonezawa, Toshihiko Iwamura, Hiroshi Kanasaki, Koji Fujimoto, Shizuo Nakada, Kazuhide Ajiki, Mitsuhiro Nakamura
  • Patent number: 5948181
    Abstract: A hot-rolled stainless steel strip contains at least 10 wt % Cr and 1.0 wt % or less of Si, and has a controlled scale thickness of not more than 2.5 .mu.m in the surface layer. The average thickness of the Si-containing oxide layer formed in the scale/alloy substitute interface is 0.1 .mu.m or less. The hot-rolled stainless steel strip is produced by hot rolling at an elongation rate of at least 150 or hot rough rolling to form a sheet bar, descaling by spraying superhigh pressure water to the surface of the sheet bar at an impact pressure (p) of 25 kgf/cm.sup.2 or more and a flow rate density of 0.002 l/cm.sup.2 or more, and then finish rolling so that the maximum reduction ratio per pass satisfies certain disclosed criteria.
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: September 7, 1999
    Assignee: Kawasaki Steel Corporation
    Inventors: Masaaki Kohno, Kazuhide Ishii, Kunio Fukuda, Takumi Ujiro, Susumu Satoh
  • Patent number: 5944921
    Abstract: A supermartensitic stainless steel having high mechanical strength and corrosion resistance showing the following percentage composition C.ltoreq.0.05; Cr 12-15; Ni 4-7; Mo 1.5-2; N 0.06-0.12; Mn 0.5-1; Cu<0.3; P<0.02; S.ltoreq.0.005; Al<0.02; Si.ltoreq.1; the rest being iron and minor impurities, with the further requirement that the percentages of Cr, Mo and N satisfy the following formula: (Cr+3.3 Mo+16 N).gtoreq.19. Said steel allows to obtain manufactured articles having excellent mechanical strength and corrosion resistance characteristics.
    Type: Grant
    Filed: November 11, 1997
    Date of Patent: August 31, 1999
    Assignee: Dalmine S.p.A.
    Inventors: Giuseppe Cumino, Massimo Barteri
  • Patent number: 5868875
    Abstract: A ferritic non-ridging stainless steel and process therefor. A chromium alloyed steel melt is deoxidized with a sub-equilibrium amount of titanium and nitrogen and continuously cast into a strip or a slab or cast into an ingot having an as-cast fine equiaxed microstructure substantially free of columnar grains. The as-cast steel contains .ltoreq.0.010% Al, up to 0.08% C, 0.10-1.50% Mn, .ltoreq.0.05% N, .ltoreq.1.5% Si, 8-25% Cr, <2.0% Ni and is deoxidized with titanium, all percentages by weight, the balance Fe and residual elements. Preferably, the titanium is controlled so that (Ti/48)/?(C/12)+(N/14)!>1.5. A hot processed continuous sheet may be formed from a continuously cast slab without surface grinding, may be descaled, cold reduced to a final thickness and recrystallization annealed. An anneal prior to cold reduction is not required to obtain an annealed sheet essentially free of ridging.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: February 9, 1999
    Inventors: Eizo Yoshitake, Alan R. McKague
  • Patent number: 5861068
    Abstract: Stainless steel is improved in anti-microbial property by the addition of Cu in an amount of 0.4-5.0 wt. % and the precipitation of Cu-rich phase at the ratio of 0.2 vol. % or more. The Cu-rich phase is precipitated as minute particles uniformly dispersed in the matrix not only at the surface layer but also at the interior by heat treatment such as annealing or aging at 500.degree.-900.degree.. Since the anti-microbial property is derived from the material itself, the underlying stainless steel does not lose the excellent anti-microbial property even after it is polished or mechanically worked. Due to the anti-microbial property, the stainless steel is useful as material in various fields requiring sanitary environments, for example, kitchen goods, electric home appliances, devices or tools at hospitals, parts or interiors for building and grips or poles for electric trains or buses.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: January 19, 1999
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Morihiro Hasegawa, Katsuhisa Miyakusu, Naoto Okubo, Sadayuki Nakamura
  • Patent number: 5833919
    Abstract: The present invention provides a Fe--Mn--Cr--Al cryogenic alloy having high ductility, strength, toughness and corrosion-resistance, and a process for preparing the same. The cryogenic structural alloy of the invention is prepared by the steps of: air-induced melting of a metallic alloy composition which consists of Fe 48.6 to 64.7 wt %, Mn 25.0 to 35.0 wt %, Cr 10.0 to 13.0 wt %, Al 0.1 to 2.0 wt %, C 0.1 to 0.4 wt % and Si 0.1 to 1.0 wt %; hot-rolling of the melted alloy at 1,090.degree. to 1,110 .degree. C.; and, solution heat treatment of the hot-rolled alloy at 1,040.degree. to 1,060.degree. C. for 50 to 70 minutes.
    Type: Grant
    Filed: January 9, 1997
    Date of Patent: November 10, 1998
    Assignee: Korea Advanced Institute of Science and Technology
    Inventors: Soon-Hyung Hong, Young-Soo Han
  • Patent number: 5759304
    Abstract: In a process for producing hot rolled steel strip with adjusted strength a steel with 0.04 to 0.06% carbon, at most 1% silicon, at most 1% manganese, 13 to 18% chromium, at most 2% nickel, balance carbide formers and iron, inclusive of impurities due to melting, is melted, the actual content of carbide formers within the specified limits is determined, a rolling oversize for a subsequent hot rolling is established in dependence on the actual content of carbide formers, and the hot rolled strip is solution annealed at a temperature of 920.degree. to 1050.degree. C. and quenched to a ferritic-martensitic structure and cold rolled down to the specified final thickness.
    Type: Grant
    Filed: January 21, 1994
    Date of Patent: June 2, 1998
    Assignee: Rexnord Kette GmbH & Co. KG
    Inventor: Ehrhard Kluge
  • Patent number: 5746845
    Abstract: A high-strength member of precipitation hardening martensitic steel is manufactured through the steps of heating precipitation hardening martensitic stainless steel at an austenitizing temperature, performing the first plastic working at a temperature between 200.degree. C. and 700.degree. C. so as to leave a part of austenite as retained austenite at the time of cooling the steel at Ms point or below thereafter, cooling the steel at the temperature not higher than Ms point, performing the next plastic working at a temperature not higher than As point so as to transform the retained austenite into martensite, and performing age hardening treatment at a temperature between not lower than 370.degree. C. and lower than 480.degree. C.
    Type: Grant
    Filed: September 27, 1995
    Date of Patent: May 5, 1998
    Assignee: Daido Tokushuko Kabushiki Kaisha
    Inventors: Hiroaki Yoshida, Sachihiro Isogawa
  • Patent number: 5716465
    Abstract: A high-corrosion-resistant martensitic stainless steel possessing excellent weldability and SSC resistance, having a tempered martensitic structure, characterized by comprising steel constituents satisfying by weight C: 0.005 to 0.035%, Si: not more than 0.50%, Mn: 0.1 to 1.0%, P: not more than 0.03%, S: not more than 0.005%, Mo: 1.0 to 3.0%, Cu: 1.0 to 4.0%, Ni: 1.5 to 5.0%, Al: not more than 0.06%, N: not more than 0.01%, and Cr satisfying a requirement represented by the formula 13>Cr+1.6Mo.gtoreq.8,C+N.gtoreq.0.03,40C+34N+Ni+0.3Cu-1.1Cr-1.8 Mo.gtoreq.10,or further comprising at least one element selected from the group consisting of Ti: 0.05 to 0.1%, Zr: 0.01 to 0.2%, Ca: 0.001 to 0.02%, and REM: 0.003 to 0.4%, with the balance consisting essentially of Fe. A process for producing a martensitic stainless steel, comprising the steps of: subjecting a steel plate, produced by hot-rolling a stainless steel slab having the above composition, to austenitization at a temperature of Ac.sub.3 point to 1000.
    Type: Grant
    Filed: August 27, 1996
    Date of Patent: February 10, 1998
    Assignee: Nippon Steel Corporation
    Inventors: Takuya Hara, Asahi Hitoshi, Hiroshi Tamehiro, Taro Muraki, Akira Kawakami
  • Patent number: 5494537
    Abstract: For a purpose of providing a high strength and toughness stainless steel strip having not only a high strength of at least 1800 N/mm.sup.2 but also a high Erichsen break stress, which is a measure of toughness of a thin sheet, of as high as at least 1000 N/mm.sup.2, there is provided a stainless steel strip consists essentially of in mass % C: up to 0.1%, (exclusive of 0%); Si more than 1.0% and not more than 4.0%; Mn: up to 5.0% (exclusive of 0%); Ni: from 4.0 to 10.0%; Cr :from 12.0 to 18.0%; Cu :up to 5.0% (inclusive of 0%); Mo: from 1.0 to 5.0%; N: up to (exclusive of 0%); the balance being Fe and impurities with the proviso of C+N.gtoreq.0.1%, and wherein the alloying elements are adjusted so that a value of Md(N) defined by the following equation:Md(N)=580-520.times.[% C]-2.times.[% Si]-16.times.[% Mn]-16.times.[% Cr]-23.times.[% Ni]-26.times.[% Cu]-10.times.
    Type: Grant
    Filed: February 3, 1995
    Date of Patent: February 27, 1996
    Assignee: Nisshin Steel Co. Ltd.
    Inventors: Katsuhisa Miyakusu, Sadao Hirotsu, Koki Tomimura
  • Patent number: 5433801
    Abstract: Steel which is particularly useful for making a razor blade of high corrosion resistance contains more than 0.45%, but less than 0.55%, of carbon, 0.4 to 1.0% of silicon, 0.5 to 1.0% of manganese, 12 to 14% of chromium and 1.0 to 1.6% of molybdenum, all by weight, in addition to iron and inevitable impurities, and has a carbide density of 100 to 150 particles per 100 square microns as annealed. The razor blade has a Vickers hardness of at least 620 and a carbide density of 10 to 45 particles per 100 square microns, and preferably has a specific distribution of residual austenite content. The improved properties of the razor blade are achieved by an improved process of heat treatment which includes austenitizing the steel at a temperature of 1075.degree. C. to 1120.degree. C., cooling it to a temperature between -60.degree. C. and -80.degree. C. for hardening it, and tempering it at a temperature of 250.degree. C. to 400.degree. C.
    Type: Grant
    Filed: October 15, 1993
    Date of Patent: July 18, 1995
    Inventors: Wolfgang Althaus, Atsushi Kumagai
  • Patent number: 5419791
    Abstract: This is a method for heat assisted forming, annealing, and hardening 360.degree. sheet metal shapes in a clean environment in a single facility that results in dimensionally correct, cost-effective, contaminant free parts.
    Type: Grant
    Filed: July 21, 1993
    Date of Patent: May 30, 1995
    Inventor: Carroll W. Folmer
  • Patent number: 5223053
    Abstract: A process for strengthening heavy, thick-section forgings of precipitation age hardenable iron base superalloys. The process includes initial recrystallization to achieve a uniform grain size, intermediate temperature warm working at controlled strain rates and for limited amounts of deformation, and precipitation heat treating. The controlled warm working conditions avoid further recrystallization, thus preserving the strain hardening which improves the mechanical properties.
    Type: Grant
    Filed: January 27, 1992
    Date of Patent: June 29, 1993
    Assignee: United Technologies Corporation
    Inventors: Fred P. Cone, John A. Miller, Brendan J. Cryns, Robert Zanoni
  • Patent number: 5213629
    Abstract: A far-infrared emitter of high corrosion resistance is prepared by an oxidizing heat treatment of a body made from a stainless steel of 20-35% by weight of chromium, 0.5-5.0% by weight of molybdenum, up to 3.0% by weight of manganese and up to 3.0% by weight of silicon at 900.degree.-1200 .degree. C. to form an oxidized surface film having a thickness of at least 0.2 mg/cm.sup.2. Further, a far-infrared emitter of a high emissivity approximating a black body is prepared by subjecting a body made from a stainless steel of 10-35% by weight of chromium, 1.0-4.0% by weight of silicon and up to 3.0% by weight of manganese to a blasting treatment to roughen the surface followed by an oxidizing heat treatment at 900.degree.-1200 .degree. C. to form an oxide film on the surface in the form of protrusions having a length of at least 5 .mu.m.
    Type: Grant
    Filed: May 1, 1992
    Date of Patent: May 25, 1993
    Assignees: Kasasaki Steel Corporation, Osaka Gas Co., Ltd.
    Inventors: Kazuhide Ishii, Tatsuo Kawasaki, Noriyuki Kuriyama, Shoji Dohi, Akio Nakashiba, Souhei Miyazaki
  • Patent number: 5178693
    Abstract: A process for the production of a stainless steel strip having excellent spring characteristics as such and good formability, wherein a cold rolled strip of a stainless steel comprising, in addition to Fe, from 10.0 to 20.0% by weight of Cr, from 0.01 to 0.15% by weight of C, and at least one of Ni, Mn and Cu in an amount of from 0.1 to 4.0% by weight, is continuously passed through a continuous heat treatment furnace where it is heated to a temperature range for a two-phase of ferrite and austenite, rapidly cooled to provide a strip of a duplex structure, consisting essentially of ferrite and martensite, optionally temper rolled at a rolling reduction of not more than 10%, and continuously passed through a continuous heat treatment furnace to effect aging of not longer than 10 minutes.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: January 12, 1993
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Katsuhisa Miyakusu, Teruo Tanaka, Hiroshi Fujimoto, Chizui Toyokihara
  • Patent number: 5131960
    Abstract: By solution-annealing and water-quenching of a hot-rolled ferritic chromium steel comprising 0.03 to 0.07% carbon, not more than 1% silicon, not more than 1% manganese, 13 to 18% chromium, not more than 2% nickel, balance iron and impurities arising from melting, a ferritic martensitic microstructure can be obtained to achieve high strength, hardness and toughness.
    Type: Grant
    Filed: September 13, 1990
    Date of Patent: July 21, 1992
    Assignee: Rexnord Kette GmbH & Co. KG
    Inventor: Ehrhard Kluge