Nitrogen Containinig Patents (Class 420/128)
  • Patent number: 6599469
    Abstract: Disclosed is a non-heat treated steel for soft niriding, which can provide forged parts exhibiting equal to or larger than the limit strain at which cracks occur in straightening by bending and equal to or larger than the fatigue strength when compared with the parts of conventional heat treated steel, such as S48C. The non-heat treated steel for soft nitriding consists essentially of, by weight, C: 0.2-0.6%, Si: 0.05-1.0%, Mn: 0.25-1.0%, S: 0.03-0.2%, Cr: up to 0.2%, sol-Al: up to 0.045%, Ti: 0.002-0.01%, N: 0.005-0.025%, and O: 0.001-0.005%; provided that the conditions, 0.12[Ti%]<[O%]<2.5[Ti%] and 0.04[N%]<[O%]<0.75[N%], are met; the balance being Fe and inevitable impurities; and the structure after hot forging being a mixed structure of ferrite and pearlite.
    Type: Grant
    Filed: January 29, 2002
    Date of Patent: July 29, 2003
    Assignee: Daido Steel Co., Ltd.
    Inventors: Kazuhisa Ishida, Koichiro Inoue
  • Patent number: 6582835
    Abstract: Dip-coated ferrite stainless steel sheet usable in the automobile exhaust sector, characterized in that it comprises a steel core with the following composition by weight: 10.5%≦chromium≦20% 0%≦aluminum≦0.6% 0.003%≦carbon≦0.06% 0.003%≦nitrogen≦0.04% 0%≦silicon≦0.6% 0%≦manganese≦0.6% 0%≦sulfur≦0.002% iron and impurities inherent in processing, and a metal coating deposited by dipping the strip in a molten metal bath containing in particular aluminum and at least one rare earth element: cerium, lanthanum, praseodymium, neodymium, mixed metal and/or yttrium.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: June 24, 2003
    Assignee: Usinor
    Inventors: Laurent Antoni, Raphael Craen
  • Patent number: 6565676
    Abstract: A stretched mask having a high tensile strength and favorable high-temperature creep properties and free from tape twist, and a material for the stretched mask. A low-carbon steel sheet containing 70 ppm to 170 ppm of nitrogen on a weight basis is heat-treated at a temperature at which recrystallization does not take place. The heat-treated material is provided with a resist pattern for forming apertures and subjected to etching to form apertures.
    Type: Grant
    Filed: May 18, 2001
    Date of Patent: May 20, 2003
    Inventors: Akira Makita, Yutaka Matsumoto, Taizo Sato, Yoshikazu Watanabe
  • Patent number: 6562152
    Abstract: A TRIP-type high strength steel plate having good workability is provided which, while reducing the amount of alloying elements added which increase the production cost, ensures a contemplated retained austenite structure, has good adhesion to zinc plating, and can also be applied to highly corrosion resistant surface treated steel plates. The high strength steel plate having improved workability and plating adhesion is such that a high concentration, i.e., 0.03 to 2.0% by weight, of nitrogen is incorporated, the contents of silicon and aluminum, which form nitride, are preferably regulated respectively to not more than 0.5% by weight and not more than 0.3% by weight, and, in addition, calcium, sodium, magnesium, etc. are optionally added to control the formation of iron nitride, whereby the volume fraction of the retained austenite phase in the metal structure is regulated to 3 to 20% by weight.
    Type: Grant
    Filed: June 27, 2001
    Date of Patent: May 13, 2003
    Assignee: Nippon Steel Corporation
    Inventors: Hidekuni Murakami, Yoshihisa Takada, Masayoshi Suehiro
  • Patent number: 6511553
    Abstract: The present invention provides a steel for steel sheets excellent in workability and showing significantly decreased formation of surface defects, and a method of deoxidizing molten steel for the steel for steel sheets which prevents nozzle clogging during continuous-casting the molten steel. That is, the steel for steel sheets excellent in workability, comprises, based on weight, 0.0001 to 0.0030% of C, up to 0.03% of Si, 0.05 to 0.30% of Mn, up to 0.015% of P, 0.001 to 0.015% of S, up to 0.008% of Al, 0.02 to 0.08% of Ti, 0.0005 to 0.0020% of Ca, 0.0005 to 0.01% of N, optionally containing at least one of 0.001 to 0.02 wt % of Nb and 0.0001 to 0.0010 wt % of B, and the balance of Fe and unavoidable impurities.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: January 28, 2003
    Assignee: Nippon Steel Corporation
    Inventors: Junji Nakashima, Takashi Sawai, Mitsuo Uchimura, Wataru Yamada, Shigenori Tanaka, Yasuharu Sakuma, Akinobu Murasato
  • Patent number: 6428631
    Abstract: A high-strength steel sheet having excellent fatigue property, excellent formability and resistance to softening of the heat affected zone after welding, comprising: 0.01 to 0.15 mass % of C, 0.005 to 1.0 mass % of Si, 0.1 to 2.2 mass % of Mn, 0.001 to 0.06 mass % of P, 0.001 to 0.01 mass % of S, 0.0005 to 0.01 mass % of N, 0.001 to 0.1 mass % of Al, 0.005 to 0.05 mass % of Nb, 0.05 to 0.5 mass % of Mo, when necessary, 0.001 to 0.02 mass % of Ti, 0.2 to 2.0 mass % of Cu and 0.05 to 2.0 mass % of Ni, and the remainder of Fe, wherein the components satisfy the following expression (A). 0.
    Type: Grant
    Filed: March 16, 2000
    Date of Patent: August 6, 2002
    Assignee: Nippon Steel Corporation
    Inventors: Toshimasa Tomokiyo, Hirokazu Taniguchi, Ryo Maruta
  • Patent number: 6425963
    Abstract: High tensile strength hot-rolled steel sheet suitable for use in interior materials for automobiles and a method for producing the same, in which bake hardenability, fatigue resistance, crash resistance, and resistance to room temperature aging are improved, containing 0.01% to 0.12% by weight of carbon, 2.0% by weight or less of silicon, 0.01% to 3.0% by weight of manganese, 0.2% by weight or less of phosphorus, 0.001% to 0.1% by weight of aluminum, and 0.003% to 0.02% by weight of nitrogen and subjected to hot rolling and cooling at a cooling rate of 50° C./s or more within 0.5 second after hot rolling; the hot-rolled steel sheet has a structure including a ferrite having an average grain diameter of 8 &mgr;m or less as a primary phase, the amount of solute Nitrogen ranges from 0.003% to 0.01%, and the ratio, Ngb/Ng, of an average concentration Ngb of nitrogen dissolved in the ferrite grain boundary to an average concentration Ng of nitrogen dissolved in ferrite grains ranges from 100 to 10,000.
    Type: Grant
    Filed: January 24, 2000
    Date of Patent: July 30, 2002
    Assignee: Kawasaki Steel Corporation
    Inventors: Shinjiro Kaneko, Tetsuo Shimizu, Osamu Furukimi
  • Patent number: 6361624
    Abstract: A method of producing a fully stabilized extra low carbon porcelain enameling steel having excellent formability and fish scaling resistance as well as superior enamel adherence. The method includes hot rolling a slab to strip, the slab having a composition consisting essentially of in weight percent: 0.005 max. C, 0.35 max. Mn, 0.015 max. P, 0.015 max. S, 0.015 max. Si, 0.025 to 0.055 Al, 0.006 to 0.015 N, 0.03 to 0.06 Ti, 0.02 to 0.05 Cb, up to 0.03 Sb, the balance Fe and inevitable impurities. The hot rolled strip is cold rolled at least 65% and box annealed until a cold spot temperature within the range of 610 to 705 degrees C. is reached. The invention includes the product made according to the process.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: March 26, 2002
    Assignee: USX Corporation
    Inventor: George Franklin Altemus
  • Publication number: 20020017342
    Abstract: A TRIP-type high strength steel plate having good workability is provided which, while reducing the amount of alloying elements added which increase the production cost, ensures a contemplated retained austenite structure, has good adhesion to zinc plating, and can also be applied to highly corrosion resistant surface treated steel plates. The high strength steel plate having improved workability and plating adhesion is such that a high concentration, i.e., 0.03 to 2.0% by weight, of nitrogen is incorporated, the contents of silicon and aluminum, which form nitride, are preferably regulated respectively to not more than 0.5% by weight and not more than 0.3% by weight, and, in addition, calcium, sodium, magnesium, etc. are optionally added to control the formation of iron nitride, whereby the volume fraction of the retained austenite phase in the metal structure is regulated to 3 to 20% by weight.
    Type: Application
    Filed: June 27, 2001
    Publication date: February 14, 2002
    Inventors: Hidekuni Murakami, Yoshihisa Takada, Masayoshi Suehiro
  • Publication number: 20020017341
    Abstract: Improved Fe—Hf—C—N and Fe—Hf—N materials and preparation methods thereof are disclosed. Such materials possess a high saturation magnetic flux density and an excellent soft magnetic property at a high frequencies of more than tens of MHz, without requiring an additional heat treatment, while avoiding an amorphous phenomenon therein and increasing grain energy. An iron-based soft magnetic thin film alloy has an empirical formula of FexHfyCzNv (where, x, y, z, and v respectively denote atomic %, 68≦x≦85, 4≦y≦10, 0≦z≦12, 3≦v≦20, 15≦y+z+v≦32, and x+y+z+v=100), and its fine structure is formed of nano size crystalline grains including nitrides or carbides of &agr;-Fe and Hf.
    Type: Application
    Filed: January 5, 1999
    Publication date: February 14, 2002
    Inventors: HI JUNG KIM, SUK HEE HAN, JONGRYOUL KIM, JAE YONG SONG
  • Publication number: 20020014285
    Abstract: A fine ferrite-based steel is disclosed, wherein at least 60% of the ferrite grain boundary is a large angle grain boundary of at least 15°, and the mean ferrite grain size is not more than 2.5 &mgr;m. The fine ferrite-based steel of the invention has a high strength and a long fatigue life.
    Type: Application
    Filed: September 21, 1998
    Publication date: February 7, 2002
    Inventors: TOHRU HAYASHI, SHIRO TORIZUKA, KANEAKI TSUZAKI, KOTOBU NAGAI, OSAMU UMEZAWA
  • Patent number: 6344093
    Abstract: A high tensile strength steel product for high heat input welding having excellent toughness in the heat-affected zone and having a tensile strength of at least 490 MPa contains, in terms of percent by weight, from about 0.05% to about 0.18% of C, 0.6% or less of Si, from about 0.80% to about 1.80% of Mn, 0.005% or less of Al, 0.030% or less of P, 0.004% or less of S, 0.005% or less of Nb, from about 0.04% to about 0.15% of V, from about 0.0050% to about 0.00150% of N, and from about 0.010% to about 0.050% of Ti, the ratio of the Ti content to the Al content, Ti/Al, satisfying 5.0 or more, and further contains at least one of from about 0.0010% to about 0.0100% of Ca and from about 0.0010% to about 0.0100% of REM, and the balance being Fe and incidental impurities.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: February 5, 2002
    Assignee: Kawasaki Steel Corporation
    Inventors: Akio Ohmori, Fumimaru Kawabata, Keniti Amano
  • Patent number: 6312529
    Abstract: Steel compositions and processes are described that provide optimum resistance to austenite grain coarsening in cold-formed and carburized components for automotive and machine structural applications. The steel compositions include, in weight percent, 0.1-0.3% C 150-220 ppm N and a grain refining addition selected from the group consisting of Al, V plus Al and Nb plus Al, the balance comprising iron and other alloying elements typically found in carburizing grades of steel. The steels are processed by reheating to a temperature in the vicinity of solution temperature of the least soluble species of grain refining precipitate and then hot worked. The hot-worked steel is cooled at an accelerated rate to 500° C. and then subcritically annealed, cold formed in at least one operation with intermediate anneals subcritically annealed after the last cold-forming operation, and carburized quenched and tempered (6).
    Type: Grant
    Filed: October 7, 1999
    Date of Patent: November 6, 2001
    Assignee: The Timken Company
    Inventors: Michael J. Leap, James C. Wingert
  • Patent number: 6303240
    Abstract: A soft magnetic thin film having a compositional formula FeaBbNc, wherein a, b and c each denote atomic percent and B denotes at least one of Co, Ni and Ru, and wherein the compositional range is given by 0<b≦5, and 0<c≦5. The film may exhibit uniaxial anisotropy with a uniaxial anisotropy field strength of 1-5 Oe. The film has a coercivity 2.5-4 Oe or less and a saturated magnetic flux density B25 of at least 16 kG measured at a magnetic field of 25 Oe. The film is produced by subjecting a deposited thin film of the compositional formula to heat treatment at a temperature of 220 to 450° C., within or without magnetic field and, has an average crystal grain size of not more than 50 nm.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 16, 2001
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Osamu Shimizu, Kanji Nakanishi
  • Patent number: 6287395
    Abstract: A high-energy weldable soft magnetic steel with high toughness in the heat-affected zone of weld joints, high specific electric resistance to reduce eddy currents, aging resistance and weathering resistance comprises 0.65 to <1.0% chromium, >1.0 to 2.0% silicon, 0.25 to 0.55% copper, 0.003 to 0.008% nitrogen, 0.15 to <0.6% manganese, 0.02 to 0.07% aluminumsolu., 0.01 to 0.02% titanium, 0 to 0.15% carbon, 0 to 0.045% phosphorus, the balance iron and unavoidable impurities.
    Type: Grant
    Filed: February 5, 1999
    Date of Patent: September 11, 2001
    Assignee: Thyssen Stahl AG
    Inventors: Udo Schriever, Hans-Joachim Tschersich
  • Patent number: 6238492
    Abstract: A soft magnetic thin micro-crystalline film of FeaTbNc (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo, and W and 0<b≦20, and 0<c≦22 except the range of b≦7.5 and c≦5, shows low coercivity Hc of 80-400 Am−1 (1-5 Oe) which is stable upon heating at elevated temperatures for glass bonding. This film is produced by crystallizing an amorphous alloy film of the similar composition at 350-650° C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at a higher frequency. It can also provide low magnetostriction around &lgr;s=0. A composite magnetic head is made using this thin film. A diffusion preventive SiO2 layer is disposed between ferrite cores, and this thin film in the magnetic head prevents an interdiffusion layer and suppresses beat in the output signal.
    Type: Grant
    Filed: October 24, 1997
    Date of Patent: May 29, 2001
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
  • Patent number: 6217678
    Abstract: The present invention provides a steel wire rod or bar which exhibits good cold deformability even though it does not undergo spheroidizing annealing after hot rolling. The steel wire rod or bar with good cold deformability is characterized in that its ferrite structure contains no less than 25 nitride and carbide particles in a mixed state or composite state per 25 &mgr;m on average in a sectional area three-fourths of the diameter within the circumference of the rod or bar. Such nitride and carbide precipitates contribute to the reduction of flow stress at temperatures raised by heat generation at the time of cold deforming.
    Type: Grant
    Filed: April 21, 1999
    Date of Patent: April 17, 2001
    Assignee: Kabushiki Kaisha Kobe Seiko Sho
    Inventors: Kan Momozaki, Hideo Hata, Toyofumi Hasegawa
  • Patent number: 6187117
    Abstract: A method of making a weathering grade steel plate includes the steps of establishing a minimum yield strength:plate thickness target from one of 50 KSI:up to 4″, 65 KSI:up to 1.5″, and 70 KSI:up to 1.25″. A modified weathering grade alloy composition is cast into a slab employing effective levels of manganese, carbon, niobium, vanadium, nitrogen, and titanium. The cast slab is heated and rough rolled to an intermediate gauge plate. The intermediate gauge plate is controlled rolled and subjected to one of air cooling or accelerated cooling depending on the minimum yield strength and thickness target. With the controlled alloy chemistry, rolling and cooling, the final gauge plate exhibits discontinuous yielding and can be used for applications requiring a 70 KSI minimum yield strength in plate thicknesses up to 1.25″, a 65 KSI minimum yield strength in plate thickness up to 1.50″ and a 50 KSI minimum yield strength for plates as thick as 4″.
    Type: Grant
    Filed: January 20, 1999
    Date of Patent: February 13, 2001
    Assignees: Bethlehem Steel Corporation, Pohang Iron & Steel Co., Ltd.
    Inventors: Yulin Shen, Richard L. Bodnar, Jang-Yong Yoo, Wung-Yong Choo
  • Patent number: 6183606
    Abstract: A method of producing high coercivity FePt—Si3N4 granular composite thin films for magnetic recording media is invented. The method includes magnetron co-sputtering of FePt and Si3N4 targets at controlled sputtering power and sputtering argon gas pressure to form a selective composition of granular FePt—Si3N4 thin film on a low temperature substrate, then post-annealed in vacuum at selective time period and temperature. Two kinds of FePt targets can be used. One is the FePt alloy target. The other one is a composite target consisting of an iron disk overlaid with small Pt pieces. This arrangement provides a wide range of effective target compositions and therefore film compositions. FePt—Si3N4 films were deposited on natural oxidized silicon wafer or quartz glass substrate at room temperature. The as-deposited film has soft magnetic properties and granular structure with soft magnetic &ggr;-FePt particles dispersed in amorphous Si3N4 matrix.
    Type: Grant
    Filed: November 3, 1999
    Date of Patent: February 6, 2001
    Assignee: National Science Council of Republic of China
    Inventors: Po-Cheng Kuo, Chih-Ming Kuo
  • Patent number: 6149862
    Abstract: An alloy and alloy product has about 1.3% to 1.7% by weight concentration of silicon, along with iron, alloying elements, and inevitable impurities and exhibits improved resistance to hydrogen embrittlement and sulfide stress cracking in an intensive hydrogen-charged medium wherein H from the medium acts as an alloying element. The alloy is characterized by an Fe--Si--H system wherein Fe is a donor element with respect to Si and Si is an acceptor element with respect to Fe. Further, the alloying elements are Fe--Si noninteractive elements with respect to Fe and Si, such that the presence of the alloying elements are not donor or acceptor elements with respect to Fe or Si. In several alloy compositions, the alloy has between about 1.38% to 1.63% weight Si. The alloy may further include between about 0.10% to 0.25% weight of C. In one particular alloy, the alloy composition includes about 0.18% of C; although, in one alloy product, an alloy is used having about 0.16% to 0.24% weight of C.
    Type: Grant
    Filed: May 18, 1999
    Date of Patent: November 21, 2000
    Assignee: The Atri Group Ltd.
    Inventors: Naum I. Gliklad, Avgust B. Kuslitskiy, Leonid A. Kuslitskiy
  • Patent number: 6083455
    Abstract: The present invention relates to manufacturing methods of nitrided steel parts, having high tensile strength, high fatigue strength, and excellent bending roughness, through nitriding without thermal refining, to thus-manufactured steel parts, and to steel products for nitriding, and steels for nitriding having a specific chemical composition, serving as steel stock for the manufacture of such steel parts. The chemical composition is as follows: C: over 0.20 to 0.60%, Si: 0.05 to 1.0%, Mn: 0.20 to 1.50%, P: 0.08% or less, S: 0.005 to 0.10%, Cu: 0.30% or less, Ni: 0.30% or less, Cr: 0.30% or less, Mo: 0.30% or less, V: 0.20% or less, Nb: 0.05% or less, Ti: 0.003 to 0.03%, Al: 0.08% or less, Ca: 0.005% or less, Pb: 0.30% or less, N: 0.008 to 0.030%, and the balance of Fe and unavoidable impurities. Steel products preferably have the ferrite-pearlite microstructure having a ferrite percentage of not less than 10%.
    Type: Grant
    Filed: January 5, 1998
    Date of Patent: July 4, 2000
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Masato Kurita, Koji Watari, Toru Kato, Harunori Kakimi, Mitsuo Uno, Masanori Sakamoto, Yoshihiko Kamada
  • Patent number: 5993571
    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
    Inventors: Hirohito Eto, Hiromasa Takada, Tetsuroh Hashiguchi, Osamu Ohyama
  • Patent number: 5976715
    Abstract: The invention is embodied in a soft magnetic thin film article comprising an iron--chromium-nitrogen (Fe--Cr--N) based alloy and methods for making such article. The soft magnetic thin film article is formed using an iron--chromium--nitrogen based alloy with tantalum in one embodiment and with at least one of the elements titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), molybdenum (Mo), niobium (Nb) or tungsten (W) in another embodiment. The article is formed such that the alloy has a relatively high saturation magnetization (e.g., greater than approximately 15 kG) and a relatively low coercivity (e.g., less than approximately 2.0 oersteds) in an as-deposited condition or, alternatively, with a very low temperature treatment (e.g., below approximately 150.degree. C.). The inventive films are suitable for use in electromagnetic devices, for example, in microtransformer cores, inductor cores and in magnetic read-write heads.
    Type: Grant
    Filed: November 6, 1997
    Date of Patent: November 2, 1999
    Assignee: Lucent Techologies Inc.
    Inventors: Li-Han Chen, Sungho Jin, Wei Zhu, Robert Bruce van Dover
  • Patent number: 5858129
    Abstract: Disclosed is an austenite stainless steel comprising: no more than 0.05% by weight of C; no more than 0.25% by weight of Si; no more than 0.40% by weight of Mn; no more than 0.040% by weight of P; no more than 0.003% by weight of S; 30.0 to 40.0% by weight of Ni; 20.0 to 26.0% by weight of Cr; 5.0 to 8.0% by weight of Mo; no more than 0.1% by weight of Al; 0.001 to 0.010% by weight of B; 0.15 to 0.30% by weight of N; and balance of Fe and inevitable impurity. The austenite stainless steel satisfying formula (1) and (2) mentioned below (wherein "Cr", "Mo", "N", "Si" and "Mn" mean content of each element).Cr+3.3Mo+20N.gtoreq.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: January 12, 1999
    Assignee: Nippon Yakin Kogyo Co., Ltd.
    Inventors: Yutaka Kobayashi, Takeya Toge, Yoshito Fujiwara
  • Patent number: 5853903
    Abstract: A cold-rolled steel sheet or a zinc or zinc alloy layer coated steel sheet containing 0.0010 to 0.01 wt % of C and having a steel composition containing one or two kinds of 0.005 to 0.08 wt % of Nb and 0.01 to 0.07 wt % of Ti in the ranges given by {(12/93)Nb+(12/48)Ti*} .gtoreq.0.0005, 0.ltoreq.C-{(12/93)Nb+(12/48)Ti*}.ltoreq.0.0015, and Ti*=Ti-{(48/32)S+(48/14)N } , in which a bake hardenability BH f the steel sheet at 170.degree. C..times.20 min after 2% tensile prestrain is 10 to 35 MPa and the BH (MPa) and a yield strength YP (MPa) of the steel sheet satisfy the ranges given by BH.gtoreq.exp(-0.115.multidot.YP+23.0) and 0.67.multidot.BH+160.ltoreq.YP.ltoreq.-0.8.multidot.BH+280.
    Type: Grant
    Filed: April 28, 1997
    Date of Patent: December 29, 1998
    Assignee: NKK Corporation
    Inventors: Yoshihiro Hosoya, Fusato Kitano, Yasunobu Nagataki
  • Patent number: 5830285
    Abstract: A fine graphite uniform dispersion steel material excellent in cold workability, cuttability and hardenability, which has graphite finely and uniformly dispersed therein, and a production method for producing the same. The steel contains at least 0.30 to 1.0% of C, 0.4 to 1.3% of Si, 0.3 to 1.0% of Mn, 0.0003 to 0.006% of B, 0.002 to 0.010% of N and 0.05 to 0.20% of Mo as the basic components and contains graphite having a mean particle diameter of not more than 4.0 .mu.m and a number of particles per unit and of at least 3,000 per mm.sup.2. The production method includes at least the steps of cooling the steel having these components at a cooling start temperature of not less than an A.sub.rl point, a cooling end temperature of not more than an M.sub.s point and a mean cooling rate of 5.degree. to 100.degree. C./s.
    Type: Grant
    Filed: August 23, 1996
    Date of Patent: November 3, 1998
    Assignee: Nippon Steel Corporation
    Inventors: Sakae Katayama, Toshimi Tarui, Masahiro Toda, Ken-ichiro Naito
  • Patent number: 5800728
    Abstract: An iron-rare earth metal permanent magnetic composition, comprising predominant phase having a body-centered tetragonal structure, and consisting essentially of an iron-based alloy having a composition represented by the formula:Fe.sub.a R.sub.b M.sub.c N.sub.d B.sub.e C.sub.f Co.sub.g Ni.sub.hwherein R represents at least one element selected from the group consisting of Y, Th and the lanthanide elements;M represents at least one element selected from the group consisting of Ti, Cr, V, Zr, Nb, Al, Mo, Mn, Hf, Ta, W, Mg, Si, Sn, Ge and Ga;the elements are present in atomic percentages indicated by a, b, c, d, e, f, g and h, wherein a+b+c+d+e+f+g+h=100 atomic %; and further,3.ltoreq.b.ltoreq.300.ltoreq.c.ltoreq.300.ltoreq.d.ltoreq.500.ltoreq.e.ltoreq.500.ltoreq.f.ltoreq.50provided that 0.3.ltoreq.d+e+f.ltoreq.500.ltoreq.g.ltoreq.50 and0.ltoreq.h<30.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: September 1, 1998
    Assignee: Hitachi Metals, Ltd.
    Inventor: Masao Iwata
  • Patent number: 5772797
    Abstract: A soft magnetic thin micro-crystalline film of FeT.sub.b N.sub.c (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b<20 and 0<c<22 except the range of b.ltoreq.7.5 and c.ltoreq.5, shows low coercivity Hc of 80-400 Am.sup.-1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding.This film is produced by crystallizing an amorphous alloy film of the similar composition at 350.degree.-650.degree. C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around .gamma.s=0.Composite magnetic head is made using this thin film. Diffusion preventive SiO.sub.2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.
    Type: Grant
    Filed: January 2, 1997
    Date of Patent: June 30, 1998
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
  • Patent number: 5750222
    Abstract: An organic resin-coated seamless can with necked-in portion is disclosed, which is produced by subjecting a resin-coated steel sheet to drawing-re-drawing for reducing thickness or to drawing-re-drawing-ironing for reducing thickness-ironing and which has a ratio of diameter of necked-in portion to diameter of body of 0.9 or less than that, said steel sheet being coated by 5- to 30-.mu.m thick organic resin layer on both surfaces of aluminum-killed, surface-treated steel sheet of 0.01 to 0.13 % by weight in total carbon amount and not more than 6.5 .mu.m in average grain diameter having been subjected to over-aging after continuous annealing to adjust to not more than 10 ppm in solid-dissolved carbon amount. This can scarcely has rough surface or pinholes in the necked-in portion even when the necked-in portion has been considerably compressed upon its formation.
    Type: Grant
    Filed: May 1, 1995
    Date of Patent: May 12, 1998
    Assignee: Toyo Seikan Kaisya, Ltd.
    Inventors: Ikuo Komatsu, Nobuyuki Sato, Katsuhiro Imazu
  • Patent number: 5750044
    Abstract: A magnet consists essentially of 4-8 at % of R, 10-20 at % of N, 2-10 at % of M, and the balance of T wherein R is at least one rare earth element, Sm being present in R in a proportion of at least 50 at %, T is Fe or Fe and Co, M is Zr with or without partial replacement by at least one element of Ti, V, Cr, Nb, Hf, Ta, Mo, W, Al, C, and P. Contained in the magnet are a hard magnetic phase based on R, T, and N and containing at least one crystalline phase selected from TbCu.sub.7, Th.sub.2 Zn.sub.17, and Th.sub.2 Ni.sub.17 types and a soft magnetic phase consisting of a T phase having a bcc structure, the soft magnetic phase having a mean grain size of 5-60 nm and being present in a proportion of 10-60% by volume. This construction ensures high coercivity, high squareness ratio, and high maximum energy product.
    Type: Grant
    Filed: July 11, 1995
    Date of Patent: May 12, 1998
    Assignee: TDK Corporation
    Inventors: Tetsuhito Yoneyama, Tomomi Yamamoto, Tetsuya Hidaka, Akira Fukuno
  • Patent number: 5725685
    Abstract: A soft magnetic alloy thin film includes a fine crystalline phase and an amorphous phase. The fine crystalline phase includes an average crystalline grain size of 10 nm or less in diameter and has body-centered cubic structure mainly composed of Fe. The amorphous phase has a nitrogen (N) compound as the main composition and occupies at least 50% of the structure of the thin film. An element M is incorporated at least in the amorphous phase, and includes at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, W, and rare earth metal elements. A plane-type magnetic device is made using this thin film.
    Type: Grant
    Filed: October 29, 1996
    Date of Patent: March 10, 1998
    Assignee: Alps Electric Co., Ltd.
    Inventors: Yasuo Hayakawa, Akihiro Makino
  • Patent number: 5656101
    Abstract: A soft magnetic alloy thin film includes a fine crystalline phase and an amorphous phase. The fine crystalline phase includes an average crystalline grain size of 10 nm or less in diameter and has body-centered cubic structure mainly composed of Fe. The amorphous phase has a nitrogen (N) compound as the main composition and occupies at least 50% of the structure of the thin film. An element M is incorporated at least in the amorphous phase, and includes at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, W, and rare earth metal elements. A plane-type magnetic device is made using this thin film.
    Type: Grant
    Filed: March 28, 1995
    Date of Patent: August 12, 1997
    Assignee: Alps Electric Co., Ltd.
    Inventors: Yasuo Hayakawa, Akihiro Makino
  • Patent number: 5648044
    Abstract: Graphite steel for a machine structural use exhibiting excellent cutting characteristic, cold forging characteristic and fatigue resistance, the graphite steel for a machine structural use containing: C: 0.1 wt % to 1.5 wt %; Si: 0.5 wt % to 2.0 wt %; Mn: 0.1 wt % to 2.0 wt %; B: 0.0003 wt % to 0.0150 wt %; Al: 0.005 wt % to 0.1 wt %; O.ltoreq.0.0030 wt %; P.ltoreq.0.020 wt %; S.ltoreq.0.035 wt %; N: 0.0015 wt % to 0.0150 wt %; and a balance consisting of Fe and unavoidable impurities, wherein substantially overall quantity of C is precipitated as graphite and size of graphite is 20 .mu.m or less.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: July 15, 1997
    Assignee: Kawasaki Steel Corporation
    Inventors: Toshiyuki Hoshino, Takashi Iwamoto, Akihiro Matsuzaki, Keniti Amano
  • Patent number: 5432645
    Abstract: The thin film of the invention for use in a magnetic head has an atomic ratio composition of the formula:(Fe.sub.100-z Ni.sub.z).sub.100-x-y M.sub.x N.sub.ywherein M is at least one member selected from the group consisting of Mg, Ca, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, and B, 6.ltoreq.x.ltoreq.14, 6.2.ltoreq.y.ltoreq.15, 0.6.ltoreq.y/x.ltoreq.2.0, and 0.ltoreq.z.ltoreq.10, and has a relative intensity ratio of Fe (200) peak to Fe (110) peak in an X-ray diffraction spectrum of at least 1 and high Fe (100) orientation, with a film surface oriented in (200) plane. Heat treatment improves the (100) orientation. The thin film has very high heat resistance of remaining stable at 700.degree. C. or higher and excellent soft magnetic properties in that it has a high saturation magnetic flux density Bs, a low coercive force, a high magnetic permeability, and minimized magnetostriction. It is hard enough.
    Type: Grant
    Filed: March 21, 1994
    Date of Patent: July 11, 1995
    Assignee: TDK Corporation
    Inventors: Kouichi Terunuma, Masahiro Miyazaki
  • Patent number: 5417739
    Abstract: A method of making stabilized ultra-low carbon steel having a high nitrogen content for enameling applications. The preferred method involves two phases. The first phase occurs in the basic oxygen furnace wherein nitrogen gas is combined with oxygen gas and blown into the melt through the oxygen lance. After the oxygen blow the carbon content of the melt is approximately 0.03% and the nitrogen content is at least about 0.016 to 0.020%. In the second phase the melt is introduced to a vacuum circulation decarburizer where the carbon content of the steel is reduced to ultra low levels on the order of 0.005%. The nitrogen content is maintained at a level of at least about 0.01% by introducing nitrogen gas into the vacuum decarburization vessel as the lift gas through inert gas tuyeres.
    Type: Grant
    Filed: December 30, 1993
    Date of Patent: May 23, 1995
    Assignee: LTV Steel Company, Inc.
    Inventors: Richard R. Watkins, Robert Blossey, Gregory Wotell
  • Patent number: 5382305
    Abstract: The soft magnetic thin film of the invention has an atomic ratio composition of the formula:[(Fe.sub.1-y Ni.sub.y).sub.1-x M.sub.x ].sub.1-z N.sub.zwherein M is at least one member selected from the group consisting of Mg, Ca, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, and B, 0.001.ltoreq.x.ltoreq.0.15, 0.ltoreq.y.ltoreq.0.1, and 0.001.ltoreq.z.ltoreq.0.15, and has a relative intensity ratio of Fe (200) peak to Fe (110) peak in an X-ray diffraction spectrum of at least 1/3 and high Fe (100) orientation. It has excellent soft magnetic properties in that it has a high saturation magnetic flux density Bs, heat resistance, a low coercive force Hc, and a high magnetic permeability .mu.. A magnetic head using such a thin film has improved otherwise properties, recording/reproducing sensitivity, and electromagnetic properties, and is highly reliable.
    Type: Grant
    Filed: August 16, 1993
    Date of Patent: January 17, 1995
    Assignee: TDK Corporation
    Inventors: Kouichi Terunuma, Masahiro Miyazaki
  • Patent number: 5326527
    Abstract: A fully killed steel has a composition of from about 0.005 to about 0.020 percent titanium and from about 0.004 to about 0.015 percent nitrogen, with the mole ratio of titanium to nitrogen being less than about 3.42. One grade of this steel exhibiting a 42 KSI minimum yield strength has from about 0.15 to about 0.27 percent carbon and from 0 to about 0.04 percent vanadium. Another grade exhibiting a 50 KSI minimum yield strength has from about 0.05 to about 0.27 percent carbon and at least about 0.02 percent vanadium. The balance of each steel is iron and other elements. Copper may optionally be provided for strength and corrosion resistance. The steel is prepared by continuous casting and hot rolling, without any quenching and tempering required to achieve the desired properties.
    Type: Grant
    Filed: September 8, 1992
    Date of Patent: July 5, 1994
    Assignee: Bethlehem Steel Corporation
    Inventors: Richard L. Bodnar, Steven S. Hansen
  • Patent number: 5304258
    Abstract: A magnetic alloy film suitable for high density recording has a composition of (Fe.sub.x M.sub.y N.sub.z).sub.a L.sub.b, where L is Cu and/or Ag. The provision of Cu and/or Ag in a range from 0.5 to 5 atomic % enhances thermal stability of the soft magnet properties of the alloy.
    Type: Grant
    Filed: April 22, 1991
    Date of Patent: April 19, 1994
    Assignee: NEC Corporation
    Inventors: Nobuyuki Ishiwata, Chizuko Wakabayashi
  • Patent number: 5277977
    Abstract: Ultrafine particles of Fe-Co-P material with a Fe/Co atomic ratio of from 95/5 to 70/30 and a (Fe+Co)/P atomic ratio of from 85/15 to 60/40 show improved ferromagnetic properties. The average particle size is from 0.005 to 0.1 .mu.m. Such ultrafine particles are prepared through gas phase reaction by evaporating a source material. They are useful in both magnetic and thermomagnetic recording media ensuring high density recording.
    Type: Grant
    Filed: December 29, 1989
    Date of Patent: January 11, 1994
    Assignee: TDK Corporation
    Inventors: Yasumichi Tokuoka, Jiro Yoshinari
  • Patent number: 5244627
    Abstract: A ferromagnetic thin film comprising Fe as a main component, at least one element of B, C, Al and Si and at least one transition metal element except noble metals Au, Ag, Ru, Pd, Os, Ir and Pt. This can accomplish a ferromagnetic thin film having a high saturation flux density, a high initial permeability and a low coercive force, and also having an excellent corrosion resistance and thermal resistance. The ferromagnetic thin film having the above high performances can be manufactured in a high yield by forming the above materials into a film in an atmosphere of a mixed gas of Ar and N.sub.2, and thereafter heating the film at a given temperature. It is possible to give a magnetic head suitable for high-density recording, that enables good recording and reproducing on and from a magnetic recording medium having a high coercive force.
    Type: Grant
    Filed: December 11, 1991
    Date of Patent: September 14, 1993
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Toshiyuki Katsuki
  • Patent number: 5141570
    Abstract: High strength low carbon steel wire rods excellent in the cold drawing property have a composite structure in which an acicular low temperature transformation phase comprising a martensite, bainite and/or the mixed structure thereof that comprises, by weight %,C: 0.02-0.30%,Si: less than 2.5%,Mn: less than 2.5% andthe balance of iron and inevitable impurities and that may partially contain retained austenite is uniformly dispersed at the volume ratio of from 10 to 70% in the ferrite phase, and in which the weight of (C+N) in solution in the ferrite phase is less than 40 ppm.
    Type: Grant
    Filed: December 19, 1990
    Date of Patent: August 25, 1992
    Assignee: Kabushiki Kaisha Kobe Seiko Sho
    Inventors: Toshiaki Yutori, Takehiko Kato, Yasuhiro Hosogi
  • Patent number: 5100613
    Abstract: A vanadium-nitrogen microalloyed steel is continuously hot rolled to C-shaped sections that meet property requirements for side rails of truck frames with no heat treatment. Sections with different thicknesses of the web and flange regions can also be prepared by the same processing. The composition of the steel is from about 0.16 to about 0.20 percent carbon, from about 1.2 to about 2.0 percent manganese, from about 0.45 to about 0.55 percent silicon, from about 0.10 to about 0.30 percent vanadium, from about 0.001 to about 0.030 percent aluminum, from about 0.010 to about 0.027 percent nitrogen, less than about 0.030 percent phosphorus, less than about 0.030 percent sulfur, balance iron totalling 100 percent, with all percentages by weight. Variations of this steel containing either from about 0.01 to about 0.02 percent titanium or 0.04 to about 0.07 percent aluminum are also permissible.
    Type: Grant
    Filed: October 16, 1990
    Date of Patent: March 31, 1992
    Assignee: Bethlehem Steel Co.
    Inventors: Richard L. Bodnar, Steven S. Hansen
  • Patent number: 5084795
    Abstract: A metal-in-gap type magnetic head having a small undulation of reproduction output caused by a pseudo-gap and method of manufacture thereof are provided, wherein the magnetic head employs as a back core a ferrite (particularly, a ferrite containing Sn) and employs in a metal portion which constitutes a front core an alloy film (particularly, a composition transition alloy film) having a composition expressed by T-M-X-N, where T is at least one metal element selected from a group consisting of Fe, Co and Ni, M is at least one metal element selected from a group consisting of Nb, Zr, Ti, Ta, Hf, Cr, Mo, W and Mn, X is at least one metalloid element selected from a group consisting of B, Si and Ge, and N is nitrogen.
    Type: Grant
    Filed: February 5, 1990
    Date of Patent: January 28, 1992
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Sakakima, Keita Ihara, Koichi Osano
  • Patent number: 5053194
    Abstract: A formable thin steel sheet such as hot rolled sheet, cold rolled sheet or surface treated sheet comprises not more than 0.003 wt. % of C, not more than 1.0 wt % of Si, not more than 1.0 wt % of Mn, not more than 0.15 wt % of P, not more than 0.020 wt % of S, not more than 0.0045 wt % of O, not more than 0.0020 wt % of N, not more than 0.15 wt % of Al provided that a ratio of Al/N is not less than 30, and the balance being Fe and inevitable impurities, and has not only improved formability for press forming, deep drawing or the like but also improved fatigue resistance as a welded joint.
    Type: Grant
    Filed: December 12, 1989
    Date of Patent: October 1, 1991
    Assignee: Kawasaki Steel Corporation
    Inventors: Yoshio Yamazaki, Susumu Okada, Susumu Satoh, Toshiyuki Kato, Hideo Abe, Keiji Nishimura
  • Patent number: 5028280
    Abstract: A nitrogen-containing Fe-based soft magnetic alloy suitable for use as the material of a magnetic head core, as well as a method for manufacturing the soft magnetic alloy film. Unlike a mere nitride alloy film, the soft magnetic alloy of the present invention has a compositionally modulated structure in which at least the nitrogen content is periodically modulated in the direction of thickness of the film so as to have a nitride layer rich at least in nitrogen and a non-nitride layer poor at least in nitrogen. The soft magnetic alloy film of the invention comprises a main constituent of Fe, at least one metalloid element selected from the group consisting of B, Si and C, and at least one metal element selected from the group consisting of Nb, Ta, Zr and Ti and has fine Fe-based grains included therein.
    Type: Grant
    Filed: December 11, 1989
    Date of Patent: July 2, 1991
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keita Ihara, Hiroshi Sakakima, Koichi Osano
  • Patent number: 5017335
    Abstract: A microalloyed, fully killed steel has a composition, in weight percent, of from about 0.20 to about 0.45 percent carbon, from about 0.90 to about 1.70 percent manganese, from about 0.10 to about 0.35 percent silicon, from about 0.01 to about 0.04 percent aluminum, from about 0.05 to about 0.20 percent vanadium, from about 0.008 to about 0.024 percent nitrogen, balance iron. The steel is particularly useful when hot rolled to a railway joint bar section, and air cooled. The resulting joint bar meets AREA specifications in the as-rolled condition, without the need for a reheat and oil quench heat treatment after rolling.
    Type: Grant
    Filed: June 29, 1989
    Date of Patent: May 21, 1991
    Assignee: Bethlehem Steel Co.
    Inventors: Bruce L. Bramfitt, Steven S. Hansen
  • Patent number: 4975242
    Abstract: A carbon steel useful for machine structural use having improved cold forgability and induction hardenability comprises particular amounts of C, Si, Mn, Cr, S, P, O, N or further Mo and the balance being substantially Fe.
    Type: Grant
    Filed: November 27, 1989
    Date of Patent: December 4, 1990
    Assignees: Honda Gikan Kogyo Kabushiki Kaisha, Kawasaki Steel Corp.
    Inventors: Toshiyuki Hoshino, Nobuhisa Tabata, Isao Machida, Masayoshi Saga, Takeshi Takagi
  • Patent number: 4969962
    Abstract: Novel magnetic alloys for magnetic heads are provided and are broadly of the formula, Fe-O-N. In a more specific embodiment, the alloys are of the compositional formula, Fe.sub.v N.sub.w O.sub.x M.sub.y, wherein M represents a member selected from the group consisting of Ta, Nb, Si and mixtures thereof, and v, w, x and y are, respectively, such values by atomic percent that 1.ltoreq.w.ltoreq.20, 1.ltoreq.x.ltoreq.20 and 0.5.ltoreq.y.ltoreq.6 provided that v+w+x+y=100. These alloys may further comprise at least one element of the platinum group or of group VIa of the periodic table in an amount of from 0.3 to 3 atomic percent in total so that their resistance to corrosion is improved.
    Type: Grant
    Filed: August 16, 1989
    Date of Patent: November 13, 1990
    Assignee: Victor Company of Japan, Ltd.
    Inventors: Yasushi Watanabe, Hirofumi Imaoka
  • Patent number: 4865661
    Abstract: A high strength austenitic steel having a yield strength above 600 N/mm.sup.2 at 02% permanent strain, containing about 0.5 to 1.5% by weight of nitrogen, about 6 to 12% by weight cobalt, and less than 5% by weight nickel. The steel is treated at about 1050.degree. C. to 1200.degree. C. and then quenched in water.
    Type: Grant
    Filed: October 31, 1988
    Date of Patent: September 12, 1989
    Assignee: Fried. Krupp GmbH
    Inventors: Peter Dahlmann, Johannes Jachowski, Paul Pant, Gerald Stein
  • Patent number: 4855105
    Abstract: A wear-resistant steel contains carbon, manganese, silicon, sulphur, phosphorus, nitrogen, titanium, and iron with the following proportions of these components in weight %:______________________________________ Carbon 0.4-1.3 Manganese 3-11.5 Sulphur up to 0.5. Phosphorus up to 0.1 Titanium 0.01-0.15 Nitrogen 0.02-0.9 Iron the balance.
    Type: Grant
    Filed: September 3, 1987
    Date of Patent: August 8, 1989
    Assignee: Belorussky Tekhnologichesky Institut Imeni S.M. Kirova
    Inventors: Nikolai A. Svidunovich, Leonid I. Parfenov, Alexandr I. Garost, Gennady A. Sorokin, Viktor N. Volkov, Viktor A. Obiedkov, Valery K. Karbanovich, Vladimir V. Vashkevich, Alexandr N. Verbitsky