Patents Assigned to JFE Steel Corporation, a Corporation of Japan
  • Publication number: 20120048063
    Abstract: High compressibility iron powder that is suitably used for parts with excellent magnetic characteristics or high density sintered parts and that has good productivity is provided from pure iron powder which includes, as impurities in percent by mass, C: 0.005% or less, Si: more than 0.01% and 0.03% or less, Mn: 0.03% or more and 0.07% or less, P: 0.01% or less, S: 0.01% or less, O: 0.10% or less, and N: 0.001% or less, and whose particle includes four or less crystal grains on average and has a micro Vickers hardness (Hv) of 80 or less on average. The circularity of the iron powder is preferably 0.7 or more.
    Type: Application
    Filed: January 30, 2007
    Publication date: March 1, 2012
    Applicant: JFE STEEL CORPORATION a corporation of Japan
    Inventors: Toshio Maetani, Satoshi Uenosono, Aya Uenosono, Masateru Ueta
  • Publication number: 20100282376
    Abstract: An ultra soft high carbon hot-rolled steel sheet has excellent workability. The steel sheet is a high carbon hot-rolled steel sheet containing 0.2 to 0.7% C, and has a structure in which mean grain size of ferrite is 20 ?m or larger, the volume percentage of ferrite grains having 10 ?m or smaller size is 20% or less, mean diameter of carbide is in a range from 0.10 ?m to smaller than 2.0 ?m, the percentage of carbide grains having 5 or more of aspect ratio is 15% or less, and the contact ratio of carbide is 20% or less.
    Type: Application
    Filed: February 26, 2007
    Publication date: November 11, 2010
    Inventors: Hideyuki Kimura, Takeshi Fujita, Nobuyuki Nakamura, Naoya Aoki, Masato Sasaki, Satoshi Ueoka, Shunji Iizuka
  • Publication number: 20090277544
    Abstract: A high-tensile strength welded steel tube has excellent formability and torsional fatigue endurance after being formed into cross-sectional shape and then stress-relief annealed. A steel material used has a composition which contains C, Si, Al, 1.01% to 1.99% Mn, 0.041% to 0.150% Ti, 0.017% to 0.150% Nb, P, S, N, and O such that the sum of the content of Ti and that of Nb is 0.08% or more, the content of each of C, Si, and Al being within an appropriate range, the content of each of P, S, N, and O being adjusted to a predetermined value or less.
    Type: Application
    Filed: June 19, 2007
    Publication date: November 12, 2009
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Shunsuke Toyoda, Masatoshi Aratani, Yoshikazu Kawabata, Yuji Hashimoto, Koji Suzuki, Kei Sakata, Makio Gunji, Akio Sato, Tetsuro Sawaki
  • Publication number: 20090272469
    Abstract: A steel composition contains: 0.05% or less of C; 0.5% or less of Si; 0.20% to 1.80% of Mn; 0.03% or less of P; 0.005% or less of S; 14.0% to 18.0% of Cr; 5.0% to 8.0% of Ni; 1.5% to 3.5% of Mo; 0.5% to 3.5% of Cu; 0.05% or less of Al; 0.20% or less of V; 0.01% to 0.15% of N; and 0.006% or less of O on a mass basis, and satisfies the following expressions: Cr+0.65Ni+0.6Mo+0.55Cu?20C?18.5 and Cr+Mo+0.3Si?43.5C?0.4Mn?Ni?0.3Cu?9N?11 (where Cr, Ni, Mo, Cu, C, Si, Mn, and N represent their respective contents (mass %)). After such a steel pipe material is formed into a steel pipe, the steel pipe is quenched by cooling after heating to a temperature of the AC3 transformation point or more and tempered at a temperature of the AC1 transformation point or less. The composition may further contain at least one element of Nb and Ti; at least one element selected from the group consisting of Zr, B, and W; or Ca, singly or in combination.
    Type: Application
    Filed: April 2, 2009
    Publication date: November 5, 2009
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Mitsuo Kimura, Takanori Tamari, Takaaki Toyooka
  • Publication number: 20090252641
    Abstract: A steel sheet contains, in terms of percent by mass, C: 0.01 to 0.2%, Si: 2.0% or less, and Mn: 3.0% or less and has a martensite phase as dominant phase and ferrite with a grain size of 20 ?m or less as a second phase. The ferrite is contained in area ratio of 1% to 30% and the amount of solute carbon being 0.01 percent by mass of more. The steel sheet can provide a hot-rolled steel sheet suitable for automobile steel sheet, i.e., has excellent press workability and excellent strain aging property whereby the tensile strength significantly increases by heat treatment at about the same temperature as typical baking process after the press-working. Moreover, hardening of the ferrite phase improves the fatigue strength after the strain aging.
    Type: Application
    Filed: March 29, 2006
    Publication date: October 8, 2009
    Applicant: JFE Steel Corporation a corporation of Japan
    Inventors: Toru Hoshi, Saiji Matsuoka
  • Publication number: 20090214892
    Abstract: A high strength steel sheet and a method for manufacturing the same has superior phosphatability properties and hot-dip galvannealed properties besides a tensile strength of 950 MPa or more and a high ductility, and also having a small variation in mechanical properties with the change in annealing conditions.
    Type: Application
    Filed: February 18, 2009
    Publication date: August 27, 2009
    Applicants: JFE Steel Corporation, a corporation of Japan, ThyssenKrupp Steel AG, a corporation of Germany
    Inventors: Kenji Kawamura, Taro Kizu, Shusaku Takagi, Kohei Hasegawa, Hiroshi Matsuda, Akio Kobayashi, Yasunobu Nagataki, Yasuhi Tanaka, Thomas Heller, Brigitte Hammer, Jian Bian, Gunter Stich, Rolf Bode
  • Publication number: 20090202384
    Abstract: A high tensile strength hot-rolled steel sheet having superior strain aging hardenability, which has high formability and stable quality characteristics, and in which satisfactory strength is obtained when the steel sheet is formed into automotive components, thus enabling the reduction in weight of automobile bodies. Specifically, a method for producing a high tensile strength hot-rolled steel sheet having superior strain aging hardenability with a BH of 80 MPa or more, a ?TS of 40 MPa or more, and a tensile strength of 440 MPa or more includes the steps of heating a steel slab to 1,000° C. or more, the steel slab containing, in percent by mass, 0.15% or less of C, 0.45% or less of Si, 3.0% or less of Mn, 0.08% or less of P, 0.02% or less of S, 0.02% or less of Al, 0.0050% to 0.0250% of N, and optionally 0.1% or less in total of at least one of more than 0.02% to 0.1% of Nb and more than 0.02% to 0.1% of V, the ratio N (mass %)/Al (mass %) being 0.
    Type: Application
    Filed: February 9, 2009
    Publication date: August 13, 2009
    Applicant: JFE Steel Corporation, a Corporation of Japan
    Inventors: Akio Tosaka, Sinjiro Kaneko, Yoichi Tominaga, Noriyuki Katayama, Nobutaka Kurosawa, Kei Sakata, Osamu Furukimi
  • Publication number: 20090061133
    Abstract: A two-piece can has sufficient can strength and excellent corrosion resistance and to provide a method for forming the two-piece can easily without generating cracks. The two-piece can uses a laminated steel sheet as the base material and having a can body in a shape of cylinder integrated with bottom. The can body is treated by diametral reduction to become the diameter of opening side thereof smaller than the diameter of can body, and to satisfy the formulae (1) and (2). There is formed a bead at the opening side of the can body, being curled outward from the can at the tip of the opening in a shape of circular arc or vertically long ellipse in cross section, and is further formed a bead having a cross sectional shape of further curled at the tip thereof, an upper bead, and a lower bead: 1.5?h/(R?r)??(1) d/R?0.25??(2) where, h is the height from the can bottom to the tip of the opening, R is the net blank radius, r is the radius of the can bottom, and d is the radius of the tip of the opening.
    Type: Application
    Filed: August 10, 2006
    Publication date: March 5, 2009
    Applicant: JFE Steel Corporation a corporation of Japan
    Inventors: Katsumi Kojima, Yuka Nishihara, Hiroshi Kubo, Yoshihiko Yasue, Yasuhide Oshima, Hiroki Iwasa
  • Publication number: 20090041608
    Abstract: An iron-based powder mixture for powder metallurgy is provided, in which iron-based powder is blended with at least one selected from talc and steatite, and preferably further blended with metallic soap, thereby when a compacted body is sintered, furnace environment is not adversely affected, and excellent compaction performance is achieved even in a low temperature range of less than 100° C., and more preferably, an obtained sintered body has excellent machining performance.
    Type: Application
    Filed: February 14, 2007
    Publication date: February 12, 2009
    Applicant: JFE Steel Corporation a corporation of Japan
    Inventors: Yukiko Ozaki, Tomoshige Ono, Shigeru Unami, Masashi Fujinaga
  • Publication number: 20090034203
    Abstract: In a Cr—Cu alloy that is formed by powder metallurgy and contains a Cu matrix and flattened Cr phases, the Cr content in the Cr—Cu alloy is more than 30% to 80% or less by mass, and the average aspect ratio of the flattened Cr phases is more than 1.0 and less than 100. The Cr—Cu alloy has a small thermal expansion coefficient in in-plane directions, a high thermal conductivity, and excellent processability. A method for producing the Cr—Cu alloy is also provided. A heat-release plate for semiconductors and a heat-release component for semiconductors, each utilizing the Cr—Cu alloy, are also provided.
    Type: Application
    Filed: February 14, 2007
    Publication date: February 5, 2009
    Applicants: JFE Precision Corporation, a corporation of Japan, JFE Steel Corporation, a corporation of Japan
    Inventors: Hoshiaki Terao, Hiroki Ota, Hideaki Kobiki, Satoshi Uenosono, Aya Uenosono
  • Publication number: 20080264530
    Abstract: A hot forged product including hardened areas introduced by partial cooling after hot forging, and unhardened areas, wherein Vickers hardness V1 of the hardened areas on the surface and Vickers hardness V2 of the unhardened areas satisfy the following formula (1): (V1?V2)/V2: 0.1 to 0.8.
    Type: Application
    Filed: June 5, 2006
    Publication date: October 30, 2008
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Kazukuni Hase, Hideto Kimura, Takaaki Toyooka
  • Publication number: 20080190520
    Abstract: In a grain-oriented electrical steel sheet having phosphate-based coatings, which contain no chromium and which impart a tension, on the surfaces of a steel sheet with ceramic underlying films therebetween, the coating amount of oxygen in the underlying film is 2.0 g/m2 or more and 3.5 g/m2 or less relative to both surfaces of the steel sheet. Consequently, a grain-oriented electrical steel sheet with a chromium-less coating is provided. The resulting steel sheet has coating properties at the same level as those of a steel sheet with chromium-containing coatings and realizes high hygroscopicity resistance and a low iron loss without variations.
    Type: Application
    Filed: November 7, 2005
    Publication date: August 14, 2008
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Makoto Watanabe, Hiroaki Toda, Mineo Muraki
  • Publication number: 20080060728
    Abstract: A method for manufacturing a non-oriented electrical steel sheet including hot-rolling a steel slab containing 0-0.010% of C; at least one of Si and Al in a total amount of 0.03% to 0.5%; 0.5% or less of Mn; 0.10% or more to 0.26% or less of P; 0.015% or less of S; and 0.010% or less of N, on a mass percentage basis, the remainder being Fe and unavailable impurities, under conditions of a heating temperature in a single-phase austenite region and a coiling temperature of 650° C. or less; descaling the hot-rolled sheet to cold-roll the descaled sheet once or twice or more with an intermediate annealing sub-step therebetween; and then finish-annealing the cold-rolled sheet at a temperature of 700° C. or more in the single-phase ferrite region.
    Type: Application
    Filed: October 29, 2007
    Publication date: March 13, 2008
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Masaaki Kohno, Masaki Kawano, Atsuhito Honda, Akio Fujita
  • Publication number: 20080000737
    Abstract: A stainless steel sheet with excellent heat and corrosion resistances for a brake disk is provided. Specifically, in mass %, C: less than 0.10%, Si: 1.0% or less, Mn: 1.0 to 2.5%, P: 0.04% or less, S: 0.01% or less, Cr: more than 11.5% but not more than 15.0%, Ni: 0.1 to 1.0%, Al: 0.10% or less, Nb: more than 0.08% but not more than 0.6%, V: 0.02 to 0.3%, and N: more than 0.03% but not more than 0.10% are contained so that 0.03?{C+N?(13/93)Nb}?0.10, (5Cr+10Si+15Mo+30Nb+50V?9Ni?5Mn?3Cu?225N?270C)?45, and {(14/50)V+(14/90)Nb}<N (wherein Cr, Si, Mo, Nb, Ni, Mn, Cu, V, N, and C represent the contents (mass %) of the corresponding elements) are satisfied. With such a composition, the stainless steel sheet for a brake disk can be provided with both excellent heat resistance and excellent corrosion resistance after tempering.
    Type: Application
    Filed: October 20, 2005
    Publication date: January 3, 2008
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Junichiro Hirasawa, Takumi Ojiro, Osamu Furukimi
  • Publication number: 20070199632
    Abstract: A steel part having a long rolling contact fatigue life and capable of further increasing the life of a bearing under severer using condition than usual conditions. The steel part includes steel having a composition containing 0.7% by mass to 1.1% by mass of C, 0.5% by mass to 2.0% by mass of Si, 0.4% by mass to 2.5% by mass of Mn, 1.6% by mass to 5.0% by mass of Cr, 0.1% by mass to less than 0.5% by mass of Mo, 0.010% by mass to 0.050% by mass of Al, less than 0.0015% by mass of Sb as an impurity, and the balance composed of Fe and inevitable impurities, the steel being hardened and tempered. In the steel structure of a portion from the surface to a depth of 5 mm, residual cementite has a grain diameter of 0.05 to 1.5 ?m, prior austenite has a grain diameter of 30 ?m or less, and the ratio by volume of the residual austenite is less than 25%.
    Type: Application
    Filed: February 15, 2007
    Publication date: August 30, 2007
    Applicants: JFE Steel Corporation,a corporation of Japan, JTEKT Corporation, a corporation of Japan
    Inventors: Takashi Iwamoto, Kunikazu Tomita, Hideto Kimura, Takaaki Toyooka, Hisato Nishisaka, Masao Goto, Hisashi Harada
  • Publication number: 20070144632
    Abstract: A steel having excellent formability, fatigue endurance after quenching, low temperature toughness, resistance for hydrogen embrittlement, and corrosion fatigue endurance. A method includes heating a steel slab at 1160° C. to 1320° C., hot-finish-rolling the steel slab at a finisher delivery temperature of 750° C. to 980° C., and then coiling the hot-rolled steel at a coiling temperature of 560° C. to 740° C. after slow cooling for a time of 2 seconds or more to produce a hot-rolled steel strip having a structure in which the ferrite grain diameter df corresponding to a circle is 1.1 ?m to less than 1.2 ?m and the ferrite volume fraction Vf is 30% to 98%, the steel slab containing 0.18 to 0.29% of C, 0.06 to 0.45% of Si, 0.91 to 1.85% of Mn, 0.019% or less of P, 0.0029% or less of S, 0.015 to 0.075% of sol. Al, 0.0049% or less of N, 0.0049% or less of O, 0.0001 to 0.0029% of B, 0.001 to 0.019% of Nb, 0.001 to 0.029% of Ti, 0.001 to 0.195% of Cr, and 0.001 to 0.
    Type: Application
    Filed: December 9, 2004
    Publication date: June 28, 2007
    Applicants: JFE Steel Corporation, a corporation of Japan, Toyota Jidosha Kabushiki Kaisha, a corporation of Japan
    Inventors: Shunsuke Toyoda, Kei Sakata, Akio Sato, Koichi Kaneko, Hiroshi Kawaguchi
  • Publication number: 20070119521
    Abstract: A high strength steel, including about 0.05 to about 0.25% of C, less than about 0.5% of Si, about 0.5 to about 3.0% of Mn, not more than about 0.06% of P, not more than about 0.01% of S, about 0.50 to about 3.0% of Sol. Al, not more than about 0.02% of N, about 0.1 to about 0.8% of Mo, about 0.02 to about 0.40% of Ti, and the balance of iron and unavoidable impurities, wherein the steel has a structure formed of at least three phases including a bainite phase, and a retained austenite phase in addition to a ferrite phase having a composite carbide containing Ti and Mo dispersed and precipitated therein, wherein the total volume of the ferrite phase and the bainite phase is not smaller than 80%, the volume of the bainite phase is about 5% to about 60%, and the volume of the retained austenite phase is about 3 to about 20%.
    Type: Application
    Filed: November 3, 2006
    Publication date: May 31, 2007
    Applicants: JFE Steel Corporation, a corporation of Japan, ThyssenKrupp Steel AG, a corporation of Germany
    Inventors: Takeshi Yokota, Akio Kobayashi, Kazuhiro Seto, Yoshihiro Hosoya, Thomas Heller, Brigitte Hammer, Rolf Bode, Gunter Stich
  • Publication number: 20070123920
    Abstract: Providing a ceramic-coated medical appliance quite excellent in insulating performance which has no negative effects on tissues or cells of an organism subjected to surgery; a ceramic-coated genetic control needle which has no risk of breaking during use nor no unfavorable effects, such as destruction or tear-off, on sliced tissues or tissue areas around the needle at site of penetration into a lesion and which cuts off a cell nucleus or injects an immunological solution into the nucleus without causing any negative effects on tissues around the penetrated needle; and a fabrication method for the same.
    Type: Application
    Filed: October 10, 2006
    Publication date: May 31, 2007
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Yukio Inokuti, Hirotaro Mori, Hiroyuki Fukuda, Masaaki Ebara
  • Publication number: 20070051203
    Abstract: A method for discharging a reduced product produced on a movable hearth of a movable-hearth furnace uses a discharging device. The discharging device includes a removal unit for removing the reduced product from the movable hearth, a separation unit for separating the reduced product from a solid reductant, a leaving-returning unit for either leaving substances other than the reduced product on a solid reductant layer or returning the substances onto the solid reductant layer, and a discharge unit for discharging the reduced product to the outside of the movable-hearth furnace.
    Type: Application
    Filed: November 7, 2006
    Publication date: March 8, 2007
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Natsuo Ishiwata, Tatsuya Ozawa, Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Tetsuya Kikui
  • Publication number: 20060169365
    Abstract: The present invention relates to a high strength cold rolled steel sheet composed of ferrite grains having an average grain diameter of 10 ?m or less, in which the average number per unit area of Nb(C, N) precipitates having a diameter of 50 nm or more is 7.0×10?2/?m2 or less, and a zone having a width of 0.2 to 2.4 ?m and an average area density of NbC precipitates of 60% or less of that of the central portion of the ferrite grains is formed along grain boundaries of the ferrite grains, for example, the steel sheet consisting of 0.004 to 0.02% of C, 1.5% or less of Si, 3% or less of Mn, 0.15% or less of P, 0.02% or less of S, 0.1 to 1.5% of sol.Al, 0.001 to 0.007% of N, 0.03 to 0.2% of Nb, by mass, and the balance of Fe and inevitable impurities. The steel sheet of the present invention is most preferably used for automobile panel parts since it has the TS of 340 MPa or more and the superior surface strain resistance and press formability.
    Type: Application
    Filed: November 26, 2004
    Publication date: August 3, 2006
    Applicant: JFE Steel Corporation, a corporation of Japan
    Inventors: Yoshihiko Ono, Yasunobu Nagataki, Kozo Harada, Hisanori Ando