Over 0.1 Percent Aluminum Containing, But Less Than 4 Percent Patents (Class 420/103)
  • Patent number: 11795531
    Abstract: A high-strength galvanized steel sheet of the present invention includes a steel sheet having a specific chemical composition, and a steel structure containing, in terms of area ratio, 4% or more and 20% or less of retained austenite, 30% or less (including 0%) of ferrite, 40% or more of martensite, and 10% or more and 50% or less of bainite; and a galvanized layer provided on the steel sheet, in which an amount of diffusible hydrogen in the steel is less than 0.20 mass ppm, a tensile strength is 1100 MPa or more, a relationship between a tensile strength TS (MPa), an elongation El (%), and a sheet thickness t (mm) satisfies a (1) formula below, and a yield ratio YR is 67% or more. TS×(El+3?2.
    Type: Grant
    Filed: March 29, 2019
    Date of Patent: October 24, 2023
    Assignee: JFE Steel Corporation
    Inventors: Hiromi Yoshitomi, Yoshihiko Ono, Tatsuya Nakagaito
  • Patent number: 11739392
    Abstract: A high-strength steel sheet having a tensile strength TS of 1320 MPa or more and excellent workability. The high-strength steel sheet has a chemical composition containing, by mass %, C: 0.20% or more and 0.40% or less, Si: 0.5% or more and 2.5% or less, Mn: more than 2.4% and 5.0% or less, P: 0.1% or less, S: 0.01% or less, Al: 0.01% or more and 0.5% or less, N: 0.010% or less, and Fe and inevitable impurities. A microstructure of the steel sheet includes, in terms of area fraction with respect to the whole steel sheet microstructure, lower bainite in an amount of 40% or more and less than 85%, martensite including tempered martensite in an amount of 5% or more and less than 40%, retained austenite in an amount of 10% or more and 30% or less, and polygonal ferrite in an amount of 10% or less (including 0%).
    Type: Grant
    Filed: February 7, 2017
    Date of Patent: August 29, 2023
    Assignee: JFE STEEL CORPORATION
    Inventors: Yusuke Kimata, Yoshihiko Ono, Kenji Kawamura
  • Patent number: 10151010
    Abstract: A soft nitrided induction hardened steel part which is excellent in bearing fatigue strength comprised of a predetermined chemical composition wherein a dissolved N concentration from the surface to 0.2 mm depth is 0.05 to 1.50%, a Vicker's hardness from the surface to 0.2 mm depth after tempering at 300° C. is HV 600 or more, and t/r?0.35 when an effective hardened layer depth “t” is 0.5 mm or more and a radius of a breakage risk site or half of the thickness is “r” (mm).
    Type: Grant
    Filed: May 30, 2013
    Date of Patent: December 11, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Tatsuya Koyama, Suguru Yoshida
  • Patent number: 9732404
    Abstract: Steel sheet, the composition of the steel of which comprises, the contents being expressed by weight: 0.08%?C?0.23%, 1%?Mn?2%, 1?Si?2%, Al?0.030%, 0.1%?V?0.25%, Ti?0.010%, S?0.015%, P?0.1%, 0.004%?N?0.012%, and, optionally, one or more elements chosen from: Nb?0.1%, Mo?0.5%, Cr?0.3%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.
    Type: Grant
    Filed: July 7, 2006
    Date of Patent: August 15, 2017
    Assignee: ArcelorMittal France
    Inventors: Patrick Barges, Colin Scott, Gerard Petitgand, Fabien Perrard
  • Patent number: 9039962
    Abstract: A steel for an induction hardening including, by mass %, C: more than 0.75% to 1.20%, Si: 0.002 to 3.00%, Mn: 0.20 to 2.00%, S: 0.002 to 0.100%, Al: more than 0.050% to 3.00%, P: limited to 0.050% or less, N: limited to 0.0200% or less, O: limited to: 0.0030% or less, and the balance composing of iron and unavoidable impurities, wherein an Al content and a N content satisfy, by mass %, Al?(27/14)×N>0.050%.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: May 26, 2015
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Manabu Kubota, Toshiharu Aiso, Kei Miyanishi
  • Publication number: 20150098857
    Abstract: A steel material contains: by mass %, C: greater than 0.05% to 0.18%; Mn: 1% to 3%; Si: greater than 0.5% to 1.8%; Al: 0.01% to 0.5%; N: 0.001% to 0.015%; one or both of V and Ti: 0.01% to 0.3% in total; Cr: 0% to 0.25%; Mo: 0% to 0.35%; a balance: Fe and impurities; and 80% or more of bainite by area %, and 5% or more in total of one or two or more selected from a group consisting of ferrite, martensite and austenite by area %, in which an average block size of the above-described bainite is less than 2.0 ?m, an average grain diameter of all of the above-described ferrite, martensite and austenite is less than 1.0 ?m, an average nanohardness of the above-described bainite is 4.0 GPa to 5.0 GPa, and MX-type carbides each having a circle-equivalent diameter of 10 nm or more exist with an average grain spacing of 300 nm or less therebetween.
    Type: Application
    Filed: August 21, 2013
    Publication date: April 9, 2015
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kaori Kawano, Yasuaki Tanaka, Masahito Tasaka, Yoshiaki Nakazawa, Toshiro Tomida
  • Publication number: 20150090377
    Abstract: A steel sheet for hot pressing use according to the present invention has a specified chemical component composition, wherein some of Ti-containing precipitates contained in the steel sheet, each of which having an equivalent circle diameter of 30 nm or less, have an average equivalent circle diameter of 6 nm or less, the precipitated Ti amount and the total Ti amount in the steel fulfill the relationship represented by formula (1) shown below, and the sum total of the fraction of bainite and the fraction of martensite in the metal microstructure is 80 area % or more. Precipitated Ti amount (mass %)?3.4[N]?0.5×[(total Ti amount (mass %))?3.4[N]]??(1) (In the formula (1), [N] represents the content (mass %) of N in the steel.
    Type: Application
    Filed: March 1, 2013
    Publication date: April 2, 2015
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Toshio Murakami, Junya Naitou, Keisuke Okita, Shushi Ikeda
  • Patent number: 8986468
    Abstract: A cold rolled steel sheet satisfying on the basis of percent by mass the chemical composition of 0.06-0.6% C, 0.1-2% Si, 0.01-3% Al, 1-4% Si+Al, 1-6% Mn, Si/Mn?0.40, in which there exists 10 or more pieces/100 ?m2 of Mn—Si composite oxide having Mn—Si atom ratio (Mn/Si) of 0.5 or over and major axis of from 0.01 ?m to 5 ?m and also having a covering ratio of 10% or below at which the surface of the steel sheet is covered with oxide containing Si as the main component.
    Type: Grant
    Filed: March 23, 2006
    Date of Patent: March 24, 2015
    Assignee: Kobe Steel, Ltd.
    Inventors: Masaaki Miura, Shinji Kozuma, Yoichi Mukai, Yoshinobu Omiya
  • Publication number: 20150071811
    Abstract: A dual phase or complex phase steel strip showing no tigerstripes. The steel strip includes, in mass percent, the following elements: C 0.08-0.11%; Mn 1.70-2.20%; Si at most 0.1%; Cr 0.40-0.70%; Mo at most 0.3%; Ni at most 1.0%, Al 0.01-1.50%; Nb at most 0.07%; P equal to or more than 0.005%; N equal to or less than 0.015%; Ti equal to or less than 0.1%; V equal to or less than 0.1%; B equal to or less than 0.01%; wherein the sum of Cr, Mo and Ni is at least 0.5%; the balance being Fe and inevitable impurities.
    Type: Application
    Filed: April 5, 2013
    Publication date: March 12, 2015
    Inventors: Egbert Jansen, Edward Anton Frederik Span, Richard Mostert, Theo Arnold Kop
  • Publication number: 20150071812
    Abstract: A steel material having a chemical composition of, by mass %, C: greater than 0.05% to 0.2%, Mn: 1% to 3%, Si: greater than 0.5% to 1.8%, Al: 0.01% to 0.5%, N: 0.001% to 0.015%, Ti or a sum of V and Ti: greater than 0.1% to 0.25%, Ti: 0.001% or more, Cr: 0% to 0.25%, Mo: 0% to 0.35%, and a balance: Fe and impurities, includes a steel structure being a multi-phase structure having a main phase made of ferrite of 50 area % or more, and a second phase containing one or two or more selected from a group consisting of bainite, martensite and austenite, in which an average nanohardness of the above-described second phase is less than 6.
    Type: Application
    Filed: July 22, 2013
    Publication date: March 12, 2015
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kaori Kawano, Masahito Tasaka, Yoshiaki Nakazawa, Yasuaki Tanaka, Toshiro Tomida
  • Publication number: 20150064497
    Abstract: A dual phase or complex phase steel strip showing no tigerstripes. The steel strip having an ultimate tensile strength Rm classifying for 1000 MPa steel category, includes (in mass percent) C 0.09-0.19%; Mn 1.9-2.6%; Si at most 0.1%; Cr 0.4-0.8%; Mo at most 0.3%; Ni at most 0.4%; Al 0.02-1.3%; and optionally one or more of the following elements: Nb at most 0.08%; P equal to or more than 0.0005%; N equal to or less than 0.015%; Ti equal to or less than 0.1%; V equal to or less than 0.1%; B equal to or less than 0.01%; wherein the sum of Cr, Mo and Ni is at least 0.5%; the balance being Fe and inevitable impurities.
    Type: Application
    Filed: April 5, 2013
    Publication date: March 5, 2015
    Applicant: TATA Steel IJMUIDEN BV
    Inventors: Egbert Jansen, Edward Anton Frederik Span, Richard Mostert, Theo Arnold Kop
  • Publication number: 20150047752
    Abstract: A high strength interstitial free low density steel and method for producing the steel.
    Type: Application
    Filed: April 10, 2013
    Publication date: February 19, 2015
    Applicant: TATA STEEL NEDERLAND TECHNOLOGY B.V.
    Inventors: Cheng Liu, Radhakanta Rana
  • Publication number: 20150027597
    Abstract: This invention relates to a high strength bake-hardenable low density steel and to a method for producing said the steel.
    Type: Application
    Filed: February 19, 2013
    Publication date: January 29, 2015
    Applicant: TATA STEEL NEDERLAND TECHNOLOGY BV
    Inventors: Cheng Liu, Radhakanta Rana
  • Publication number: 20150027602
    Abstract: A steel sheet for hot pressing use according to the present invention has a specified chemical component composition, wherein some of Ti-containing precipitates contained in the steel sheet, each of which having an equivalent circle diameter of 30 nm or less, have an average equivalent circle diameter of 3 nm or more, the precipitated Ti amount and the total Ti amount in the steel fulfill the relationship represented by formula (1) shown below, and the sum total of the fraction of bainite and the fraction of martensite in the metal microstructure is 80 area % or more. Precipitated Ti amount (mass %)?3.4[N]>0.5×[total Ti amount (mass %)?3.4[N]]??(1) (In the formula (1), [N] represents the content (mass %) of N in the steel.
    Type: Application
    Filed: March 1, 2013
    Publication date: January 29, 2015
    Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (Kobe Steel, Ltd.)
    Inventors: Toshio Murakami, Junya Naitou, Keisuke Okita, Shushi Ikeda
  • Publication number: 20150030882
    Abstract: The invention relates to a steel plate, the chemical composition of which comprises, the contents being expressed by weight: 0.010%?C?0.20%, 0.06%?Mn?3%, Si?1.5%, 0.005%?Al?1.5%, S?0.030%, P?0.040%, 2.5%?Ti?7.2%, (0.45×Ti)?0.35%?B?(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni?1%, Mo?1%, Cr?3%, Nb?0.1%, V?0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.
    Type: Application
    Filed: October 14, 2014
    Publication date: January 29, 2015
    Inventors: Frederic BONNET, Olivier BOUAZIZ, Jean-Claude CHEVALLOT
  • Publication number: 20150023834
    Abstract: A hot-rolled steel sheet including, in terms of % by mass, 0.030% to 0.120% of C, 1.20% or less of Si, 1.00% to 3.00% of Mn, 0.01% to 0.70% of Al, 0.05% to 0.20% of Ti, 0.01% to 0.10% of Nb, 0.020% or less of P, 0.010% or less of S, and 0.005% or less of N, and a balance consisting of Fe and impurities, in which 0.106?(C %-Ti %*12/48-Nb %*12/93)>0.012 is satisfied; a pole density of {112}(110) at a position of ¼ plate thickness is 5.7 or less; an aspect ratio (long axis/short axis) of prior austenite grains is 5.3 or less; a density of (Ti, Nb)C precipitates having a size of 20 nm or less is 109 pieces/mm3 or more; a yield ratio YR, which is the ratio of a tensile strength to a yield stress, is 0.80 or more; and a tensile strength is 590 MPa or more.
    Type: Application
    Filed: January 8, 2013
    Publication date: January 22, 2015
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Eisaku Sakurada, Kunio Hayashi, Koichi Sato, Shunji Hiwatashi
  • Publication number: 20150020992
    Abstract: A non-scaling heat-treatable steel with particular suitability for producing hardened or die-hardened components is disclosed, characterized by the following chemical composition in % by weight: C 0.04-0.50; Mn 0.5-6.0; Al 0.5-3.0; Si 0.05-3.0; Cr 0.05-3.0; Ni less than 3.0; Cu less than 3.0; Ti 0.010-?0.050; B 0.0015-?0.0040; P less than 0.10; S less than 0.05; N less than 0.020; remainder iron and unavoidable impurities. Further disclosed is a method for producing a non-scaling hardened component from the steel and a method for producing a hot strip from a steel.
    Type: Application
    Filed: March 19, 2013
    Publication date: January 22, 2015
    Inventors: Joachim Schöttler, Friedrich Luther, Stefan Mütze
  • Publication number: 20140377124
    Abstract: Disclosed are a non-oriented electrical steel plate with low iron loss and high magnetic conductivity and a manufacturing process therefor. The casting blank of the steel plate comprises the following components: Si: 0.1-2.0 wt %, Al: 0.1-1.0 wt %, Mn: 0.10-1.0 wt %, C: ?0.005 wt %, P: ?0.2 wt %, S: ?0.005 wt %, N: ?0.005 wt %, the balance being Fe and unavoidable impurities. The magnetic conductivity of the steel plate meets the following relationship formula: ?10+?13+?15?13982?586.5P15/50; ?10+?13+?15?10000, wherein P15/50 is the iron loss at a magnetic induction intensity of 1.5 T at 50 Hz; ?10, ?13, and ?15 are relative magnetic conductivities at induction intensities of 1.0 T, 1.3 T, and 1.5 T at 50 Hz, respectively. The steel plate can be used for manufacturing highly effective and ultra-highly effective electric motors.
    Type: Application
    Filed: March 27, 2012
    Publication date: December 25, 2014
    Applicant: BAOSHAN IRON & STEEL CO., LTD.
    Inventors: Aihua Ma, Bo Wang, Xiandong Liu, Liang Zou, Shishu Xie, Hongxu Hei
  • Publication number: 20140377123
    Abstract: The present invention is a weld metal formed by gas shielded arc welding using a flux cored wire, the welded metal having a predetermined chemical composition, residual austenite particles being present in an amount of at least 2500 particles/mm2, and the volume fraction of residual austenite particles being at least 4.0%.
    Type: Application
    Filed: February 25, 2013
    Publication date: December 25, 2014
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd)
    Inventors: Hidenori Nako, Takuya Kochi, Wataru Urushihara, Munenobu Sato, Yoshihiko Kitagawa
  • Publication number: 20140338797
    Abstract: Steel with high strength and good formability is produced with compositions and methods for forming austenitic and martensitic microstructure in the steel. Carbon, manganese, molybdenum, nickel copper and chromium may promote the formation of room temperature stable (or meta-stable) austenite by mechanisms such as lowering transformation temperatures for non-martensitic constituents, and/or increasing the hardenability of steel. Thermal cycles utilizing a rapid cooling below a martensite start temperature followed by reheating may promote formation of room temperature stable austenite by permitting diffusion of carbon into austenite from martensite.
    Type: Application
    Filed: May 16, 2014
    Publication date: November 20, 2014
    Inventors: Grant A. Thomas, Jose Mauro B. Losz
  • Publication number: 20140338798
    Abstract: Steel with high strength and good formability is produced with compositions and methods for forming austenitic and martensitic microstructure in the steel. Carbon, manganese, molybdenum, nickel copper and chromium may promote the formation of room temperature stable (or meta-stable) austenite by mechanisms such as lowering transformation temperatures for non-martensitic constituents, and/or increasing the hardenability of steel. Thermal cycles utilizing a rapid cooling below a martensite start temperature followed by reheating may promote formation of room temperature stable austenite by permitting diffusion of carbon into austenite from martensite.
    Type: Application
    Filed: May 16, 2014
    Publication date: November 20, 2014
    Inventors: Grant A. Thomas, Luis G. Garza-Martinez
  • Publication number: 20140334966
    Abstract: A hot-rolled steel sheet for nitriding or a cold-rolled steel sheet for nitriding excellent in fatigue strength contains a steel particularly containing appropriate amounts of Cr, V, and B, in which a dislocation density within 50 ?m in the sheet thickness direction from the surface is not less than 2.0 times nor more than 10.0 times as compared to a dislocation density at the position of ¼ in the sheet thickness direction, its manufacturing method includes: on a hot-rolled steel sheet or a cold-rolled steel sheet having the previously described components, performing pickling; and then performing skin pass rolling under the condition that a reduction ratio is 0.5 to 5.
    Type: Application
    Filed: November 19, 2012
    Publication date: November 13, 2014
    Inventors: Eisaku Sakurada, Shunji Hiwatashi, Kunio Hayashi, Shinichi Suzuki
  • Patent number: 8876986
    Abstract: Disclosed is a high-strength cold-rolled steel sheet having improved stretch-flange formability and excellent hydrogen embrittlement resistance. In addition to Fe, C, Si, Mn, P, S, N, and Al, the steel sheet contains V or at least one element of Nb, Ti and Zr. The contents of the at least one element of Nb, Ti and Zr, if present, satisfy the expression of [% C]?[% Nb]/92.9×12?[% Ti]/47.9×12?[% Zr]/91.2×12>0.03. The steel sheet has an area ratio of tempered martensite of 50% or more with ferrite as the remainder. The number of precipitates having a circle-equivalent diameter of 1 to 10 nm is 20 particles or more per 1 ?m2 of the tempered martensite. The number of precipitates containing V or the at least one element of Nb, Ti and Zr and having a circle-equivalent diameter of 20 nm or more is 10 particles or less per 1 ?m2 of the tempered martensite.
    Type: Grant
    Filed: October 1, 2009
    Date of Patent: November 4, 2014
    Assignee: Kobe Steel, Ltd.
    Inventors: Hideo Hata, Toshio Murakami, Akira Ibano, Fumio Yuse, Junichiro Kinugasa
  • Patent number: 8864922
    Abstract: A method for manufacturing a precipitation hardening cold-rolled steel sheet with an excellent yield ratio. The method may include the steps of hot rolling a steel slab with finish rolling at a temperature of Ar3 transformation point or more to form a hot-rolled steel sheet, coiling the hot-rolled steel sheet at a temperature of 550-600 ° C., cold rolling the hot-rolled steel sheet at a reduction ratio of 50% or more; and recovery-recrystallization annealing the cold-rolled steel sheet at a line speed of 150-200 mpm and at a temperature of 780-820° C. in a continuous annealing furnace. The recovery-recrystallization annealing may provide a recrystallization ratio of 65-75%. The steel slab includes, by weight %: C: 0.07-0.10%, Mn: 1.41-1.70%, P: 0.05-0.07%, S: 0.005% or less, N: 0.005% or less, acid-soluble Al: 0.10-0.15%, Nb: 0.06-0.09%, B: 0.0008-0.0012%, Sb: 0.02-0.06%, and the balance comprising Fe and other unavoidable impurities.
    Type: Grant
    Filed: March 1, 2013
    Date of Patent: October 21, 2014
    Assignee: POSCO
    Inventor: Sang-Ho Han
  • Publication number: 20140308156
    Abstract: Provided are a steel sheet for warm press forming that can have high strength, good elongation, and thus improved crashworthiness after being warm pressed, and a warm-pressed member formed of the steel sheet, and manufacturing methods thereof. The steel sheet for warm press forming includes, by weight %, C: 0.01% to 0.5%, Si: 3.0% or less (excluding 0%), Mn: 3% to 15%, P: 0.0001% to 0.1%, S: 0.0001% to 0.03%, Al: 3.0% or less (excluding 0%), N: 0.03% or less (excluding 0%), and the balance of Fe and inevitable impurities.
    Type: Application
    Filed: November 5, 2012
    Publication date: October 16, 2014
    Inventors: Jin-Keun Oh, Kyoo-Young Lee, Yeol-Rae Cho, Eul-Yong Choi, Ki-Soo Kim
  • Patent number: 8852360
    Abstract: This high strength hot-rolled steel sheet includes: in terms of percent by mass, C: 0.05 to 0.12%; Si: 0.8 to 1.2%; Mn: 1.6 to 2.2%; Al: 0.30 to 0.6%; P: 0.05% or less; S: 0.005% or less; and N: 0.01% or less, with the remainder being Fe and unavoidable impurities, wherein a microstructure includes specific ranges (in area %) of ferrite phases as well as martensite phases, and a maximum concentration of Al detected by a glow discharge emission spectroscopic analysis is in a range of 0.75 mass % or less in a region from a surface of the steel sheet to a thickness of 500 nm after being acid-pickled.
    Type: Grant
    Filed: November 16, 2010
    Date of Patent: October 7, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Hiroyuki Tanahashi, Shinya Saitoh, Masashi Fukuda, Hiroyuki Okada, Kunio Hayashi, Toshimasa Tomokiyo, Nobuhiro Fujita
  • Patent number: 8828153
    Abstract: A high-strength cold-rolled steel sheet providing a product with a good surface condition after press forming, having excellent bake hardenability and anti room temperature aging property, and having a dual phase structure with a tensile strength of at least 340 MPa is provided. A high-strength cold-rolled steel sheet has a structure comprising a main phase which is a ferrite and a secondary phase which is a low temperature transformation product including a martensite and has a hardness distribution of the ferrite phase in an arbitrary cross section having a length of 10 mm in the widthwise 10 direction of the sheet which satisfies the relationship prescribed by (HV(max)?HV(ave))<0.5×(Hv(ave). HV(max) is the maximum Vickers hardness of ferrite grains in a region at a distance of from (?)t to (¼)t in the thickness direction from the surface when the thickness of the high-strength cold-rolled steel sheet is t, and Hv(ave) is the average Vickers hardness of ferrite grains in this region.
    Type: Grant
    Filed: December 8, 2010
    Date of Patent: September 9, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Jun Haga, Nobusato Kojima
  • Publication number: 20140241933
    Abstract: A high-strength cold-rolled steel sheet excellent in ductility, work hardenability, and stretch flangeability, and having tensile strength of 780 MPa or more includes: a chemical composition containing, in mass percent, C: more than 0.020% to less than 0.30%, Si: more than 0.10% to 3.00% or less, Mn: more than 1.00% to 3.50% or less; and metallurgical structure whose main phase is a low-temperature transformation product, and whose secondary phase contains retained austenite. The retained austenite has a volume fraction relative to overall structure of more than 4.0% to less than 25.0% and an average grain size of less than 0.80 ?m, and of the retained austenite, the number density of retained austenite grains whose grain size is 1.2 ?m or more is 3.0×10?2 grains/?m2 or less.
    Type: Application
    Filed: June 27, 2012
    Publication date: August 28, 2014
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Jun Haga, Takuya Nishio, Masayuki Wakita, Yasuaki Tanaka, Norio Imai, Toshiro Tomida
  • Patent number: 8815025
    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: Grant
    Filed: November 3, 2006
    Date of Patent: August 26, 2014
    Assignees: JFE Steel Corporation, ThyssenKrupp Steel AG
    Inventors: Takeshi Yokota, Akio Kobayashi, Kazuhiro Seto, Yoshihiro Hosoya, Thomas Heller, Brigitte Hammer, Rolf Bode, Günter Stich
  • Publication number: 20140227127
    Abstract: This oriented electrical steel sheet is a non-oriented electrical steel sheet consisting of, in mass %: C: not less than 0.0001% and not more than 0.0040%, Si: more than 3.0% and not more than 3.7%, sol.Al: not less than 0.3% and not more than 1.0%, Mn: not less than 0.5% and not more than 1.5%, Sn: not less than 0.005% and not more than 0.1%, Ti: not less than 0.0001% and not more than 0.0030%, S: not less than 0.0001% and not more than 0.0020%, N: not less than 0.0001% and not more than 0.003%, Ni: not less than 0.001% and not more than 0.2%, P: not less than 0.005% and not more than 0.05%, with a balance consisting of Fe and impurities, in which a resistivity ? at room temperature ?60 ??cm, and saturation magnetic flux density Bs at room temperature ?1.945 T are established, and the components contained satisfy 3.5?Si+(?)×sol.Al+(?)×Mn?4.25.
    Type: Application
    Filed: March 27, 2013
    Publication date: August 14, 2014
    Inventors: Yoshiaki Natori, Kenichi Murakami, Takeaki Wakisaka, Hisashi Mogi, Takuya Matsumoto, Tomoji Shono, Tatsuya Takase, Junichi Takaobushi
  • Patent number: 8802005
    Abstract: The present invention is steel for surface hardening for machine structural use which contains, by mass %, C: 0.3 to 0.6%, Si: 0.02 to 2.0%, Mn: 0.35 to less than 1.5%, and Al: 0.01 to 0.5%, is restricted to B: less than 0.0003%, S: 0.0001 to 0.021%, N: 0.003 to 0.0055%, P: 0.0001 to 0.03%, and O: 0.0001 to 0.0050%, has a ratio Mn/S of Mn and S satisfying 70 to 30,000, has a balance of Fe and unavoidable impurities, and, when nitrided, then induction hardened, has a surface hardenability of a Vicker's hardness when tempered at 300° C. of 650 or more.
    Type: Grant
    Filed: January 15, 2010
    Date of Patent: August 12, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Atsushi Mizuno, Masayuki Hashimura, Kei Miyanishi, Shuji Kozawa
  • Publication number: 20140213375
    Abstract: The invention relates to a method of producing a martensitic steel comprising a content of other metals such that it can be hardened by intermetallic compound and carbide precipitation, with an Al content of between 0.4% and 3%. The heat shaping temperature of the last heat shaping pass of said steel is lower than the solubility temperature of the aluminum nitrides in the steel, and the treatment temperature for each potential heat treatment after said last heat shaping pass is lower than the solid-state solubility temperature of the aluminum nitrides in said steel.
    Type: Application
    Filed: July 16, 2013
    Publication date: July 31, 2014
    Applicants: Aubert & Duval, SNECMA
    Inventors: Laurent FERRER, Philippe Heritier
  • Publication number: 20140205488
    Abstract: A cold rolled, annealed TRIP steel sheet which has a composition including (in wt. %): C: 0.1-0.3; Mn: 4-10, Al: 0.05-5, Si: 0.05-5; and Nb: 0.008-0.1, the remainder being iron and inevitable residuals. The cold rolled sheet has an ultimate tensile strength of at least 1000 MPa, and a total elongation of at least 15%. The cold rolled sheet may have at least 20% retained austenite in its microstructure and may have greater than 50% lath-type annealed ferrite structure. The cold rolled sheet may have an ultra fine grain size of less than 5 micron for the retained austenite and ferrite.
    Type: Application
    Filed: January 22, 2013
    Publication date: July 24, 2014
    Inventors: Hyun Jo Jun, Narayan Subramaniam Pottore, Nina Michailovna Ponstein, Oleg N. Yakubovsky
  • Publication number: 20140150930
    Abstract: The present invention relates to a hot press forming steel plate made of a composition comprising: 0.3-1.0 wt % of C; 0.0-4.0 wt % of Mn; 1.0-2.0 wt % of Si; 0.01-2.0 wt % of Al; 0.015 wt % or less of S; 0.01 wt % or less of N; and the remainder being Fe and unavoidable impurities. Further, the present. invention relates to a method for manufacturing the hot press forming steel plate, characterized by comprising the steps of: heating, to between 1100 and 1300° C., a steel slab having the composition; performing hot rolling finishing between. an Ar3 transformation point and 950° C.; and performing winding between MS and 720° C. Further, the present invention. relates to a hot press formed member characterized by having the composition, and having a dual phase microstructure made of bainite and residual austenite.
    Type: Application
    Filed: July 15, 2011
    Publication date: June 5, 2014
    Inventors: Kyoo-Young Lee, Jin-Keun Oh, Jong-Sang Kim, Tae-Kyo Han
  • Publication number: 20140150249
    Abstract: A semi-processed electrical steel is provided comprising the elements .005 ? Tin ? .09% 0 < Carbon ? 0.050% .10 ? Manganese ? 1.00% .005 ? Phosphorus ? .120% .0 < Sulfur ? .010% .50 ? Silicon ? 2.50% .01 ? Aluminum ? 1.60% .0 ? Antimony < .
    Type: Application
    Filed: December 3, 2012
    Publication date: June 5, 2014
    Inventor: Gwynne Johnston
  • Patent number: 8709336
    Abstract: The invention concerns a method for making an abrasion resistant steel plate having a chemical composition comprising: 0.35%?C?0.8%, 0%?Si?2%, 0%?Al?2%, 0.35%?Si+Al?2%, 0%?Mn?2.5%, 0%?Ni?5%, 0%?Cr?5%, 0%?Mo?0.50%, 0%?W?1.00%, 0.1%?Mo+W/2?0.50%, 0%?B?0.02%, 0%?Ti?2%, 0%?Zr?4%, 0.05%?Ti+Zr/2?2%, 0%?S?0.15%, N<0.03%; optionally from 0% to 1.5% of Cu; optionally Nb, Ta or V with Nb/2+Ta/4+V?0.5%; optionally less than 0.1% of Se, Te, Ca, Bi or Pb; the rest being iron and impurities; the composition satisfying: 0.1%?C*=C?Ti/4?Zr/8+7×N/8?0.55% and 1.05×Mn+0.54×Ni+0.50×Cr+0.3×(Mo+W/2)1/2+K>1.8, with K=0.5 if B?0.0005% and K=0 if B<0.0005% and Ti+Zr/2?7×N/2?0.05%; hardening after austenitization while cooling at a speed>0.5° C./s between a temperature>AC3 and ranging between T=800?270×C*?90×Mn?37×Ni?70×Cr?83×(Mo+W/2) and T?50° C.; then at a core speed Vr<115×ep?1.7 between T and 100° C., (ep=plate thickness in mm); cooling down to room temperature. The invention also concerns the resulting plate.
    Type: Grant
    Filed: June 17, 2008
    Date of Patent: April 29, 2014
    Assignee: Industeel Creusot
    Inventors: Jean Beguinot, Jean-Georges Brisson
  • Publication number: 20140083574
    Abstract: Disclosed are heat-hardened steel with excellent crashworthiness and a method for manufacturing heat-hardenable parts using the same. The heat-hardened steel according to the invention comprises, based on wt %; C: 0.12-0.8%; Cr: 0.01-2%; Mo: 0.2% or less; B: 0.0005-0.08%; Ca: 0.01 or less; Sb: 1.0% or less; and Ti and/or Nb: 0.2%; and the reminder being Fe and inevitable impurities. In addition, the heat-treatment hardening steel satisfies anyone of following conditions i)-iv), wherein condition i) comprises Si: 0.5-3%; Mn: 1-10% and Al: 0.05-2%; condition ii) comprises Si: 1% or less; Mn: 0.5-5%; Al: 0.1-2.5%; and Ni: 0.01-8%; condition iii) comprises Si: 0.5-3%; Mn: 1-10%; Al: 0.1% or less; and Ni: 0.01-8%; and condition iv) comprises Si: 0.5-3%; Mn: 1-10%; Al: 0.1-2.5%; and Ni: 0.01-8%.
    Type: Application
    Filed: June 30, 2011
    Publication date: March 27, 2014
    Applicant: Hyundai Hysco Co.,Ltd.
    Inventors: Seung-Man Nam, Hee-Joong Im, Seung-Ha Lee, Dong-Eun Kim, Bo-Ryong Lee, Young-Jin Kim, Man-Been Man-Been
  • Publication number: 20140065316
    Abstract: Disclosed herein are iron-based alloys having a microstructure comprising a fine-grained ferritic matrix and having a 60+ Rockwell C surface, wherein the ferritic matrix comprises <20 ?m Nb and W carbide precipitates. Also disclosed are methods of welding comprising forming a crack free hardbanding weld overlay coating with such an iron-based alloy. Also disclosed are methods of designing an alloy capable of forming a crack free hardbanding weld overlay, the methods comprising the steps of determining an amorphous forming epicenter composition, determining a variant composition having a predetermined change in constituent elements from the amorphous forming epicenter composition, and forming and analyzing an alloy having the variant composition.
    Type: Application
    Filed: August 22, 2013
    Publication date: March 6, 2014
    Applicant: Scoperta, Inc.
    Inventors: Justin Lee Cheney, John Hamilton Madok
  • Publication number: 20140044987
    Abstract: A steel sheet for a hot stamping member contains, as a chemical composition, 0.10 mass % to 0.35 mass % of C; 0.01 mass % to 1.0 mass % of Si; 0.3 mass % to 2.3 mass % of Mn; 0.01 mass % to 0.5 mass % of Al; limited to 0.03 mass % or less of P; limited to 0.02 mass % or less of S; limited to 0.1 mass % or less of N; and a balance consisting of Fe and unavoidable impurities, in which a standard deviation of diameters of iron carbides which are contained in a region from a surface to a ¼ thickness position of the steel sheet is less than or equal to 0.8 ?m.
    Type: Application
    Filed: April 26, 2012
    Publication date: February 13, 2014
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hiroyuki Tanahashi, Jun Maki
  • Patent number: 8641835
    Abstract: An iron alloy according to the present invention comprises: Al in an amount of from 3 to 5.5%; Mn in an amount from 0.2 to 6%; and the balance being iron (Fe), and inevitable impurities and/or a modifying element; when the entirety is taken as 100%. Since a high damping factor is obtainable at a low-strain amplitude, this iron alloy demonstrates a stable damping property even in a high-temperature region. Moreover, since the alloying elements are Al and Mn alone, and since their contents are less, the iron alloy according to the present invention is low in cost.
    Type: Grant
    Filed: September 8, 2009
    Date of Patent: February 4, 2014
    Assignee: Kabushiki Kaisha Toyota Jidoshokki
    Inventors: Keita Yamana, Motoharu Tanizawa, Masanori Harata, Kyoichi Kinoshita
  • Publication number: 20140000770
    Abstract: A tool steel family with outstanding thermal diffusivity, hardness and wear resistance has been developed, also exhibiting good hardenability. Also its mechanical strength, as well as its yield strength, at ambient and high temperature (superior to 600° C.) are high, due to a high alloying level in spite of the high thermal conductivity. Because of its high thermal conductivity and good toughness, steels of this invention have also good resistance to thermal fatigue and thermal shock. This steels are ideal for discontinuous processes where it is interesting to reduce cycle time and that require high hardness and/or wear resistance (plastic injection molding, other plastic forming processes and curing of thermosets, hot forming of sheet . . . ). These tool steels are also appropriate for processes requiring high wear resistance and good resistance to thermal fatigue (forging, hot stamping, light-alloy injection . . . ).
    Type: Application
    Filed: January 13, 2012
    Publication date: January 2, 2014
    Applicant: ROVALMA, S.A.
    Inventor: Isaac Valls Anglés
  • Publication number: 20140003752
    Abstract: Steel for a high temperature joining process suitable, in particular for components intended for applications with high demands on fatigue and toughness properties, such as bearing components, comprising the following composition in weight-%: 0.5-0.8 C, 0- 0.15 Si, 0-1.0 Mn, 0.01-2.0 Cr, 0.01-1.0 Mo, 0.01-2.0 Ni, 0.01-1.0 of V or 0.01-1.0 of Nb, or 0.01-1.0 of both V and Nb, 0-0.002 S, 0-0.010 P, 0-0.15 Cu, 0.010-1.0 Al, the remainder being Fe and normally occurring impurities.
    Type: Application
    Filed: December 6, 2011
    Publication date: January 2, 2014
    Inventor: Thore Lund
  • Publication number: 20130323112
    Abstract: In a hot-rolled sheet, an average value of pole densities of an orientation group {100}<011> to {223}<110>, which is represented by an arithmetic mean of pole densities of orientations {100}<011>, {116}<110>, {114}<110>, {112}<110>, and {223}<110> in a thickness center portion of a thickness range of ? to ? from a surface of the steel sheet, is 1.0 to 6.5 and a pole density of a crystal orientation {332}<113> is 1.0 to 5.0; and a Lankford value rC in a direction perpendicular to a rolling direction is 0.70 to 1.10 and a Lankford value r30 in a direction that forms 30° with respect to the rolling direction is 0.70 to 1.10.
    Type: Application
    Filed: March 5, 2012
    Publication date: December 5, 2013
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Riki Okamoto, Nobuhiro Fujita, Manabu Takahashi, Kunio Hayashi, Tetsuo Kishimoto, Kazuaki Nakano, Takeshi Yamamoto
  • Publication number: 20130295402
    Abstract: Provided is a steel sheet for a formed member having enhanced ductility, a formed member, and a method for manufacturing the formed member, and more particularly, to a steel sheet for making a formed member having high strength and ductility such as an automotive structural member and a reinforcing member, a formed member, and a method for manufacturing the formed member. The steel sheet for a formed member has enhanced ductility, and includes, by weight %, C: 0.1% to 1.0%, Si+Al: 0.4% to 3.0%, Mn: 0.1% to 5.0%, P: 0.0001% to 0.1%, S: 0.0001% to 0.03%, N: 0.03% or less (but not 0%), and the balance of Fe and inevitable impurities. The formed member having high strength and ductility that can be used for forming an automotive structural member, a reinforcing member, etc. In addition, the formed member can be used for a heat-treatable impact resistant member.
    Type: Application
    Filed: December 14, 2011
    Publication date: November 7, 2013
    Applicant: POSCO
    Inventors: Jin-Keun Oh, Jai-Hyun Kwak, Yeol-Rae Cho, Ki-Soo Kim
  • Publication number: 20130284321
    Abstract: A multi-phase steel including in % wt. C: 0.14-0.25%, Mn: 1.7-2.5%, Si: 0.2-0.7%, Al: 0.5-1.5%, Cr: <0.1%, Mo: <0.05%, Nb: 0.02-0.06%, S: up to 0.01%, P: up to 0.02%, N: up to 0.01% and optionally at least one of Ti, B, and V according to the following stipulation: Ti: up to 0.1%, B: up to 0.002%, V: up to 0.15%, with the remainder iron and unavoidable impurities, wherein the microstructure has at least 10% vol. ferrite and at least 6% vol. residual austenite and the steel has a tensile strength Rm of at least 950 MPa, a yield point ReL of at least 500 MPa and an elongation at break A80 measured in the transverse direction of at least 15%. A method of producing the multi-phase steel.
    Type: Application
    Filed: September 22, 2011
    Publication date: October 31, 2013
    Applicant: THYSSENKRUPP STEEL EUROPE AG
    Inventors: Ekaterina Bocharova, Dorothea Mattissen, Roland Sebald, Daniel Krizan, Andreas Pichler
  • Publication number: 20130224064
    Abstract: A non-oriented electrical steel sheet without corrugated defect and a manufacturing method thereof is provided, the weight percentage of the chemical composition of the non-oriented electrical steel sheet is that C is no more than 0.005%, Si is 1.2-2.2%, Mn is 0.2-0.4%, P is no more than 0.2%, S is no more than 0.005%, Al is 0.2-0.6%, N is no more than 0.005%, O is no more than 0.005%, and a balance substantially being Fe, a slab can be obtained by hot metal preprocessing, smelting with converter, RH refining, and continuous casting and pouring, wherein a secondary cooling water amount is controlled, the water flowrate of cooling water is controlled to 100-190 l/min, the average superheat of liquid steel in the continuous casting process is controlled to 10-45° C., the slab is heated and hot rolled; wherein the furnace tap temperature of the slab is 1050-1150 ° C., the temperature difference between random two points in the length direction when the slab is heated, is lower than 25° C.
    Type: Application
    Filed: April 14, 2011
    Publication date: August 29, 2013
    Inventors: Feng Zhang, Xiao Chen, Wei Cao, Yezhong Sun, Changsong Ma, Jianru Zhu, Zhuolei Chen, Xiandong Liu
  • Publication number: 20130183192
    Abstract: Embodiments of the present invention comprises melting scrap steel into molten steel; decarburizing the molten steel and adding alloys; transferring the steel to ladles and casting the steel into slabs; hot rolling the slabs into sheets; pickling the sheets; annealing the sheets; cold rolling the sheets; and performing one or more of tension leveling, a rough rolling, or a coating process on the sheets after cold rolling, without an intermediate annealing process between the cold rolling and the tension leveling, the rough rolling, or the coating process. The sheet is sent to the customer for stamping and customer annealing. The new process provides an electrical steel with the similar, same, or better magnetic properties than an electrical steel manufactured using the traditional processing with an intermediate annealing step after cold rolling.
    Type: Application
    Filed: January 11, 2013
    Publication date: July 18, 2013
    Applicant: Nucor Corporation
    Inventors: Theodore E. Hill, Eric E. Gallo
  • Publication number: 20130174942
    Abstract: The invention relates to a steel plate, the chemical composition of which comprises, the contents being expressed by weight: 0.010%?C?0.20%, 0.06%?Mn?3%, Si?1.5%, 0.005%?Al?1.5%, S?0.030%, P?0.040%, 2.5%?Ti?7.2%, (0.45×Ti)?0.35%?B?(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni?1%, Mo?1%, Cr?3%, Nb?0.1%, V?0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.
    Type: Application
    Filed: June 25, 2010
    Publication date: July 11, 2013
    Applicant: ArcelorMittal France
    Inventors: Frederic BONNET, Olivier BOUAZIZ, Laure CALA
  • Patent number: 8475605
    Abstract: In the steel for a surface layer hardening which is treated with carburizing in a temperature range of 800° C. to 900° C., chemical composition thereof contains, by mass %, C: 0.10% to 0.60%, Si: 0.01% to 2.50%, Mn: 0.20% to 2.00%, S: 0.0001% to 0.10%, Cr: 2.00% to 5.00%, Al: 0.001% to 0.50%, N: 0.0020% to 0.020%, P: 0.001% to 0.050%, and O: 0.0001% to 0.0030%; the remaining portion thereof includes Fe and unavoidable impurities; and the total amount of Cr, Si, and Mn satisfies, by mass %, 2.0?Cr+Si+Mn?8.0.
    Type: Grant
    Filed: February 18, 2011
    Date of Patent: July 2, 2013
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Manabu Kubota, Tatsuro Ochi
  • Publication number: 20130153091
    Abstract: A hot-rolled steel sheet has an average value of the X-ray random intensity ratio of a {100} <011> to {223} <110> orientation group at least in a sheet thickness central portion that is in a sheet thickness range of ? to ? from a steel sheet surface of 1.0 to 6.0, an X-ray random intensity ratio of a {332} <113> crystal orientation of 1.0 to 5.0, rC which is an r value in a direction perpendicular to a rolling direction of 0.70 to 1.10, and r30 which is an r value in a direction that forms an angle of 30° with respect to the rolling direction of 0.70 to 1.10.
    Type: Application
    Filed: July 27, 2011
    Publication date: June 20, 2013
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Nobuhiro Fujita, Kunio Hayashi, Riki Okamoto, Manabu Takahashi, Tetsuo Kishimoto, Hiroshi Yoshida