With Additional Nonworking Heating Step Patents (Class 148/653)
  • Patent number: 11692259
    Abstract: Provided are a hot-dip zinc plated steel material and a method for preparing same, the hot-dip zinc plated steel material comprising: base iron comprising 0.01-1.6 wt % of Si and 1.2-3.1 wt % of Mn; a Zn—Al—Mg alloy plating layer; and an Al-rich layer formed on the interface of the base iron and Zn—Al—Mg alloy plating layer, wherein the rate of occupied surface area of the Al-rich layer is 70% or higher (including 100%).
    Type: Grant
    Filed: March 15, 2022
    Date of Patent: July 4, 2023
    Assignee: POSCO
    Inventors: Il-Ryoung Sohn, Dae-Young Kang, Jong-Sang Kim, Tae-Chul Kim, Min-Suk Oh
  • Patent number: 11344941
    Abstract: In a method for obtaining a hot-press-formed steel member, a steel sheet containing 0.10-0.30 mass % of C, 1.0-2.5 mass % of Si, 1.0-3.0 mass % of Si and Al in total, and 1.5-3.0 mass % of Mn is heated at a heating temperature of not less than the Ac3 transformation point. The steel sheet is hot-press formed for one or more times. The starting temperature of the hot pressing is not more than the heating temperature but not less than the Ms point. The average cooling rate from (Ms point?150)° C. to 40° C. is 5° C./s or less. The hot-press-formed steel member has high strength, high tensile elongation, high bendability, excellent deformation characteristics at the time of collision crush, and excellent delayed fracture resistance.
    Type: Grant
    Filed: July 18, 2012
    Date of Patent: May 31, 2022
    Assignee: Kobe Steel, Ltd.
    Inventors: Takayuki Yamano, Jiro Iwaya, Noriyuki Jimbo, Tatsuya Asai, Naoki Mizuta
  • Patent number: 11198167
    Abstract: A method of forming a hot stamped, die quenched, and die trimmed part is provided. The method includes hot stamping and die quenching a blank with a quench die and forming a die quenched panel. The quench die includes at least one slow-cooling channel. The die quenched panel is die trimmed along the at least one localized soft zone that is adjacent a hard zone. The blank may be formed from a press hardenable steel (PHS), and the at least one soft zone may have a ferritic microstructure and the at least one hard zone may have a martensitic microstructure. The at least one localized soft zone may have a microhardness between about 200 HV and about 250 HV and the hard zone may have a microhardness between about 400 HV and about 500 HV.
    Type: Grant
    Filed: June 26, 2018
    Date of Patent: December 14, 2021
    Assignee: Ford Motor Company
    Inventors: Raj Sohmshetty, Constantin Chiriac, Mikhail Minevich, Liang Huang
  • Patent number: 11198915
    Abstract: A method of quenching a press hardenable steel is provided. The method includes an initial step of die quenching a part stamped within a stamping die followed by a partial quenching after the initial step of die quenching. In various methods, the press hardenable steel is a 36MnB5 grade steel and/or the initial step of die quenching is performed at a temperature of approximately 200° C.±10° C. in a die configured for 36MnB5 grade steel. At least one method further includes opening the die followed by the partial quenching, the partial quenching comprising spraying a cooling liquid onto the part to reduce a temperature of the part below approximately 130° C.±10° C., with the option of spraying to reduce the temperature of the part below approximately 100° C.±10° C.
    Type: Grant
    Filed: February 8, 2018
    Date of Patent: December 14, 2021
    Assignee: Ford Motor Company
    Inventors: Raj Sohmshetty, Constantin Chiriac, Mikhail Minevich, Jason Balzer, S. George Luckey, Jr.
  • Patent number: 11180836
    Abstract: Provided is a low-yield-ratio high-strength-toughness thick steel plate with excellent low-temperature impact toughness, which comprises: 0.05%-0.11% of C, 0.10%-0.40% of Si, 1.60%-2.20% of Mn, S?0.003%, 0.20-0.70% of Cr, 0.20%-0.80% of Mo, 0.02%-0.06% of Nb, 3.60%-5.50% of Ni, 0.01%-0.05% of Ti, 0.01%-0.08% of Al, 0<N?0.0060%, 0<O?0.0040%, and 0<Ca?0.0045%, with the balance being Fe and inevitable impurities; in addition, Ni+Mn?5.5 is also satisfied. The manufacturing method for the above-mentioned steel plate comprises smelting, casting, heating, two-stage rolling, quenching, cooling after quenching, and tempering.
    Type: Grant
    Filed: December 8, 2015
    Date of Patent: November 23, 2021
    Assignee: BAOSHAN IRON & STEEL CO., LTD.
    Inventors: Sixin Zhao, Liandeng Yao, Xiaobo Wang, Xiaoting Zhao
  • Patent number: 11028469
    Abstract: A hot press-formed part according to an aspect of the present invention contains a predetermined chemical composition; in which a microstructure in a thickness ¼ portion includes, by unit vol %, tempered martensite: 20% to 90%, bainite: 5% to 75%, and residual austenite: 5% to 25%, and ferrite is limited to 10% or less; and a pole density of an orientation {211}<011> in the thickness ¼ portion is 3.0 or higher.
    Type: Grant
    Filed: August 16, 2016
    Date of Patent: June 8, 2021
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Mutsumi Sakakibara, Natsuko Sugiura, Kunio Hayashi, Kaoru Kawasaki
  • Patent number: 10961611
    Abstract: A high-strength steel having a yield strength at a level of 800 MPa and a method of manufacturing the same, with the components and amounts thereof by weight percentage being: C: 0.06-0.14%, Si: 0.1-0.30%, Mn: 0.8-1.60%, Cr: 0.2-0.70%, Mo: 0.1-0.40%, Ni: 0-0.30%, Nb: 0.01-0.030%, Ti: 0.01-0.030%, V: 0.01-0.05%, B: 0.0005-0.0030%, Al: 0.02-0.06%, Ca: 0.001-0.004%, N: 0.002-0.005%, P?0.02%, S?0.01%, O?0.008%, the balance of Fe and unavoidable impurities; wherein the above elements meet the following relationships: 0.40%<Ceq<0.50%, Ceq=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15; 0.7%?Mo+0.8Ni+0.4Cr+6V?1.1%; 3.7?Ti/N?7.0; 1.0?Ca/S?3.0.
    Type: Grant
    Filed: December 8, 2015
    Date of Patent: March 30, 2021
    Assignee: Baoshan Iron & Steel Co., Ltd.
    Inventors: Gang Liu, Ana Yang, Zigang Li, Fengming Song
  • Patent number: 10829841
    Abstract: This hot work tool steel has a composition containing C: 0.45 to 0.57 mass %, Si: 0.05 to 0.30 mass %, Mn: 0.45 to 1.00 mass %, Cr: 4.5 to 5.2 mass %, Ni: 0.5 mass % or less, Mo+(½) W: 1.0 to 2.0 mass %, V: 0.30 to 0.80 mass %, and N: 0.008 to 0.025 mass %, the remainder being Fe and unavoidable impurities, and the area ratio of carbide having an equivalent circle diameter of 1 ?m or less being 20% or higher. It is thereby possible to improve thermal conductivity to thereby shorten cycle time, and improving hardness after heat treatment to improve abrasion resistance while sufficient hardenability is maintained. Consequently, it is possible to obtain a hot work tool steel having excellent toughness with high hardness, excellent corrosion resistance, and minimal degradation of machinability.
    Type: Grant
    Filed: January 6, 2015
    Date of Patent: November 10, 2020
    Assignee: NIPPON KOSHUHA STEEL CO., LTD.
    Inventors: Tsuyoshi Tonomura, Kentaro Suzuki
  • Patent number: 10604817
    Abstract: Provided is a high-strength steel plate for a pressure vessel having excellent low temperature toughness after a post weld heat treatment (PWHT). The high-strength steel plate for a pressure vessel includes: by wt %, 0.02-0.15% of carbon (C), 0.05-0.50% of silicon (Si), 1.0-2.0% of manganese (Mn), 0.005-0.1% of aluminum (Al), 0.015% or less of phosphorus (P), 0.0015% or less of sulfur (S), 0.01-0.03% of niobium (Nb), 0.01-0.03% of vanadium (V), 0.01-0.03% of titanium (Ti), 0.005% or less of chromium (Cr), 0.005% or less of molybdenum (Mo), 0.02-0.50% of copper (Cu), 0.05-0.60% of nickel (Ni), 0.0002-0.0010% of boron (B), 0.0035-0.0065% of nitrogen (N), and a balance of iron (Fe) and other inevitable impurities. A microstructure of the high-strength steel plate includes a complex structure of ferrite having an area fraction of 35-40% and a balance of bainite, and the bainite has a packet size of 15 ?m or less.
    Type: Grant
    Filed: December 1, 2015
    Date of Patent: March 31, 2020
    Assignee: POSCO
    Inventors: Dae-Woo Kim, Kyung-Keun Um
  • Patent number: 10480042
    Abstract: This disclosure is directed at methods for mechanical property improvement in a metallic alloy that has undergone one or more mechanical property losses as a consequence of shearing, such as in the formation of a sheared edge portion or a punched hole. Methods are disclosed that provide the ability to improve mechanical properties of metallic alloys that have been formed with one or more sheared edges which may otherwise serve as a limiting factor for industrial applications.
    Type: Grant
    Filed: April 8, 2016
    Date of Patent: November 19, 2019
    Assignee: The NanoSteel Company, Inc.
    Inventors: Daniel James Branagan, Andrew E. Frerichs, Brian E. Meacham, Grant G. Justice, Andrew T. Ball, Jason K. Walleser, Kurtis Clark, Logan J. Tew, Scott T. Anderson, Scott Larish, Sheng Cheng, Taylor L. Giddens, Alla V. Sergueeva
  • Patent number: 10422015
    Abstract: Provided are a high-strength galvanized steel sheet containing 0.12% to 0.25% C, 0.01% to 1.00% Si, 1.5% to 4.0% Mn, 0.100% or less P, 0.02% or less S, 0.01% to 0.10% Al, 0.001% to 0.010% N, 0.005% to 0.100% Ti, and 0.0005% to 0.0050% B, the remainder being Fe and inevitable impurities, Ti>4N being satisfied. The high-strength galvanized steel sheet contains 80% to 100% martensite in terms of area fraction, 5% or less (including 0%) polygonal ferrite in terms of area fraction, and less than 3% (including 0%) retained austenite in terms of area fraction. The average hardness of martensite is 400 to 500 in terms of Vickers hardness (Hv). The average grain size of martensite is 20 ?m or less. The standard deviation of the grain size of martensite is 7.0 ?m or less.
    Type: Grant
    Filed: August 14, 2015
    Date of Patent: September 24, 2019
    Assignee: JFE Steel Corporation
    Inventors: Hiroshi Hasegawa, Koichiro Fujita
  • Patent number: 10253384
    Abstract: A cold-rolled steel sheet includes, by mass %: C: 0.020% or more and 0.080% or less; Si: 0.20% or more and 1.00% or less; Mn: 0.80% or more and 2.30% or less; and Al: 0.010% or more and 0.100% or less; and further includes: one or more of Nb and Ti which satisfy a requirement of 0.005%?Nb+Ti<0.030%, in which a structure consists of, ferrite, bainite, and other phases, an area ratio of the ferrite is 80% or more and less than 95%, an area ratio of a non-recrystallization ferrite in the ferrite is 1% or more and less than 10%, an area ratio of the bainite is 5% or more and 20% or less, a total amount of the other phases is less than 8%, an equivalent circle diameter of a carbonitride including one or both of Nb and Ti is 1 nm or more and 10 nm or less, and a tensile strength is 590 MPa or more.
    Type: Grant
    Filed: February 6, 2013
    Date of Patent: April 9, 2019
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Yusuke Kondo, Kunio Hayashi, Toshio Ogawa, Naoki Matsutani, Koichi Goto
  • Patent number: 9567659
    Abstract: The invention relates to a method for manufacturing a high-strength structural steel and to a high-strength structural steel product. The method comprises a providing step for providing a steel slab, a heating step (1) for heating said steel slab to 950 to 1300 C, a temperature equalizing step (2) for equalizing the temperature of the steel slab, a hot rolling step including a hot rolling stage of type I (5) for hot rolling the steel slab in the no-recrystallization temperature range below the recrystallization stop temperature (RST) but above the ferrite formation temperature A3, a quenching step (6) for quenching said hot-rolled steel at cooling rate of at least 20 C/s to a quenching-stop temperature (QT) between Ms and Mf temperatures, a partitioning treatment step (7, 9) for partitioning said hot-rolled steel in order to transfer carbon from martensite to austenite, and a cooling step (8) for cooling said hot-rolled steel to room temperature.
    Type: Grant
    Filed: July 2, 2012
    Date of Patent: February 14, 2017
    Assignee: RAUTARUUKKI OYJ
    Inventors: Mahesh Chandra Somani, David Arthur Porter, Leo Pentti Karjalainen, Tero Tapio Rasmus, Ari Mikael Hirvi
  • Patent number: 9394579
    Abstract: The present invention provides steel containing manganese and nickel that is used as a structural material for a cryogenic storage container for liquefied natural gas (LNG) or the like, and a manufacturing method thereof; and more particularly, to steel having good cryogenic temperature toughness and also high strength by adding low-cost Mn instead of relatively expensive Ni at an optimized ratio, refining a microstructure through controlled rolling and cooling, and precipitating retained austenite through tempering, and a manufacturing method of the steel. To achieve the object, the technical feature of the present invention is a method of manufacturing high-strength steel with cryogenic temperature toughness. In the method, a steel slab is heated to a temperature within a range of 1,000 to 1,250° C., wherein the steel slab includes, by weight: 0.01-0.06% of carbon (C), 2.0-8.0% of manganese (Mn), 0.01-6.0% of nickel (Ni), 0.02-0.6% of molybdenum (Mo), 0.03-0.5% of silicon (Si), 0.003-0.
    Type: Grant
    Filed: November 21, 2011
    Date of Patent: July 19, 2016
    Assignee: POSCO
    Inventors: Kyung-Keun Um, Jong-Kyo Choi, Woo-Kil Jang, Hee-Goon Noh, Hyun-Kwan Cho
  • Patent number: 9376738
    Abstract: The present invention provides hot forging use non heat-treated steel where controlled cooling after shaping by hot forging is used to make the main structure of the steel martensite even without subsequent reheating and heat treatment by quenching and tempering and thereby give a steel part with a high strength and high toughness and superior machineability and a hot forged non heat-treated steel part made of that steel, in particular provides a martensite type hot forging use non heat-treated steel characterized by containing, by mass %, C: 0.10 to 0.20%, Si: 0.10 to 0.50%, Mn: 1.0 to 3.0%, P: 0.001 to 0.1%, S: 0.005 to 0.8%, Cr: 0.10 to 1.50%, Al: over 0.1 to 0.20%, and N: 0.0020 to 0.
    Type: Grant
    Filed: October 27, 2008
    Date of Patent: June 28, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Shinya Teramoto, Kei Miyanishi, Masayuki Hashimura
  • Publication number: 20150114527
    Abstract: A steel for oil country tubular goods includes, as a chemical composition, by mass %, C, Si, Mn, Al, Mo, P, S, O, N, and a balance containing Fe and impurities, wherein a full width at half maximum HW of a crystal plane corresponding to a (211) crystal plane of an ? phase and a carbon content expressed in mass % in the chemical composition satisfy HW×C1/2?0.38, the carbon content and a molybdenum content expressed in mass % in the chemical composition satisfy C×Mo?0.6, a number of M2C carbides having a hexagonal crystal structure and having an equivalent circle diameter of 1 nm or more is 5 pieces or more per one square micron, and an yield strength is 758 MPa or more.
    Type: Application
    Filed: June 17, 2013
    Publication date: April 30, 2015
    Inventors: Tomohiko Omura, Yuji Arai, Kaori Kawano, Akihiro Sakamoto, Kazuo Okamura, Kenji Yamamoto, Keiichi Kondo, Koji Nagahashi, Masanao Seo
  • Patent number: 8999085
    Abstract: A high-ductility, high-strength and high Mn steel strip used for steel strips of automobiles requiring superior formability and high strength, a plated steel strip produced by using the same, and a manufacturing method thereof are disclosed. The high Mn steel strip comprises, by weight %, 0.2˜1.5% of C, 10˜25% of Mn, 0.01˜3.0% of Al, 0.005˜2.0% of Si, 0.03% or less of P, 0.03% or less of S, 0.040% or less of N, and the balance of Fe and other unavoidable impurities. The high-ductility, high-strength and high Mn steel strip, and the plated steel strip produced by using the same have superior surface properties and plating characteristics.
    Type: Grant
    Filed: December 22, 2006
    Date of Patent: April 7, 2015
    Assignee: Posco
    Inventors: Seong-Ju Kim, Kwang-Geun Chin, Hyun-Gyu Hwang, Sung-Kyu Kim, Il-Ryoung Sohn, Young-Kook Lee, Oh-Yeon Lee
  • Publication number: 20150090372
    Abstract: This disclosure deals with a class of metal alloys with advanced property combinations applicable to metallic sheet production. More specifically, the present application identifies the formation of metal alloys of relatively high strength and ductility and the use of one or more cycles of elevated temperature treatment and cold deformation to produce metallic sheet at reduced thickness with relatively high strength and ductility.
    Type: Application
    Filed: October 2, 2014
    Publication date: April 2, 2015
    Inventors: Daniel James BRANAGAN, Grant G. JUSTICE, Andrew T. BALL, Jason K. WALLESER, Brian E. MEACHAM, Kurtis CLARK, Longzhou MA, Igor YAKUBTSOV, Scott Larish, Sheng CHENG, Taylor L. GIDDENS, Andrew E. FRERICHS, Alla V. SERGUEEVA
  • Publication number: 20150090378
    Abstract: A sheet steel blank is heated to the austenite range and formed in a cooled tool pair that rapidly cools the formed product until the product's temperature drops somewhat below the temperature Ms for the start of the formation of martensite. The cooling is rapidly interrupted and the product's temperature is raised until it exceeds Ms and is maintained there until the material comes to contain more than 50% by volume bainite. The short time under the Ms temperature favours the formation of bainite and shortens the holding time.
    Type: Application
    Filed: July 4, 2012
    Publication date: April 2, 2015
    Inventors: Katarina Eriksson, Jan Larsson
  • 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
  • Publication number: 20150083284
    Abstract: A method of forming a shaped article. The method comprises providing a pre-form 40 comprising a chromium molybdenum vanadium steel alloy, heat treating the pre-form to obtain a surface hardness of between 420 and 480 according to the Vickers hardness test, and, subsequent to the heat treating step, flow forming the pre-form 40 to shape the pre-form.
    Type: Application
    Filed: September 3, 2014
    Publication date: March 26, 2015
    Inventors: Martin John RAWSON, John Harold BOSWELL, Martin TUFFS, George William WHITEHURST, Paul Owen HILL
  • Publication number: 20150059912
    Abstract: A steel plate has a chemical composition containing, by mass %, C: 0.03% or more and 0.08% or less, Si: 0.01% or more and 1.0% or less, Mn: 1.2% or more and 3.0% or less, P: 0.015% or less, S: 0.005% or less, Al: 0.08% or less, Nb: 0.005% or more and 0.07% or less, Ti: 0.005% or more and 0.025% or less, N: 0.010% or less, O: 0.005% or less and the balance being Fe and inevitable impurities, a metallographic structure including a bainite phase and island martensite, and a polygonal ferrite in surface portions within 5 mm from the upper and lower surfaces, wherein the area fraction of the island martensite is 3% to 15%, the equivalent circle diameter of the island martensite is 3.0 ?m or less, the area fraction of the polygonal ferrite in the surface portions is 10% to less than 80%.
    Type: Application
    Filed: March 29, 2013
    Publication date: March 5, 2015
    Inventors: Junji Shimamura, Kimihiro Nishimura
  • Patent number: 8968496
    Abstract: In a press-hardening plant, a contact-cooling press (12) is provided between the furnace (11) and the press-hardening press (13). Preselected parts of the blank (18) are contact-cooled such that corresponding parts of the finished product are softer and display a lower yield point.
    Type: Grant
    Filed: February 17, 2011
    Date of Patent: March 3, 2015
    Assignee: Gestamp Hardtech AB
    Inventors: Jan Larsson, Paul Akerstrom, Daniel Berglund
  • Patent number: 8968497
    Abstract: A method of making a ductile iron article is disclosed. The method includes providing a ductile iron article preform. The method also includes deforming the ductile iron article preform by hot-working to provide a hot-worked portion of the article. The method further includes cooling the article to an austempering temperature. Still further, the method includes austempering the ductile iron article preform for a predetermined time sufficient to provide an austempered article preform comprising an austempered microstructure, wherein the austempered microstructure of the hot-worked portion is different than in other portions of the article. A ductile iron wind turbine shaft is also disclosed. The ductile iron wind turbine shaft has an austempered microstructure comprising an ausferrite matrix and a plurality of graphite nodules. The austempered microstructure has a deformed portion, the deformed portion has a microstructure that is different than the microstructure of the other portion of the shaft.
    Type: Grant
    Filed: November 11, 2011
    Date of Patent: March 3, 2015
    Assignee: General Electric Company
    Inventors: Jason Robert Parolini, Junyoung Park
  • 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: 20150007912
    Abstract: A base material of a ferrous material is heated to an AC1 point, which is a temperature to cause mustenite appearance, or higher, and austenite appears in the base material 1a and 1b (S101). An amount of a strain assuming that an Mf point, which is a temperature where the base material becomes martensite completely, is decreased to be less than room temperature is introduced into the base material (S102). The all ferrous material becoming martensite on the occasion of cooling the ferrous material to room temperature is prevented. The base material is cooled to room temperature at a cooling rate where a line extrapolated a cooling curve of the base material intersects with a region where martensite is produced on the CCT diagram (S103). Austenite remains in the manufactured ferrous material at room temperature.
    Type: Application
    Filed: March 12, 2013
    Publication date: January 8, 2015
    Applicant: OSAKA UNIVERSITY
    Inventors: Hidetoshi Fujii, Yoshiaki Morisada
  • Patent number: 8926771
    Abstract: Process for manufacturing seamless precision steel tubes with improved isotropic toughness at low temperature for hydraulic cylinders comprising the following steps; —(i) providing a steel having a composition comprising 0.06-0.15% by weight of carbon, 0.30-2.5% by weight of Mn, and 0.10-0.
    Type: Grant
    Filed: June 29, 2006
    Date of Patent: January 6, 2015
    Assignee: Tenaris Connections Limited
    Inventors: Gianmario Agazzi, Emanuele Paravicini Bagliani, Andrea Poli
  • Patent number: 8926766
    Abstract: Provided is a low yield ratio, high strength and high uniform elongation steel plate having excellent strain ageing resistance equivalent to API 5L X70 Grade or lower and a method for manufacturing the same. In particular, the steel plate contains 0.06% to 0.12% C, 0.01% to 1.0% Si, 1.2% to 3.0% Mn, 0.015% or less P, 0.005% or less S, 0.08% or less Al, 0.005% to 0.07% Nb, 0.005% to 0.025% Ti, 0.010% or less N, and 0.005% or less O on a mass basis, the remainder being Fe and unavoidable impurities. The low yield ratio, high strength and high uniform elongation steel plate has a metallographic microstructure that is a two-phase microstructure consisting of bainite and M-A constituent, the area fraction of the M-A constituent being 3% to 20%, the equivalent circle diameter of the M-A constituent being 3.0 ?m or less.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: January 6, 2015
    Assignee: JFE Steel Corporation
    Inventors: Junji Shimamura, Nobuyuki Ishikawa, Nobuo Shikanai
  • Publication number: 20150000802
    Abstract: Provided is a hot-press molded article that can achieve a high level of balance between high strength and extension by region and has a region corresponding to an energy absorption site and a shock resistant site within a single molded article without applying a welding method by means of having first region having a metal structure containing both 80-97 area % of martensite and 3-20 area % of residual austenite, the remaining structure comprising no more than 5 area %, and a second region having a metal structure comprising 30-80 area % of ferrite, less than 30 area % (exclusive of 0 area %) of bainitic ferrite, no greater than 30 area % (exclusive of 0 area %) of martensite, and 3-20 area % of residual austenite.
    Type: Application
    Filed: March 15, 2013
    Publication date: January 1, 2015
    Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (Kobe Steel, Ltd.)
    Inventors: Junya Naitou, Toshio Murakami, Shushi Ikeda, Keisuke Okita
  • Publication number: 20150000798
    Abstract: A method of manufacturing a high-strength steel sheet includes, on a mass percent basis, 0.03%-0.10% C, 0.01%-0.5% Si, 0.001%-0.100% P, 0.001%-0.020% S, 0.01%-0.10% Al, 0.005%-0.012% N, the balance being Fe and incidental impurities, and microstructures that do not contain a pearlite microstructure, wherein, when Mnf=Mn [% by mass]?1.71×S [% by mass], Mnf is 0.3 to 0.6, including: forming a slab by vertical-bending type continuous casting or bow type continuous casting, wherein surface temperature of a slab corner in a region where the slab undergoes bending deformation or unbending deformation is 800° C. or lower, or 900° C. or higher; forming a steel sheet by hot-rolling the slab followed by cold rolling; annealing the steel sheet after the cold rolling; and skinpass rolling at a draft of 3% or less after the annealing.
    Type: Application
    Filed: September 16, 2014
    Publication date: January 1, 2015
    Inventors: Takumi Tanaka, Katsumi Kojima, Makoto Aratani, Hiroki Iwasa
  • Publication number: 20140377582
    Abstract: A high-strength cold-rolled steel sheet includes, as a component composition, by mass %: C: 0.075% to 0.300%; Si: 0.30% to 2.50%; Mn: 1.30% to 3.50%; P: 0.001% to 0.050%; S: 0.0001% to 0.0100%; Al: 0.001% to 1.500%; and N: 0.0001% to 0.0100%, in which a surface microstructure contains residual austenite of 3% to 10% and ferrite of 90% or less by volume fraction, an inner microstructure at a depth of t/4 from the surface assuming that a sheet thickness is t contains residual austenite of 3% to 20% by volume fraction, a ratio Hvs/Hvb between a surface hardness Hvs of the steel sheet surface and a hardness Hvb at a depth of ¼ of the thickness is more than 0.75 to 0.90, and a maximum tensile strength is 700 MPa or more.
    Type: Application
    Filed: February 4, 2013
    Publication date: December 25, 2014
    Inventors: Masafumi Azuma, Takayuki Nozaki, Chisato Wakabayashi, Koichi Sato, Hiroyuki Kawata, Nobuhiro Fujita
  • Publication number: 20140367002
    Abstract: A hot-press formed product can be achieved which has regions corresponding to a shock resistant portion and an energy absorption portion within a single formed product without applying a welding method and achieves the balance of high strength and elongation with a high level according to each region by means of having a first forming region exhibiting a metal structure containing martensite: 80-97 area % and retained austenite: 3-20 area % respectively, the remaining structure being 5 area % or less, and a second forming region exhibiting a metal structure containing annealed martensite or annealed bainite: 30-97 area %, martensite as quenched: 0-67 area %, and retained austenite: 3-20 area %.
    Type: Application
    Filed: March 15, 2013
    Publication date: December 18, 2014
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Junya Naitou, Toshio Murakami, Shushi Ikeda, Keisuke Okita
  • Publication number: 20140345753
    Abstract: A system for hot-forming blanks (P) includes at least one heating device (4) and at least one pressing device (8) arranged downstream of the at least one heating device (4), and at Least one reheating device (16) for at least partially acting upon the blanks formed in the pressing device with heat provided downstream of the pressing device (2). A method is also provided.
    Type: Application
    Filed: May 13, 2014
    Publication date: November 27, 2014
    Inventor: Matthias BORS
  • Publication number: 20140338802
    Abstract: Provided is a press-forming product manufacturing method of manufacturing a forming product having satisfactory formability for a drawing process by press-forming a metal sheet using a press-forming tool with high productivity, including: heating the metal sheet to a transformation temperature Ac1 or more; cooling the metal sheet to 600° C. or lower; forming the metal sheet by a forming tool; ending the forming process at a martensite transformation start temperature Ms or more; taking out the metal sheet from the forming tool; and cooling the metal sheet.
    Type: Application
    Filed: September 25, 2012
    Publication date: November 20, 2014
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Keisuke Okita, Junya Naitou, Shushi Ikeda
  • Patent number: 8888934
    Abstract: In a method to produce formed steel parts a primary steel material is provided, which (in % by weight) comprises C: 0.02-0.6%, Mn: 0.5-2.0%, Al: 0.01-0.06%, Si: max. 0.4%, Cr: max. 1.2%, P: max. 0.035%, S: max. 0.035%, and optionally one or more of the elements of the “Ti, Cu, B, Mo, Ni, N” group, with the proviso that Ti: max. 0.05%, Cu: max. 0.01%, B: 0.0008-0.005%, Mo: max. 0.3%, Ni: max. 0.4%, N: max. 0.01%, and the remainder as iron and unavoidable impurities. The primary material is heated through at a heating temperature (TA) lying between the Ac1 and the Ac3 temperature, such that at best incomplete austenitising of the primary material takes place, is placed into a press-form tool and formed therein into the formed steel part. The formed steel part is then heated to a bainite forming temperature (TB), which is above the martensite starting temperature (MS), however below the pearlite transformation temperature of the steel.
    Type: Grant
    Filed: April 24, 2009
    Date of Patent: November 18, 2014
    Assignee: ThyssenKrupp Steel Europe AG
    Inventor: Jian Bian
  • Patent number: 8876987
    Abstract: A high strength pressed member has excellent ductility and stretch flangeability and tensile strength of 780-1400 MPa, with a predetermined steel composition and steel microstructure relative to the entire microstructure of steel sheet, where area ratio of martensite 5-70%, area ratio of retained austenite 5-40%, area ratio of bainitic ferrite in upper bainite 5% or more, and total thereof is 40% or more, 25% or more of martensite is tempered martensite, polygonal ferrite area ratio is above 10% and below 50% to the entire microstructure of steel sheet, and average grain size is 8 ?m or less, average diameter of a group of polygonal ferrite grains is 15 ?m or less, the group of polygonal ferrite grains represented by a group of ferrite grains of adjacent polygonal ferrite grains, and average carbon content in retained austenite is 0.70 mass % or more and tensile strength is 780 MPa or more.
    Type: Grant
    Filed: October 2, 2012
    Date of Patent: November 4, 2014
    Assignee: JFE Steel Corporation
    Inventors: Hiroshi Matsuda, Yoshimasa Funakawa, Kaneharu Okuda, Kazuhiro Seto
  • Publication number: 20140261920
    Abstract: A method for manufacturing a mechanical part by hot stamping, and a mold and a system thereof. The method includes: heating a steel plate blank at a predetermined heating temperature; and placing the steel plate blank into a mold of the mechanical part, and stamping the steel plate blank to form wrinkles at a rounded corner of the mold and form the mechanical part in the mold: wherein, the mold of the mechanical part includes a female mold and a male mold, a stamping gap configured to accommodate the steel plate blank is provided between the female mold and the male mold and a width of the stamping gap at the rounded corner of the mold is larger than a thickness of the wrinkles.
    Type: Application
    Filed: December 31, 2012
    Publication date: September 18, 2014
    Inventors: Zhongde Shan, Chao Jiang, Milan Zhang, Wanhua Cai, Yongsheng Ye
  • Publication number: 20140216615
    Abstract: Provided is a stainless-steel seamless belt formed by subjecting a stainless-steel plate to a plastic forming process and having a thickness of 50 ?m or less. The seamless belt has a bending durability of 100,000 or more times in a specific bending test and has a Vickers hardness of 450 (Hv) or more.
    Type: Application
    Filed: April 4, 2014
    Publication date: August 7, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Hirotomo Tamiya
  • Patent number: 8778101
    Abstract: According to the method of production of a steel sheet pressed part with locally modified properties, the steel sheet blank is first heated in a device for heating to the austenitic temperature of the material. Next, the steel sheet blank is converted in a tool for deep drawing by deformation into a final drawn part. Subsequently, the final drawn part is cooled inside the tool for deep drawing. Various locations of the final drawn part are cooled to various temperatures and/or at various rates during the cooling process. Thereafter, the drawn part is placed in an annealing device, where retained austenite stabilization occurs by diffusion-based carbon partitioning within the material from which the drawn part is made. After stabilization, the final drawn part is removed from the annealing device and air cooled to ambient temperature.
    Type: Grant
    Filed: April 3, 2012
    Date of Patent: July 15, 2014
    Assignee: Zapadoceska Univerzita V Plzni
    Inventors: Bohuslav Maśek, Hana Jirková, Ludmila Kuĉerová, Andrea Rone{grave over (s)}ová, Stépàn Jeniĉek
  • Patent number: 8758528
    Abstract: The present invention provides a high-strength steel plate having excellent resistance to cutting crack, excellent Charpy absorbed energy, excellent DWTT properties, a low yield ratio, and a tensile strength of 900 MPa or more, a method of producing the steel plate, and a high-strength steel pipe using the steel plate. As solving means, a steel plate contains, by % by mass, 0.03 to 0.12% of C, 0.01 to 0.5% of Si, 1.5 to 3% of Mn, 0.01 to 0.08% of Al, 0.01 to 0.08% of Nb, 0.005 to 0.025% of Ti, 0.001 to 0.01% of N, and at least one component of 0.01 to 2% of Cu, 0.01 to 3% of Ni, 0.01 to 1% of Cr, 0.01 to 1% of Mo, and 0.01 to 0.1% of V; wherein the contents of Ca, O, and S satisfy the equation below; the microstructure includes ferrite and a second hard phase, the area fraction of ferrite being 10 to 50%; cementite in the second phase has an average grin size of 0.5 ?m or less; and the total amount of Nb and the like contained in carbides thereof present in steel is 10% or less of the total content in steel.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: June 24, 2014
    Assignee: JFE Steel Corporation
    Inventors: Junji Shimamura, Shigeru Endo, Mitsuhiro Okatsu
  • Publication number: 20140158256
    Abstract: There is provided a heating device, in particular an austenitization device, for a plant for hot forming blanks, wherein the heating device is for locally heating, in particular austenitization, regions of the blanks and has at least one burner. Also included is means for moving the burner and/or the flame of the burner to the regions of the blank which are to be subjected to local heating.
    Type: Application
    Filed: December 7, 2012
    Publication date: June 12, 2014
    Inventor: Matthias BORS
  • Publication number: 20140152086
    Abstract: A track link is disclosed for use with an undercarriage of a machine. The track link may have a body with a first surface and a second surface opposite the first surface. The track link may also have a shoe face extending between the first and second surfaces at a side of the body, and a roller rail extending between the first and second surfaces at a side of the body opposite the shoe face, The body may have a substantially uniform hardness of about 45 to 55 Rkw C between the shoe face and the roller rail.
    Type: Application
    Filed: November 30, 2012
    Publication date: June 5, 2014
    Applicant: Caterpillar Inc.
    Inventors: Robert Lee Meyer, Michael Dean Hasselbusch, Gergory Wayne Tomlins
  • 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
  • Patent number: 8702879
    Abstract: A method of producing a martensitic steel including 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 a last heat shaping pass of the steel is lower than the solubility temperature of aluminum nitrides in the steel, and a treatment temperature for each potential heat treatment after the last heat shaping pass is lower than the solid-state solubility temperature of the aluminum nitrides in the steel.
    Type: Grant
    Filed: July 2, 2010
    Date of Patent: April 22, 2014
    Assignees: SNECMA, Aubert & Duval
    Inventors: Laurent Ferrer, Philippe Heritier
  • Publication number: 20140096876
    Abstract: A method for manufacturing a high strength press-formed member includes preparing a steel sheet having the composition including by mass %: C: 0.12% to 0.69%, Si: 3.0% or less, Mn: 0.5% to 3.0%, P: 0.1% or less, S: 0.07% or less, Al: 3.0% or less, N: 0.010% or less, Si+Al: at least 0.7%, and remainder as Fe and incidental impurities, heating the steel sheet to a temperature of 750° C. to 1000° C. and retaining the steel sheet in that state for 5 seconds to 1000 seconds; subjecting the steel sheet to hot press-forming at a temperature of 350° C. to 900° C.; cooling the steel sheet to a temperature of 50° C. to 350° C.; heating the steel sheet to a temperature in a temperature region of 350° C. to 490° C.; and retaining the steel sheet at temperature in the temperature region for 5 seconds to 1000 seconds.
    Type: Application
    Filed: December 9, 2013
    Publication date: April 10, 2014
    Applicant: JFE Steel Corporation
    Inventors: Hiroshi Matsuda, Yoshimasa Funakawa, Yasushi Tanaka
  • Publication number: 20140069555
    Abstract: A cast slab containing C: less than 0.02 mass % and made of an Fe-based metal of an ?-? transforming component is subjected to hot rolling at a temperature of an A3 point or higher and is subjected to ?-region rolling at a temperature of 300° C. or higher and lower than the A3 point, and thereby a base metal sheet having a {100} texture in a surface layer portion is fabricated. Then, by performing a heat treatment under predetermined conditions, an Fe-based metal sheet is obtained in which a Z value is not less than 2.0 nor more than 200 when intensity ratios of respective {001}<470>, {116}<6 12 1>, and {223}<692> directions in a sheet plane by X-ray diffraction are set to A, B, and C respectively and Z=(A+0.97B)/0.98C is satisfied.
    Type: Application
    Filed: April 27, 2012
    Publication date: March 13, 2014
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Tooru Inaguma, Miho Tomita, Hiroaki Sakamoto, Youji Mizuhara
  • Publication number: 20140056749
    Abstract: A low-chromium hot-work tool steel consisting of (in wt-%): C 0.08-0.40, N 0.015-0.30, C+N 0.30-0.50, Cr 1-4, Mo 1.5-3, V 0.8-1.3, Mn 0.5-2, Si 0.1-0.5, optionally Ni<3, Co?5, B<0.01, Fe balance apart from impurities, and a process for making a low-chromium hot-work tool steel article having increased tempering resistance.
    Type: Application
    Filed: March 1, 2012
    Publication date: February 27, 2014
    Applicant: UDDEHOLMS AB
    Inventors: Jürgen Andersson, Henrik Jesperson, Hans-Olof Andrén, Lars-Erik Svensson
  • Patent number: 8652273
    Abstract: There are provided a steel for deep drawing, and a method for manufacturing the steel and a high pressure container. The steel for deep drawing includes, by weight: C: 0.25 to 0.40%, Si: 0.15 to 0.40%, Mn: 0.4 to 1.0%, Al: 0.001 to 0.05%, Cr: 0.8 to 1.2%, Mo: 0.15 to 0.8%, Ni: 1.0% or less, P: 0.015% or less, S: 0.015% or less, Ca: 0.0005 to 0.002%, Ti: 0.005 to 0.025%, B: 0.0005 to 0.0020% and the balance of Fe and inevitable impurities, wherein a microstructure of the steel has a triphase structure of ferrite, bainite and martensite. The steel for deep drawing may be useful to further improve the strength without the deterioration of the toughness by adding a trace of Ti and B, compared to the conventional steels having a strength of approximately 1100 MPa.
    Type: Grant
    Filed: September 12, 2008
    Date of Patent: February 18, 2014
    Assignee: Posco
    Inventors: Soon Taik Hong, Sung Ho Jang, Ki Hyun Bang
  • 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
  • Patent number: 8636859
    Abstract: Method for austempering at least one part of a work piece, which method comprises the steps of: a) heating at least one part of the work piece to an initial austenitizing temperature (T1); b) subjecting said at least one part of the work piece to one or more austenitizing temperatures (T1 . . . T1n) for a predetermined time to austenitize it; c) quenching said at least one part of the work piece; d) heat treating said at least one part of the work piece at one or more austempering temperatures (T2 . . . T2n) for a predetermined time to austemper it; e) cooling the at least one part of the work piece; whereby at least one of the steps a) to e) is/are at least partly carried out under Hot Isostatic Pressing (HIP) conditions.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: January 28, 2014
    Assignee: Indexator Group AB
    Inventor: Richard Larker