Zinc(zn), Zinc Base Alloy Or Unspecified Galvanizing Patents (Class 148/533)
  • Patent number: 11401595
    Abstract: A high-strength steel sheet having a TS of 780 MPa or more, excellent stretch flangeability, and excellent in-plane anisotropy of TS is provided. A high-strength steel sheet comprises: a predetermined chemical composition; a steel microstructure including, in area fraction, ferrite: 20% or more and 50% or less, lower bainite: 5% or more and 40% or less, martensite: 1% or more and 20% or less, and tempered martensite: 20% or less, and including, in volume fraction, retained austenite: 5% or more, the retained austenite having an average grain size of 2 ?m or less; and a texture having an inverse intensity ratio of ?-fiber to ?-fiber of 3.0 or less.
    Type: Grant
    Filed: August 29, 2017
    Date of Patent: August 2, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Hidekazu Minami, Shinjiro Kaneko, Reiko Sugihara, Kazunori Tahara, Kazuma Mori
  • Patent number: 11384415
    Abstract: The present invention relates to a steel alloy with high energy absorption capacity and good formability, comprising beside inevitable impurities due to smelting and iron the following components in weight percent: C 0.05-0.6% Sum of Cr+2*Ti+3*(Mo+V+Nb)+4*W=2-7%, wherein the structure of the steel alloy comprises beside martensite portions of 10-40 Vol.-% retained austenite, wherein the energy absorption capacity expressed by the product of tensile strength (Rm) and uniform strain (Ag) is higher than 12,000 MPa % and the steel alloy has a minimal tensile strength of 1000 MPa. In addition, the invention relates to a steel tube product with high energy absorption capacity and good formability, which is characterized in that it at least partially consists of such a steel alloy.
    Type: Grant
    Filed: November 16, 2016
    Date of Patent: July 12, 2022
    Assignee: Benteler Steel/Tube GmbH
    Inventors: Niko Grosse-Heilmann, Andreas Peters, Isabella-Maria Zylla, Ernst Kozeschnik, Michael Kaufmann, Jozef Balun
  • Patent number: 11377712
    Abstract: A hot dipped high manganese steel and a manufacturing method therefor. The high manganese steel comprises a steel base plate and a coating on the surface of the steel base plate. The core of the steel base plate is austenite. The surface layer of the steel base plate is a ferrite fine grain layer. The ferrite fine grain layer comprises an oxide of Al. Furthermore, the steel base plate of the hot dipped high manganese steel comprises, in mass percentages, 10 to 30% of Mn element, 1 to 2% of Al element, and 0.4 to 0.8% of C element. The manufacturing method comprises: 1) manufacturing strip steel; 2) primary annealing and acid washing; 3) secondary annealing and hot dipping.
    Type: Grant
    Filed: April 20, 2018
    Date of Patent: July 5, 2022
    Assignee: BAOSHAN IRON & STEEL CO., LTD.
    Inventors: Xinyan Jin, Yong Zhong, Guangkui Hu
  • Patent number: 11352679
    Abstract: A steel product includes the following chemical composition in wt. %: C: 0.01 to <0.3, Mn: 4 to <10, Al: 0.003 to 2.9, Mo: 0.01 to 0.8, Si: 0.02 to 0.8, Ni: 0.005 to 3, P: <0.04, S: <0.02, N: <0.02, with the remainder being iron including unavoidable steel-associated elements, wherein an alloy composition satisfies the equation 6<1.5 Mn+Ni<8; or the equation 0.11<C+Al<3, or an alloy composition contains, in addition to Ni, at least one or more of the elements, in wt. %, B: 0.0005 to 0.014; V: 0.006 to 0.1; Nb: 0.003 to 0.1; Co: 0.003 to 3; W: 0.03 to 2 or Zr: 0.03 to 1. The steel product has a microstructure of 2 to 90 vol. % austenite, less than 40 vol. % ferrite and/or bainite, with the remainder being martensite.
    Type: Grant
    Filed: October 27, 2017
    Date of Patent: June 7, 2022
    Assignee: Salzgitter Flachstahl GmbH
    Inventors: Peter Palzer, Manuel Otto, Kai Köhler, Thomas Evertz
  • Patent number: 11345973
    Abstract: Provided are a high-strength steel sheet having a yield strength of 550 MPa or more and excellent fatigue-strength of a weld and a method for manufacturing the steel sheet. A high-strength steel sheet has a specified chemical composition, a steel microstructure observed in a cross section in a thickness direction parallel to a rolling direction including 40% to 75% of a martensite phase in terms of volume fraction, in which a total volume fraction of martensite grains whose average grain diameter ratios with respect to adjacent ferrite grains are ¼ or more and 1 or less is 60% or more with respect to an entire martensite phase, and a yield strength (YP) of 550 MPa or more.
    Type: Grant
    Filed: March 29, 2018
    Date of Patent: May 31, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Lingling Yang, Tatsuya Nakagaito, Gosuke Ikeda
  • Patent number: 11339453
    Abstract: An apparatus can be used for heating a steel sheet. A positive electrode is configured to make contact with a first electrode area of the steel sheet and a negative electrode is configured to make contact with a second electrode area of the steel sheet. A cooling member includes a cooling block configured to make contact with a cooling area adjacent to a third edge parallel to a second direction. The cooling member is configured to radiate heat generated from the steel sheet. The positive electrode, the negative electrode, and the cooling member are arranged on the steel sheet such that the resistance of a path from the positive electrode to the negative electrode through an area with which the cooling member makes contact is higher than the resistance of a path from the positive electrode to the negative electrode through the cooling member.
    Type: Grant
    Filed: March 6, 2020
    Date of Patent: May 24, 2022
    Assignees: Hyundai Motor Company, Kia Motors Corporation
    Inventor: Young Tae Kim
  • Patent number: 11306381
    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: December 21, 2016
    Date of Patent: April 19, 2022
    Assignee: POSCO
    Inventors: Il-Ryoung Sohn, Dae-Young Kang, Jong-Sang Kim, Tae-Chul Kim, Min-Suk Oh
  • Patent number: 11293075
    Abstract: A steel sheet for hot press comprises: a predetermined chemical composition; and a steel microstructure that includes ferrite and cementite and in which Mn?/Mn? is 1.4 or more, where Mn? is a Mn concentration of the ferrite and Mn? is a Mn concentration of the cementite.
    Type: Grant
    Filed: June 8, 2020
    Date of Patent: April 5, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Koichi Nakagawa, Yoshikiyo Tamai
  • Patent number: 11279986
    Abstract: Provided is a cold-rolled high-strength steel having a tensile strength of not less than 1500 MPa and an excellent formability, the chemical elements thereof having the following mass percent ratios: 0.25%-0.40% of C, 1.50%-2.50% of Si, 2.0%-3.0% of Mn, 0.03%-0.06% of Al, P?0.02%, S?0.01%, N?0.01% and at least one of 0.1%-1.0% of Cr and 0.1%-0.5% of Mo, with the balance being Fe and other unavoidable impurities. The microstructure of the cold-rolled high-strength steel has 5%-20% of residual austenite and 70%-90% of martensite, and the carbon concentration ratio of the residual austenite to the martensite is greater than 3.5 and less than 15. The cold-rolled high-strength steel sheet has a high strength and an excellent formability through a rational ingredient design and microstructure control.
    Type: Grant
    Filed: September 20, 2017
    Date of Patent: March 22, 2022
    Assignee: BAOSHAN IRON & STEEL CO., LTD.
    Inventors: Shu Zhou, Yong Zhong, Li Wang
  • Patent number: 11220722
    Abstract: Provided are a steel sheet having a tensile strength of 950 MPa or more and good toughness and a method for manufacturing the same. The steel sheet has a specific composition and a metallographic structure containing: a ferrite area fraction of 30% or less (including 0%), a tempered martensite area fraction of 70% or more (including 100%), and a retained austenite area fraction of 4.5% or less (including 0%), wherein the average aspect ratio of an iron based carbide, precipitated in tempered martensite grains, having a grain size in the largest 10% is 3.5 or more.
    Type: Grant
    Filed: August 29, 2017
    Date of Patent: January 11, 2022
    Assignee: JFE Steel Corporation
    Inventors: Noriaki Kohsaka, Yoshikazu Suzuki, Takeo Kikuchi, Yoshimasa Himei
  • Patent number: 11208704
    Abstract: A high-strength cold-rolled steel sheet has a component composition containing, on a percent by mass basis, C: 0.12% or more and 0.25% or less, Si: less than 0.5%, Mn: 2.0% or more and 3.0% or less, P: 0.05% or less, S: 0.005% or less, Al: 0.01% or more and 0.10% or less, and N: 0.010% or less, the balance being Fe and incidental impurities, the total area percentage of martensite and tempered martensite satisfying 20% or more and 90% or less, the area percentage of ferrite satisfying 10% or less, the area percentage of bainite satisfying 10% or more and 80% or less, the area percentage of a martensite-austenite constituent in the bainite being 1% or more and 10% or less, the area percentage of cementite having an average grain size of 1 ?m or less in the bainite being 0.1% or more and 5.0% or less.
    Type: Grant
    Filed: April 19, 2017
    Date of Patent: December 28, 2021
    Assignee: JFE Steel Corporation
    Inventors: Takuya Hirashima, Hiromi Yoshitomi
  • Patent number: 11208709
    Abstract: Provided are a high-strength steel sheet having a yield strength of 550 MPa or higher and having a small amount of springback and width-direction uniformity in material properties as well as a manufacturing method therefor. The high-strength steel sheet has a yield strength (YP) of 550 MPa or higher and has a specific component composition and a microstructure containing a ferrite phase, 40 to 70% of a martensite phase in area ratio, and 5 to 30% of a bainite phase in area ratio, where: an average grain size of the martensite phase is 2 to 8 ?m and an average grain size of the ferrite phase is 11 ?m or less on a cross-section in the thickness direction and in a direction orthogonal to a rolling direction; and the average grain size of the ferrite phase is 3.0 times or less the average grain size of martensite.
    Type: Grant
    Filed: February 21, 2018
    Date of Patent: December 28, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Lingling Yang, Noriaki Kohsaka, Tatsuya Nakagaito
  • Patent number: 11174529
    Abstract: A high-strength steel sheet having a microstructure represented by, in area %, martensite: 5% or more; ferrite: 20% or more; and pearlite: 5% or less. A ratio of the number of bulging type martensite grains to the number of martensite grains on grain boundary triple points of a matrix is 70% or more, wherein: the bulging type martensite grain is on one of the grain boundary triple points of the matrix; and at least one of grain boundaries of the bulging type martensite grain, the grain boundaries connecting two adjacent grain boundary triple points of the bulging type martensite grain and grains of the matrix, has a convex curvature to an outer side with respect to line segments connecting the two adjacent grain boundary triple points. An area ratio VM/A0 is 1.0 or more.
    Type: Grant
    Filed: May 6, 2016
    Date of Patent: November 16, 2021
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Riki Okamoto, Yoshinari Ishida, Yoshihiro Suwa, Takafumi Yokoyama
  • Patent number: 11131003
    Abstract: A method for producing a cold rolled steel sheet having a tensile strength?1470 MPa and a total elongation TE?19%, the method comprising the steps of annealing at an annealing temperature AT?Ac3 a non-treated steel sheet whose chemical composition contains in weight %: 0.34%?C?0.40%, 1.50%?Mn?2.30%, 1.50?Si?2.40%, 0%<Cr?0.5%, 0%<Mo?0.3%, 0.01%?Al?0.07%, the remainder being Fe and unavoidable impurities, quenching the annealed steel sheet by cooling it to a quenching temperature QT<Ms transformation point and between 150° C. and 250° C., and making a partitioning treatment by reheating the quenched steel sheet to a partitioning temperature PT between 350° C. and 420° C. and maintaining the steel sheet at this temperature during a partitioning time Pt between 15 seconds and 120 seconds.
    Type: Grant
    Filed: May 15, 2019
    Date of Patent: September 28, 2021
    Assignee: ARCELORMITTAL
    Inventors: Olga A. Girina, Damon Panahi
  • Patent number: 11111553
    Abstract: A high-strength steel sheet having a tensile strength (TS) of 1,320 MPa or more and good workability. The high-strength steel sheet has a specific component composition and a steel microstructure containing, on an area-percentage basis with respect to the entire steel microstructure, 40% or more and less than 85% of a lower bainite, 5% or more and less than 40% martensite including tempered martensite, 10% or more and 30% or less retained austenite, and 10% or less (including 0%) polygonal ferrite, the retained austenite having an average C content of 0.60% by mass or more. Additionally, a Mn segregation value at a surface of the steel sheet is 0.8% or less, the ratio R/t of a limit bending radius (R) to a thickness (t) of the steel sheet is 2.0 or less, and tensile strength×total elongation of the steel sheet is 15,000 MPa % or more.
    Type: Grant
    Filed: February 7, 2017
    Date of Patent: September 7, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Yusuke Kimata, Yoshihiko Ono, Kenji Kawamura
  • Patent number: 11060158
    Abstract: The present invention relates to a method of manufacturing a directional electric steel plate having excellent surface wettability and magnetic properties. More particularly, the present invention relates to a directional electric steel plate in which a surface of a steel plate consisting of Si: 2.0 to 6.5%, acid soluble Al: 0.4 to 5%, Mn: 0.20% or less (0% exclusive), N: 0.010% or less (0% exclusive), S: 0.010% or less (0% exclusive), P: 0.005 to 0.05%, C: 0.04 to 0.12% and a balance of Fe and other unavoidable impurities is hot-dip plated with aluminum or an aluminum-silicon alloy, and heat-treated, so that aluminum on the hot-dip plated layer is diffused or infiltrated into the steel plate, and a method of manufacturing the same.
    Type: Grant
    Filed: December 21, 2015
    Date of Patent: July 13, 2021
    Assignee: POSCO
    Inventor: Dae Hyun Song
  • Patent number: 11021776
    Abstract: A hot rolled, ultra-high strength, complex metallographic structured or multi-phase structured steel that improves formability during stamping or forming process, while possessing one or more of the following properties: excellent castability, rollability and coatability, excellent structural performance, excellent stretch formability, excellent stretch flangeability, excellent dent resistance, excellent durability, excellent impact performance, excellent intrusion and crash resistance without the purposeful addition of boron.
    Type: Grant
    Filed: November 3, 2017
    Date of Patent: June 1, 2021
    Assignee: NUCOR CORPORATION
    Inventor: Weiping Sun
  • Patent number: 11008632
    Abstract: A steel sheet is provided that has a tensile strength of 540 MPa or more, includes a particular composition; and has a steel structure containing ferrite and a secondary phase, in which an area fraction of the ferrite is 50% or more, the secondary phase contains 1.0% or more and 25.0% or less of martensite in terms of area fraction with respect to the entirety, the ferrite has an average crystal grain size of 3 ?m or more, a difference in hardness between the ferrite and the martensite is 1.0 GPa or more and 8.0 GPa or less, and, in a texture of the ferrite, an inverse intensity ratio of ?-fiber to ?-fiber is 0.8 or more and 7.0 or less.
    Type: Grant
    Filed: March 7, 2017
    Date of Patent: May 18, 2021
    Assignee: JFE Steel Corporation
    Inventors: Hidekazu Minami, Yoshimasa Funakawa, Shinjiro Kaneko
  • Patent number: 10982309
    Abstract: Disclosed are a hot-rolled galvanized steel sheet having excellent galling resistance and formability, and a method for manufacturing the same. The hot-rolled galvanized steel sheet, includes: a base steel; and a hot-rolled galvanizing layer formed on the surface of the base steel, wherein the hot-rolled galvanizing layer provides a hot-rolled galvanized steel sheet having a Mn crystallite having a size of 10 ?m or less between the resin dendrites of zinc that form sequins.
    Type: Grant
    Filed: August 22, 2017
    Date of Patent: April 20, 2021
    Assignee: POSCO
    Inventors: Sang-Heon Kim, Hyeon-Seok Hwang, Suk-Kyu Lee, Sun-Ho Jeon, Yon-Kyun Song, Bong-Hwan Yoo
  • Patent number: 10954580
    Abstract: A method for producing a steel sheet having a microstructure including 71% to 91% martensite and bainite, 9% to 13% retained austenite, and at most 20% ferrite is provided. The method includes providing a cold-rolled steel sheet including, in weight percent: 0.13%?C?0.22%, 1.2%?Si?2.3%, 0.02%?Al?1.0%, with 1.25%?Si+Al?2.35%, 2.4%?Mn?3%, Ti?0.05%, Nb?0.05% and a remainder of Fe and unavoidable impurities, annealing the steel sheet to obtain 80% to 100% austenite and 0% to 20% ferrite, quenching the steel sheet at a cooling rate between 20° C./s and 50° C./s to a quenching temperature between 240° C. and 310° C., heating the steel sheet to a partitioning temperature between 400° C. and 465° C. and maintaining the steel sheet at the partitioning temperature for 50 to 250 seconds, then immediately cooling the sheet to room temperature. Steel sheets are also provided.
    Type: Grant
    Filed: December 21, 2016
    Date of Patent: March 23, 2021
    Assignee: ARCELORMITTAL
    Inventors: Pavan Venkatasurya, Hyun Jo Jun
  • Patent number: 10774405
    Abstract: Steel has a chemical composition that contains 0.050% to 0.40% of C, 0.50% to 3.0% of Si, 3.0% to 8.0% of Mn, and 0.001% to 3.0% of sol. Al, by mass %, and has a metallographic structure that contains 10% to 40% of austenite in terms of % by volume. The average concentration of C in austenite is 0.30% by 0.60%, by mass %, structure uniformity, which is represented by a value obtained by subtracting the minimum value from the maximum value of Vickers hardness that is measured, in the metallographic structure is 30 Hv or less, and the tensile strength is 900 MPa to 1800 MPa.
    Type: Grant
    Filed: January 6, 2014
    Date of Patent: September 15, 2020
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Koutarou Hayashi, Akira Seki, Kazuya Mishio, Shuhei Shimokawa
  • Patent number: 10731241
    Abstract: An Al—Zn—Si—Mg alloy coated strip that has Mg2Si phase particles that are ?2 ?m and have a globular shape. A method of forming an Al—Zn—Si—Mg alloy coated strip comprises (a) heat treating a solidified coating to facilitate globularisation of Mg2Si phase particles in the coating and/or (b) changing the coating bath chemistry to form intermetallic compound phases that act as nucleation sites for Mg2Si phase particles with the result that small Mg2Si particles form on solidification of the coating.
    Type: Grant
    Filed: May 27, 2010
    Date of Patent: August 4, 2020
    Assignee: Bluescope Steel Limited
    Inventors: Ross McDowall Smith, Qiyang Liu, Joe Williams
  • Patent number: 10718044
    Abstract: A hot-dip galvanized steel sheet includes: a predetermined chemical composition; and a steel structure represented by: in terms of area ratio, polygonal ferrite: 10% or less; upper bainite: 20% or less; retained austenite: 5% or less; and martensite: 70% or more, in which: martensite having Fe carbides at a number density of 1×106/mm2 or more is contained by 50% or more, in terms of area ratio, with respect to the entire amount of martensite; and the steel structure has an average effective crystal grain diameter of 5.0 ?m or less.
    Type: Grant
    Filed: July 15, 2016
    Date of Patent: July 21, 2020
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Takafumi Yokoyama, Kunio Hayashi, Masafumi Azuma, Eisaku Sakurada, Hiroyuki Kawata, Genki Abukawa
  • Patent number: 10711336
    Abstract: Provided is an alloyed hot-dip galvanized steel sheet including a base steel sheet, the base steel sheet containing a given amount of C, Si, Mn, and other elements. The alloyed hot-dip galvanized steel sheet is provided with an alloyed hot-dip galvanized layer on a surface of the base steel sheet, the alloyed hot-dip galvanized layer containing, in mass %, Fe: more than or equal to 5% and less than or equal to 15%, and having a thickness of more than or equal to 3 ?m and less than or equal to 30 ?m.
    Type: Grant
    Filed: November 8, 2018
    Date of Patent: July 14, 2020
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Soshi Fujita, Shintaro Yamanaka
  • Patent number: 10604829
    Abstract: Disclosed herein is a high-strength plated steel sheet having a plated layer on the surface of a base steel sheet and containing predetermined steel components. The steel sheet includes, in the order from the interface of the base steel sheet and the plated layer towards the base steel sheet: a soft layer having a Vickers hardness that is 90% or less of the Vickers hardness at a portion t/4 of the base steel sheet, where t is a sheet thickness of the base steel sheet; and a hard layer consisting of a structure which is mainly composed of martensite and bainite and in which the average grain size of prior austenite is 20 ?m or less. The average depth D of the soft layer is 20 ?m or greater, and the average depth d of an internal oxide layer is 4 ?m or greater and smaller than D.
    Type: Grant
    Filed: January 5, 2016
    Date of Patent: March 31, 2020
    Assignee: Kobe Steel, Ltd.
    Inventors: Muneaki Ikeda, Michiharu Nakaya
  • Patent number: 10590521
    Abstract: Steel strip provided with a hot dip galvanized zinc alloy coating layer, in which the coating of the steel strip is carried out in a bath of molten zinc alloy, the zinc alloy in the coating of: 0.3-2.3 weight % magnesium; 0.6-2.3 weight % aluminium; optional <0.2 weight % of one or more additional elements; unavoidable impurities; the remainder being zinc in which the zinc alloy coating layer has a thickness of 3-12 ?m.
    Type: Grant
    Filed: May 3, 2017
    Date of Patent: March 17, 2020
    Assignee: TATA STEEL IJMUIDEN B.V.
    Inventors: Theodorus Franciscus Jozef Maalman, Robert Bleeker, Margot Julia Vlot
  • Patent number: 10584407
    Abstract: Zn alloy plated steel material having excellent weldability and processed-part corrosion resistance and a method for production of Zn alloy plated steel material are provided. In the Zn alloy plated steel material comprising base steel material and a Zn alloy plating layer, the Zn alloy plating layer includes, by wt %, Al: 0.1-5.0%, Mg: 0.1-5.0%, as well as a remainder of Zn and inevitable impurities. The Zn alloy plated steel material includes a lower interface layer and an upper interface layer between the base steel material and the Zn alloy plating layer, wherein the lower interface layer is formed on the base steel material and has a dense structure, and the upper interface layer is formed on the lower interface layer and has a network-type or island-type structure.
    Type: Grant
    Filed: December 24, 2015
    Date of Patent: March 10, 2020
    Assignee: POSCO
    Inventors: Min-Suk Oh, Sang-Heon Kim, Tae-Chul Kim, Jong-Sang Kim, Hyun-Chu Yun, Bong-Hwan Yoo, Il-Ryoung Sohn
  • Patent number: 10570473
    Abstract: Provided is a high-strength cold-rolled steel sheet having excellent ductility and stretch-flangeability as well as weldability in a range in which a tensile strength is 980 MPa or higher and a 0.2% yield strength is less than 700 MPa (preferably 500 MPa or higher). In the high-strength cold-rolled steel sheet of the present invention, the chemical composition is adjusted as appropriate, and the area ratio of below-mentioned metal structures at a position of ¼ sheet thickness in the steel sheet satisfies following requirements: tempered martensite: 10 area % to less than 30 area %, bainite: more than 70 area %, total of tempered martensite and bainite: 90 area % or more, ferrite: 0 area % to 5 area %, and retained austenite: 0 area % to 4 area %. The high-strength cold-rolled steel sheet has excellent ductility, stretch-flangeability, and weldability, and has a tensile strength of 980 MPa or higher and a 0.2% yield strength of less than 700 MPa.
    Type: Grant
    Filed: March 19, 2015
    Date of Patent: February 25, 2020
    Assignee: Kobe Steel, Ltd.
    Inventors: Michitaka Tsunezawa, Michiharu Nakaya
  • Patent number: 10563280
    Abstract: The present invention relates to a high-strength and high-manganese steel sheet suitable for an outer panel or a vehicle body of a transport vehicle and, more specifically, to a high-strength and high-manganese steel sheet having excellent vibration-proof properties and a method for producing the same.
    Type: Grant
    Filed: December 24, 2013
    Date of Patent: February 18, 2020
    Assignee: POSCO
    Inventors: Sung-Kyu Kim, Kwang-Geun Chin, Tae-Jin Song, Tai-Ho Kim, Won-Tae Cho, Sun-Ho Jeon
  • Patent number: 10550457
    Abstract: Zn alloy plated steel material having excellent weldability and processed-part corrosion resistance and a method for production of Zn alloy plated steel material are provided. In the Zn alloy plated steel material comprising base steel material and a Zn alloy plating layer, the Zn alloy plating layer includes, by wt %, Al: 0.1-5.0%, Mg: 0.1-5.0%, as well as a remainder of Zn and inevitable impurities. The Zn alloy plated steel material includes a lower interface layer and an upper interface layer between the base steel material and the Zn alloy plating layer, wherein the lower interface layer is formed on the base steel material and has a dense structure, and the upper interface layer is formed on the lower interface layer and has a network-type or island-type structure.
    Type: Grant
    Filed: December 24, 2015
    Date of Patent: February 4, 2020
    Assignee: POSCO
    Inventors: Min-Suk Oh, Sang-Heon Kim, Tae-Chul Kim, Jong-Sang Kim, Hyun-Chu Yun, Bong-Hwan Yoo, Il-Ryoung Sohn
  • Patent number: 10544477
    Abstract: A method for manufacturing a high-strength galvanized steel sheet includes performing hot rolling, cold rolling, first annealing, pickling, and second annealing. The first annealing is performed to obtain a steel sheet having a steel microstructure including ferrite in an amount of 10% or more and 60% or less in terms of area ratio, and martensite, bainite, and retained austenite in a total amount of 40% or more and 90% or less in terms of area ratio. The second annealing includes heating to an annealing temperature of 750° C. or higher and 850° C. or lower, holding at the annealing temperature for 10 seconds or more and 500 seconds or less, cooling at an average cooling rate of 1° C./s or more and 15° C./s or less, performing a galvanizing treatment, and cooling to a temperature of 150° C. or lower at an average cooling rate of 5° C./s or more and 100° C./s or less.
    Type: Grant
    Filed: June 9, 2015
    Date of Patent: January 28, 2020
    Assignee: JFE Steel Corporation
    Inventors: Hideyuki Kimura, Koichiro Fujita, Hiroshi Hasegawa, Mai Aoyama
  • Patent number: 10538830
    Abstract: A steel sheet of the present invention has a steel structure obtained by performing a soaking at a dual phase region temperature of Ac1 temperature or higher and lower than Ac3 temperature for a soaking time of 15 seconds or longer and 35 seconds or shorter, next, performing a primary cooling to a temperature range of 250° C. or higher and 380° C. or lower within 3 seconds at a cooling rate of 0.5° C./s or more and 30° C./s or less, and performing a retention in a temperature range of 260° C. or higher and 370° C. or lower for 180 seconds or longer and 540 seconds or shorter, in which a yield ratio is 65% or less and tensile strength is 590 MPa or more after the primary cooling.
    Type: Grant
    Filed: October 5, 2012
    Date of Patent: January 21, 2020
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Yuji Fukumoto, Takashi Aramaki, Junichi Yasui, Norimitsu Harada
  • Patent number: 10526671
    Abstract: A high-strength cold-rolled steel sheet having excellent ductility and stretch flangeability includes: a chemical composition consisting, in mass %, C: 0.06 to 0.3, Si: 0.6 to 2.5%, Mn: 0.6 to 3.5%, P: at most 0.1%, S: at most 0.05%, Ti: 0 to 0.08%, Nb: 0 to 0.04%, total of Ti and Nb: 0 to 0.10%, sol.Al: 0 to 2.0%, Cr: 0 to 1%, Mo: 0 to 0.3%, V: 0 to 0.3%, B: 0 to 0.005%, Ca: 0 to 0.003%, REM: 0 to 0.003% and the remainder of Fe and impurities; a microstructure having a main phase including at least 40 area % in total of martensite and/or bainite; and a texture in which proportion of an average X-ray intensity in an {100}<011> to {211}<011> orientations relative to an average X-ray intensity of a random structure not having a texture is less than 6.
    Type: Grant
    Filed: February 13, 2013
    Date of Patent: January 7, 2020
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Kengo Hata, Toshiro Tomida, Norio Imai, Jun Haga, Takuya Nishio
  • Patent number: 10472692
    Abstract: A method for manufacturing a high-strength sheet having improved formability and ductility accord which the chemical composition of the steel contains, in percent by weight: 0.25%<C?0.4% 2.3%?Mn?3.5% 2.3%?Si?3% Al?0.040% the remainder being Fe and unavoidable impurities, the method comprising the steps of annealing a rolled sheet made of said steel by soaking it at an annealing temperature AT higher than the Ac3 transformation point of the steel, quenching the sheet by cooling it down to a quenching temperature QT between Ms?65° C. and Ms?115° C., being in order to obtain a final structure containing at least 65% of martensite and at least 5% of residual austenite, the sum of the ferrite and bainite contents being less than 10%, Ms being the Ms transformation point of the steel according to the Andrews formula, heating the sheet up to an overaging temperature PT between 360° C. and 500° C.
    Type: Grant
    Filed: July 3, 2015
    Date of Patent: November 12, 2019
    Assignee: ArcelorMittal
    Inventors: Gunhild Föjer, Michel Soler, Jean-Christophe Hell
  • Patent number: 10465272
    Abstract: Provided is a high-strength hot-dip galvanized steel sheet having excellent plating adhesion, formability, and hole expandability with an ultimate tensile strength of 980 MPa or more, the hot-dip galvanized steel sheet comprising a hot-dip galvanized layer formed on a surface of a base steel sheet. The base steel sheet contains, by mass %, C: 0.05% to 0.4%; Si: 0.01% to 3.0%; Mn: 0.1% to 3.0%; Al: 0.01 to 2.0%; in which Si+Al>0.5%, P: limited to 0.04% or less; S: limited to 0.05% or less; N: limited to 0.01% or less; and a balance including Fe and inevitable impurities, a microstructure of the base steel sheet contains 40% or more by total volume fraction of martensite and bainite, 8% or more by volume fraction of residual austenite, and a balance of the microstructure being ferrite or ferrite and 10% or less by volume fraction of pearlite.
    Type: Grant
    Filed: September 6, 2017
    Date of Patent: November 5, 2019
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Chisato Wakabayashi, Masafumi Azuma, Nobuhiro Fujita, Kohichi Sano
  • Patent number: 10400301
    Abstract: The present invention relates to a high-strength steel sheet and, more specifically, to a dual-phase steel sheet having excellent formability, so as to be appropriately applied to vehicle panels and the like, and a manufacturing method therefor.
    Type: Grant
    Filed: November 26, 2015
    Date of Patent: September 3, 2019
    Assignee: POSCO
    Inventors: Sang-Ho Han, Yeon-Sang Ahn
  • Patent number: 10378077
    Abstract: A method for producing a cold rolled steel sheet having a tensile strength ?1470 MPa and a total elongation TE?19%, the method comprising the steps of annealing at an annealing temperature AT?Ac3 a non-treated steel sheet whose chemical composition contains in weight %: 0.34%?C?0.40%, 1.50%?Mn?2.30%, 1.50?Si?2.40%, 0%<Cr?0.5%, 0%<Mo?0.3%, 0.01%?A1?0.07%, the remainder being Fe and unavoidable impurities, quenching the annealed steel sheet by cooling it to a quenching temperature QT<Ms transformation point and between 150° C. and 250° C., and making a partitioning treatment by reheating the quenched steel sheet to a partitioning temperature PT between 350° C. and 420° C. and maintaining the steel sheet at this temperature during a partitioning time Pt between 15 seconds and 120 seconds.
    Type: Grant
    Filed: July 3, 2014
    Date of Patent: August 13, 2019
    Assignee: ArcelorMittal
    Inventors: Olga A. Girina, Damon Panahi
  • Patent number: 10344361
    Abstract: The present invention relates to an ultra-high strength, hot-dip galvanized steel sheet having excellent surface quality and coating adherence and to a method for manufacturing thereof, the ultra-high strength, hot-dip galvanized steel sheet comprising: 0.1-0.3% by weight carbon (C); 0.1-2.0% by weight silicon (Si); 0.005-1.5% by weight aluminum (Al); 1.5-3.5% by weight manganese (Mn); 0.04% by weight or less phosphorus (P) (excluding 0% by weight); 0.015% by weight or less sulphur (S) (excluding 0% by weight); 0.02% by weight or less nitrogen (N) (excluding 0% by weight); the balance being Fe; and other inevitable impurities, and further comprising 0.01 wt.% to 0.07 wt.% of at least one kind of element selected from the group consisting of bismuth (Bi), tin (Sn) and antimony (Sb).
    Type: Grant
    Filed: December 8, 2015
    Date of Patent: July 9, 2019
    Assignee: POSCO
    Inventors: Myung-Soo Kim, Ki-Cheol Kang
  • Patent number: 10344350
    Abstract: The present disclosure relates to a production of a high-strength steel sheet with excellent combination of strength and ductility, and a method of manufacturing the same. In accordance with a method of manufacturing a high-strength steel sheet, the method may include: heating a steel sheet which can have a residual austenite upon cooling, to form an austenite; primary cooling the austenitized steel sheet to T1 for a bainite region and subjecting to a primary isothermal transformation; and secondary cooling the primary isothermal transformed steel sheet to T2, which is lower than T1 by 50° C. ore more, for a bainite region, and subjecting to a secondary isothermal transformation.
    Type: Grant
    Filed: December 16, 2015
    Date of Patent: July 9, 2019
    Assignee: KOREA INSTITUTE OF MACHINERY AND MATERIALS
    Inventor: Chang-Hoon Lee
  • Patent number: 10301701
    Abstract: Disclosed is a high-strength hot-dip galvanized steel sheet produced from a steel sheet containing Si and Mn as a base material and a method for producing the same. The method using the following conditions for a heating process for annealing: (1) The rate of temperature rise when the temperature inside an annealing furnace is in a temperature range of from 450° C. to A° C. inclusive (where A is an arbitrary value selected in a range of 500?A) is 7° C./sec. or more; (2) The maximum steel sheet temperature reached during the annealing is 600° C. or higher and 750° C. or lower; (3) When the temperature of the steel sheet is in a temperature range of from 600° C. to 750° C. inclusive during the annealing, the transit time of the steel sheet is 30 seconds or longer and 10 minutes or shorter, and the dew point of an atmosphere is ?45° C. or lower.
    Type: Grant
    Filed: February 6, 2015
    Date of Patent: May 28, 2019
    Assignee: JFE STEEL CORPORATION
    Inventors: Yusuke Fushiwaki, Yoshiyasu Kawasaki
  • Patent number: 10167541
    Abstract: Provided is an alloyed hot-dip galvanized steel sheet including a base steel sheet, the base steel sheet containing a given amount of C, Si, Mn, and other elements. The alloyed hot-dip galvanized steel sheet is provided with an alloyed hot-dip galvanized layer on a surface of the base steel sheet, the alloyed hot-dip galvanized layer containing, in mass %, Fe: more than or equal to 5% and less than or equal to 15%, and having a thickness of more than or equal to 3 ?m and less than or equal to 30 ?m.
    Type: Grant
    Filed: November 5, 2013
    Date of Patent: January 1, 2019
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Soshi Fujita, Shintaro Yamanaka
  • Patent number: 10106867
    Abstract: A steel strip is annealed in a vertical annealing furnace including a heating zone and a soaking zone through which the steel strip is vertically conveyed, an atmosphere gas is supplied into the furnace to form a furnace gas that is discharged from a steel strip entrance at a lower portion of the heating zone, a part of the furnace gas is sucked and discharged into a refiner to form a gas having a lowered dew point that is returned into the furnace. A gas injector having a plurality of gas outlets arranged in a direction of a travel of the steel strip is disposed to suppress a mixing of an atmosphere in the furnace upstream of the gas injector and an atmosphere in the furnace downstream of the gas injector, and a temperature of the steel strip passing through the gas injector is controlled to 600° C. to 700° C.
    Type: Grant
    Filed: June 10, 2013
    Date of Patent: October 23, 2018
    Assignee: JFE Steel Corporation
    Inventor: Hideyuki Takahashi
  • Patent number: 10087511
    Abstract: There are provided a method for manufacturing a high manganese hot-dip galvanized steel sheet having superior coatability and ultra-high strength, and a high manganese hot-dip galvanized steel sheet manufactured by the method. The method includes: cold rolling a hot-rolled steel sheet to form a cold-rolled steel sheet, the hot-rolled steel sheet including, by wt %, C: 0.3% to 1%, Mn: 8% to 25%, Si: 0.1% to 3%, Al: 0.01% to 8%, Cr: 0.1% to 2%, Ti: 0.01% to 0.2%, B: 0.0005% to 0.01%, Ni: 0.01% to 2%, Sn: 0.06% to 0.2%, and a balance of Fe and inevitable impurities; heating the cold-rolled steel sheet; cooling the heated steel sheet to, or maintaining the heated steel sheet; and performing a hot-dip galvanizing process on the cooled or temperature-maintained steel sheet by dipping the cooled or temperature-maintained steel sheet into a hot-dip galvanizing bath.
    Type: Grant
    Filed: December 19, 2013
    Date of Patent: October 2, 2018
    Assignee: POSCO
    Inventors: Sun-Ho Jeon, Kwang-Geun Chin, Won-Tae Cho
  • Patent number: 10030280
    Abstract: The present invention provides a steel sheet with chemical components including, by mass %, 0.18-0.35% of C, 1.0%-3.0% of Mn, 0.01%-1.0% of Si, 0.001%-0.02% of P, 0.0005%-0.01% of S, 0.001%-0.01% of N, 0.01%-1.0% of Al, 0.005%-0.2% of Ti, 0.0002%-0.005% of B, and 0.002%-2.0% of Cr, and the balance of Fe and inevitable impurities, wherein: by volume %, a fraction of the ferrite is 50% or more, and a fraction of a non-recrystallized ferrite is 30% or less; and Cr?/CrM is 2 or less, where Cr? is a concentration of Cr subjected to solid solution in iron carbide and CrM is a concentration of Cr subjected to solid solution in a base material, or Mn0/MnM is 10 or less, where Mn0 is a concentration of Mn subjected to solid solution in an iron carbide, and MnM is a concentration of Mn subjected to solid solution in a base material.
    Type: Grant
    Filed: October 21, 2011
    Date of Patent: July 24, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kunio Hayashi, Toshimitsu Aso, Toshimasa Tomokiyo
  • Patent number: 9994941
    Abstract: A high strength cold rolled steel sheet has a chemical composition including, by mass %, C: 0.06 to 0.13%, Si: 1.2 to 2.3%, Mn: 0.6 to 1.6%, P: not more than 0.10%, S: not more than 0.010%, Al: 0.01 to 0.10% and N: not more than 0.010%, the balance comprising Fe and inevitable impurities. The steel sheet includes a microstructure containing not less than 90% in terms of volume fraction of ferrite with an average grain diameter of less than 20 ?m and 1.0 to 10% in terms of volume fraction of pearlite with an average grain diameter of less than 5 ?m. The ferrite has an average Vickers hardness of not less than 130. The steel sheet has a yield ratio of not less than 65% and a tensile strength of not less than 590 MPa.
    Type: Grant
    Filed: December 3, 2012
    Date of Patent: June 12, 2018
    Assignee: JFE Steel Corporation
    Inventors: Katsutoshi Takashima, Yuki Toji, Kohei Hasegawa
  • Patent number: 9920407
    Abstract: A cold rolled steel sheet according to the present invention satisfies an expression of (5×[Si]+[Mn])/[C]>11 when [C] represents an amount of C by mass %, [Si] represents an amount of Si by mass %, and [Mn] represents an amount of Mn by mass %, a metallographic structure before hot stamping includes 40% to 90% of a ferrite and 10% to 60% of a martensite in an area fraction, a total of an area fraction of the ferrite and an area fraction of the martensite is 60% or more, a hardness of the martensite measured with a nanoindenter satisfies an H2/H1<1.10 and ?HM<20 before the hot stamping, and TS×? which is a product of a tensile strength TS and a hole expansion ratio ? is 50000 MPa·% or more.
    Type: Grant
    Filed: January 11, 2013
    Date of Patent: March 20, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Toshiki Nonaka, Satoshi Kato, Kaoru Kawasaki, Toshimasa Tomokiyo
  • Patent number: 9896751
    Abstract: High strength steel sheet and high strength galvanized steel sheet which are excellent in shapeability which secure a tensile maximum strength 900 MPa or more high strength while obtaining excellent ductility and stretch flangeability, which sheets have predetermined compositions of ingredients, have steel sheet structures which contain volume fraction 1 to 20% of residual austenite phases, and which have martensite transformation points of the residual austenite phases of ?60° C. or less.
    Type: Grant
    Filed: July 27, 2012
    Date of Patent: February 20, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hiroyuki Kawata, Naoki Maruyama, Akinobu Murasato, Akinobu Minami, Takeshi Yasui, Yuji Yamaguchi, Natsuko Sugiura
  • Patent number: 9828663
    Abstract: Provided is a galvannealed steel sheet with excellent anti-powdering property when press forming is performed, without controlling the contents of chemical elements in steel which are effective for strengthening a steel sheet, such as Si and P, to be low in order to achieve required material properties and without increasing cost due to, for example, processes being complicated. A galvannealed steel sheet with excellent anti-powdering property has a coated layer taking in grains of a base steel sheet such that the grains constitute 2.0% or more and 15.0% or less of the coated layer in terms of cross section area ratio.
    Type: Grant
    Filed: June 18, 2013
    Date of Patent: November 28, 2017
    Assignee: JFE Steel Corporation
    Inventors: Yoichi Makimizu, Yoshitsugu Suzuki, Hideki Nagano, Yasunobu Nagataki
  • Patent number: 9790567
    Abstract: A coated dual-phase steel and process for producing the coated dual-phase steel is provided. The process includes providing a steel slab with a desired chemistry, soaking the slab at an elevated temperature and then hot rolling the slab to produce hot-rolled strip. The hot-rolled strip is coiled and has a ferrite-pearlite microstructure. The coiled hot-rolled strip is cold-rolled into cold-rolled sheet with at least a 60% reduction in thickness compared to the thickness of the coiled hot-rolled strip. The cold-rolled sheet is subjected to an intercritical anneal followed by rapid cooling with the absence of an isothermal heat treatment or hold after rapid cooling near the molten metal pot temperature—during which, before or after which the steel is coated. The coated steel sheet has a dual-phase ferrite-martensite microstructure, a yield strength of at least 310 MPa, a tensile strength of at least 580 MPa and a total elongation to failure of at least 18%.
    Type: Grant
    Filed: November 20, 2013
    Date of Patent: October 17, 2017
    Assignee: Thyssenkrupp Steel USA, LLC
    Inventors: Ranbir Jamwal, Joseph Frimpong, Bertram Wilhelm Ehrhardt, Harald Van Bracht, Roger Dale Boggs, Stanley Wayne Bevans
  • Patent number: 9708684
    Abstract: There is provided a hot-dip galvanized steel sheet and a hot-dip galvannealed steel sheet, which have excellent elongation properties, and methods for manufacturing the hot-dip galvanized steel sheet and the hot-dip galvannealed steel sheet. The present disclosure relates to a hot-dip galvanized steel sheet in which a hot-dip galvanized layer is formed on a surface of a base steel sheet, the hot-dip galvanized steel sheet having excellent elongation properties and being characterized by the composition and the microstructure thereof.
    Type: Grant
    Filed: December 23, 2015
    Date of Patent: July 18, 2017
    Assignee: POSCO
    Inventors: Sang Ho Han, Seong Ho Han