Copper Containing Patents (Class 420/49)
  • Patent number: 11866814
    Abstract: An austenitic stainless steel, which consists of by mass percent, C: not more than 0.02%, Si: not more than 1.5%, Mn: not more than 2%, Cr: 17 to 25%, Ni: 9 to 13%, Cu: more than 0.26% not more than 4%, N: 0.06 to 0.35%, sol. Al: 0.008 to 0.03%. One or more elements selected from Nb, Ti, V, TA, Hf, and Zr in controlled amounts can be included with the balance being Fe and impurities. P, S, Sn, As, Zn, Pb and Sb among the impurities are controlled as P: 0.006 to 0.04%, S: 0.0004 to 0.03%, Sn: 0.001 to 0.1%, As: not more than 0.01%, Zn: not more than 0.01%, Pb: not more than 0.01% and Sb: not more than 0.01%. The amounts of S, P, Sn, As, Zn, Pb and Sb and the amounts of Nb, Ta, Zr, Hf, and Ti are further controlled using formulas.
    Type: Grant
    Filed: January 23, 2020
    Date of Patent: January 9, 2024
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Takahiro Osuki, Kazuhiro Ogawa, Hiroyuki Hirata, Yoshitaka Nishiyama
  • Patent number: 11817226
    Abstract: An insertable flux thimble interface for use in a bottom nozzle of a fuel assembly in a nuclear reactor (i.e., a bottom nozzle insert) is disclosed herein. In various aspects, the bottom nozzle insert has properties that are different from traditional bottom nozzle flux thimble interfaces. The properties of the bottom nozzle insert may mitigate wear phenomena observed on the flux thimble. For example, the bottom nozzle insert may be constructed from material that is different from the material of the bottom nozzle. In some aspects, the bottom nozzle insert is constructed from material that has a hardness that is less than the hardness the bottom nozzle material. In other aspects, the bottom nozzle insert is constructed from a material that has a hardness that is less than the hardness of the flux thimble material.
    Type: Grant
    Filed: November 10, 2021
    Date of Patent: November 14, 2023
    Assignee: Westinghouse Electric Company LLC
    Inventors: Yuriy Aleshin, Thanh H. Do
  • Patent number: 11306378
    Abstract: The present disclosure relates to a duplex stainless steel comprising in weight % (wt %): C less than 0.03; Si less than 0.60; Mn 0.40 to 2.00; P less than 0.04; S less than or equal to 0.01; Cr more than 30.00 to 33.00; Ni 6.00 to 10.00; Mo 1.30 to 2.90; N 0.15 to 0.28; Cu 0.60 to 2.20; Al less than 0.05; balance Fe and unavoidable impurities. The present disclosure also relates to a component or a construction material comprising the duplex stainless steel. Additionally, the present disclosure also relates to a process for manufacturing a component comprising said duplex stainless steel.
    Type: Grant
    Filed: February 14, 2019
    Date of Patent: April 19, 2022
    Assignee: Sandvik Intellectual Property AB
    Inventors: Tomas Antonsson, Lars Nylöf
  • Patent number: 11268177
    Abstract: An austenitic stainless steel according to the present invention has a chemical composition containing, by mass %: C: 0.01 to 0.15%; Si: 2.0% or less; Mn: 3.0% or less; Cr: 10.0 to 20.0%; Ni: 5.0 to 13.0%; N: 0.01 to 0.30%; Nb: 0 to 0.5%; Ti: 0 to 0.5%; and V: 0 to 0.5%, with the balance: Fe and impurities, wherein an average grain size is 10.0 ?m or less, a difference in value of an average lattice constant dAve. (={d?(111)×I?(111)+d?(200)×I?(200)+d?(220)×I?(220)+d?(311)×I?(311)}/{I?(111)+I?(200)+I?(220)+I?(311)}) of an austenite phase between a surface portion and a center portion is 0.010 ? or more, and a value of a diffraction peak integrated intensity ratio r (=100×?I?/?IALL) at a surface is 95% or more.
    Type: Grant
    Filed: September 27, 2016
    Date of Patent: March 8, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Kazuhiko Adachi, Akihiro Nishimura, Shinichi Teraoka, Hideki Fujii
  • Patent number: 11261503
    Abstract: The invention relates to a method for producing a flat steel product made of a medium manganese steel having a TRIP/TWIP effect. The aim of the invention is to achieve an improvement in the yield strength when a sufficient residual deformability of the produced flat steel product is obtained. This aim is achieved by the following steps: cold rolling a hot or cold strip, annealing the cold-rolled hot or cold strip at 500 to 840° C. for 1 minute to 24 hours, temper rolling or finishing the annealed hot or cold strip to form a flat steel product having a degree of deformability between 0.3% and 60%. The invention further relates to a flat steel product produced according to said method and to a use thereof.
    Type: Grant
    Filed: September 13, 2017
    Date of Patent: March 1, 2022
    Assignee: Salzgitter Flachstahl GmbH
    Inventors: Peter Palzer, Thomas Evertz, Manuel Otto, Kai Köhler
  • Patent number: 11149324
    Abstract: This high strength austenitic stainless steel having excellent resistance to hydrogen embrittlement includes, in terms of mass %, C: 0.2% or less, Si: 0.2% to 1.5%, Mn: 0.5% to 2.5%, P: 0.06% or less, S: 0.008% or less, Ni: 10.0% to 20.0%, Cr: 16.0% to 25.0%, Mo: 3.5% or less, Cu: 3.5% or less, N: 0.01% to 0.50%; and O: 0.015% or less, with the balance being Fe and unavoidable impurities, in which an average size of precipitates is 100 nm or less and an amount of the precipitates is 0.001% to 1.0% in terms of mass %.
    Type: Grant
    Filed: March 23, 2016
    Date of Patent: October 19, 2021
    Assignee: NIPPON STEEL STAINLESS STEEL CORPORATION
    Inventors: Kazuhisa Matsumoto, Masaharu Hatano
  • Patent number: 10770991
    Abstract: A method of manufacturing a vibration type actuator providing a satisfactory actuator performance even when an increase in speed is achieved and having a contact spring. The actuator includes an elastic member and a hollow protrusion having a side wall portion protruding with respect to a surface of the elastic member, a contact portion configured to come into contact with a body, and a first connection portion connecting the side wall portion and the contact portion, the method includes, forming the hollow protrusion including the side wall portion and a distal end portion by performing drawing on an elastic plate and forming the contact portion and the first connection portion by performing drawing or squeezing on the distal end portion, wherein the contact portion is surrounded by the first connection portion.
    Type: Grant
    Filed: July 6, 2017
    Date of Patent: September 8, 2020
    Assignee: Canon Kabushiki Kaisha
    Inventor: Atsushi Kimura
  • Patent number: 9770744
    Abstract: A method for producing a flat steel product with high reflectivity, in which at least one surface has an arithmetic mean roughness Ra of less than 0.03 ?m includes providing a flat steel product, at least one surface of which has an arithmetic mean roughness Ra of less than 2.5 ?m. The flat steel product is cold rolled in a plurality of rolling passes. Also a flat steel product with high reflectivity in the finished re-rolled state on at least one of its surface has a low arithmetic mean roughness, a high gloss, and a high directed reflection. A solar concentrator is produced from such a flat steel product.
    Type: Grant
    Filed: August 27, 2013
    Date of Patent: September 26, 2017
    Assignees: ThyssenKrupp Steel Europe AG, Outokumpu Nirosta GmbH
    Inventors: Roman Glass, Utz Karsten, Jörg Kazmierski, Nina Kolbe, Hans-Joachim Krautschick, Klaus Manfred Lange, Stefan Peter Puls, Janine Schauer-Paβ, Bernd Schuhmacher, Dirk Wiemer, Frank Wörster
  • Patent number: 9702030
    Abstract: A precipitation hardening type martensitic stainless steel of an embodiment contains: Cr: 8.5 to 12.5%; Mo: 1 to 2%; Ni: 8.5 to 11.5%; Ti: 0.6 to 1.4%; C: 0.0005 to 0.05%; Al: 0.0005 to 0.25%; Cu: 0.005 to 0.75%; Nb: 0.0005 to 0.3%; Si: 0.005 to 0.75%; Mn: 0.005 to 1%; and N: 0.0001 to 0.03% by mass, and the balance of Fe and unavoidable impurities.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: July 11, 2017
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Reki Takaku, Haruki Ohnishi, Masayuki Yamada, Yoriharu Murata, Kenichi Imai
  • Patent number: 9243314
    Abstract: A high-Si content austenitic stainless steel, which exhibits stable acid resistance and excellent corrosion resistance in high-temperature and concentrated nitric acid, has a chemical composition comprising: C: at most 0.04%; Si: 2.5-7.0%; Mn: at most 10%; P at most 0.03%; S: at most 0.03%; N: at most 0.035%; sol. Al: at most 0.03%; Cr: 7-20%; Ni: 10-22%; optionally, one or more types selected from Nb, Ti, Ta and Zr: 0.05-0.7% in total; and the remainder being Fe and impurities, wherein a total amount of B1 type inclusions measured by a method according to JIS G0555 (2003) Annex 1 “Microscopic Testing for the Non-Metallic Inclusions on the Point Counting Principle” is not more than 0.03% by area %.
    Type: Grant
    Filed: July 26, 2012
    Date of Patent: January 26, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Tomoyuki Sukawa, Shinnya Yamamoto, Kouichi Takeuchi, Hayato Kita, Shuuji Yoshida, Katsuhiko Taketsu, Masayuki Shibuya
  • Publication number: 20150132177
    Abstract: A stainless clad steel includes a stainless steel having Pitting Index of 35 or more as a cladding material, wherein the ratio of Cr concentration/Fe concentration in a passivation film portion of the above-described cladding material to Cr concentration/Fe concentration in a parent phase portion of the above-described cladding material is 1.20 or more and, in addition, the amount of precipitation of a ? (sigma) phase of the surface of the above-described cladding material is 2.0% or less on an area ratio basis.
    Type: Application
    Filed: March 5, 2013
    Publication date: May 14, 2015
    Inventors: Yoshihiro Yazawa, Shunichi Tachibana, Keiichiro Kishi, Yota Kuronuma, Toshiyuki Hoshino
  • Publication number: 20150099140
    Abstract: The invention relates generally to welding and, more specifically, to welding wires for arc welding, such as Gas Metal Arc Welding (GMAW) or Flux Core Arc Welding (FCAW). A disclosed tubular welding wire has a sheath and a core, and the tubular welding wire includes an organic stabilizer component, a rare earth component, and a corrosion resistant component comprising one or more of: nickel, chromium, and copper.
    Type: Application
    Filed: October 8, 2014
    Publication date: April 9, 2015
    Inventors: Mario Anthony Amata, Steven Edward Barhorst, Tre' Dorell Heflin-King
  • Publication number: 20150050180
    Abstract: The present invention relates to duplex ferritic austenitic stainless steel for the use chemical industry for nitric acid environments wherein good uniform corrosion resistance and high strength are required. The microstructure of the stainless steel has 35-65 volume % of ferrite, preferably 45-55 volume % of ferrite, the balance being austenite. The chemical composition contains less than 0.03 weight % carbon, less than 1 weight % silicon, less than 3 weight % manganese, 26-29.5 weight % chromium, 5-8.5 weight % nickel, 1-3 weight % molybdenum, 0.25-0.35 weight % nitrogen, 1-3 weight % copper, the rest being iron and inevitable impurities occurring in stainless steels.
    Type: Application
    Filed: November 1, 2012
    Publication date: February 19, 2015
    Inventors: Alexander Thulin, Jan Y. Jonsson, Mats Liljas, Rachel Pettersson, Jan-Olof Andersson, Staffan Hertzman
  • Patent number: 8906171
    Abstract: The invention relates to a method of producing a TWIP and nano twinned austenitic stainless steel. The austenitic steel should not contain more than 0.018 wt % C, 0.25-0.75 wt % Si, 1.5-2 wt % Mn, 17.80-19.60 wt % Cr, 24.00-25.25 wt % Ni, 3.75-4.85 wt % Mo, 1.26-2.78 wt % Cu, 0.04-0.15 wt % N, and the balance of Fe. In order to form nano twins in the material the austenitic stainless steel should be brought to a temperature below 0° C., and imparted a plastic deformation to such a degree that the desired nano twins are formed, e.g. to a plastic deformation of around 30%. The invention also relates to the thus produced austenitic stainless steel.
    Type: Grant
    Filed: September 25, 2012
    Date of Patent: December 9, 2014
    Assignee: Sandvik Intellectual Property
    Inventors: Ulrika Magnusson, Guocai Chai
  • Publication number: 20140328715
    Abstract: The invention relates to a method of producing a TWIP and nano twinned austenitic stainless steel. The austenitic steel should not contain more than 0.018 wt % C, 0.25-0.75 wt % Si, 1.5-2 wt % Mn, 17.80-19.60 wt % Cr, 24.00-25.25 wt % Ni, 3.75-4.85 wt % Mo, 1.26-2.78 wt % Cu, 0.04-0.15 wt % N, and the balance of Fe. In order to form nano twins in the material the austenitic stainless steel should be brought to a temperature below 0° C., and imparted a plastic deformation to such a degree that the desired nano twins are formed, e.g. to a plastic deformation of around 30%. The invention also relates to the thus produced austenitic stainless steel.
    Type: Application
    Filed: September 25, 2012
    Publication date: November 6, 2014
    Applicant: SANDVIK INTELLECTUAL PROPERTY AB
    Inventors: Ulrika Magnusson, Guocai Chai
  • Patent number: 8865060
    Abstract: An austenitic stainless steel, which consists of by mass percent, C: not more than 0.02%, Si: not more than 1.5%, Mn: not more than 2%, Cr: 17 to 25%, Ni: 9 to 13%, Cu: more than 0.26% not more than 4%, N: 0.06 to 0.35%, sol. Al: 0.008 to 0.03%. One or more elements selected from Nb, Ti, V, TA, Hf, and Zr in controlled amounts can be included with the balance being Fe and impurities. P, S, Sn, As, Zn, Pb and Sb among the impurities are controlled as P: 0.006 to 0.04%, S: 0.0004 to 0.03%, Sn: 0.001 to 0.1%, As: not more than 0.01%, Zn: not more than 0.01%, Pb: not more than 0.01% and Sb: not more than 0.01%. The amounts of S, P, Sn, As, Zn, Pb and Sb and the amounts of Nb, Ta, Zr, Hf, and Ti are further controlled using formulas.
    Type: Grant
    Filed: February 8, 2012
    Date of Patent: October 21, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Takahiro Osuki, Kazuhiro Ogawa, Hiroyuki Hirata, Yoshitaka Nishiyama
  • Publication number: 20140250966
    Abstract: A ferrous alloy is provided for coining The ferrous alloy includes a composition of: 4.00-10.80 wt % of chromium (Cr), 8.00-25.00 wt % of nickel (Ni), 3.00-6.00 wt % of copper (Cu), and a balance of iron (Fe) and incidental impurities.
    Type: Application
    Filed: March 11, 2013
    Publication date: September 11, 2014
    Applicant: CRS Holdings Inc.
    Inventor: Christopher F. Pilliod
  • Publication number: 20140154129
    Abstract: Stainless steel for fuel cell separators contains C: ?0.03%, Si: ?1.0%, Mn: ?1.0%, S: ?0.01%, P: ?0.05%, Al: ?0.20%, N: ?0.03%, Cr: 16 to 40%, and one or more of Ni: ?20%, Cu: ?0.6% and Mo: ?2.5%, the balance being Fe and inevitable impurities. According to X-ray photoelectron spectroscopy, the surface of the stainless steel contains fluorine and provides a 3.0 or higher ratio of the total of atomic concentrations of Cr and Fe in other than the metallic forms calculated from data resulting from the separation of peaks of Cr and Fe into metallic peaks and peaks other than the metallic peaks to the total of atomic concentrations of Cr and Fe in the metallic forms calculated from data resulting from the separation of peaks of Cr and Fe into metallic peaks and peaks other than the metallic peaks.
    Type: Application
    Filed: July 25, 2012
    Publication date: June 5, 2014
    Applicant: JFE STEEL CORPORATION
    Inventors: Noriko Makiishi, Hisato Noro, Shin Ishikawa, Shinsuke Ide, Tomohiro Ishii, Masayasu Nagoshi
  • Patent number: 8741215
    Abstract: To provide an inexpensive heat-resisting steel for engine valves by causing Fe-based heat-resisting steel to exhibit high temperature strength not inferior to that of Ni-based heat-resisting steel. A heat-resisting steel for engine valves excellent in high temperature strength containing, in % by mass, C: 0.20 to 0.50%, Si: 1.0% or less, Mn: 5.0% or less, P: 0.1 to 0.5%, Ni: 8.0 to 15.0%, Cr: 16.0 to 25.0%, Mo: 2.0 to 5.0%, Cu: 0.5% or less, Nb: 1.0% or less (including 0%), W: 8.0% or less (including 0%), N: 0.02 to 0.2%, B: 0.01% or less, and remnants of Fe and impurities, wherein the heat-resisting steel for engine valves satisfies formulae below: 442P(%)+12Mo(%)+5W(%)+7Nb(%)+328N(%)+171?300??Formula (1) ?38.13P(%)+1.06Mo(%)+0.13W(%)+9.64Nb(%)+13.52N(%)+4.83?0.12??Formula (2).
    Type: Grant
    Filed: April 19, 2010
    Date of Patent: June 3, 2014
    Assignees: Hitachi Metals, Ltd., Honda Motor Co., Ltd.
    Inventors: Katsuhiko Ohishi, Takehiro Ohno, Toshihiro Uehara
  • Publication number: 20140134039
    Abstract: Austenitic stainless steel is disclosed herein. In the described embodiments, the austenitic stainless steel comprises 16.00 wt % of Chromium to 30.00 wt % of Chromium; 8.00 wt % of Nickel to 27.00 wt % of Nickel; no more than 7.00 wt % of Molybdenum; 0.40 wt % of Nitrogen to 0.70 wt % of Nitrogen, 1.0 wt % of Manganese to 4.00 wt % of Manganese, and less than 0.10 wt % of Carbon, wherein the ratio of the Manganese to the Nitrogen is controlled to less than or equal to 10.0. Austenitic stainless steel based on specified minimum PREN (Pitting Resistance Equivalent Number) values is also disclosed. (1) PRE=wt % Cr+3.3×wt % (Mo)+16 wt % N>=25 for N in range of 0.40-0.70. (2) PRE=wt % Cr+3.3×wt % (Mo+W)+16 wt % N>=27 for N in range of 0.40-0.70 with W present.
    Type: Application
    Filed: May 24, 2012
    Publication date: May 15, 2014
    Applicant: UNITED PIPELINES ASIA PACIFIC PTE LIMITED
    Inventor: Cecil Vernon Roscoe
  • Publication number: 20140127073
    Abstract: There is provided a carburization resistant metal material suitable as a raw material for cracking furnaces, reforming furnaces, heating furnaces, heat exchangers, etc. in petroleum and gas refining, chemical plants, and the like. This metal material consists of, by mass %, C: 0.03 to 0.075%, Si: 0.6 to 2.0%, Mn: 0.05 to 2.5%, P: 0.04% or less, S: 0.015% or less, Cr: higher than 16.0% and less than 20.0%, Ni: 20.0% or higher and less than 30.0%, Cu: 0.5 to 10.0%, Al: 0.15% or less, Ti: 0.15% or less, N: 0.005 to 0.20%, and O (oxygen): 0.02% or less, the balance being Fe and impurities. The metal material may further contain one kind or more kinds of Co, Mo, W, Ta, B, V, Zr, Nb, Hf, Mg, Ca, Y, La, Ce and Nd.
    Type: Application
    Filed: May 29, 2012
    Publication date: May 8, 2014
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Yoshitaka Nishiyama, Hirokazo Okada, Takahiro Osuki, Etsuo Dan
  • Patent number: 8663549
    Abstract: To provide an inexpensive heat-resisting steel for engine valves by causing Fe-based heat-resisting steel to exhibit high temperature strength not inferior to that of Ni-based heat-resisting steel. A heat-resisting steel for engine valves excellent in high temperature strength containing, in % by mass, C: 0.20 to 0.50%, Si: 1.0% or less, Mn: 5.0% or less, P: 0.1 to 0.5%, Ni: 8.0 to 15.0%, Cr: 16.0 to 25.0%, Mo: 2.0% or less (including 0%), Cu: 0.5% or less, Nb: 1.0% or less (including 0%), W: 2.0% or less (including 0%), N: 0.02 to 0.30%, B: 0.01% or less, and remnants of Fe and impurities, wherein the heat-resisting steel for engine valves satisfies formulae below: 156.42P(%)+0.91Mo(%)+0.73W(%)?12.27Nb(%)+220.96N(%)+120.59?170??Formula (1) 13.70P(%)?6.97Mo(%)?4.32W(%)?3.29Nb(%)+119.10N(%)+27.75?25??Formula (2).
    Type: Grant
    Filed: June 23, 2010
    Date of Patent: March 4, 2014
    Assignees: Hitachi Metals, Ltd., Honda Motor Co., Ltd.
    Inventors: Katsuhiko Ohishi, Akihiro Toji
  • Publication number: 20140030134
    Abstract: A purpose of the present invention is to provide a martensitic stainless steel applicable in environments involving both wet carbon dioxide gas and wet hydrogen sulfide and excellent in weldability, manufacturability, and resistance to strain age hardening. Provided is a martensitic stainless steel having excellent corrosion resistance and resistance to strain age hardening comprising, in percent by mass, 0.02% or less of C, 0.02% or less of N, 0.1 to 0.5% of Si, 0.1 to 0.5% of Mn, 10 to 13% Cr, Ni exceeding 5.0% but 8% or less, 1.5 to 3% of Mo, 0.01 to 0.05% of V, 0.16 to 0.30% of Zr, 0.01 to 0.05% of Ta, and the balance of Fe and unavoidable impurities, wherein the martensitic stainless steel satisfies the condition that the sum of the carbon and the nitrogen exceeds 0.02% but 0.04% or less.
    Type: Application
    Filed: April 11, 2011
    Publication date: January 30, 2014
    Applicant: NKK TUBES
    Inventors: Shuji Hashizume, Yusuke Minami, Yu Yamamoto
  • Publication number: 20130336834
    Abstract: The present invention provides austenitic stainless steel which is not only excellent in brazeability, but is also excellent in corrosion resistance in an environment where condensation of combustion exhaust gas causes formation of condensed water which contains nitric acid ions or sulfuric acid ions and which is low in pH or in an environment of an aqueous solution which contains chloride ions, which contains, by mass %, C: 0.080% or less, Si: 1.2 to 3.0%, Mn: 0.4 to 2.0%, P: 0.03% or less, S: 0.003% or less, Ni: 6.0 to 12.0%, Cr: 16.0 to 20.0%, Cu: 0.2 to 3.0%, Al: 0.002 to 0.10%, N: 0.030 to 0.150%, and Mo: 0.1 to 1.0%, has a balance of Fe and unavoidable impurities, and satisfies Formula (A): 1.6?[Cu]×[Si?]4.4 and Formula (B): 0.16?2[N]+[Mo?]1.0.
    Type: Application
    Filed: March 28, 2012
    Publication date: December 19, 2013
    Applicant: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Tooru Matsuhashi, Jun Tokunaga
  • Publication number: 20130315776
    Abstract: A duplex stainless steel, which can suppress precipitation of a ? phase under high heat input welding, is excellent in SCC resistance under high-temperature chloride environments and has a high strength. The duplex stainless steel includes a chemical composition containing, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 28.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities, and satisfying Expression (1) and Expression (2); a structure having a ferrite rate of at least 50%; and a yield strength of at least 550 MPa or more: 2.
    Type: Application
    Filed: February 10, 2012
    Publication date: November 28, 2013
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kenta Yamada, Hiroyuki Nagayama, Masahiko Hamada, Daisuke Motoya, Hisashi Amaya
  • Publication number: 20130287620
    Abstract: The present invention aim at providing a steel for steam turbine blades which is excellent in terms of strength and toughness. The steel of the present invention has a composition which contains, in terms of % by mass, 0.02-0.10% of C, up to 0.25% of Si, 0.001-0.10% of Mn, up to 0.010% of P, up to 0.010% of S, 8.5-10.0% of Ni, 10.5-13.0% of Cr, 2.0-2.5% of Mo, 0.001-0.010% of N, 1.15-1.50% of Al, less than 0.10% of Cu, up to 0.20% of Ti, and the remainder being incidental impurities and Fe, and which satisfies 6.0?Ni/Al?8.0, 9.0?Nieq?11.0 and 17.0?Creq?19.0, in which Nieq=[Ni]+0.11[Mn]?0.0086([Mn]2)+0.44[Cu]+18.4[N]+24.5[C] Creq=[Cr]+1.21[Mo]+0.48[Si]+2.2[Ti]+2.48[A1].
    Type: Application
    Filed: April 24, 2013
    Publication date: October 31, 2013
    Applicant: DAIDO STEEL CO., LTD.
    Inventors: Hiroyuki TAKABAYASHI, Shigeki UETA
  • Patent number: 8486204
    Abstract: The hinge is made with a metal injection molding process from an alloy having at least: from 4 to 32 wt % Mn, from 16 to 37 wt % Cr, and from Fe that fills up the rest of the percentage.
    Type: Grant
    Filed: November 17, 2010
    Date of Patent: July 16, 2013
    Assignee: Shin Zu Shing Co., Ltd.
    Inventors: Yu-Chi Lu, Yu-Chan Hsieh, Shun-Tian Lin
  • Publication number: 20120315180
    Abstract: A stainless steel music string having a composition in percent by weight (wt %) of, 0.01?C?0.04; 0.01?N?0.06; 0.1?Si?1.0; 0.2?Mn?2.0; 5.0?Ni?10; 16?Cr?20; 0.2?Cu?3.0; 0?Mo?2.0; 0?W?0.5; 0?V?0.5; 0?Ti?1.0; 0?Al?1.0; 0?Nb?1.0; 0?Co?1.0, and the balance being Fe and normally occurring impurities The music string also includes at least 90% martensite phase by volume.
    Type: Application
    Filed: December 22, 2010
    Publication date: December 13, 2012
    Applicant: SANDVIK INTELLECTUAL PROPERTY AB
    Inventors: Anders Soderman, Lars Nylof
  • Publication number: 20120301347
    Abstract: An austenitic stainless steel alloy consisting essentially of, in terms of weight percent ranges 0.15-0.5C; 8-37Ni; 10-25Cr; 2.5-5Al; greater than 0.6, up to 2.5 total of at least one element selected from the group consisting of Nb and Ta; up to 3Mo; up to 3Co; up to 1W; up to 3Cu; up to 15Mn; up to 2Si; up to 0.15B; up to 0.05P; up to 1 total of at least one element selected from the group consisting of Y, La, Ce, Hf, and Zr; <0.3Ti+V; <0.03N; and, balance Fe, where the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale comprising alumina, and a stable essentially single phase FCC austenitic matrix microstructure, the austenitic matrix being essentially delta-ferrite free and essentially BCC-phase-free. A method of making austenitic stainless steel alloys is also disclosed.
    Type: Application
    Filed: May 24, 2011
    Publication date: November 29, 2012
    Applicant: UT-Battelle, LLC
    Inventors: Govindarajan MURALIDHARAN, Yukinori Yamamoto, Michael P. Brady
  • Publication number: 20120237388
    Abstract: An austenitic stainless steel sheet for springs having both a high strength and excellent formability has a chemical composition comprising C: 0.01-0.15%, Si: at most 3.0%, Mn: at most 3.0%, Cr: 10.0-30.0%, Ni: 4.0-20.0%, N: at most 0.40%, and a remainder of Fe and impurities, and it has a metallurgical structure such that the austenite content ?s (%) in the surface region of the steel sheet and the austenite content ?c (%) in the center region of the sheet thickness satisfy (?s+?c)/2?55 and ?s/?c?0.10, with the remaining structure being primarily strain-induced martensite.
    Type: Application
    Filed: May 10, 2012
    Publication date: September 20, 2012
    Applicant: SUMITOMO METAL INDUSTRIES, LTD.
    Inventor: Masayoshi SAWADA
  • Patent number: 8268101
    Abstract: The invention relates to an austenitic stainless steel strip having an elastic limit Rp0.2 which is greater than or equal to 600 MPa, a breaking load Rm which is greater than or equal to 800 MPa, an elongation A80 which is greater than or equal to 40% and a bright surface finish of the bright annealed type. The invention also relates to a method for the continuous production of said austenitic stainless steel strip.
    Type: Grant
    Filed: April 6, 2006
    Date of Patent: September 18, 2012
    Assignee: Aperam Stainless France
    Inventors: Francois Conrad, Christian Proudhon, Patrick Borgna
  • Publication number: 20120190321
    Abstract: A nonmagnetic stainless steel which has a higher electrical resistivity than existing nonmagnetic alloys, a production process for producing the stainless steel, and a radio wave receiver. The receiver has a main case and rear cover constituted of a nonmagnetic stainless steel having an electrical resistivity as high as more than 100 ??·cm and consisting of C: not more than 0.1%, Si: 4.0-7.5%, Mn: not more than 2.0%, Ni: 25.5-30.0%, Cr: 15.0-20.0%, Mo: 0.1-3.0%, Cu: 0-2.0%, in mass % and the balance Fe and impurities. Even if some variable magnetic flux generated by a coil of an antenna runs through the main case and the rear cover, the receiving efficiency of the antenna can be prevented from being reduced by eddy current loss and a sufficient radio receiving sensitivity can be obtained. This nonmagnetic stainless steel is produced by hot and/or cold plastic working and subsequent solution treating conducted at 1,000-1,180° C.
    Type: Application
    Filed: July 29, 2010
    Publication date: July 26, 2012
    Applicants: HITACHI METALS, LTD., CASIO COMPUTER CO., LTD.
    Inventors: Junichi Sato, Toshihiro Uehara, Kenji Yokoyama
  • Publication number: 20120171070
    Abstract: A alloy and a process of forming a alloy are disclosed. The alloy has a predetermined grain boundary morphology. The alloy includes by weight greater than about 0.06 percent carbon, up to about 0.0015 percent sulfur, less than about 16 percent chromium, between about 39 percent and about 44 percent nickel, between about 2.5 percent and about 3.3 percent niobium, between about 1.4 percent and about 2 percent titanium, up to about 0.5 percent aluminum, up to about 0.006 percent boron, up to about 0.3 percent copper, up to about 0.006 percent nitrogen, and greater than about 0.5 percent molybdenum.
    Type: Application
    Filed: January 3, 2011
    Publication date: July 5, 2012
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Ganjiang FENG, George A. GOLLER, Raymond Joseph STONITSCH, Jason R. PAROLINI, Shan LIU
  • Publication number: 20120141318
    Abstract: An austenitic stainless steel, which consists of by mass percent, C: not more than 0.02%, Si: not more than 1.5%, Mn: not more than 2%, Cr: 17 to 25%, Ni: 9 to 13%, Cu: more than 0.26% not more than 4%, N: 0.06 to 0.35%, sol. Al: 0.008 to 0.03%. One or more elements selected from Nb, Ti, V, TA, Hf, and Zr in controlled amounts can be included with the balance being Fe and impurities. P, S, Sn, As, Zn, Pb and Sb among the impurities are controlled as P: 0.006 to 0.04%, S: 0.0004 to 0.03%, Sn: 0.001 to 0.1%, As: not more than 0.01%, Zn: not more than 0.01%, Pb: not more than 0.01% and Sb: not more than 0.01%. The amounts of S, P, Sn, As, Zn, Pb and Sb and the amounts of Nb, Ta, Zr, Hf, and Ti are further controlled using formulas.
    Type: Application
    Filed: February 8, 2012
    Publication date: June 7, 2012
    Applicant: SUMITOMO METAL INDUSTRIES, LTD.
    Inventors: Takahiro OSUKI, Kazuhiro OGAWA, Hiroyuki HIRATA, Yoshitaka NISHIYAMA
  • Patent number: 8071020
    Abstract: A high strength Cr—Ni alloy material excellent in hot workability and stress corrosion cracking resistance, and seamless pipe for oil well application which consists of, by mass percent, C: 0.05% or less, Si: 0.05 to 1.0%, Mn: 0.01% or more and less than 3.0%, P: 0.05% or less, S: 0.005% or less, Cu: 0.01 to 4%, Ni: 25% or more and less than 35%, Cr: 20 to 30%, Mo: 0.01% or more and less than 4.0%, N: 0.10 to 0.30%, Al: 0.03 to 0.30%, O (oxygen): 0.01% or less, and REM (rare earth metal): 0.01 to 0.20% with the balance being Fe and impurities, and also satisfies the conditions in the following formula (1). N×P/REM?0.40??formula (1) where P, N, and REM in the formula (1) respectively denote the contents (mass %) of P, N, and REM. The high strength Cr—Ni alloy material may further contain one or more types of W, Ti, Nb, Zr, V, Ca, and Mg, instead of part of Fe.
    Type: Grant
    Filed: June 16, 2009
    Date of Patent: December 6, 2011
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Yohei Otome, Masaaki Igarashi, Hisashi Amaya, Hirokazu Okada
  • Patent number: 7901519
    Abstract: A precipitation hardenable martensitic stainless steel that includes, in percent by weight, 11.0 to 12.5 percent chromium, 1.0 to 2.5 percent molybdenum, 0.15 to 0.5 percent titanium, 0.7 to 1.5 percent aluminum, 0.5 to 2.5 percent copper, 9.0 to 11.0 percent nickel, up to 0.02 percent carbon, up to 2.0 percent tungsten, and up to 0.001 percent boron. Articles formed from the stainless steel and methods of forming the same are also disclosed.
    Type: Grant
    Filed: December 10, 2003
    Date of Patent: March 8, 2011
    Assignee: ATI Properties, Inc.
    Inventor: Wei-Di Cao
  • Patent number: 7842141
    Abstract: A steel composition contains: 0.05% or less of C; 0.5% or less of Si; 0.20% to 1.80% of Mn; 0.03% or less of P; 0.005% or less of S; 14.0% to 18.0% of Cr; 5.0% to 8.0% of Ni; 1.5% to 3.5% of Mo; 0.5% to 3.5% of Cu; 0.05% or less of Al; 0.20% or less of V; 0.01% to 0.15% of N; and 0.006% or less of O on a mass basis, and satisfies the following expressions: Cr+0.65Ni+0.6Mo+0.55Cu?20C?18.5 and Cr+Mo+0.3Si?43.5C?0.4Mn?Ni?0.3Cu?9N?11 (where Cr, Ni, Mo, Cu, C, Si, Mn, and N represent their respective contents (mass %)). After such a steel pipe material is formed into a steel pipe, the steel pipe is quenched by cooling after heating to a temperature of the AC3 transformation point or more and tempered at a temperature of the AC1 transformation point or less.
    Type: Grant
    Filed: April 2, 2009
    Date of Patent: November 30, 2010
    Assignee: JFE Steel Corporation
    Inventors: Mitsuo Kimura, Takanori Tamari, Takaaki Toyooka
  • Patent number: 7754142
    Abstract: A high-carbon austenitic iron-base alloy with good corrosion and wear resistance, particularly useful for valve seat insert applications when corrosion resistance is required, comprises about 1.8-3.5 wt % carbon, about 12-24 wt % chromium, about 0.5-4 wt % silicon, about 12-25 wt % nickel, about 2-12 wt % molybdenum and tungsten combined, about 0.05-4 wt % niobium and vanadium combined, about 0-1 wt % titanium, about 0.01-0.2 wt % aluminum, about 0.05-3 wt % copper, and less than 1.5 wt % manganese, with the balance being iron and a small amount of impurities.
    Type: Grant
    Filed: April 13, 2007
    Date of Patent: July 13, 2010
    Assignee: Winsert, Inc.
    Inventor: Xuecheng Liang
  • Patent number: 7754144
    Abstract: An austenitic stainless steel HTUPS alloy includes, in weight percent: 15 to 30 Ni; 10 to 15 Cr; 2 to 5 Al; 0.6 to 5 total of at least one of Nb and Ta; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1 W; up to 0.5 Cu; up to 4 Mn; up to 1 Si; 0.05 to 0.15 C; up to 0.15 B; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni wherein said alloy forms an external continuous scale comprising alumina, nanometer scale sized particles distributed throughout the microstructure, said particles comprising at least one composition selected from the group consisting of NbC and TaC, and a stable essentially single phase fcc austenitic matrix microstructure, said austenitic matrix being essentially delta-ferrite-free and essentially BCC-phase-free.
    Type: Grant
    Filed: April 16, 2008
    Date of Patent: July 13, 2010
    Assignees: UT-Battelle, LLC, University of Tennessee Research Foundation
    Inventors: Michael P Brady, Michael L Santella, Yukinori Yamamoto, Chain-tsuan Liu
  • Publication number: 20100133096
    Abstract: Use of an austenitic stainless steel wherein the chemical composition comprises 10-20 weight % nickel, 10-20 weight % chromium, 30-50 weight % iron, maximum 17 weight % of another element or elements and the balance iron and/or chromium and/or nickel as construction material in a device or structural components that are exposed to an oxygen and/or a hydrogen and/or a hydrofluoric acid environment.
    Type: Application
    Filed: June 27, 2007
    Publication date: June 3, 2010
    Applicant: HYDROGEN TECHNOLOGIES AS
    Inventors: Rolf Steen Hansen, Sten Egil Johnsen, Hans Jörg Fell, Egil Rasten
  • Publication number: 20100054983
    Abstract: An austenitic stainless steel, which comprises by mass %, C<0.04%, Si?1.5%, Mn?2%, Cr: 15 to 25%, Ni: 6 to 30%, N: 0.02 to 0.35%, sol. Al?0.03% and further contains one or more elements selected from Nb?0.5%, Ti?0.4%, V?0.4%, Ta?0.2%, Hf?0.2% and Zr?0.2%, with the balance being Fe and impurities, and among the impurities P?0.04%, S?0.03%, Sn?0.1%, As?0.01%, Zn?0.01%, Pb?0.01% and Sb?0.01%, and satisfy the conditions F1=S+{(P+Sn)/2}+{(As+Zn+Pb+Sb)/5}?0.0075 and 0.05?F2=Nb+Ta+Zr+Hf+2Ti+(V/10)?1.7?9×F1 has not only excellent liquation cracking resistance in the HAZ on the occasion of welding and excellent embrittling cracking resistance in the HAZ during a long period of use at high temperatures but also excellent polythionic acid SCC resistance and high temperature strength.
    Type: Application
    Filed: August 28, 2009
    Publication date: March 4, 2010
    Inventors: Takahiro OSUKI, Kazuhiro OGAWA, Hiroyuki HIRATA, Yoshitaka NISHIYAMA
  • Publication number: 20100034689
    Abstract: An austenitic stainless steel, which comprises by mass %, C: 0.04 to 0.18%, Si?1.5%, Mn?2.0%, Ni: 6 to 30%, Cr: 15 to 30%, N: 0.03 to 0.35%, sol. Al?0.03% and further contains one or more elements selected from Nb?1.0%, V?0.5% and Ti?0.5%, with the balance being Fe and impurities, and among the impurities P?0.04%, S?0.03%, Sn?0.1%, As?0.01%, Zn?0.01%, Pb?0.01% and Sb?0.01%, and satisfy the conditions P1=S+{(P+Sn)/2}+{(As+Zn+Pb+Sb)/5}?0.06 and 0.2?P2=Nb+2(V+Ti)?1.7?10×P1 has high strength and excellent resistance to cracking due to grain boundary embrittlement in the welded portion during the use at high temperatures. Therefore, the said steel can be suitably used as materials for constructing machines and equipment, such as power plant boilers, which are to be used at high temperatures for a long period of time.
    Type: Application
    Filed: August 11, 2009
    Publication date: February 11, 2010
    Inventors: Hiroyuki Hirata, Kazuhiro Ogawa, Takahiro Osuki, Hirokazu Okada, Hiroyuki Semba
  • Publication number: 20100034690
    Abstract: There is provided a metal material having excellent workability and metal dusting resistance, which is suitable as a raw material for cracking furnaces, reforming furnaces, heating furnaces, heat exchangers, etc. in petroleum refining, petrochemical plants, and the like. The metal material is characterized by consisting of, by mass %, C: 0.08 to 0.4%, Si: 0.6 to 2.0%, Mn: 0.05 to 2.5%, P: 0.04% or less, S: 0.015% or less, Cr: 18 to 30%, Ni: 20% or higher and less than 30%, Cu: 0.5 to 10.0%, Al: 0.01 to 1%, Ti: 0.01 to 1%, N: 0.15% or less, and O (oxygen): 0.02% or less, the balance being Fe and impurities, and satisfying Expression (1). C?0.062×Si+0.033×Cu?0.004×Cr+0.043??(1) in which the symbol of element in Expression (1) represents the content of that element in mass %.
    Type: Application
    Filed: August 11, 2009
    Publication date: February 11, 2010
    Inventors: Yoshitaka Nishiyama, Takahiro Osuki, Satoshi Matsumoto
  • Publication number: 20100035115
    Abstract: An Au plated film 12 is formed on the surface of a plate-formed metal base 13 composed of a metal less noble than Au, and the product is cut along a planned cutting line 18 reflecting a contour of a desired component, to thereby form a separator 10. Thus-formed separator 10 has the Au plated film 12 formed on the main surface 10a thereof, and has a cutting plane 16 formed as an end face 16 stretched up to the main surface 10a. The metal base 13 exposes in a part of the cutting plane 16, in a width of the exposed region of 1 mm or less. This is successful in providing a metal component for fuel cell which is satisfactory in the corrosion resistance and allows easy fabrication at low costs, a method of manufacturing the same, and also in providing a fuel cell having thus-fabricated metal component for fuel cell.
    Type: Application
    Filed: October 5, 2009
    Publication date: February 11, 2010
    Inventors: Shinobu TAKAGI, Masaki SHINKAWA, Mikio URA, Shinichi YAGI, Yasushi KANETA, Tatsuo HISADA
  • Publication number: 20100028716
    Abstract: Brazing alloy with a composition consisting essentially of FeaNiRestCrbMocCudSieBfPg, wherein 0 atomic %<=a<=50 atomic %; 5 atomic %<=b<=18 atomic %; 0.2 atomic %<c<=3 atomic %; 4 atomic %<=e<=15 atomic %; 4 atomic %<=f<=15 atomic %; 0 atomic %<=g<=6 atomic %; rest Ni, and wherein if 0 atomic %<a<=50 atomic %; then 0.5 atomic %<=d<3 atomic % and if a=0, then 0.5 atomic %<=d<=5 atomic %.
    Type: Application
    Filed: August 1, 2007
    Publication date: February 4, 2010
    Inventors: Dieter Nuetzel, Thomas Hartmann
  • Publication number: 20090202380
    Abstract: The invention relates to an austenitic stainless steel strip having an elastic limit Rp0.2 which is greater than or equal to 600 MPa, a breaking load Rm which is greater than or equal to 800 MPa, an elongation A80 which is greater than or equal to 40% and a bright surface finish of the bright annealed type. The invention also relates to a method for the continuous production of said austenitic stainless steel strip.
    Type: Application
    Filed: April 6, 2006
    Publication date: August 13, 2009
    Applicant: UGINE & ALZ FRANCE
    Inventors: Francois Conrad, Christian Proudhon, Patrick Borgna
  • Publication number: 20090196783
    Abstract: An austenitic stainless steel welded joint, which comprises by mass %, C: 0.05 to 0.25%, Si: not more than 2%, Mn: 0.01 to 3%, P: 0.05 to 0.5%, S: not more than 0.03%, Cr: 15 to 30%, Ni: 6 to 55%, sol. Al: 0.001 to 0.1% and N: not more than 0.03%, with the balance being Fe and impurities, and satisfies the formula of (Cr+1.5×Si+2×P)/(Ni+0.31×Mn+22×C+14.2×N+5×P)?1.388, has high creep strength, and moreover, is economical and excellent in weldability. Therefore, the said austenitic stainless steel welded joint can be widely applied as steel pipes, steel plates and so on in such fields where not only high-temperature strength and corrosion resistance but also weldability is required. Each element symbol in the above formula represents the content by mass percent of the element concerned.
    Type: Application
    Filed: January 23, 2009
    Publication date: August 6, 2009
    Inventors: Takahiro Osuki, Kazuhiro Ogawa, Hirokazu Okada, Masaaki Igarashi
  • Publication number: 20090162239
    Abstract: The martensitic stainless steel according to the invention includes, in percent by mass, 0.010% to 0.030% C, 0.30% to 0.60% Mn, at most 0.040% P, at most 0.0100% S, 10.00% to 15.00% Cr, 2.50% to 8.00% Ni, 1.00% to 5.00% Mo, 0.050% to 0.250% Ti, at most 0.25% V, at most 0.07% N, and at least one of at most 0.50% Si and at most 0.10% Al, the balance consists of Fe and impurities, and the martensitic stainless steel satisfies Expression (1) and has a yield stress in the range from 758 MPa to 862 MPa. In this way, the martensitic stainless steel has a yield stress of 110 ksi grade (a yield stress in the range from 758 MPa to 862 MPa) and the value produced by subtracting the yield stress from the tensile stress is not less than 20.7 MPa. 6.0?Ti/C?10.
    Type: Application
    Filed: February 20, 2009
    Publication date: June 25, 2009
    Inventors: Hideki TAKABE, Tomoki MORI, Masakatsu UEDA
  • Publication number: 20090017238
    Abstract: A martensitic stainless steel pipe having a heat-affected zone with high resistance to intergranular stress corrosion cracking is provided. In particular, the martensitic stainless steel pipe contains less than 0.0100% of C; less than 0.0100% of N; 10% to 14% of Cr; and 3% to 8% of Ni on a mass basis. Alternatively, the martensitic stainless steel pipe may further contain Si, Mn, P, S, and Al within an appropriate content range. The martensitic stainless steel pipe may further contain one or more selected from the group consisting of 4% or less of Cu, 4% or less of Co, 4% or less of Mo, and 4% or less of W and one or more selected from the group consisting of 0.15% or less of Ti, 0.10% or less of Nb, 0.10% or less of V, 0.10% or less of Zr, 0.20% or less of Hf, and 0.20% or less of Ta on a mass basis. The content Csol defined by the following equation is equal to less than 0.0050%: Csol=C??×Cpre, wherein Cpre=12.0{Ti/47.9+½(Nb/92.9+Zr/91.2)+?(V/50.9+Hf/178.5+Ta/180.9)?N/14.0} or Cpre=0 when Cpre<0.
    Type: Application
    Filed: December 1, 2004
    Publication date: January 15, 2009
    Applicant: JFE Steel Corporation
    Inventors: Yukio Miyata, Mitsuo Kimura, Noritsugu Itakura, Katsumi Masamura
  • Publication number: 20080304996
    Abstract: An austenitic stainless steel HTUPS alloy includes, in weight percent: 15 to 30 Ni; 10 to 15 Cr; 2 to 5 Al; 0.6 to 5 total of at least one of Nb and Ta; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1 W; up to 0.5 Cu; up to 4 Mn; up to 1 Si; 0.05 to 0.15 C; up to 0.15 B; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni wherein said alloy forms an external continuous scale comprising alumina, nanometer scale sized particles distributed throughout the microstructure, said particles comprising at least one composition selected from the group consisting of NbC and TaC, and a stable essentially single phase fcc austenitic matrix microstructure, said austenitic matrix being essentially delta-ferrite-free and essentially BCC-phase-free.
    Type: Application
    Filed: April 16, 2008
    Publication date: December 11, 2008
    Applicant: UT-BATTELLE, LLC
    Inventors: Michael P. Brady, Michael L. Santella, Yukinori Yamamoto, Chain-tsuan Liu