With Working At Or Below 120c Or Unspecified Cold Working Patents (Class 148/610)
  • Patent number: 11401573
    Abstract: A ferritic stainless steel sheet having excellent corrosion resistance, formability, and ridging resistance and a method for manufacturing the same are provided. A ferritic stainless steel sheet has a chemical composition containing, in terms of mass %, C: 0.005 to 0.030%, Si: 0.05 to 1.00%, Mn: 0.05 to 1.00%, P: 0.040% or less, S: 0.030% or less, Al: 0.001 to 0.150%, Cr: 10.8 to 14.4%, Ni: 0.01 to 2.50%, and N: 0.005 to 0.060%, with the balance being Fe and incidental impurities. The elongation after fracture is 28% or more, and the ridging height of a surface of a steel sheet to which a tensile strain of 23% has been applied in a rolling direction is 3.0 ?m or less.
    Type: Grant
    Filed: April 13, 2018
    Date of Patent: August 2, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Shuji Nishida, Tomohiro Ishii, Masataka Yoshino, Mitsuyuki Fujisawa
  • Patent number: 11174540
    Abstract: Provided is a hot-rolled and annealed ferritic stainless steel sheet excellent in surface quality after bending work has been performed. A hot-rolled and annealed ferritic stainless steel sheet has a thickness of 5.0 mm or more and a chemical composition containing, by mass %, C: 0.001% to 0.025%, Si: 0.05% to 0.70%, Mn: 0.05% to 0.50%, P: 0.050% or less, S: 0.01% or less, Cr: 10.0% to 18.0%, Ni: 0.01% to 1.00%, Al: 0.001% to 0.10%, N: 0.001% to 0.025%, Ti: 0.01% to 0.40%, and a balance of Fe and inevitable impurities, in which a difference between maximum and minimum values of an average crystal grain diameter determined by using measuring method 1 is 50 ?m or less, and in which a difference between maximum and minimum values of a crystal grain elongation rate determined by using measuring method 2 is 5.0 or less.
    Type: Grant
    Filed: September 21, 2018
    Date of Patent: November 16, 2021
    Assignee: JFE Steel Corporation
    Inventors: Hidetaka Kawabe, Mitsuyuki Fujisawa, Hiroshi Shimizu, Tomohiko Uchino
  • Patent number: 11091824
    Abstract: A ferritic stainless steel and a heat exchanger using the ferritic stainless steel are provided. The ferritic stainless steel includes, in mass %, C: 0.030% or less, N: 0.020% or less, Si: 0.5% or less, Mn: 1.0% or less, P: 0.05% or less, S: 0.01% or less, Cr: 16% to 25%, Nb: 0.05% to 1.0%, Al: 0.003% to 0.20%, and a balance comprising Fe and unavoidable impurities. The Al oxide is present on the surface of the material, the surface coverage ratio by the Al oxide is 5% to 70%, the surface roughness in Ra measured by red laser is 0.010-0.15 ?m, and the thickness from the surface to the point, which includes the value of a half peak of the Al content on the surface, satisfies 300 nm or less, the value of a half peak of the Al content in an elemental profile expressed by a cation ratio.
    Type: Grant
    Filed: July 16, 2015
    Date of Patent: August 17, 2021
    Assignee: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Tooru Matsuhashi, Yuuichi Tamura
  • Patent number: 10801084
    Abstract: Provided are a material for cold rolled stainless steel sheets having sufficient corrosion resistance, excellent surface quality, excellent formability, and excellent ridging resistance; a method for manufacturing the same; and a cold rolled steel sheet. A material for cold rolled stainless steel sheets according to the present invention contains C: 0.005% to 0.025%, Si: 0.02% to 0.50%, Mn: 0.55% to 1.0%, P: 0.040% or less, S: 0.01% or less, Cr: 15.5% to 18.0%, Ni: 0.01% to 1.0%, Al: 0.001% to 0.10%, and N: 0.005% to 0.025% on a mass basis, the remainder being Fe and inevitable impurities, and has a metallographic structure containing 5% to 20% of a martensite phase in terms of volume fraction, the remainder being a ferrite phase.
    Type: Grant
    Filed: July 2, 2015
    Date of Patent: October 13, 2020
    Assignee: JFE Steel Corporation
    Inventors: Akito Mizutani, Masataka Yoshino, Mitsuyuki Fujisawa, Chikara Kami
  • Patent number: 10738372
    Abstract: A method of processing fully austenitic stainless steels, comprising the following steps: (1) performing a solution treatment on a raw material with a certain chemical composition, and cooling to get samples, the raw material contains: 0˜0.2% of C, 0˜0.2% of N, not more than 0.03% of P, not more than 0.001% of S, 0.5%˜1% of Si, 1.0%˜2.0% of Mn, 15%˜17% of Cr, 5%˜7% of Ni by weight, the remaining is Fe, and the content of C and N should not be zero simultaneously with a total content of both at 0.15%˜0.2%; and (2) performing hot-working for deformation of the samples obtained in step (1), to get a fully austenitic stainless steel. The stainless steel prepared by the hot-working deformation of the present invention has a yield strength of 2 to 3 times of that before hot-working deformation and an elongation of 1.05 to 1.2 times of that before hot-working deformation.
    Type: Grant
    Filed: June 5, 2017
    Date of Patent: August 11, 2020
    Assignee: Zhejiang University
    Inventors: Hongtao Wang, Jiabin Liu, Youtong Fang
  • Patent number: 10550454
    Abstract: Provided is a cold-rolled ferritic stainless steel sheet having a chemical composition that contains, by mass %, C: 0.01% or more and 0.05% or less, Si: 0.02% or more and 0.75% or less, Mn: 0.1% or more and 1.0% or less, P: 0.04% or less, S: 0.01% or less, Al: 0.001% or more and 0.10% or less, N: 0.01% or more and 0.06% or less, Cr: 16.0% or more and 18.0% or less, and the balance being Fe and inevitable impurities. The metallographic structure includes a ferrite phase, in which the average grain diameter is 10 ?m or less, in which the proportion of ferrite grains having a grain diameter of 10 ?m or more and less than 40 ?m is 60% or more, and in which the proportion of ferrite grains having a grain diameter of less than 5 ?m is less than 20%.
    Type: Grant
    Filed: July 2, 2015
    Date of Patent: February 4, 2020
    Assignee: JFE Steel Corporation
    Inventors: Ayako Ta, Yukihiro Matsubara, Yukio Kimura, Keisuke Nakazono, Masataka Yoshino
  • Patent number: 10358689
    Abstract: Ferritic stainless steel sheet which is excellent in ridging resistance which comprises, by mass %, Cr: 10 to 30%, Sn: 0.005 to 1%, C: 0.001 to 0.1%, N: 0.001 to 0.1%, Si: 0.01 to 3.0%, Mn: 0.01 to 3.0%, P: 0.005 to 0.1%, and S: 0.0001 to 0.01% and has a balance of Fe and unavoidable impurities and which has an X-ray diffraction strength in the {100}<012> orientation from a surface layer to t/4 (“t” is sheet thickness) of 2 or more.
    Type: Grant
    Filed: November 13, 2017
    Date of Patent: July 23, 2019
    Assignee: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Junichi Hamada, Eiichiro Ishimaru
  • Patent number: 10337093
    Abstract: A method of processing a non-magnetic alloy workpiece comprises heating the workpiece to a warm working temperature, open die press forging the workpiece to impart a desired strain in a central region of the workpiece, and radial forging the workpiece to impart a desired strain in a surface region of the workpiece. In a non-limiting embodiment, after the steps of open die press forging and radial forging, the strain imparted in the surface region is substantially equivalent to the strain imparted in the central region. In another non-limiting embodiment, the strain imparted in the central and surface regions are in a range from 0.3 inch/inch to 1 inch/inch, and there exists no more than a 0.5 inch/inch difference in strain of the central region compared with the strain of the surface region of the workpiece. An alloy forging processed according to methods described herein also is disclosed.
    Type: Grant
    Filed: October 13, 2015
    Date of Patent: July 2, 2019
    Assignee: ATI PROPERTIES LLC
    Inventors: Robin M. Forbes Jones, George J. Smith, Jr., Jason P. Floder, Jean-Philippe A. Thomas, Ramesh S. Minisandram
  • Patent number: 10312385
    Abstract: Provided are a solar cell substrate made of stainless steel foil which contains 7% to 40% by mass Cr and has a coefficient of linear expansion of 12.0×10?6/° C. or less at 0° C. to 100° C. and a thickness of 20 ?m to 200 ?m is subjected to the preparatory heat treatment for stress relief in an atmosphere consisting of one or more selected from an N2 gas, an H2 gas, an Ar gas, an AX gas, and an HN gas within the range of 250° C. to 1,050° C.; a back-contact made of a Mo layer is formed on a surface of the stainless steel foil subjected to the preparatory heat treatment or an insulating coating is formed on a surface of the stainless steel foil followed by forming the back-contact including the Mo layer thereon; and an absorber layer made of Cu(In1-xGax)Se2 is formed on the back-contact by performing coating formation heat treatment.
    Type: Grant
    Filed: May 23, 2012
    Date of Patent: June 4, 2019
    Assignee: JFE Steel Corporation
    Inventors: Yasuhiro Yamaguchi, Atsutaka Honda, Naoki Nishiyama, Tokio Nakada
  • Patent number: 10155999
    Abstract: A method for manufacturing a metal structure (130) for use in a downhole assembly comprises plastically deforming at least a portion of the metal structure (130); and heating at least the deformed portion of the metal structure to a temperature below its critical and/or transformation temperature. An assembly for performing the method comprises a production fixture (370) configured to receive the metal structure (130), wherein the production fixture is adapted to undergo heating to a temperature below and/or up to the critical and/or transformation temperature of the metal structure. By heating at least the deformed portion of the metal structure to a temperature below its critical and/or transformation temperature, the metal structure may undergo stress relief, which may help prevent undesirable movement of deformed portion, e.g. collet fingers of a catching apparatus, against the direction of deformation after impact(s) and/or shock(s) from moving objects, in use.
    Type: Grant
    Filed: March 14, 2014
    Date of Patent: December 18, 2018
    Assignee: Weatherford Technology Holdings, LLC
    Inventor: Oliver Webster
  • Patent number: 9631249
    Abstract: Martensitic mixed phase stainless steel, which has in well balance between excellent strength and formability and excellent fatigue properties, and is inexpensive, and suitable for spring members, has: a chemical composition comprising C: 0.1-0.4%, Si: at most 2.0%, Mn: 0.1-6.0%, Cr: 10.0-28.0%, N: at most 0.17%, the remainder of Fe and impurities, and a metallurgical structure which includes a ferrite phase and a martensitic phase, and also a retained austenite phase of 5 volume % or less if necessary, and which satisfies a relationship of CM/CF?5.0 where an average value CF of C content existing in the ferrite phase, and an average value CM of C content existing in the martensite.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: April 25, 2017
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kazuhiko Adachi, Takashi Maeda, Masayuki Shibuya, Kazuyoshi Fujisawa, Yuuichi Fukumura
  • Patent number: 9249475
    Abstract: A ferritic stainless steel suited for use as a member for heat exchangers to be brazed with Ni-based filler metal or Cu-based filler metal, comprising, on the basis of mass percent, C: 0.03% or less, Si: 3% or less, Mn: 2% or less, P: 0.05% or less, S: 0.03% or less, Cr: from 11 to 30%, Nb: from 0.15 to 0.8%, and N: 0.03% or less, wherein the balance is composed of Fe and incidental impurities, and wherein a value A determined by the following equation is 0.10 or greater: A=Nb?(C×92.9/12+N×92.9/14).
    Type: Grant
    Filed: May 11, 2009
    Date of Patent: February 2, 2016
    Assignee: NISSHIN STEEL CO., LTD.
    Inventors: Akinori Kawano, Taichirou Mizoguchi, Kouki Tomimura, Wakahiro Harada
  • Patent number: 9130199
    Abstract: A stainless steel for a fuel cell having good corrosion resistance throughout a wide potential range and a method for producing the same are provided. In particular, a coating having an intensity ratio [(OO/OH)/(Cr/Fe)] of 1.0 or more determined by X-ray photoelectron spectroscopy analysis is formed by performing an anodic electrolyzation treatment on a surface of a stainless steel in an electrolyte solution, the stainless steel containing 16% by mass or more of Cr and preferably having a composition that includes, in terms of percent by mass, C: 0.03% or less, Si: 1.0% or less, Mn: 1.0% or less, S: 0.01% or less, P: 0.05% or less, Al: 0.20% or less, N: 0.03% or less, Cr: 20 to 40%, at least one selected from Nb, Ti, and Zr, in total: 1.0% or less, and the balance being Fe and unavoidable impurities.
    Type: Grant
    Filed: July 22, 2010
    Date of Patent: September 8, 2015
    Assignee: JFE Steel Corporation
    Inventors: Shinsuke Ide, Tomohiro Ishii, Naoki Nishiyama, Shin Ishikawa, Takumi Ujiro, Noriko Makiishi
  • Publication number: 20150083283
    Abstract: The present invention is directed to a heat-resistant austenitic stainless steel sheet comprising, by mass %, C: 0.03% to 0.06%, N: 0.1% to 0.3%, Si: 1% or less Mn: 3% or less, P: 0.04% or less, S: 0.03% or less, Ni: 5 to 12%, Cr: 15 to 20%, Al: 0.01% to 0.1%, Nb: 0.05% to 0.3%, V: 0.05% to 0.30%, Ti: 0.03% or less, (Nb+V)/(C+N):2 or less and further a balance of Fe and unavoidable impurities, and wherein an amount of precipitates mainly comprised of carbonitrides is 1% or less.
    Type: Application
    Filed: March 28, 2013
    Publication date: March 26, 2015
    Applicant: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Yoshiharu Inoue, Fumio Fudanoki, Junichi Hamada
  • Patent number: 8961713
    Abstract: The present invention provides stainless steel foil for flexible display use which enables fabrication of a TFT substrate for display use which is superior in shape recovery after being rolled up or bent and which is high in surface flatness and is characterized by having a thickness of 20 ?m to 200 ?m, a surface roughness Ra of 50 nm or less, and a shape recovery of a distortion angle of 10° or less after being wound around a 30 mm diameter cylinder.
    Type: Grant
    Filed: May 13, 2009
    Date of Patent: February 24, 2015
    Assignee: Nippon Steel Materials Co, Ltd.
    Inventors: Noriko Yamada, Toyoshi Ogura, Yuji Kubo, Shuji Nagasaki
  • Patent number: 8961717
    Abstract: The present invention provides stainless steel foil for flexible display use which enables fabrication of a TFT substrate for display use which is superior in shape recovery after being rolled up or bent and which is high in surface flatness and is characterized by having a thickness of 20 ?m to 200 ?m, a surface roughness Ra of 50 nm or less, and a shape recovery of a distortion angle of 10° or less after being wound around a 30 mm diameter cylinder.
    Type: Grant
    Filed: February 28, 2014
    Date of Patent: February 24, 2015
    Assignee: Nippon Steel & Sumikin Materials Co., Ltd.
    Inventors: Noriko Yamada, Toyoshi Ogura, Yuji Kubo, Shuji Nagasaki
  • Publication number: 20150020933
    Abstract: Provided is a heat-resistant cold rolled ferritic stainless steel sheet containing, in terms of mass %, 0.02% or less of C, 0.1% to 1.0% of Si, greater than 0.6% to 1.5% of Mn, 0.01% to 0.05% of P, 0.0001% to 0.0100% of S, 13.0% to 20.0% of Cr, 0.1% to 3.0% of Mo, 0.005% to 0.20% of Ti, 0.3% to 1.0% of Nb, 0.0002% to 0.0050% of B, 0.005% to 0.50% of Al, and 0.02% or less of N, with the balance being Fe and inevitable impurities, in which {111}-oriented grains are present at an area ratio of 20% or greater in a region from a surface layer to t/4 (t is a sheet thickness), {111}-oriented grains are present at an area ratio of 40% or greater in a region from t/4 to t/2, and {011}-oriented grains are present at an area ratio of 15% or less in the entire region in a thickness direction.
    Type: Application
    Filed: March 26, 2013
    Publication date: January 22, 2015
    Applicant: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Junichi Hamada, Yuji Koyama, Yoshiharu Inoue, Tadashi Komori, Fumio Fudanoki, Toshio Tanoue, Naoto Ono
  • 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: 20140338800
    Abstract: A steel product, such as a strip, plate, sheet, bar or wire, manufactured from austenitic stainless steel. A steel product, wherein: a—the average grain size of the recrystallized austenitic structure of said product is at most 6 , b—less than 50% of the structure of said product is non-recrystallized austenite c—the yield strength (Rpo.2) is at least 350 MPa, d—the tensile strength (Rm) is at least 600 MPa, and e—the uniform elongation (Ag) of said product is at least 5%, depending on the strength. The invention also relates to a method.
    Type: Application
    Filed: January 20, 2012
    Publication date: November 20, 2014
    Applicant: JL MATERIALS TECHNOLOGY OY
    Inventor: Jouko Leinonen
  • Patent number: 8696835
    Abstract: An austenitic stainless steel for use in a hydrogen gas atmosphere comprises, in mass %, C: 0.10% or less, Si: 1.0% or less, Mn: 0.01 to 30%, P: 0.040% or less, S: 0.01% or less, Cr: 15 to 30%, Ni: 5.0 to 30%, Al: 0.10% or less, N: 0.001 to 0.30% with the balance Fe and inevitable impurities. An X-ray (111) integration intensity of a cross section along the direction rectangular to the working direction is five times that in a random direction or less, and the X-ray integration intensity ratio of a cross section along the working direction satisfies I(220)/I(111)?10. The high strength steel can also contain one or more of the groups of Mo and W; V, Nb, Ta, Ti, Zr and Hf; B; Cu and Co; Mg, Ca, La, Ce, Y, Sm, Pr and Nd.
    Type: Grant
    Filed: November 24, 2010
    Date of Patent: April 15, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Hiroyuki Semba, Masaaki Igarashi, Tomohiko Omura, Mitsuo Miyahara, Kazuhiko Ogawa
  • Publication number: 20140060428
    Abstract: A metal plate for laser processing (such as a stainless steel plate or a titanium plate) and preferably an austenitic stainless steel plate suitable for use as a metal mask or the like which undergoes fine processing with a laser has an average grain diameter d (?m) and a plate thickness t (?m) which satisfy the equation d?0.0448·t?1.28.
    Type: Application
    Filed: February 29, 2012
    Publication date: March 6, 2014
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kazuyoshi Fujisawa, Masayuki Shibuya, Kouichi Takeuchi
  • Patent number: 8628631
    Abstract: The present invention provides a ferritic stainless steel casting and a sheet thereof excellent in deep drawability, punch stretchability and ridging resistance and a method for producing the casting and the sheet. In the present invention, a chemical composition is controlled so that the amounts of C, N, Si, Mn, P and Ti may be reduced to the utmost for securing high workability and, on the basis of the chemical composition, the roping and ridging of a steel sheet product is reduced by adding Mg, thus dispersing Mg containing oxides that accelerate the formation of nuclei for solidification and, resultantly, suppressing the development of coarse columnar crystals in a casting. The present invention is characterized in that the average composition of the Mg containing oxides dispersing in a casting satisfies the following expressions <2> and <3>, 17.4(Al2O3)+3.9(MgO)+0.3(MgAl2O4)+18.7(CaO)?500??<2>, (Al2O3)+(MgO)+(MgAl2O4)+(CaO)?95??<3>.
    Type: Grant
    Filed: April 5, 2011
    Date of Patent: January 14, 2014
    Assignee: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Akihiko Takahashi, Junichi Hamada, Ken Kimura, Takashi Morohoshi, Yoshihito Yamada, Toyohiko Kakihara, Satoshi Hashimoto
  • Patent number: 8608873
    Abstract: A stainless steel and a flat cold product produced therefrom, which can be easily produced in an economical manner. A steel according to the invention, in the cold-rolled state, has a microstructure with 5-15% by volume ?-ferrite and austenite as the remainder. It contains (in % by weight): C: 0.05-0.14%, Si: 0.1-1.0%, Mn: 4.0-12.0%, Cr: >17.5-22.0%, Ni: 1.0-4.0%, Cu: 1.0-3.0%, N: 0.03-0.2%, P: max. 0.07%, S: max. 0.01%, Mo: max. 0.5%, optionally one or more elements from the group consisting of Ti, Nb, B, V, Al, Ca, As, Sn, Sb, Pb, Bi, and H wherein Ti: max. 0.02%, Nb: max. 0.1%, B: max. 0.004%, V: max. 0.1%, Al: 0.001-0.03%, Ca: 0.0005-0.003%, As: 0.003-0.015%, Sn: 0.003-0.01%, Pb: max. 0.01%, Bi: max. 0.01%, H: max. 0.0025%, and remainder Fe and unavoidable impurities.
    Type: Grant
    Filed: September 3, 2009
    Date of Patent: December 17, 2013
    Assignee: Outokumpu Nirosta GmbH
    Inventors: Cornel Abratis, Lutz Ernenputsch, Wilfried Klos, Hans-Joachim Krautschick, Michael Sachtleber
  • Publication number: 20130167987
    Abstract: Provided is a low iron loss high strength non-oriented electromagnetic steel sheet and a method for manufacturing the same. The method comprises hot-rolling a slab comprising 0.005 weight % or less of C, 4.0 weight % or less of Si, 0.1 weight % or less of P, 0.03 weight % or less of S, 0.1 to 2.0 weight % of Mn, 0.3 to 2.0 weight % of Al, 0.003 weight % or less of N, 0.005 weight % or less of Ti, the remainder being Fe and unavoidable impurities, cold-rolling the slab, and finally annealing the slab such that the fractional area of the non-recrystallization tissue at the cross sectional surface of the steel sheet is 50% or lower (not including 0%).
    Type: Application
    Filed: December 22, 2011
    Publication date: July 4, 2013
    Applicant: POSCO
    Inventors: Jae-Song Kim, Jae-Kwan Kim, Su-Yong Sin, Yong-Soo Kim
  • Patent number: 8465604
    Abstract: A ferritic stainless steel sheet having excellent corrosion resistance and a method of manufacturing the steel sheet are provided. Specifically, the ferritic stainless steel sheet of the invention contains C of 0.03% or less, Si of 1.0% or less, Mn of 0.5% or less, P of 0.04% or less, S of 0.02% or less, Al of 0.1% or less, Cr of 20.5% to 22.5%, Cu of 0.3% to 0.8%, Ni of 1.0% or less, Ti of 4×(C %+N %) to 0.35%, Nb of less than 0.01%, N of 0.03% or less, and C+N of 0.05% or less, and has the remainder including Fe and inevitable impurities, wherein 240+35×(Cr %?20.5)+280×{Ti %?4×(C %+N %)}?280 is satisfied.
    Type: Grant
    Filed: July 31, 2006
    Date of Patent: June 18, 2013
    Assignee: JFE Steel Corporation
    Inventors: Kazuhide Ishii, Tomohiro Ishii, Osamu Furukimi
  • Patent number: 8440029
    Abstract: A stainless steel having good conductivity and ductility for use in a fuel cell separator is provided. In particular, the stainless steel has a composition of, in terms of % by mass, C: 0.01% or less, Si: 1.0% or less, Mn: 1.0% or less, S: 0.01% or less, P: 0.05% or less, Al: 0.20% or less, N: 0.02% or less, Cr: 20 to 40%, Mo: 4.0% or less, and at least one selected from Nb, Ti, and Zr: 0.05 to 0.60% in total, the balance being Fe and unavoidable impurities. At least one precipitate having an equivalent circle diameter of 0.1 ?m or more is present per 100 ?m2, a ratio of a thickness t (?m) to a maximum diameter Dmax (?m) of the precipitates satisfies formula (1) below 20?t/Dmax??(1) and the thickness is 200 ?m or less.
    Type: Grant
    Filed: July 26, 2010
    Date of Patent: May 14, 2013
    Assignee: JFE Steel Corporation
    Inventors: Shinsuke Ide, Atsutaka Honda, Shin Ishikawa, Takumi Ujiro
  • Patent number: 8333851
    Abstract: A method for producing a two-phase stainless steel pipe, which comprises: preparing a two-phase stainless steel material consisting of, by mass %, C: 0.03% or less, Si: 1% or less, Mn: 0.1 to 2%, Cr: 20 to 35%, Ni: 3 to 10%, Mo: 0 to 4%, W: 0.5 to 6%, Cu: 0 to 3% and N: more than 0.175 and up to 0.35%, and the balance being Fe and impurities; forming a material pipe by subjecting to a hot working: and performing a cold drawing, where the cold drawing is characterized in being performed under the conditions that the working ratio Rd, in terms of the reduction of area, in the final cold drawing step is within a range from 5 to 35%, and the following formula (1) is satisfied: Rd(%)?(MYS?55)/17.2?{1.2×Cr+3.0×(Mo+0.5×W)}??(1).
    Type: Grant
    Filed: July 8, 2008
    Date of Patent: December 18, 2012
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventor: Hitoshi Suwabe
  • Patent number: 8303733
    Abstract: This stainless steel sheet includes, in terms of mass %, C: 0.001 to 0.1%, N: 0.01 to 0.15%, Si: 0.01 to 2%, Mn: 0.1 to 10%, P: 0.05% or less, S: 0.01% or less, Ni: 0.5 to 5%, Cr: 10 to 25%, and Cu: 0.5 to 5%, with a remainder being Fe and unavoidable impurities, and contains a ferrite phase as a main phase and 10% or more of an austenite phase, wherein a work-hardening rate in a strain range of up to 30% is 1000 MPa or more which is measured by a static tensile testing and a difference between static and dynamic stresses which occur when 10% of deformation is caused is 150 MPa or more. This method for producing a stainless steel includes annealing a cold-rolled steel sheet under conditions where a holding temperature is set to be in a range of 950 to 1150° C. and a cooling rate until 400° C. is set to be in a range of 3° C./sec or higher.
    Type: Grant
    Filed: January 22, 2009
    Date of Patent: November 6, 2012
    Assignee: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Junichi Hamada, Haruhiko Kajimura, Eiichiro Ishimaru
  • Patent number: 8293038
    Abstract: The present invention provides a ferritic stainless steel casting and a sheet thereof excellent in deep drawability, punch stretchability and ridging resistance and a method for producing the casting and the sheet. In the present invention, a chemical composition is controlled so that the amounts of C, N, Si, Mn, P and Ti may be reduced to the utmost for securing high workability and, on the basis of the chemical composition, the roping and ridging of a steel sheet product is reduced by adding Mg, thus dispersing Mg containing oxides that accelerate the formation of nuclei for solidification and, resultantly, suppressing the development of coarse columnar crystals in a casting. The present invention is characterized in that the average composition of the Mg containing oxides dispersing in a casting satisfies the following expressions <2> and <3>, 17.4(Al2O3)+3.9(MgO)+0.3(MgAl2O4)+18.7(CaO)?500??<2>, (Al2O3)+(MgO)+(MgAl2O4)+(CaO)?95??<3>.
    Type: Grant
    Filed: November 13, 2007
    Date of Patent: October 23, 2012
    Assignee: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Akihiko Takahashi, Junichi Hamada, Ken Kimura, Takashi Morohoshi, Yoshihito Yamada, Toyohiko Kakihara, Satoshi Hashimoto
  • Patent number: 8293037
    Abstract: A method for producing a duplex stainless steel pipe having a minimum yield strength of 758.3 to 965.2 MPa, comprises first hot working and optionally solution heat treating a duplex stainless steel material pipe having a chemical composition consisting, by mass %, of C: 0.03% or less, Si: 1% or less, Mn: 0.1 to 4%, Cr: 20 to 35%, Ni: 3 to 10%, Mo: 0 to 6%, W: 0 to 6%, Cu: 0 to 3% and N: 0.15 to 0.60%, the balance being Fe and impurities. The pipe is then cold rolled under conditions that the working ratio Rd, in terms of the reduction of area, in the final cold rolling step falls within a range from 10 to 80%, and formula (1) is satisfied: Rd=exp[{In(MYS)?In(14.5×Cr+48.3×Mo+20.7×W+6.9×N)}/0.195]??(1) wherein Rd is a reduction in area %, MYS is the targeted yield strength (MPa), and Cr, Mo, W and N are in mass %.
    Type: Grant
    Filed: July 18, 2011
    Date of Patent: October 23, 2012
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Hitoshi Suwabe, Toshihide Ono
  • Publication number: 20120234438
    Abstract: Provided are a cold-rolled steel sheet which undergoes a small load at the time of cold-rolling, has excellent press formability and high strength, and a method of manufacturing the cold-rolled steel sheet. A hot-rolled steel sheet having the composition comprising by mass %, 0.10 to 0.30 C, 0.2 or more Mn, 0.01 or more Ni, 0.5 to 2.5 Mn+Ni, 1.2 to 9.0 Cr, and Fe and unavoidable impurities as a balance, and has a tensile strength of 1000 MPa or less is subjected to pickling and, is subjected to cold rolling at a total rolling reduction of 60% or more thus forming a cold-rolled steel sheet. A final continuous annealing treatment is performed at a soaking temperature of 750° C. or above and at a cooling rate of 3° C./s to 100° C./s so that the cold-rolled steel sheet which has a tensile strength of 1280 MPa or more, breaking elongation of 3% or more, and a thickness of 0.05 to 0.60 mm is manufactured.
    Type: Application
    Filed: June 17, 2010
    Publication date: September 20, 2012
    Applicants: Nakayama Steel Works, Ltd., Toyo Kohan Co., Ltd.
    Inventors: Satoshi Oi, Shigeyoshi Nishiyama, Fuyuki Yoshida, Yuji Kusumoto, Osamu Akisue
  • Patent number: 8262815
    Abstract: The present invention provides high purity ferrite stainless steel able to reduce deterioration in surface conditions due to pitting corrosion or rusting or other corrosion to an extent no different from SUS304 or better without inviting a drop in manufacturability or workability and without relying on the addition of rare elements, and a method of production of the same, that is, ferritic stainless steel containing, by mass %, C: 0.01% or less, Si: 0.01 to 0.20%, Mn: 0.01 to 0.30%, P: 0.04% or less, S: 0.01% or less, Cr: 13 to 22%, N: 0.001 to 0.020%, Ti: 0.05 to 0.35%, Al: 0.005 to 0.050%, Sn: 0.001 to 1%, and a balance of Fe and unavoidable impurities to which Sn is added to modify the passive film and improve the corrosion resistance. To improve the effect of modification of the passive film by the addition of Sn, after the final annealing, the steel is held in the 200 to 700° C. temperature range for 1 minute or more.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: September 11, 2012
    Assignee: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Masaharu Hatano, Akihiko Takahashi
  • Patent number: 8226780
    Abstract: This ferrite-austenite stainless steel sheet includes: in terms of mass %, C: 0.1% or less; Cr: 17 to 25%; Si: 1% or less; Mn: 3.7% or less; Ni: 0.6 to 3%; Cu: 0.1 to 3%; and N: 0.06% or more and less than 0.15%, with the remainder being Fe and inevitable impurities, wherein the steel sheet has a two-phase structure consisting of a ferrite phase and an austenite phase, a volume fraction of the austenite phase is in a range of 15 to 70%, and in a sheet plane (ND) of a center of a sheet thickness, grains of the ferrite phase having a crystal orientation satisfying ND//{111}±10° and grains of the ferrite phase having a crystal orientation satisfying ND//{101}±10° are present in a total content of 10% by area or more.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: July 24, 2012
    Assignees: Nippon Steel, Sumikin Stainless Steel Corporation
    Inventors: Masaharu Hatano, Akihiko Takahashi, Eiichiro Ishimaru, Ken Kimura
  • Patent number: 8177929
    Abstract: A metal gasket formed from a suitable iron-nickel chromium alloy includes at least one embossment that exhibits essentially full functional recovery at temperatures exceeding 1000° F. and including in the range of 1100° F. to 1600° F. or more and which is made from sheet material that is work hardened and strengthened by cold rolling, or a combination of cold rolling and precipitation hardening, without any post embossment heat treating that would act to further harden the material. Suitable iron-nickel-chromium alloys include those comprising, by weight, greater than 18% nickel; greater than 14% chrome and 0.1-10% of at least one element selected from the group consisting of Mo, Ti, V, Al, Co, Nb, Ta and Cu, with the balance being substantially Fe, wherein the gasket sheet alloy has a deformed microstructure.
    Type: Grant
    Filed: March 18, 2010
    Date of Patent: May 15, 2012
    Assignee: Federal-Mogul World Wide, Inc.
    Inventor: Thomas Zurfluh
  • Patent number: 8172959
    Abstract: There are provided an austenitic stainless steel having high stress corrosion crack resistance, characterized by containing, in percent by weight, 0.030% or less C, 0.1% or less Si, 2.0% or less Mn, 0.03% or less P, 0.002% or less S, 11 to 26% Ni, 17 to 30% Cr, 3% or less Mo, and 0.01% or less N, the balance substantially being Fe and unavoidable impurities; a manufacturing method for an austenitic stainless steel, characterized in that a billet consisting of the said austenitic stainless steel is subjected to solution heat treatment at a temperature of 1000 to 1150° C.; and a pipe and a in-furnace structure for a nuclear reactor to which the said austenitic stainless steel is applied.
    Type: Grant
    Filed: January 13, 2005
    Date of Patent: May 8, 2012
    Assignees: Mitsubishi Heavy Industries, Ltd., The Tokyo Electric Power Company, Inc.
    Inventors: Yasuhiro Sakaguchi, Toshihiko Iwamura, Hiroshi Kanasaki, Hidehito Mimaki, Masaki Taneike, Shunichi Suzuki, Kenrou Takamori, Suguru Ooki, Naoki Anahara, Naoki Hiranuma, Toshio Yonezawa
  • Patent number: 8097098
    Abstract: The invention concerns martensitic stainless steel, characterized in that its composition in weight percentages is as follows: 9%=Cr=13%; 1.5%=Mo=3%; 8%=Ni=14%; 1%=Al=2%; 0.5%=Ti=1.5% with AI+Ti=2.25%; traces=Co=2%; traces=W=1% with Mo+(W/2)=3%; traces=P=0.02%; traces=S=0.0050%; traces=N=0.0060%; traces=C=0.025%; traces=Cu=0.5%; traces=Mn=3%; traces=Si=0.25%; traces=O=0.0050%; and is such that: Ms (° C.)=1302 42 Cr 63 Ni 30 Mo+20AI-15W-33Mn-28Si-30Cu-13Co+10 Ti=50Cr eq/Ni eq=1.05 with Cr eq (%)=Cr+2Si+Mo+1.5 Ti+5.5 AI+0.6W Ni eq (%)=2Ni+0.5 Mn+3O C+25 N+Co+0.3 Cu. The invention also concerns a method for making a mechanical part using said steel, and the resulting part.
    Type: Grant
    Filed: June 26, 2006
    Date of Patent: January 17, 2012
    Assignee: Aubert & Duval
    Inventor: Jacques Montagnon
  • Publication number: 20120000580
    Abstract: A corrosion-resistant austenitic steel is claimed which, in each case relative to 100 mass percent, contains 20 to 32% manganese, 10 to 15% chromium, a total of 0.5 to 1.3% carbon and nitrogen, wherein the ratio of carbon to nitrogen is 0.5 to 1.5, the remainder being iron and melt-related impurities. The claimed steel can be produced and processed at normal pressure and has TWIP properties. It is in particular suited for producing structural components in constructs, such as in the automotive industry.
    Type: Application
    Filed: March 3, 2010
    Publication date: January 5, 2012
    Applicant: MAX-PLANCK-INSTITUT FUER EISENFORSCHUNG GMBH
    Inventors: Sebastian Weber, Lais Mujica Roncery
  • Patent number: 7947136
    Abstract: An austenitic, substantially ferrite-free steel alloy and a process for producing components therefrom. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.
    Type: Grant
    Filed: March 16, 2010
    Date of Patent: May 24, 2011
    Assignees: Boehler Edelstahl GmbH & Co KG, Schoeller-Bleckmann Oilfield Technology GmbH
    Inventors: Gabriele Saller, Herbert Aigner, Josef Bernauer, Raimund Huber
  • Publication number: 20110061777
    Abstract: A ferritic stainless steel sheet and a method for manufacturing the ferritic stainless steel sheet include a composition which contains 0.0030 to 0.012 mass percent of C, 0.13 mass percent or less of Si, 0.25 mass percent or less of Mn, 0.04 mass percent or less of P, 0.005 mass percent or less of S, 0.06 mass percent or less of Al, 0.0030 to 0.012 mass percent of N, 20.5 to 23.5 mass percent of Cr, 0.3 to 0.6 mass percent of Cu, 0.5 mass percent or less of Ni, 0.3 to 0.5 mass percent of Nb, 0.05 to 0.15 mass percent of Ti, and the balance being Fe and inevitable impurities is hot-rolled at a finishing temperature of 900° C. or more and at a coiling temperature of 400 to 550° C., softening annealing is performed on an obtained hot-rolled steel sheet, picking is further performed, and cold rolling is subsequently performed.
    Type: Application
    Filed: June 18, 2008
    Publication date: March 17, 2011
    Applicant: JFE STEEL CORPORATION
    Inventors: Tomohiro Ishii, Yoshimasa Funakawa, Shuji Okada, Masayuki Ohta
  • Publication number: 20110000589
    Abstract: This ferrite-austenite stainless steel sheet includes: in terms of mass %, C: 0.1% or less; Cr: 17 to 25%; Si: 1% or less; Mn: 3.7% or less; Ni: 0.6 to 3%; Cu: 0.1 to 3%; and N: 0.06% or more and less than 0.15%, with the remainder being Fe and inevitable impurities, wherein the steel sheet has a two-phase structure consisting of a ferrite phase and an austenite phase, a volume fraction of the austenite phase is in a range of 15 to 70%, and in a sheet plane (ND) of a center of a sheet thickness, grains of the ferrite phase having a crystal orientation satisfying ND//{111}±10° and grains of the ferrite phase having a crystal orientation satisfying ND//{101}±10° are present in a total content of 10% by area or more.
    Type: Application
    Filed: January 30, 2009
    Publication date: January 6, 2011
    Applicant: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Masaharu Hatano, Akihiko Takahashi, Eiichiro Ishimaru, Ken Kimura
  • Publication number: 20100223927
    Abstract: Disclosed is a ferritic stainless steel sheet with excellent thermal fatigue properties, including, by mass %, 0.03% or less of C, 1.0% or less of Si, 1.5% or less of Mn, 0.6% or less of Ni, 10˜20% of Cr, 0.05˜0.30% of Ti, 0.51˜0.65% of Nb, 0˜less than 0.10% of Mo, 0.8˜2.0% of Cu, 0˜0.10% of Al, 0.0005˜0.02% of B, 0˜0.20% of V, and 0.03% or less of N, with the balance being Fe and inevitable impurities, having a composition satisfying the following equations (1) and (2) and having a structure in which ?-Cu phase grains each having a long diameter of 0.5 ?m or more are present in a density of 10 or less per 25 ?m2: Nb?8(C+N)?0 . . . (1), 10Si+20Mo+30Cu+20(Ti+V)+160Nb?(Mn+Ni)?100 . . . (2). The ferritic stainless steel sheet, having a relatively inexpensive component composition, has excellent thermal fatigue properties, and is suitable for use in an automotive exhaust-gas path member, including an exhaust manifold, a catalyst converter, a front pipe, or a center pipe.
    Type: Application
    Filed: April 8, 2010
    Publication date: September 9, 2010
    Inventors: Manabu OKU, Takeo Tomita, Yosuke Sumi, Yasuhisa Tanaka
  • Patent number: 7758707
    Abstract: The invention relates to a martensitic stainless steel to be used for making a razor, surgical and similar blades or other cutting tools, which steel contains 0.40 to 0.55 wt % carbon, 0.8 to 1.5 wt % silicon, 0.7 to 0.85 wt % manganese, 13.0 to 14.0 wt % chromium, 1.0 to 1.5 wt % molybdenum and 0.2 to 0.4 wt % nickel, 0.02 to 0.04 wt % nitrogen, the balance of the steel being iron and inevitable impurities. The invention also relates to a method of manufacturing the said steel.
    Type: Grant
    Filed: June 16, 2006
    Date of Patent: July 20, 2010
    Assignee: Outokumpu Oyj
    Inventor: Chris Millward
  • Publication number: 20100126644
    Abstract: The present invention relates to ferritic-austenitic stainless steel oriented to have low Ni which is excellent in corrosion resistance, particularly in corrosion resistance in a neutral chloride environment, and has high “uniform elongation”—a factor governing workability—and a method of production for the same. There are independently provided ferritic-austenitic stainless steels and methods of production for the same particularly having a corrosion resistance in a neutral chloride environment satisfying PI value(=Cr+3Mo+10N—Mn)?18% and having a uniform elongation satisfying ?10?Md?110 (where Md=551?462({C}+[N])?9.2[Si]?8.1[Mn]?13.7[Cr]?29[Ni]?29[Cu]?18.
    Type: Application
    Filed: August 1, 2008
    Publication date: May 27, 2010
    Inventors: Masaharu Hatano, Akihiko Takahashi, Eiichiro Ishimaru, Ken Kimura
  • Patent number: 7708841
    Abstract: An austenitic, substantially ferrite-free steel alloy and a process for producing components therefrom. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.
    Type: Grant
    Filed: December 2, 2004
    Date of Patent: May 4, 2010
    Assignees: Boehler Edelstahl GmbH & Co KG, Schoeller-Bleckmann Oilfield Technology GmbH
    Inventors: Gabriele Saller, Herbert Aigner, Josef Bernauer, Raimund Huber
  • Publication number: 20090314394
    Abstract: The invention relates to a method for manufacturing a ductile, high strength austenitic stainless steel object from an austenitic stainless, steel strip, in which method the strip is cold worked in order to promote the formation of martensite into the microstructure of the strip, and the strip having a dual-phase microstructure is further processed. The strip is then shaped to a desired object having at least one curved or arcuate area and during the shaping of the object the different areas of the strip are deformed in different degrees. The desired object is further reversion annealed in order to reverse martensite back to the austenite form and a hardening effect is achieved in order to have an essentially fine grain microstructure for at least the curved or arcuate area of the object.
    Type: Application
    Filed: January 15, 2008
    Publication date: December 24, 2009
    Applicant: OUTOKUMPU OYJ
    Inventors: Tero Taulavuori, Antero Kyröläinen, Terho Torvinen
  • Patent number: 7494551
    Abstract: A Ti-containing ferritic stainless steel sheet and a manufacturing method thereof include stainless steels being formed while a refining load is decreased and having a low yield strength which exhibits superior workability. The Ti-containing ferritic stainless steel sheet contains on mass percent basis: 0.01% or less of C; 0.5% or less of Si; 0.3% or less of Mn; 0.01% to 0.04% of P; 0.01% or less of S; 8% to 30% of Cr; 1.0% or less of Al; 0.05% to 0.5% of Ti; 0.04% or less of N, 8?Ti/(C+N)?30 being satisfied; and the balance being substantially Fe and incidental impurities, wherein a grain size number of ferrite grain is 6.0 or more, and an average diameter Dp of precipitation diameters, each being [(a long axis length of a Ti base precipitate+a short axis length thereof)/2], of the Ti base precipitates in the steel sheet is in the range of from 0.05 ?m to 1.0 ?m.
    Type: Grant
    Filed: June 16, 2003
    Date of Patent: February 24, 2009
    Assignee: JFE Steel Corporation
    Inventors: Yoshihiro Yazawa, Osamu Furukimi, Yasushi Kato
  • Patent number: 7429302
    Abstract: A structural hot-rolled or cold-rolled stainless steel sheet having improved intergranular corrosion resistance and toughness at the welding heat affected zone and further having low strength and high elongation. The composition of the steel sheet contains less than about 0.008 mass percent of C; about 1.0 mass percent or less of Si; about 1.5 mass percent or less of Mn; about 11 to about 15 mass percent of Cr; more than about 1.0 mass percent and about 2.5 mass percent or less of Ni; less than about 0.10 mass percent of Al; about 0.009 mass percent or less of N; about 0.04 mass percent or less of P; about 0.01 mass percent or less of S; and the balance being Fe and incidental impurities. These contents satisfy the expressions: (Cr)+1.2×(Ni)?15.0; (Ni)+0.5×(Mn)+30×(C)?3.0; (C)+(N)?0.015; and (Cr)?(Mn)?1.7×(Ni)?27×(C)?100×(N)?9.0.
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: September 30, 2008
    Assignee: JFE Steel Corporation
    Inventors: Junichiro Hirasawa, Takumi Ujiro, Osamu Furukimi
  • Patent number: 7416619
    Abstract: The present invention relates to new kitchen utensils, in particular relates to an application of a material in kitchen utensils. The present invention solves the problems of long-term presence in the field. SUS436L is used for kitchen utensils. SUS436L chemical composition (wt %) comprises Cr 16-19, C?0.025, Si?1.00, Mn?1.00, N?0.02, Ni?0.60, Ti?0.75, Mo 0.75-1.50 and balance of Fe. The kitchen utensils have all excellence of present kitchen utensils, overcome its disadvantage and possess high property of heat conduction and magnetoconductivity. The kitchen utensils are used in induction cooker, possess the all and the one structure and have low cost.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: August 26, 2008
    Assignee: Xinhui Rixing Stainless Steel Product Company Limited
    Inventor: Iou Lei
  • Patent number: 7412300
    Abstract: Briefly, in accordance with one or more embodiments, one or more thermal forming treatments may be predicted to achieve a desired shape and/or microstructure in a workpiece.
    Type: Grant
    Filed: February 27, 2006
    Date of Patent: August 12, 2008
    Assignee: General Electric Company
    Inventors: David Peter Mika, Michael Evans Graham, Wenwu Zhang
  • Patent number: 7396421
    Abstract: A duplex stainless steel containing C, Si, Mn, P, S, Al, Ni, Cr, Mo, N (nitrogen, O (oxygen), Ca, Mg, Cu, B, and W, and the balance Fe and impurities, where a number of oxide-based inclusions, which have a total content of Ca and Mg of 20 to 40% by mass and also have a long diameter of not less than 7 ?m, is not more than a 10 per 1 mm2 of the cross section perpendicular to the working direction, or further, the number of oxide-based inclusions, which have a content of S of not less than 15% by mass and also have a long diameter of not less than 1 ?m, is not more than 10 per 0.1 mm2 of the cross section perpendicular to the working direction. Particularly, the contents of Cu, B and W are desirably 0.2 to 2%, 0.001 to 0.01%, and 0.1 to 4% by mass, respectively.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: July 8, 2008
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Tomohiko Omura, Satoshi Matsumoto