Patents by Inventor Eiichiro Ishimaru

Eiichiro Ishimaru has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11946126
    Abstract: A welded structure including a base material made of duplex stainless steel and a welded portion formed by welding the base materials to each other, wherein the base material has a predetermined chemical composition, a volume fraction of a ferrite phase in a metallographic structure of a weld metal of the welded portion is 45 to 75%, a ratio of a hardness of the weld metal to a hardness of the base material is 0.80 to 1.20, and an amount of precipitates formed in the ferrite phase of the weld metal is less than 10% in area fraction.
    Type: Grant
    Filed: March 31, 2021
    Date of Patent: April 2, 2024
    Assignee: NIPPON STEEL STAINLESS STEEL CORPORATION
    Inventors: Eiichiro Ishimaru, Takuya Sakuraba, Yuji Kaga, Toyohiko Kakihara
  • Publication number: 20240002969
    Abstract: This titanium material is a dual phase stainless steel sheet containing an austenite and a ferrite and has a predetermined chemical composition, wherein, in a center part in a sheet thickness of a cross section in a perpendicular-to-rolling direction which is a direction perpendicular to a rolling direction on a rolled surface and a direction parallel to a sheet thickness direction, an area ratio S<001>/S<111> which is a ratio of an area proportion S<001> of a texture of a ferrite with the <001> direction oriented in the perpendicular-to-rolling direction to an area proportion S<111> of a texture of a ferrite with the <111> direction oriented in the perpendicular-to-rolling direction is 0.90 to 1.10.
    Type: Application
    Filed: November 26, 2021
    Publication date: January 4, 2024
    Applicant: NIPPON STEEL Stainless Steel Corporation
    Inventors: Takuya SAKURABA, Eiichiro ISHIMARU
  • Publication number: 20230357906
    Abstract: A martensite-based stainless steel material has a composition containing: 0.30 to 0.60% by mass of C; 0.05 to 1.00% by mass of Si; 0.05 to 1.50% by mass of Mn; 0.040% by mass or less of P; 0.030% by mass or less of S; 13.0 to 18.0% by mass of Cr; 0.01 to 0.30% by mass of Ni; 0.01 to 1.00% by mass of Mo; 0.030% by mass or less of Al; 0.010 to 0.350% by mass of N; 0.0001 to 0.0030% by mass of Ca; and 0.001 to 0.010% by mass of O; 2.5 C+N being 1.10% or more, and the balance being Fe and impurities. The martensite-based stainless steel material has an average grain diameter of carbides of 0.50 ?m or less. Also, the number of the carbides having a size of 10 ?m or more is 0.20/cm2 or less.
    Type: Application
    Filed: December 17, 2021
    Publication date: November 9, 2023
    Inventors: Kou NISHIMURA, Eiichiro ISHIMARU, Koichi TSUBOI
  • Publication number: 20230250522
    Abstract: An austenitic stainless steel material consisting of, on a mass basis, 0.200% or less of C, 1.00 to 3.50% of Si, 5.00% or less of Mn, 4.00 to 10.00% of Ni, 12.00 to 18.00% of Cr, 3.500% or less of Cu, 1.00 to 5.00% of Mo, and 0.200% or less of N, a total amount of C and N is 0.100% or more, and the balance is Fe and impurities; wherein the austenitic stainless steel material has a composition having a value of Md30 of -40.0 to 0° C.; the austenitic stainless steel material has a metallographic structure comprising 25 to 35% by volume of strain-induced martensite phase; and the austenitic stainless steel material has a tensile strength (TS) of 1450 MPa or more, an elongation at break (EL) of 12.0% or more, TS x EL of 24000 or more, and a stress relaxation percentage of 1.20% or less.
    Type: Application
    Filed: May 11, 2021
    Publication date: August 10, 2023
    Applicant: NIPPON STEEL STAINLESS STEEL CORPORATION
    Inventors: Naoki HIRAKAWA, Masaya TANAKA, Eiichiro ISHIMARU
  • Publication number: 20220411909
    Abstract: A welded structure including a base material made of duplex stainless steel and a welded portion formed by welding the base materials to each other, wherein the base material has a predetermined chemical composition, a volume fraction of a ferrite phase in a metallographic structure of a weld metal of the welded portion is 45 to 75%, a ratio of a hardness of the weld metal to a hardness of the base material is 0.80 to 1.20, and an amount of precipitates formed in the ferrite phase of the weld metal is less than 10% in area fraction.
    Type: Application
    Filed: March 31, 2021
    Publication date: December 29, 2022
    Applicant: NIPPON STEEL STAINLESS STEEL CORPORATION
    Inventors: Eiichiro ISHIMARU, Takuya SAKURABA, Yuji KAGA, Toyohiko KAKIHARA
  • Publication number: 20220073761
    Abstract: This clear-coated stainless steel sheet (10) includes a stainless steel sheet (20), and a clear-coated film (30) formed on at least one surface (20a) of the stainless steel sheet (20) and having an average film thickness of 0.05 ?m or more and 3.00 ?m or less.
    Type: Application
    Filed: March 27, 2020
    Publication date: March 10, 2022
    Applicant: NIPPON STEEL Stainless Steel Corporation
    Inventors: Satoshi SAMPEI, Nobuhiko HIRAIDE, Tooru MATSUHASHI, Eiichiro ISHIMARU
  • Patent number: 10513763
    Abstract: A Cr-containing ferritic stainless steel sheet is desired with improved corrosion resistance and rust resistance as well as improved ridging resistance. To achieve these results, the ferritic stainless steel sheet derives the relationship between Ap, which shows the ?-phase rate at 1100° C. due to a predetermined ingredient, and Sn in ferritic stainless steel which becomes a dual phase structure of ?+? in the hot rolling temperature region, applies and adds Sn, and hot rolls the steel to give a total rolling rate of 15% or more in 1100° C. or higher hot rolling to thereby obtain ferritic stainless steel sheet which has good ridging resistance, which also has excellent corrosion resistance and rust resistance, and which can be applied to general durable consumer goods, wherein 0.060?Sn?0.634?0.0082Ap and 10?Ap?70.
    Type: Grant
    Filed: April 15, 2019
    Date of Patent: December 24, 2019
    Assignee: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Masaharu Hatano, Eiichiro Ishimaru, Akihiko Takahashi, Ken Kimura, Shinichi Teraoka
  • Patent number: 10513747
    Abstract: A ferritic stainless steel sheet containing, by mass %, C: 0.020% or less, Cr: 10.0% to 25.0%, N: 0.020% or less, Sn: 0.010% to 0.50%, and one or more of Ti: 0.60% or less, Nb: 0.60% or less, V: 0.60% or less, and Zr: 0.60% or less so as to satisfy Equation (1): (Ti/48+V/51+Zr/91+Nb/93)/(C/12+N/14)?1.0, wherein a difference between a stress ?1 (N/mm2) after prestrain imparting tensile deformation with 7.5% of strain, and an upper yield stress ?2 (N/mm2) when the steel sheet is subjected to heat treatment at 200° C. for 30 minutes and then to tension again after the tensile deformation is 8 or less.
    Type: Grant
    Filed: March 14, 2014
    Date of Patent: December 24, 2019
    Assignee: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Ken Kimura, Junichi Hamada, Eiichiro Ishimaru, Akihito Yamagishi, Naoto Hansaki
  • Publication number: 20190241998
    Abstract: A Cr-containing ferritic stainless steel sheet is desired with improved corrosion resistance and rust resistance as well as improved ridging resistance. To achieve these results, the ferritic stainless steel sheet derives the relationship between Ap, which shows the ?-phase rate at 1100° C. due to a predetermined ingredient, and Sn in ferritic stainless steel which becomes a dual phase structure of ?+? in the hot rolling temperature region, applies and adds Sn, and hot rolls the steel to give a total rolling rate of 15% or more in 1100° C. or higher hot rolling to thereby obtain ferritic stainless steel sheet which has good ridging resistance, which also has excellent corrosion resistance and rust resistance, and which can be applied to general durable consumer goods, wherein 0.060?Sn?0.634?0.0082Ap and 10?Ap?70.
    Type: Application
    Filed: April 15, 2019
    Publication date: August 8, 2019
    Applicant: Nippon Steel & Sumikin Stainless Steel Corporation
    Inventors: Masaharu Hatano, Eiichiro Ishimaru, Akihiko Takahashi, Ken Kimura, Shinichi Teraoka
  • Patent number: 10358707
    Abstract: A Cr-containing ferritic stainless steel sheet is desired with improved corrosion resistance and rust resistance as well as improved ridging resistance. To achieve these results, the ferritic stainless steel sheet derives the relationship between Ap, which shows the ?-phase rate at 1100° C. due to a predetermined ingredient, and Sn in ferritic stainless steel which becomes a dual phase structure of ?+? in the hot rolling temperature region, applies and adds Sn, and hot rolls the steel to give a total rolling rate of 15% or more in 1100° C. or higher hot rolling to thereby obtain ferritic stainless steel sheet which has good ridging resistance, which also has excellent corrosion resistance and rust resistance, and which can be applied to general durable consumer goods, wherein 0.060?Sn?0.634?0.0082Ap and 10?Ap?70.
    Type: Grant
    Filed: August 22, 2017
    Date of Patent: July 23, 2019
    Assignee: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Masaharu Hatano, Eiichiro Ishimaru, Akihiko Takahashi, Ken Kimura, Shinichi Teraoka
  • 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: 9938598
    Abstract: The present invention provides a low-alloy high-purity ferritic stainless steel sheet provided with improved oxidation resistance and high-temperature strength by utilizing Sn addition in trace amounts without relying on excessive alloying of Al and Si which reduces fabricability and weldability or addition of rare elements such as Nb, Mo, W, and rare earths, and a process for producing the same. The high-purity ferritic stainless steel sheet includes C: 0.001 to 0.03%, Si: 0.01 to 2%, Mn: 0.01 to 1.5%, P: 0.005 to 0.05%, S: 0.0001 to 0.01%, Cr: 16 to 30%, N: 0.001 to 0.03%, Al: 0.05 to 3%, and Sn: 0.01 to 1% (% by mass), with the remainder being Fe and unavoidable impurities. A stainless steel slab having such steel components is heated, wherein an extraction temperature is 1100 to 1250° C., and a winding temperature after hot rolling is 650° C. or lower. A hot-rolled sheet is annealed at 900 to 1050° C., and cooled at 10° C./sec or less over a temperature range of 550 to 850° C.
    Type: Grant
    Filed: January 23, 2012
    Date of Patent: April 10, 2018
    Assignee: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Masaharu Hatano, Eiichiro Ishimaru, Akihiko Takahashi
  • Publication number: 20180066335
    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: Application
    Filed: November 13, 2017
    Publication date: March 8, 2018
    Applicant: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Junichi HAMADA, Eiichiro ISHIMARU
  • Publication number: 20170349988
    Abstract: The present invention focuses on Sn and has as its problem to not only improve the corrosion resistance and rust resistance of Cr-containing ferritic stainless steel but also improve the ridging resistance. The present invention derives the relationship between Ap, which shows the ?-phase rate at 1100° C. due to a predetermined ingredient, and Sn in ferritic stainless steel which becomes a dual phase structure of ?+? in the hot rolling temperature region, applies and adds Sn, and hot rolls the steel to give a total rolling rate of 15% or more in 1100° C. or higher hot rolling to thereby obtain ferritic stainless steel sheet which has good ridging resistance, which also has excellent corrosion resistance and rust resistance, and which can be applied to general durable consumer goods: 0.060?Sn?0.634?0.
    Type: Application
    Filed: August 22, 2017
    Publication date: December 7, 2017
    Applicant: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Masaharu HATANO, Eiichiro ISHIMARU, Akihiko TAKAHASHI, Ken KIMURA, Shinichi TERAOKA
  • Patent number: 9837567
    Abstract: Provided is a stainless steel substrate for a solar cell, the stainless steel substrate including, by mass %, Cr: 9% to 25%, C: 0.03% or less, Mn: 2% or less, P: 0.05% or less, S: 0.01% or less, N: 0.03% or less, Al: 0.005% to 5.0%, Si: 0.05% to 4.0%, and a remainder including Fe and unavoidable impurities, in which an oxide film containing (i) Al2O3 in an amount of 50% or more or containing (i) Al2O3 and (ii) SiO2 in a total amount of 50% or more is formed on a surface of stainless steel having a composition which contains Al: 0.5% or more and/or Si: 0.4% or more and satisfies the following expression (1). Cr+10Si+Mn+Al>24.
    Type: Grant
    Filed: May 2, 2014
    Date of Patent: December 5, 2017
    Assignee: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Masaharu Hatano, Eiichiro Ishimaru, Kenji Hattori
  • Patent number: 9771640
    Abstract: A ferritic stainless steel sheet having ridging resistance contains, by mass, 0.025 to 0.30% C, 0.01 to 1.00% Si, 0.01 to 2.00% Mn, 0.050% or less P, 0.020% or less S, 11.0 to 22.0% Cr, and 0.022 to 0.10% N. In addition, Ap, which is defined as 420C+470N+23Ni+9Cu+7Mn?11.5(Cr+Si)?12Mo?52Al?47Nb?49Ti+189 wherein each of Sn, C, N, Ni, Cu, Mn, Cr, Si, Mo, Al, Nb, and Ti denotes the content of the element, satisfies 10?Ap?70. Furthermore, a content of Sn satisfies 0.060?Sn?0.634?0.0082Ap. Residual ingredients are Fe and unavoidable impurities, and a metal structure of the steel sheet is a ferrite single phase. The ferritic stainless steel sheet has a ridging height of less than 6 ?m. This ferritic stainless steel sheet improves the corrosion resistance and rust resistance of Cr-containing ferritic stainless steel as well as the ridging resistance.
    Type: Grant
    Filed: June 18, 2012
    Date of Patent: September 26, 2017
    Assignee: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Masaharu Hatano, Eiichiro Ishimaru, Akihiko Takahashi, Ken Kimura, Shinichi Teraoka
  • Patent number: 9289964
    Abstract: An alloy-saving type high purity ferritic stainless steel sheet, comprising a steel sheet which contains, by mass %, C: 0.001 to 0.03%, Si: 0.01 to 1%, Mn: 0.01 to 1.5%, P: 0.005 to 0.05%, S: 0.0001 to 0.01%, Cr: 13 to 30%, N: 0.001 to 0.03%, Al: 0.005 to 1%, and Sn: 0.01 to 1% and has a balance of Fe and unavoidable impurities and which has a surface film, the surface film containing one or both of Al and Si in a total of 5 to 50 at % and Sn, an average concentration of Cr in the surface film being 1.1 to 3 times the concentration of Cr inside the steel sheet, and the surface film having a surface roughness of an arithmetic average roughness Ra of 0.1 to 1.5 ?m.
    Type: Grant
    Filed: March 5, 2012
    Date of Patent: March 22, 2016
    Assignee: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Masaharu Hatano, Hiroyuki Matsuyama, Akihito Yamagishi, Naoto Hansaki, Eiichiro Ishimaru
  • Publication number: 20160079455
    Abstract: Provided is a stainless steel substrate for a solar cell, the stainless steel substrate including, by mass %, Cr: 9% to 25%, C: 0.03% or less, Mn: 2% or less, P: 0.05% or less, S: 0.01% or less, N: 0.03% or less, Al: 0.005% to 5.0%, Si: 0.05% to 4.0%, and a remainder including Fe and unavoidable impurities, in which an oxide film containing (i) Al2O3 in an amount of 50% or more or containing (i) Al2O3 and (ii) SiO2 in a total amount of 50% or more is formed on a surface of stainless steel having a composition which contains Al: 0.5% or more and/or Si: 0.4% or more and satisfies the following expression (1). Cr+10Si+Mn+Al>24.
    Type: Application
    Filed: May 2, 2014
    Publication date: March 17, 2016
    Applicant: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Masaharu HATANO, Eiichiro ISHIMARU, Kenji HATTORI
  • Publication number: 20160017451
    Abstract: A ferritic stainless steel sheet exhibiting small increase in strength after aging heat treatment in the present invention contains, by mass %, C: 0.020% or less, Cr: 10.0% to 25.0%, N: 0.020% or less, Sn: 0.010% to 0.50%, and one or more of Ti: 0.60% or less, Nb: 0.60% or less, V: 0.60% or less, and Zr: 0.60% or less so as to satisfy the following Equation (1), in which the difference between stress ?1 (N/mm2) after prestrain imparting tensile deformation with 7.5% of strain, and upper yield stress ?2 (N/mm2) when the steel sheet is subjected to heat treatment at 200° C. for 30 minutes and then to tension again after the tensile deformation is 8 or less. (Ti/48+V/51+Zr/91+Nb/93)/(C/12+N/14)?1.
    Type: Application
    Filed: March 14, 2014
    Publication date: January 21, 2016
    Applicant: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Ken KIMURA, Junichi HAMADA, Eiichiro ISHIMARU, Akihito YAMAGISHI, Naoto HANSAKI
  • Publication number: 20150376732
    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: Application
    Filed: February 4, 2014
    Publication date: December 31, 2015
    Applicant: NIPPON STEEL & SUMIKIN STAINLESS STEEL CORPORATION
    Inventors: Junichi HAMADA, Eiichiro ISHIMARU