Patents by Inventor Chikara Kami

Chikara Kami 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: 11220732
    Abstract: Provided is a ferritic stainless steel sheet excellent in shape of weld zone and corrosion resistance of a weld zone with a material of a different kind formed by performing welding with austenitic stainless steel. A ferritic stainless steel sheet having a chemical composition containing, by mass %, C: 0.003% to 0.020%, Si: 0.01% to 1.00%, Mn: 0.01% to 0.50%, P: 0.040% or less, S: 0.010% or less, Cr: 20.0% to 24.0%, Cu: 0.20% to 0.80%, Ni: 0.01% to 0.60%, Al: 0.01% to 0.08%, N: 0.003% to 0.020%, Nb: 0.40% to 0.80%, Ti: 0.01% to 0.10%, Zr: 0.01% to 0.10%, and the balance being Fe and inevitable impurities, in which relational expression (1) below is satisfied: 3.0?Nb/(2Ti+Zr+0.5Si+5Al)?1.5??(1), here, in relational expression (1), each of the atomic symbols denotes the content (mass %) of the corresponding chemical element.
    Type: Grant
    Filed: June 15, 2017
    Date of Patent: January 11, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Hidetaka Kawabe, Shuji Nishida, Mitsuyuki Fujisawa, Chikara Kami
  • Publication number: 20210277494
    Abstract: Provided is a ferritic stainless steel in which cracking is unlikely to be caused in the vicinity of a weld zone by the stress due to expansion, contraction, and deformation due to the thermal effect of welding in the case of performing welding after deep drawing and which is excellent in corrosion resistance in the vicinity of the weld zone. The ferritic stainless steel has a composition containing C: 0.001% to 0.020%, Si: 0.01% to 0.30%, Mn: 0.01% to 0.50%, P: 0.04% or less, S: 0.01% or less, Cr: 18.0% to 24.0%, Ni: 0.01% to 0.40%, Mo: 0.30% to 3.0%, Al: 0.01% to 0.15%, Ti: 0.01% to 0.50%, Nb: 0.01% to 0.50%, V: 0.01% to 0.50%, Co: 0.01% to 6.00%, B: 0.0002% to 0.0050%, and N: 0.001% to 0.020% on a mass basis, the remainder being Fe and inevitable impurities. The composition satisfies 0.30%?Ti+Nb+V?0.60%.
    Type: Application
    Filed: May 25, 2017
    Publication date: September 9, 2021
    Applicant: JFE Steel Corporation
    Inventors: Tomohiro Ishii, Mitsuyuki Fujisawa, Reiko Sugihara, Chikara Kami
  • Patent number: 10988825
    Abstract: A martensitic stainless steel has a chemical composition containing, by mass %, C: 0.030% or more and less than 0.20%, Si: 0.01% or more and 2.0% or less, Mn: 0.01% or more and 3.0% or less, P: 0.050% or less , S: 0.010% or less, Cr: 10.0% or more and 16.0% or less, Ni: 0.01% or more and 0.80% or less, Al: 0.001% or more and 0.50% or less, Zr: 0.005% or more and 0.50% or less, and N: 0.030% or more and less than 0.20%, with the balance consisting of Fe and inevitable impurities.
    Type: Grant
    Filed: March 9, 2017
    Date of Patent: April 27, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Tetsuyuki Nakamura, Shin Ishikawa, Chikara Kami
  • Patent number: 10988853
    Abstract: Stainless steel sheets including a Ni and O-containing coating on the surface that has excellent weld penetration characteristics and excellent crevice corrosion resistance, and a method for producing such stainless steel sheets. A stainless steel sheet includes a Ni and O-containing coating on a surface of the stainless steel sheet. The Ni and O-containing coating has a coating weight of greater than or equal to 0.1 g/m2 and less than or equal to 20 g/m2. The Ni and O-containing coating has a composition including, in at. %, Ni: greater than or equal to 25% and less than or equal to 60%, and O: greater than or equal to 40% and less than or equal to 70%.
    Type: Grant
    Filed: January 5, 2017
    Date of Patent: April 27, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Junichiro Hirasawa, Shin Ishikawa, Chikara Kami, Shinji Ootsuka
  • Patent number: 10975459
    Abstract: Provided is a ferritic stainless steel excellent in oxidation resistance and thermal fatigue resistance. The ferritic stainless steel contains, in mass %, C: 0.020% or less, Si: more than 0.1% and 3.0% or less, Mn: 0.05 to 2.0%, P: 0.050% or less, S: 0.010% or less, Al: 0.3 to 6.0%, N: 0.020% or less, Cr: 12 to 30%, Nb: more than 0.3% and 1.0% or less, Ti: 0.01 to 0.5%, Mo: 0.3 to 6.0%, Co: 0.01 to 3.0%, and Ni: 0.02 to 1.0%, the balance being Fe and unavoidable impurities. Moreover, Si+Al>1.0%, Al—Mn>0%, and Nb—Ti>0% hold.
    Type: Grant
    Filed: September 20, 2016
    Date of Patent: April 13, 2021
    Assignee: JFE Steel Corporation
    Inventors: Tetsuyuki Nakamura, Shin Ishikawa, Chikara Kami
  • Patent number: 10900104
    Abstract: A method for manufacturing a hot rolled steel sheet having a low yield ratio and that is excellent in low-temperature toughness, the steel sheet having a specified chemical composition. The method comprises hot rolling a steel material into a steel sheet, cooling the steel material using a cooling process comprising a first cooling and a second cooling, and performing a coiling process on the steel sheet in such a manner that the coiling temperature is 450° C. or more in terms of surface temperature of the steel sheet.
    Type: Grant
    Filed: July 5, 2018
    Date of Patent: January 26, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Chikara Kami, Sota Goto
  • Patent number: 10876180
    Abstract: A method of manufacturing a hot rolled steel sheet for a square column for building structural members includes a hot rolling step, a cooling step, and a coiling step performed on a steel to form a hot rolled steel sheet, wherein the steel has a composition containing, in terms of % by mass, C: 0.07 to 0.18%, Mn: 0.3 to 1.5%, P: 0.03% or less, S: 0.015% or less, Al: 0.01 to 0.06%, N: 0.0006% or less, and the balance being Fe and unavoidable impurities.
    Type: Grant
    Filed: June 13, 2017
    Date of Patent: December 29, 2020
    Assignee: JFE Steel Corporation
    Inventors: Chikara Kami, Yuta Tamura, Takato Tamai, Shuji Kawamura
  • Patent number: 10837075
    Abstract: A hot rolled and annealed ferritic stainless steel sheet includes a composition that contains, on a mass percent basis, 0.015% or less of C, 1.00% or less of Si, 1.00% or less of Mn, 0.040% or less of P, 0.010% or less of S, 12.0% or more and 23.0% or less of Cr, 0.20% or more and 1.00% or less of Al, 0.020% or less of N, 1.00% or more and 2.00% or less of Cu, and 0.30% or more and 0.65% or less of Nb, Si and Al being contained so as to satisfy expression (1) described below, the balance being Fe and incidental impurities, and the hot rolled and annealed ferritic stainless steel sheet having a Vickers hardness less than 205, Si?Al (1) (where in expression (1), Si represents the content of Si (% by mass), and Al represents the content of Al (% by mass)).
    Type: Grant
    Filed: February 3, 2015
    Date of Patent: November 17, 2020
    Assignee: JFE Steel Corporation
    Inventors: Tetsuyuki Nakamura, Hiroki Ota, Chikara Kami
  • 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
  • Publication number: 20200308677
    Abstract: Provided is a ferritic stainless steel sheet excellent in shape of weld zone and corrosion resistance of a weld zone with a material of a different kind formed by performing welding with austenitic stainless steel. A ferritic stainless steel sheet having a chemical composition containing, by mass %, C: 0.003% to 0.020%, Si: 0.01% to 1.00%, Mn: 0.01% to 0.50%, P: 0.040% or less, S: 0.010% or less, Cr: 20.0% to 24.0%, Cu: 0.20% to 0.80%, Ni: 0.01% to 0.60%, Al: 0.01% to 0.08%, N:. 0.003% to 0.020%, Nb: 0.40% to 0.80%, Ti: 0.01% to 0.10%, Zr: 0.01% to 0.10%, and the balance being Fe and inevitable impurities, in which relational expression (1) below is satisfied: 3.0?Nb/(2Ti+Zr+0.5 Si+5 Al)?1.5 ??(1), here, in relational expression (1), each of the atomic symbols denotes the content (mass %) of the corresponding chemical element.
    Type: Application
    Filed: June 15, 2017
    Publication date: October 1, 2020
    Applicant: JFE Steel Corporation
    Inventors: Hidetaka Kawabe, Shuji Nishida, Mitsuyuki Fujisawa, Chikara Kami
  • Patent number: 10745774
    Abstract: A ferrite-martensite dual-phase stainless steel has satisfactory corrosion resistance and workability for a material for the body of a freight car and excellent low-temperature toughness. The ferrite-martensite dual-phase stainless steel has a specified chemical composition, in which inequalities (I) and (II) below are satisfied, and a steel microstructure including a dual phase of a ferrite phase and a martensite phase, in which the content of the martensite phase is 5% or more and 95% or less in terms of vol. %: 10.5?Cr+1.5×Si?13.5??(I) 1.5?30×(C+N)+Ni+0.5×Mn?6.0??(II), where Cr and Si in inequality (I) above and C, N, Ni, and Mn in inequality (II) above respectively represent the contents (mass %) of the corresponding chemical elements.
    Type: Grant
    Filed: October 27, 2014
    Date of Patent: August 18, 2020
    Assignee: JFE Steel Corporation
    Inventors: Tomohiro Ishii, Hiroki Ota, Chikara Kami, Saiichi Murata, Mitsuyuki Fujisawa, Genichi Ishibashi
  • Patent number: 10714764
    Abstract: A stainless steel sheet for fuel cell separators including a substrate made of stainless steel sheet, and low-electrical-resistivity metal particles, where the substrate has a textured structure formed on a surface thereof with the average interval between the projected parts of the textured structure being 10 nm or more and 300 nm or less, the low-electrical-resistivity metal particles have an average particle size of 50 nm to 1.0 ?m, the low-electrical-resistivity metal particles are attached to the surface of the substrate having the textured structure at a density of 1.0 particle or more for 1 ?m2, and a ratio of the average particle size of the low-electrical-resistivity metal particles to the average interval between the projected parts is 1.0 to 15.0.
    Type: Grant
    Filed: December 15, 2016
    Date of Patent: July 14, 2020
    Assignee: JFE STEEL CORPORATION
    Inventors: Takayoshi Yano, Shin Ishikawa, Chikara Kami
  • Patent number: 10655195
    Abstract: The disclosure is to provide a martensitic stainless steel excellent in strength, workability and corrosion resistance. The martensitic stainless steel comprises a chemical composition containing, in mass %: C: 0.020% or more and less than 0.10%, Si: 0.01% or more and 2.0% or less, Mn: 0.01% or more and 3.0% or less, P: 0.050% or less, S: 0.050% or less, Cr: 10.0% or more and 16.0% or less, Ni: 0.01% or more and 0.80% or less, Al: 0.001% or more and 0.50% or less, and N: more than 0.050% and 0.20% or less, satisfying N % C %, and the balance containing Fe and incidental impurities, where C % and N % indicate respectively the contents of C and N (mass %) in the steel.
    Type: Grant
    Filed: April 15, 2016
    Date of Patent: May 19, 2020
    Assignee: JFE STEEL CORPORATION
    Inventors: Tetsuyuki Nakamura, Takashi Samukawa, Mitsuyuki Fujisawa, Chikara Kami
  • Patent number: 10516174
    Abstract: A metal sheet for separators of polymer electrolyte fuel cells comprises: a substrate made of metal; and a surface-coating layer with which a surface of the substrate is coated, with a strike layer in between, wherein a coating ratio of the strike layer on the substrate is 2% to 70%, the strike layer is distributed in a form of islands, and a maximum diameter of the islands of the strike layer as coating portions is 1.00 ?m or less and is not greater than a thickness of the surface-coating layer.
    Type: Grant
    Filed: July 29, 2016
    Date of Patent: December 24, 2019
    Assignee: JFE STEEL CORPORATION
    Inventors: Takayoshi Yano, Shin Ishikawa, Chikara Kami
  • Patent number: 10458013
    Abstract: Provided is a ferritic stainless steel having a chemical composition containing, in mass %: 0.003% to 0.025% of C; 0.05% to 1.00% of Si; 0.05% to 1.00% of Mn; 0.04% or less of P; 0.01% or less of S; 16.0% to 23.0% of Cr; 0.20% to 0.80% of Cu; 0.05% to 0.60% of Ni; 0.20% to 0.70% of Nb; 0.005% to 0.020% of N; and the balance being Fe and incidental impurities, in which a nitrogen-enriched layer is present that has a nitrogen concentration peak value of 0.03 mass % to 0.30 mass % at a depth of within 0.05 ?m of a surface of the steel.
    Type: Grant
    Filed: November 17, 2015
    Date of Patent: October 29, 2019
    Assignee: JFE STEEL CORPORATION
    Inventors: Kunio Fukuda, Shin Ishikawa, Mitsuyuki Fujisawa, Katsuhisa Yamauchi, Chikara Kami
  • Patent number: 10450625
    Abstract: Provided is a ferritic stainless steel that has excellent corrosion resistance and displays good brazing properties when brazing is carried out at high temperature using a Ni-containing brazing metal. These effects are obtained as a result of the steel having a chemical composition containing, in mass %: 0.003%-0.020% of C; 0.05%-1.00% of Si; 0.10%-0.50% of Mn, 0.04% or less of P; 0.01% or less of S; 16.0%-25.0% of Cr; 0.05%-0.60% of Ni; 0.25%-0.45% of Nb; 0.005%-0.15% of Al; 0.005%-0.030% of N; and at least one selected from 0.50%-2.50% of Mo and 0.05%-0.80% of Cu, the balance being Fe and incidental impurities, and as a result of a nitrogen-enriched layer being created that has a nitrogen concentration peak value of 0.03 to 0.30 mass % at a depth of within 0.05 ?m of a surface of the steel.
    Type: Grant
    Filed: July 23, 2015
    Date of Patent: October 22, 2019
    Assignee: JFE STEEL CORPORATION
    Inventors: Kunio Fukuda, Mitsuyuki Fujisawa, Tomohiro Ishii, Shin Ishikawa, Chikara Kami
  • Patent number: 10415126
    Abstract: A ferritic stainless steel having excellent thermal fatigue resistance, excellent oxidation resistance, and excellent high-temperature fatigue resistance is provided. The ferritic stainless steel contains, in terms of % by mass, C: 0.020% or less, Si: 3.0% or less, Mn: 2.0% or less, P: 0.040% or less, S: 0.030% or less, Cr: 10.0% to 20.0%, N: 0.020% or less, Nb: 0.005% to 0.15%, Al: 0.20% to 3.0%, Ti: 5× (C+N)% to 0.50%, Cu: 0.55% to 1.60%, B: 0.0002% to 0.0050%, Ni: 0.05% to 1.0%, 0: 0.0030% or less, and the balance being Fe and unavoidable impurities. Additionally, the ferritic stainless steel satisfies that Al/O?100.
    Type: Grant
    Filed: May 12, 2015
    Date of Patent: September 17, 2019
    Assignee: JFE STEEL CORPORATION
    Inventors: Tetsuyuki Nakamura, Hiroki Ota, Chikara Kami
  • Patent number: 10400298
    Abstract: There is provided is a high-carbon hot-rolled steel sheet and method for producing the same. The steel sheet has excellent hardenability consistently, even when annealed in a nitrogen atmosphere, and excellent formability. The steel sheet has a hardness in the range of 83 HRB or less and a total elongation of 30% or more before being subjected to a quenching treatment.
    Type: Grant
    Filed: July 8, 2014
    Date of Patent: September 3, 2019
    Assignee: JFE STEEL CORPORATION
    Inventors: Yuka Miyamoto, Takashi Kobayashi, Chikara Kami, Hayato Saito, Kaneharu Okuda
  • Patent number: 10400318
    Abstract: A ferritic stainless steel that a composition including in terms of % by mass, C: 0.015% or less, Si: 1.0% or less, Mn: 1.0% or less, P: 0.040% or less, S: 0.010% or less, Cr: 10.0% to 23.0%, Al: 0.2% to 1.0%, N: 0.015% or less, Cu: 1.0% to 2.0%, Nb: 0.30% to 0.65%, Ti: 0.50% or less, O: 0.0030% or less, and the balance being Fe and unavoidable impurities, wherein a Si content and an Al content satisfy Si?Al, and the Al content and an O content satisfy Al/O?100.
    Type: Grant
    Filed: May 12, 2015
    Date of Patent: September 3, 2019
    Assignee: JFE STEEL CORPORATION
    Inventors: Tetsuyuki Nakamura, Hiroki Ota, Chikara Kami
  • Patent number: 10400299
    Abstract: There is provided a high-carbon hot-rolled steel sheet and method for producing the same. The steel sheet has excellent hardenability consistently, even when annealed in a nitrogen atmosphere, and excellent workability. The steel sheet has a hardness in the range of 65 or less in terms of HRB and a total elongation El of 40% or more before a quenching treatment is performed.
    Type: Grant
    Filed: July 8, 2014
    Date of Patent: September 3, 2019
    Assignee: JFE STEEL CORPORATION
    Inventors: Yuka Miyamoto, Takashi Kobayashi, Chikara Kami