Patents by Inventor Tetsuya Mega
Tetsuya Mega 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).
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Patent number: 10077489Abstract: A steel sheet for soft-nitriding has a composition containing: C: 0.05% or more to 0.10% or less; Si: 0.5% or less; Mn: 0.7% or more to 1.5% or less; P: 0.05% or less; S: 0.01% or less; Al: 0.01% or more to 0.06% or less; Cr: 0.5% or more to 1.5% or less; Nb: 0.005% or more to 0.025% or less; and N: 0.005% or less, on a mass percent basis, such that C and Nb satisfy 0.10?Nb/C?0.30 (where C and Nb are respective contents of the elements (by mass %)), wherein balance comprises Fe and incidental impurities, and a microstructure that is a complex-phase microstructure containing ferrite and pearlite, and the microstructure having a ratio of a microstructure other than the ferrite and the pearlite of 1% or less, and the microstructure having a ratio of polygonal ferrite in the ferrite of less than 50%.Type: GrantFiled: June 27, 2012Date of Patent: September 18, 2018Assignee: JFE Steel CorporationInventors: Takashi Kobayashi, Nobuyuki Nakamura, Tetsuya Mega
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Patent number: 9212411Abstract: A high-strength steel sheet includes a composition containing, in mass percent, 0.08% to 0.20% of carbon, 0.2% to 1.0% of silicon, 0.5% to 2.5% of manganese, 0.04% or less of phosphorus, 0.005% or less of sulfur, 0.05% or less of aluminum, 0.07% to 0.20% of titanium, and 0.20% to 0.80% of vanadium, the balance being iron and incidental impurities.Type: GrantFiled: June 29, 2010Date of Patent: December 15, 2015Assignee: JFE Steel CorporationInventors: Koichi Nakagawa, Takeshi Yokota, Kazuhiro Seto, Satoshi Kinoshiro, Yuji Tanaka, Katsumi Yamada, Tetsuya Mega, Katsumi Nakajima
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Patent number: 9194017Abstract: Hot-rolled steel has a chemical composition containing, by mass %, C: 0.18% or more and 0.29% or less, N: 0.0050% or less, Ti: 0.002% or more and 0.05% or less, B: 0.0005% or more and 0.0050% or less, and appropriately controlled amounts of Si, Mn, P, S, Al, and a tensile strength of 500 MPa or less with a variation in tensile strength of 60 MPa or less throughout a region including the edges in the width direction of the steel sheet, and having excellent cold formability and hardenability.Type: GrantFiled: March 15, 2011Date of Patent: November 24, 2015Assignee: JFE Steel CorporationInventors: Nobuyuki Nakamura, Takashi Kobayashi, Tetsuya Mega
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Publication number: 20150299830Abstract: A steel sheet for soft-nitriding has a composition containing: C: 0.05% or more to 0.10% or less; Si: 0.5% or less; Mn: 0.7% or more to 1.5% or less; P: 0.05% or less; S: 0.01% or less; Al: 0.01% or more to 0.06% or less; Cr: 0.5% or more to 1.5% or less; Nb: 0.005% or more to 0.025% or less; and N: 0.005% or less, on a mass percent basis, such that C and Nb satisfy 0.10?Nb/C?0.30 (where C and Nb are respective contents of the elements (by mass %)), wherein balance comprises Fe and incidental impurities, and a microstructure that is a complex-phase microstructure containing ferrite and pearlite, and the microstructure having a ratio of a microstructure other than the ferrite and the pearlite of 1% or less, and the microstructure having a ratio of polygonal ferrite in the ferrite of less than 50%.Type: ApplicationFiled: June 27, 2012Publication date: October 22, 2015Applicant: JFE Steel CorporationInventors: Takashi Kobayashi, Nobuyuki Nakamura, Tetsuya Mega
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Patent number: 9068238Abstract: Described is a high tensile strength hot rolled steel sheet having high strength and formability, and a manufacturing method. It has tensile strength ?980 MPa and excellent formability, and specifically identified ranges by mass % of C, Si, Mn, P, S, N, Al, Ti, V, Solute V, and Solute Ti; (ii) microstructure with fine carbides dispersion precipitated therein, the fine carbides containing Ti and V and having the average particle diameter <10 nm, as well as volume ratio with respect to the entire microstructure ?0.007; and matrix as ferrite phase having area ratio with respect to the entire microstructure ?97%. C, Ti, V, S and N satisfy (1) Ti?0.08 +(N/14×48+S/32×48) and (2) 0.8?(Ti/48+V/51)/(C/12)?1.2, where “C”, “Ti”, “V”, “S” and “N” represent contents (mass %) of corresponding elements, respectively.Type: GrantFiled: March 30, 2011Date of Patent: June 30, 2015Assignee: JFE STEEL CORPORATIONInventors: Tamako Ariga, Katsumi Nakajima, Tetsuya Mega
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Publication number: 20130206289Abstract: A high-strength hot-rolled steel sheet having excellent formability has a composition containing, by mass, 0.04% to 0.1% of C, 0.3% to 1.3% of Si, 0.8% to 1.8% of Mn, 0.03% or less of P, 0.005% or less of S, 0.005% or less of N, 0.005% to 0.1% of Al, and at least one element selected from 0.002% to less than 0.03% of Ti, 0.002% to less than 0.03% of V, and 0.002% to less than 0.02% of Nb, the balance being Fe and incidental impurities. The steel sheet has a microstructure in which the area fraction of ferrite phase in the entire structure is 85% or more, the area fraction of bainite phase in the entire structure is 10% or less, the area fraction of phases other than the ferrite and bainite phases in the entire structure is 5% or less, and the area fraction of acicular ferrite phase in the entire ferrite phase is 30% to less than 80%.Type: ApplicationFiled: August 9, 2011Publication date: August 15, 2013Applicant: JFE STEEL CORPORATIONInventors: Katsumi Nakajima, Tetsuya Mega, Reiko Mizuno, Noriaki Moriyasu
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Publication number: 20130186526Abstract: Hot-rolled steel has a chemical composition containing, by mass%, C: 0.18% or more and 0.29% or less, N: 0.0050% or less, Ti: 0.002% or more and 0.05% or less, B: 0.0005% or more and 0.0050% or less, and appropriately controlled amounts of Si, Mn, P, S, Al, and a tensile strength of 500 MPa or less with a variation in tensile strength of 60 MPa or less throughout a region including the edges in the width direction of the steel sheet, and having excellent cold formability and hardenability.Type: ApplicationFiled: March 15, 2011Publication date: July 25, 2013Applicant: JFE STEEL CORPORATIONInventors: Nobuyuki Nakamura, Takashi Kobayashi, Tetsuya Mega
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Publication number: 20130133790Abstract: Described is a high tensile strength hot rolled steel sheet having high strength and formability, and a manufacturing method. It has tensile strength?980 MPa and excellent formability, and specifically identified ranges by mass % of C, Si, Mn, P, S, N, Al, Ti, V, Solute V, and Solute Ti; (ii) microstructure with fine carbides dispersion precipitated therein, the fine carbides containing Ti and V and having the average particle diameter<10 nm, as well as volume ratio with respect to the entire microstructure?0.007; and matrix as ferrite phase having area ratio with respect to the entire microstructure?97%. C, Ti, V, S and N satisfy (1) Ti?0.08+(N/14×48+S/32×48) and (2) 0.8?(Ti/48+V/51)/(C/12)?1.2, where “C”, “Ti”, “V”, “S” and “N” represent contents (mass %) of corresponding elements, respectively.Type: ApplicationFiled: March 30, 2011Publication date: May 30, 2013Applicant: JFE STEEL CORPORATIONInventors: Tamako Ariga, Katsumi Nakajima, Tetsuya Mega
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Publication number: 20120107633Abstract: A high-strength steel sheet includes a composition containing, in mass percent, 0.08% to 0.20% of carbon, 0.2% to 1.0% of silicon, 0.5% to 2.5% of manganese, 0.04% or less of phosphorus, 0.005% or less of sulfur, 0.05% or less of aluminum, 0.07% to 0.20% of titanium, and 0.20% to 0.80% of vanadium, the balance being iron and incidental impurities.Type: ApplicationFiled: June 29, 2010Publication date: May 3, 2012Applicant: JFE STEEL CORPORATIONInventors: Koichi Nakagawa, Takeshi Yokota, Kazuhiro Seto, Satoshi Kinoshiro, Yuji Tanaka, Katsumi Yamada, Tetsuya Mega, Katsumi Nakajima
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Publication number: 20110048588Abstract: A cold-rolled steel sheet has a partially recrystallized grain structure with a degree of unrecrystallization of 25% to 90% and a Rockwell hardness HRB of 83 or more, the cold-rolled steel sheet containing 0.01% to 0.15% C, 0.03% or less Si, 0.10% to 0.70% Mn, 0.025% or less P, 0.025% or less S, 0.01% to 0.05% Al, and 0.008% or less N on a mass basis, the remainder being Fe and unavoidable impurities, wherein the mean diameter of ferrite is 2 to 10 ?m and these components satisfy Formula (1): (C %)+0.15×(Mn %)+0.85×(P %)?0.21, wherein (M %) represents the content (mass percent) of an element M.Type: ApplicationFiled: February 26, 2009Publication date: March 3, 2011Applicant: JFE Steel CorporationInventors: Tetsuya Mega, Nobuyuki Nakamura, Takashi Kobayashi, Yasunobu Nagataki, Takayoshi Kabeya
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Patent number: 7527700Abstract: The present invention relates to a high strength hot rolled steel sheet consisting of 0.04 to 0.15% C, 1.5% or less Si, 0.5 to 1.6% Mn, 0.04% or less P, 0.005% or less S, 0.04% or less Al, 0.03 to 0.15% Ti, 0.03 to 0.5% Mo, by mass, and balance of Fe and inevitable impurities, and having a microstructure consisting of ferrite containing precipitates, second phase of bainite and/or martensite, and other phase, wherein the percentage of the ferrite containing precipitates is 40 to 95%, and the percentage of the other phase is 5% or less. For example, the high strength hot rolled steel sheet having a thickness of 1.4 mm shows a tensile strength of 780 MPa or higher, an elongation of 22% or higher elongation, and a hole expansion ratio of 60% or higher, thus the steel sheet is suitable for reinforcing members automobile cabin and crash worthiness members of automobile.Type: GrantFiled: April 21, 2004Date of Patent: May 5, 2009Assignee: JFE Steel CorporationInventors: Nobusuke Kariya, Shusaku Takagi, Tetsuo Shimizu, Tetsuya Mega, Kei Sakata, Hiroshi Takahashi
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Patent number: 7485194Abstract: This disclosure proposes a high-strength hot rolled steel sheet having excellent anti-die-galling property and anti-fatigue property, in which the steel sheet has a composition including C: not less than 0.02 mass % but not more than 0.2 mass %, Si: not less than 0.2 mass % but not more than 1.2 mass %, Mn: not less than 1.0 mass % but not more than 3.0 mass %, Mo: not less than 0.1 mass % but not more than 1.0 mass %, Al: not less than 0.01 mass % but not more than 0.1 mass %, P: not more than 0.03 mass % S: not more than 0.01 mass % and the remainder being substantially Fe and inevitable impurities, and has a steel microstructure containing not less than 55 vol % of ferrite and not less than 10 vol % but not more than 40 vol % of martensite provided that a total of both is not less than 95 vol %, and a ratio ds/dc of an average crystal grain size ds of the ferrite in a surface layer portion of the steel sheet to an average crystal grain size dc of the ferrite in a center portion of the steel sheet is 0.Type: GrantFiled: May 23, 2002Date of Patent: February 3, 2009Assignee: JFE Steel CorporationInventors: Tetsuya Mega, Kei Sakata
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Patent number: 7347902Abstract: According to the invention, a high-strength hot rolled steel sheet having an excellent shape fixability as hot-rolled and an excellent fatigue durability after the forming, excellent weldability and phosphatability and a tensile strength of not less than 590 MPa level can be obtained by comprising C: not less than 0.02 mass % but not more than 0.2 mass %, Si: not less than 0.5 mass % but not more than 2.0 mass %, Mn: not less than 1.0 mass % but not more than 3.0 mass %, Al: not less than 0.01 mass % but not more than 0.1 mass %, N: not less than 0.002 mass % but not more than 0.006 mass %, P: not more than 0.03 mass %, S: not more than 0.01 mass % and solid-soluted (C+N): not less than 0.Type: GrantFiled: June 4, 2002Date of Patent: March 25, 2008Assignee: JFE Steel CorporationInventors: Tetsuya Mega, Kei Sakata, Kazuhiro Seto
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Publication number: 20040238084Abstract: According to the invention, a high-strength hot rolled steel sheet having an excellent shape fixability as hot-rolled and an excellent fatigue durability after the forming, excellent weldability and phosphatability and a tensile strength of not less than 590 MPa level can be obtained by comprising C: not less than 0.02 mass % but not more than 0.2 mass %, Si: not less than 0.5 mass % but not more than 2.0 mass %, Mn: not less than 1.0 mass % but not more than 3.0 mass %, Al: not less than 0.01 mass % but not more than 0.1 mass %, N: not less than 0.002 mass % but not more than 0.006 mass %, P: not more than 0.03 mass %, S: not more than 0.01 mass % and solid-soluted (C+N): not less than 0.Type: ApplicationFiled: July 8, 2004Publication date: December 2, 2004Inventors: Tetsuya Mega, Kei Sakata, Kazuhiro Seto
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Publication number: 20040231393Abstract: This invention proposes a high-strength hot rolled steel sheet having excellent anti-die-galling property and anti-fatigue property, in which the steel sheet has a composition comprising C: not less than 0.02 mass % but not more than 0.2 mass %, Si: not less than 0.2 mass % but not more than 1.2 mass %, Mn: not less than 1.0 mass % but not more than 3.0 mass %, Mo: not less than 0.1 mass % but not more than 1.0 mass %, Al: not less than 0.01 mass % but not more than 0.1 mass %, P: not more than 0.03 mass % and S: not more than 0.01 mass % and the remainder being substantially Fe and inevitable impurities, and has a steel microstructure containing not less than 55 vol % of ferrite and not less than 10 vol % but not more than 40 vol % of martensite provided that a total of both is not less than 95 vol %, and a ratio ds/dc of an average crystal grain size ds of the ferrite in a surface layer portion of the steel sheet to an average crystal grain size dc of the ferrite in a center portion of the steel sheet is 0.Type: ApplicationFiled: June 14, 2004Publication date: November 25, 2004Inventors: Tetsuya Mega, Kei Sakata
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Patent number: 5172183Abstract: An improved glow discharge atomic emission spectroscopy method and apparatus is offered in which the introduction of a rare gas into a glow discharge tube is temporarily cut off and after the inside of the glow discharge tube is maintained at a higher degree of vacuum, a preliminary discharge is executed to remove adsorbed or extraneous substances on the specimen surface, and then the analysis of the specimen surface is performed. The method and the apparatus described in the above are suitable for quick and simple analysis of the uppermost surface layer of a solid specimen in the direction of depth.Type: GrantFiled: March 18, 1991Date of Patent: December 15, 1992Assignee: Kawasaki Steel CorporationInventors: Tetsuya Mega, Michio Katayama, Masao Yokoi, Yasuko Furunushi