Patents by Inventor Yoshihiko Ono
Yoshihiko Ono 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: 10697039Abstract: Provided are a high-strength steel sheet and a method for manufacturing the steel sheet. The high-strength steel sheet has a specified chemical composition with the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 25% or less of a ferrite phase, 75% or more of a bainite phase and/or a martensite phase, and 5% or less of cementite, in which, in a surface layer that is a region within 50 ?m from the surface in the thickness direction, the area ratio of a ferrite phase is 5% to 20%, and a tensile strength is 1180 MPa or more.Type: GrantFiled: August 28, 2015Date of Patent: June 30, 2020Assignee: JFE Steel CorporationInventors: Nobusuke Kariya, Yoshihiko Ono, Yoshimasa Funakawa, Kazuma Mori, Reiko Sugihara, Kenji Kawamura
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Publication number: 20200157647Abstract: A steel sheet and a manufacturing method therefor are provided. A steel sheet has a component composition and contains 6 to 80% of ferrite and 20 to 94% of a microstructure composed of one or two or more of upper bainite, fresh martensite, tempered martensite, lower bainite, and retained ?, and contains 7 to 20% of retained ?, where: an area ratio (S?UB) of retained ? having a particle width of 0.18 to 0.60 ?m, a particle length of 1.7 to 7.0 ?m, and an aspect ratio of 5 to 15 is 0.2 to 5%; and a total area ratio (S?Block) of fresh martensite having an equivalent circle diameter of 1.5 to 15 ?m and an aspect ratio of 3 or less and/or retained ? particles having an equivalent circle diameter of 1.5 to 15 ?m and an aspect ratio of 3 or less is 3% or less (including 0%).Type: ApplicationFiled: April 13, 2018Publication date: May 21, 2020Applicant: JFE Steel CorporationInventors: Yoshihiko Ono, Junya Tobata, Hiroyuki Akimoto
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Patent number: 10655201Abstract: A high-strength, cold-rolled steel sheet having a tensile strength of 980 MPa or more, the steel sheet having a chemical composition containing, by mass %, C: 0.070% to 0.100%, Si: 0.50% to 0.70%, Mn: 2.40% to 2.80%, P: 0.025% or less, S: 0.0020% or less, Al: 0.020% to 0.060%, N: 0.0050% or less, Nb: 0.010% to 0.060%, Ti: 0.010% to 0.030%, B: 0.0005% to 0.0030%, Sb: 0.005% to 0.015%, Ca: 0.0015% or less, Cr: 0.01% to 2.00%, Mo: 0.01% to 1.00%, Ni: 0.01% to 5.00%, Cu: 0.01% to 5.Type: GrantFiled: February 16, 2016Date of Patent: May 19, 2020Assignee: JFE STEEL CORPORATIONInventors: Nobusuke Kariya, Yoshihiko Ono, Yoshimasa Funakawa, Kazuma Mori, Reiko Sugihara
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Publication number: 20200071802Abstract: A high-strength cold rolled steel sheet having mechanical characteristics having a tensile strength of not less than 780 MPa, a yield ratio of not more than 70%, and a small in-plane anisotropy of a tensile characteristicis obtained by hot rolling a steel slab comprising by mass % C: 0.07 to 0.12%, Si: not more than 0.7%, Mn: 2.2 to 2.8% and Ti and Nb: 0.02 to 0.08% in total, and cold rolling the sheet, followed by continuous annealing to form a steel texture comprised of ferrite having an area ratio of 40 to 80% with respect to the whole texture, and a second phase constituted by tempered martensite, fresh martensite and bainite, wherein the total area ratio of the bainite and the tempered martensite to the second phase is 50 to 80%, and the aspect ratio of the fresh martensite is in the range of 1.0 to 1.5.Type: ApplicationFiled: March 8, 2018Publication date: March 5, 2020Applicant: JFE Steel CorporationInventors: Takuya Hirashima, Kenji Kawamura, Yoshihiko Ono, Yuma Honda
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Publication number: 20200071784Abstract: A high-strength cold-rolled steel sheet has a composition that contains, in terms of mass %, C: 0.10% or more and 0.50% or less, Si: 1.0% or more and 3.0% or less, Mn: 1.0% or more and 2.5% or less, P: 0.05% or less, S: 0.02% or less, Al: 0.01% or more and 1.5% or less, N: 0.005% or less, Cu: 0.05% or more and 0.50% or less, and the balance being Fe and unavoidable impurities, wherein a proportion of a steel sheet surface covered with oxides mainly composed of Si is 1% or less, a proportion of the steel sheet surface covered with Fe oxides is 40% or less, CuS/CuB is 4.0 or less, and a tensile strength is 1180 MPa or more, when CuS denotes the Cu content in a steel sheet surface layer and CuB denotes the Cu content in a base material.Type: ApplicationFiled: February 15, 2017Publication date: March 5, 2020Inventors: Shimpei Yoshioka, Yoshihiko Ono, Hiroyuki Masuoka
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Publication number: 20200017933Abstract: A cold rolled steel sheet having a high strength, an aging resistance, a high yield ratio and a small anisotropy of tensile strength is obtained by hot rolling and cold rolling a steel material containing in percent by mass C: 0.06-0.14%, Si: less than 0.50%, Mn: 1.6-2.5%, Nb: not more than 0.080% (including 0%), Ti: not more than 0.080% (including 0%), provided that Nb and Ti are contained in an amount of 0.020-0.080% in total, subjecting a cold rolled steel sheet continuous annealing including steps of soaking-annealing at a temperature of 840-940° C. for a holding time of 30-120 seconds, cooling from the soaking temperature to 600° C. at a rate of not less than 5° C./s, retaining in a temperature range of 600-500° C. for 30-300 seconds and then conducting a secondary cooling to apply such a steel structure that martensite is finely dispersed into ferrite base.Type: ApplicationFiled: February 5, 2018Publication date: January 16, 2020Inventors: Yuma Honda, Yoshihiko Ono
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Patent number: 10435762Abstract: A high-strength cold-rolled steel sheet has a composite structure containing 0.15 to 0.25% by mass of C, 1.8 to 3.0% by mass of Mn, and 0.0003 to 0.0050% by mass of B, and having a ferrite volume fraction of 20% to 50%, a retained austenite volume fraction of 7% to 20%, a martensite volume fraction of 1% to 8%, and the balance containing bainite and tempered martensite, and in the composite structure, ferrite has an average crystal grain diameter of 5 ?m or less, retained austenite has an average crystal grain diameter of 0.3 to 2.0 ?m and an aspect ratio of 4 or more, martensite has an average crystal grain diameter of 2 ?m or less, a metal phase containing both bainite and tempered martensite has an average crystal grain diameter of 7 ?m or less, the ratio of the volume fraction of tempered martensite to the volume fraction of a metal structure other than ferrite is 0.60 to 0.85, and the average C concentration in retained austenite is 0.65% by mass or more.Type: GrantFiled: March 13, 2015Date of Patent: October 8, 2019Assignee: JFE Steel CorporationInventors: Katsutoshi Takashima, Yoshihiko Ono, Kohei Hasegawa
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Publication number: 20190203317Abstract: A steel sheet having a specified chemical composition and a method for producing the steel sheet. The steel sheet has a microstructure including martensite and bainite. The total area fraction of the martensite and the bainite to the entirety of the microstructure is 95% or more and 100% or less. The balance of the microstructure is at least one of ferrite and retained austenite. The microstructure includes specific inclusion clusters, the content of the inclusion clusters in the microstructure being 5 clusters/mm2 or less. The microstructure includes prior-austenite grains having an average size of more than 5 ?m. The steel sheet has a tensile strength of 1320 MPa or more.Type: ApplicationFiled: September 28, 2017Publication date: July 4, 2019Applicant: JFE STEEL CORPORATIONInventors: Shimpei YOSHIOKA, Yoshihiko ONO, Kenta HIDAKA, Ryosuke YAMAGUCHI
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Publication number: 20190194775Abstract: A steel sheet having a specified chemical composition and a method for producing the steel sheet. The steel sheet has a microstructure including martensite and bainite. The total area fraction of the martensite and the bainite to the entirety of the microstructure is more than 90% and 100% or less. The microstructure includes inclusion clusters A and B, the content of the clusters A in the microstructure being 2 clusters/mm2 or less, and the content of the clusters B in the microstructure being 5 clusters/mm2 or less. The microstructure includes carbide particles including Fe as a main constituent which have an aspect ratio of 2.0 or less and a major axis of 0.30 ?m or more and 2 ?m or less. The content of the carbide particles in the microstructure is 4000 particles/mm2 or less. The microstructure includes prior ? grains having an average size of 6 to 15 ?m.Type: ApplicationFiled: September 28, 2017Publication date: June 27, 2019Applicant: JFE STEEL CORPORATIONInventors: Yoshihiko ONO, Shimpei YOSHIOKA, Nobuyuki NAKAMURA, Hiroshi HASEGAWA
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Publication number: 20190112681Abstract: A steel sheet having excellent fatigue resistance as a material for automobile parts and a TS of 590 MPa or more, and a method for producing the same. The steel sheet has a composition comprising, by mass %, C: 0.04% or more and 0.15% or less, Si: 0.3% or less, Mn: 1.0% or more and 2.6% or less, P: 0.1% or less, S: 0.01% or less, Al: 0.01% or more and 0.1% or less, N: 0.015% or less, one or two of Ti and Nb: 0.01% or more and 0.2% or less in a total, and the balance being Fe and unavoidable impurities. The steel sheet has 50% or more of ferrite and 10% or more and 50% or less of martensite in terms of an area ratio, and a microstructure in which a standard deviation of nano-hardness is 1.50 GPa or less and tensile strength of 590 MPa or more.Type: ApplicationFiled: January 16, 2017Publication date: April 18, 2019Applicant: JFE STEEL CORPORATIONInventors: Tatsuya NAKAGAITO, Yoshimasa FUNAKAWA, Yoshihiko ONO, Hiroshi HASEGAWA
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Publication number: 20190040490Abstract: Provided is a high-strength cold-rolled steel sheet has a chemical composition containing, by mass %, C: 0.10% or more and 0.6% or less, Si: 1.0% or more and 3.0% or less, Mn: more than 2.5% and 10.0% or less, P: 0.05% or less, S: 0.02% or less, Al: 0.01% or more and 1.5% or less, N: 0.005% or less, Cu: 0.05% or more and 0.50% or less, and the balance being Fe and inevitable impurities, and a tensile strength of 1180 MPa or more, in which a steel sheet surface coverage of oxides mainly containing Si is 1% or less, a steel sheet surface coverage of iron-based oxides is 40% or less, CuS/CuB is 4.0 or less, and a tensile strength is 1180 MPa or more, where CuS denotes a Cu concentration in a surface layer of a steel sheet and CUB denotes a Cu concentration in base steel.Type: ApplicationFiled: February 15, 2017Publication date: February 7, 2019Applicant: JFE Steel CorporationInventors: Shimpei Yoshioka, Yoshihiko Ono, Yusuke Kimata, Hiroyuki Masuoka
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Publication number: 20190040483Abstract: A high-strength steel sheet having a tensile strength (TS) of 1,320 MPa or more and good workability. The high-strength steel sheet has a specific component composition and a steel microstructure containing, on an area-percentage basis with respect to the entire steel microstructure, 40% or more and less than 85% of a lower bainite, 5% or more and less than 40% martensite including tempered martensite, 10% or more and 30% or less retained austenite, and 10% or less (including 0%) polygonal ferrite, the retained austenite having an average C content of 0.60% by mass or more. Additionally, a Mn segregation value at a surface of the steel sheet is 0.8% or less, the ratio R/t of a limit bending radius (R) to a thickness (t) of the steel sheet is 2.0 or less, and tensile strength×total elongation of the steel sheet is 15,000 MPa % or more.Type: ApplicationFiled: February 7, 2017Publication date: February 7, 2019Applicant: JFE STEEL CORPORATIONInventors: Yusuke KIMATA, Yoshihiko ONO, Kenji KAWAMURA
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Publication number: 20190040482Abstract: A high-strength steel sheet having a tensile strength TS of 1320 MPa or more and excellent workability. The high-strength steel sheet has a chemical composition containing, by mass %, C: 0.20% or more and 0.40% or less, Si: 0.5% or more and 2.5% or less, Mn: more than 2.4% and 5.0% or less, P: 0.1% or less, S: 0.01% or less, Al: 0.01% or more and 0.5% or less, N: 0.010% or less, and Fe and inevitable impurities. A microstructure of the steel sheet includes, in terms of area fraction with respect to the whole steel sheet microstructure, lower bainite in an amount of 40% or more and less than 85%, martensite including tempered martensite in an amount of 5% or more and less than 40%, retained austenite in an amount of 10% or more and 30% or less, and polygonal ferrite in an amount of 10% or less (including 0%).Type: ApplicationFiled: February 7, 2017Publication date: February 7, 2019Applicant: JFE STEEL CORPORATIONInventors: Yusuke KIMATA, Yoshihiko ONO, Kenji KAWAMURA
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Publication number: 20190017156Abstract: Provided are a high-strength steel sheet having a specified chemical composition, in which a Mn-segregation degree in a region within 100 ?m from a surface thereof in a thickness direction is 1.5 or less, in a plane parallel to the surface of the steel sheet in a region within 100 ?m from the surface of the steel sheet in the thickness direction, the number of oxide-based inclusion grains having a grain long diameter of 5 ?m or more is 1000 or less/100 mm2, a proportion of the number of oxide-based inclusion grains having a chemical composition containing alumina of 50 mass % or more, silica of 20 mass % or less, and calcia of 40 mass % or less to the total number of oxide-based inclusions having a grain long diameter of 5 ?m or more is 80% or more, a specified metallographic structure, and a TS of 980 MPa or more, a high-strength galvanized steel sheet, and a manufacturing method thereof.Type: ApplicationFiled: December 26, 2016Publication date: January 17, 2019Applicant: JFE Steel CorporationInventors: Kenji Kawamura, Yoshihiko Ono, Nobusuke Kariya, Shinichi Furuya, Kohei Hasegawa
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Patent number: 10156005Abstract: A steel sheet includes a microstructure containing a volume fraction of 20% to 55% of ferrite having an average grain size of 7 ?m or less, a volume fraction of 5% to 15% of retained austenite, a volume fraction of 0.5% to 7% of martensite having an average grain size of 4 ?m or less, and a structure composed of bainite and/or tempered martensite and having an average grain size of 6 ?m or less, and a difference in nano-hardness between ferrite and the structure composed of bainite and/or tempered martensite being 3.5 GPa or less and a difference in nano-hardness between the structure composed of bainite and/or tempered martensite and martensite being 2.5 GPa or less.Type: GrantFiled: July 18, 2014Date of Patent: December 18, 2018Assignee: JFE Steel CorporationInventors: Katsutoshi Takashima, Yoshihiko Ono, Kohei Hasegawa
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Patent number: 10077486Abstract: A high-strength cold-rolled steel sheet has a composition and a microstructure. The microstructure comprises: ferrite having an average grain size of 5 ?m or less and a volume fraction of 3% to 20%, retained austenite having a volume fraction of 5% to 20%, and martensite having a volume fraction of 5% to 20%, the remainder being bainite and/or tempered martensite. The total number of retained austenite with a grain size of 2 ?m or less, martensite with a grain size of 2 ?m or less, or a mixed phase thereof is 150 or more per 2,000 ?m2 of a thickness cross section parallel to the rolling direction of the steel sheet.Type: GrantFiled: July 18, 2014Date of Patent: September 18, 2018Assignee: JFE Steel CorporationInventors: Katsutoshi Takashima, Yoshihiko Ono, Kohei Hasegawa
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Publication number: 20180100212Abstract: A cold-rolled steel sheet has: a predetermined chemical composition; and a microstructure in which tempered martensite and bainite are contained in a total area ratio of 95-100% with respect to a whole volume of the microstructure; a number of predetermined inclusion groups is at most 0.8/mm2, the inclusion groups being formed by one or more inclusion particles, the one or more inclusion particles having a major axis length of 0.3 ?m or more and extending and/or distributed in a dot-sequence manner along a rolling direction; a number of carbides mainly composed of Fe having a predetermined size is at most 3,500/mm2; a number of carbides that are distributed in the tempered martensite and/or in the bainite and that have a diameter of 10 nm to 50 nm is at least 0.7×107/mm2; and prior ? grains have a mean grain size of 18 ?m or less.Type: ApplicationFiled: March 23, 2016Publication date: April 12, 2018Applicant: JFE STEEL CORPORATIONInventors: Yoshihiko ONO, Yoshimasa FUNAKAWA, Ryosuke YAMAGUCHI, Nobuyuki NAKAMURA
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Publication number: 20180057919Abstract: A high-strength, cold-rolled steel sheet having a tensile strength of 980 MPa or more, the steel sheet having a chemical composition containing, by mass %, C: 0.070% to 0.100%, Si: 0.50% to 0.70%, Mn: 2.40% to 2.80%, P: 0.025% or less, S: 0.0020% or less, Al: 0.020% to 0.060%, N: 0.0050% or less, Nb: 0.010% to 0.060%, Ti: 0.010% to 0.030%, B: 0.0005% to 0.0030%, Sb: 0.005% to 0.015%, Ca: 0.0015% or less, Cr: 0.01% to 2.00%, Mo: 0.01% to 1.00%, Ni: 0.01% to 5.00%, Cu: 0.01% to 5.Type: ApplicationFiled: February 16, 2016Publication date: March 1, 2018Applicant: JFE STEEL CORPORATIONInventors: Nobusuke Kariya, Yoshihiko Ono, Yoshimasa Funakawa, Kazuma Mori, Reiko Sugihara
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Publication number: 20180002777Abstract: Provided are a high-strength steel sheet and a method for manufacturing the steel sheet. The high-strength steel sheet has a specified chemical composition with the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 30% or more of a ferrite phase, 40% to 65% of a bainite phase and/or a martensite phase, and 5% or less of cementite, in which, in a surface layer that is a region within 50 ?m from the surface in the thickness direction, the area ratio of a ferrite phase is 40% to 55% and the total area ratio of a bainite phase having a grain diameter of more than 5 ?m and/or a martensite phase having a grain diameter of more than 5 ?m is 20% or less, and a tensile strength is 980 MPa or more.Type: ApplicationFiled: August 28, 2015Publication date: January 4, 2018Applicant: JFE STEEL CORPORATIONInventors: Nobusuke Kariya, Yoshihiko Ono, Yoshimasa Funakawa, Kazuma Mori, Reiko Sugihara, Kenji Kawamura
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Publication number: 20180002778Abstract: Provided are a high-strength steel sheet and a method for manufacturing the steel sheet. The high-strength steel sheet has a specified chemical composition with the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 25% or less of a ferrite phase, 75% or more of a bainite phase and/or a martensite phase, and 5% or less of cementite, in which, in a surface layer that is a region within 50 ?m from the surface in the thickness direction, the area ratio of a ferrite phase is 5% to 20%, and a tensile strength is 1180 MPa or more.Type: ApplicationFiled: August 28, 2015Publication date: January 4, 2018Applicant: JFE STEEL CORPORATIONInventors: Nobusuke Kariya, Yoshihiko Ono, Yoshimasa Funakawa, Kazuma Mori, Reiko Sugihara, Kenji Kawamura