Patents by Inventor Hitoshi Nikaido
Hitoshi Nikaido 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: 11732321Abstract: Provided are: a steel sheet having a high strength and excellent stretch formability; and a method of producing the same. The steel sheet has prescribed chemical composition and structure, in which the integration degree of the (111)<112> orientation of ferrite is 3.0 or higher, and the integration degree of the (252)<2-11> orientation of martensite and tempered martensite is 5.0 or lower. The method of producing the steel sheet includes: the step of continuously casting a molten steel having the prescribed chemical composition, and performing 5 to 40% rolling reduction at a temperature of 800° C. to lower than 1,200° C. in a period after the continuous casting until cooling to room temperature; the hot rolling step of performing hot rolling with a finishing temperature of 650 to 950° C.; the step of coiling the resulting hot-rolled steel sheet at a coiling temperature of 400 to 700° C.; the step of retaining the hot-rolled steel sheet at (coiling start temperature+20° C. to 100° C.Type: GrantFiled: March 12, 2020Date of Patent: August 22, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Kengo Takeda, Hitoshi Nikaido, Hiroyuki Kawata, Takafumi Yokoyama
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Publication number: 20230141963Abstract: There is provided a steel sheet including a chemical composition consisting of, in mass %: C: 0.03 to 0.25%, Si: 0.1 to 2.0%, Mn: 1.0 to 3.0%, P: 0.200% or less, S: 0.0500% or less, Al: 0.01 to 1.00%, N: 0.0100% or less, and Ti: 0.01 to 0.25%, with the balance: Fe and impurities, and a steel micro-structure containing, in area %: ferrite: 50 to 85%, the balance being one or more kinds selected from martensite, bainite, and retained austenite, and an intensity of ?-fiber is more than 4.0 times in terms of random intensity ratio, and an average KAM value of grains having crystal orientations that form angles within 10° from ?-fiber is 1.30° or less.Type: ApplicationFiled: March 30, 2021Publication date: May 11, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Yasuaki TANAKA, Hitoshi NIKAIDO, Hiroyuki KAWATA, Natsuko SUGIURA
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Publication number: 20220145417Abstract: Provided are: a steel sheet having a high strength and excellent stretch formability; and a method of producing the same. The steel sheet has prescribed chemical composition and structure, in which the integration degree of the (111)<112> orientation of ferrite is 3.0 or higher, and the integration degree of the (252)<2-11> orientation of martensite and tempered martensite is 5.0 or lower. The method of producing the steel sheet includes: the step of continuously casting a molten steel having the prescribed chemical composition, and performing 5 to 40% rolling reduction at a temperature of 800° C. to lower than 1,200° C. in a period after the continuous casting until cooling to room temperature; the hot rolling step of performing hot rolling with a finishing temperature of 650 to 950° C.; the step of coiling the resulting hot-rolled steel sheet at a coiling temperature of 400 to 700° C.; the step of retaining the hot-rolled steel sheet at (coiling start temperature+20° C. to 100° C.Type: ApplicationFiled: March 12, 2020Publication date: May 12, 2022Applicant: NIPPON STEEL CORPORATIONInventors: Kengo TAKEDA, Hitoshi NIKAIDO, Hiroyuki KAWATA, Takafumi YOKOYAMA
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Publication number: 20220090224Abstract: Hot-rolled steel sheet having a chemical composition including, in mass %, C: 0.02 to 0.20%, Si: 0.01 to 1.50%, Mn: 0.10 to 3.00%, P: 0.10% or less, S: 0.010% or less, Al: 0.005 to 0.100%, Ti: 0.02 to 0.20%, N: 0.001 to 0.010%, Cu: 0 to 0.50%, Ni: 0 to 0.50%, Cr: 0 to 1.00%, Mo: 0 to 0.40%, Nb: 0 to 0.060%, V: 0 to 1.00%, B: 0 to 0.0100%, Ca: 0 to 0.0050%, O: 0.0100% or less, and the balance: Fe and impurities; in which: a steel micro-structure includes, in area %, ferrite: 60 to 80%, and a total of ferrite and bainite: 90% or more; an average of the crystal grain size of ferrite and bainite is 7.0 ?m or less, a standard deviation of the crystal grain size is 2.0 or less; and a standard deviation of a diameter of Ti carbo-nitrides is 10 nm or less.Type: ApplicationFiled: December 24, 2019Publication date: March 24, 2022Applicant: NIPPON STEEL CORPORATIONInventors: Takeshi TOYODA, Hitoshi NIKAIDO, Kohei NAKADA, Yui YAMASHITA, Kazuki MATSUDA
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Patent number: 10603702Abstract: A method for producing a metal sheet with raised lines uses a rolling mill including roll stands. In a preparing step, a grooved roll is prepared, the grooved roll including grooves. In a choosing step, a stand at least one stage before the last stand is chosen. In an incorporating step, the grooved roll is incorporated in as an upper roll of the chosen, specified stand. In a forming step, a workpiece is formed into a metal sheet with raised lines formed corresponding to the respective grooves. In the forming step, a maximum rolling reduction achieved by rolls of the specified stand is set to a provisional value that is lower than a required value. After the leading edge of the workpiece reaches the stand next to the specified stand, the maximum rolling reduction of the specified stand is changed to the required value.Type: GrantFiled: October 7, 2015Date of Patent: March 31, 2020Assignee: NIPPON STEEL CORPORATIONInventors: Hitoshi Nikaido, Toru Yonebayashi, Koichi Sato, Teruo Ito, Daiki Kamada
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Publication number: 20170320113Abstract: A method for producing a metal sheet with raised lines uses a rolling mill including roll stands. In a preparing step, a grooved roll is prepared, the grooved roll including grooves. In a choosing step, a stand at least one stage before the last stand is chosen. In an incorporating step, the grooved roll is incorporated in as an upper roil of the chosen, specified stand. In a forming step, a workpiece is formed into a metal sheet with raised lines formed corresponding to the respective grooves. In the forming step, a maximum rolling reduction achieved by rolls of the specified stand is set to a provisional value that is lower than a required value. After the leading edge of the workpiece reaches the stand next to the specified stand, the maximum rolling reduction of the specified stand is changed to the required value.Type: ApplicationFiled: October 7, 2015Publication date: November 9, 2017Inventors: Hitoshi NIKAIDO, Toru YONEBAYASHI, Koichi SATO, Teruo ITO, Daiki KAMADA
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Publication number: 20170291203Abstract: A method for producing a metal sheet with raised lines uses a rolling mill including a roll stand and produces a metal sheet including, on each of an upper surface and a lower surface, a plurality of raised lines extending in a rolling direction. The method includes a preparing step, an incorporating step, and a forming step. In the preparing step, grooved rolls are prepared, each of the grooved rolls including a plurality of grooves in an outer peripheral surface. In the incorporating step, the grooved rolls are incorporated in the roll stand as an upper roll and a lower roll, respectively. In the forming step, a workpiece is rolled by the rolling mill and is formed into a metal sheet with raised lines formed corresponding to the respective grooves of the grooved rolls.Type: ApplicationFiled: October 7, 2015Publication date: October 12, 2017Inventors: Hitoshi NIKAIDO, Toru YONEBAYASHI, Koichi SATO, Daiki KAMADA
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Patent number: 9649679Abstract: A water-blocking apparatus for cooling water for a hot-rolled steel sheet according to the present invention, which blocks cooling water sprayed onto a hot-rolled steel sheet at a sprayed water density of higher than 4 m3/m2/min and equal to or less than 10 m3/m2/min when the hot-rolled steel sheet is cooled after finish rolling of a hot-rolling process, includes: a plurality of water-blocking nozzles which spray water-blocking water onto the hot-rolled steel sheet. Impact areas of the water-blocking water respectively sprayed from the water-blocking nozzles are continuously lined up in a straight line in a width direction of the hot-rolled steel sheet on a surface of the hot-rolled steel sheet and the adjacent impact areas partially overlap.Type: GrantFiled: June 6, 2013Date of Patent: May 16, 2017Assignee: NIPPON STEEL SUMITOMO METAL CORPORATIONInventors: Hitoshi Nikaido, Yoshihiro Serizawa, Noriyuki Hishinuma
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Patent number: 9186710Abstract: The method for cooling a hot-rolled steel sheet of the invention includes a target ratio-setting process in which a top and bottom heat transfer coefficient ratio X1, at which a temperature standard deviation Y becomes a minimum value Ymin, is set as a target ratio Xt based on correlation data between a top and bottom heat transfer coefficient ratio X of the hot-rolled steel sheet and the temperature standard deviation Y of the hot-rolled steel sheet; and a cooling control process in which at least one of an amount of heat dissipated from a top surface by cooling and an amount of heat dissipated from a bottom surface by cooling of the hot-rolled steel sheet in the cooling section is controlled so that the top and bottom heat transfer coefficient ratio X of the hot-rolled steel sheet in the cooling section matches the target ratio Xt.Type: GrantFiled: December 6, 2012Date of Patent: November 17, 2015Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Tooru Akashi, Shingo Kuriyama, Takeo Itoh, Fuminori Tasaki, Koji Noguchi, Hitoshi Nikaido
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Publication number: 20150101386Abstract: A water-blocking apparatus for cooling water for a hot-rolled steel sheet according to the present invention, which blocks cooling water sprayed onto a hot-rolled steel sheet at a sprayed water density of higher than 4 m3/m2/min and equal to or less than 10 m3/m2/min when the hot-rolled steel sheet is cooled after finish rolling of a hot-rolling process, includes: a plurality of water-blocking nozzles which spray water-blocking water onto the hot-rolled steel sheet. Impact areas of the water-blocking water respectively sprayed from the water-blocking nozzles are continuously lined up in a straight line in a width direction of the hot-rolled steel sheet on a surface of the hot-rolled steel sheet and the adjacent impact areas partially overlap.Type: ApplicationFiled: June 6, 2013Publication date: April 16, 2015Applicant: Nippon Steel & Sumitomo Metal CorporationInventors: Hitoshi Nikaido, Yoshihiro Serizawa, Noriyuki Hishinuma
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Publication number: 20140060139Abstract: The method for cooling a hot-rolled steel sheet of the invention includes a target ratio-setting process in which a top and bottom heat transfer coefficient ratio X1, at which a temperature standard deviation Y becomes a minimum value Ymin, is set as a target ratio Xt based on correlation data between a top and bottom heat transfer coefficient ratio X of the hot-rolled steel sheet and the temperature standard deviation Y of the hot-rolled steel sheet; and a cooling control process in which at least one of an amount of heat dissipated from a top surface by cooling and an amount of heat dissipated from a bottom surface by cooling of the hot-rolled steel sheet in the cooling section is controlled so that the top and bottom heat transfer coefficient ratio X of the hot-rolled steel sheet in the cooling section matches the target ratio Xt.Type: ApplicationFiled: December 6, 2012Publication date: March 6, 2014Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Tooru Akashi, Shingo Kuriyama, Takeo Itoh, Fuminori Tasaki, Koji Noguchi, Hitoshi Nikaido