Patents by Inventor Yasushi Tsukano
Yasushi Tsukano 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: 11131612Abstract: There is provided a method for estimating a hardness of a cold worked component including: preparing a test piece for hardness measurement having a dent portion of a shape corresponding to a shape of the contact surface of the punch by using a mounting base on which a test piece is mounted and a punch of which a contact surface to be in contact with the test piece is a curved surface, and compressing the test piece mounted on the mounting base using the punch; measuring hardnesses of the test piece for hardness measurement at a plurality of hardness measurement positions in a measurement direction while taking, as the measurement direction, a direction in the dent portion in which a sheet thickness changes; performing numerical analysis to calculate equivalent plastic strains of the test piece for hardness measurement, and acquiring a hardness-equivalent plastic strain curve on the basis of the hardnesses and the equivalent plastic strains at the hardness measurement positions; and specifying a hardness fromType: GrantFiled: March 15, 2018Date of Patent: September 28, 2021Assignee: NIPPON STEEL CORPORATIONInventors: Mitsuharu Yamagata, Nobuo Yoshikawa, Yasushi Tsukano
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Patent number: 10857582Abstract: A method of manufacturing a tooth-shaped component including a process of draw-forming a workpiece so as to obtain a cylindrical container, which has a bottom surface portion and a side surface portion; a diameter-reducing process of reducing the diameter of a particular part in which a tooth tip portion is to be formed in the side surface portion of the cylindrical container, so as to increase the thickness of a corner portion such that an external shape of the corner portion between the bottom surface portion and the side surface portion satisfies the following conditional expression (?R+?H)?2t; and a tooth shape-forming process of forming the tooth tip portion in the particular part of the cylindrical container reduced in diameter in the diameter-reducing process, so as to obtain a tooth-shaped component which has the bottom surface portion, the side surface portion, and the tooth tip portion.Type: GrantFiled: January 7, 2016Date of Patent: December 8, 2020Assignee: NIPPON STEEL CORPORATIONInventors: Mitsuharu Yamagata, Shuji Yamamoto, Yasushi Tsukano
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Publication number: 20200116608Abstract: There is provided a method for estimating a hardness of a cold worked component including: preparing a test piece for hardness measurement having a dent portion of a shape corresponding to a shape of the contact surface of the punch by using a mounting base on which a test piece is mounted and a punch of which a contact surface to be in contact with the test piece is a curved surface, and compressing the test piece mounted on the mounting base using the punch; measuring hardnesses of the test piece for hardness measurement at a plurality of hardness measurement positions in a measurement direction while taking, as the measurement direction, a direction in the dent portion in which a sheet thickness changes; performing numerical analysis to calculate equivalent plastic strains of the test piece for hardness measurement, and acquiring a hardness-equivalent plastic strain curve on the basis of the hardnesses and the equivalent plastic strains at the hardness measurement positions; and specifying a hardness fromType: ApplicationFiled: March 15, 2018Publication date: April 16, 2020Applicant: NIPPON STEEL CORPORATIONInventors: Mitsuharu YAMAGATA, Nobuo YOSHIKAWA, Yasushi TSUKANO
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Patent number: 10407748Abstract: A high-carbon steel sheet has a chemical composition represented by, in mass %, C: 0.60% to 0.90%, Mn: 0.30% to 1.50%, and Cr: 0.20% to 1.00%, and others, and has a structure represented by a concentration of Mn contained in cementite: 2% or more and 8% or less, a concentration of Cr contained in cementite: 2% or more and 8% or less, an average grain diameter of ferrite: 10 ?m or more and 50 ?m or less, an average particle diameter of cementite: 0.3 ?m or more and 1.5 ?m or less, and a spheroidized ratio of cementite: 85% or more.Type: GrantFiled: November 21, 2014Date of Patent: September 10, 2019Assignee: NIPPON STEEL CORPORATIONInventors: Kengo Takeda, Toshimasa Tomokiyo, Yasushi Tsukano, Takashi Aramaki
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Publication number: 20180230582Abstract: Low carbon steel plate excellent impact resistance characteristics after carburizing and quenching and after tempering, characterized by having a predetermined chemical composition, an average grain size of carbides of 0.4 ?m to 2.0 ?m, an area ratio of pearlite of 6% or less, a ratio of a number of carbides at the ferrite grain boundaries to the number of carbides inside the ferrite grains of over 1, and a Vickers hardness of 100HV to 180HV.Type: ApplicationFiled: May 25, 2016Publication date: August 16, 2018Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Kengo TAKEDA, Kazuo HIKIDA, Ken TAKATA, Motonori HASHIMOTO, Toshimasa TOMOKIYO, Yasushi TSUKANO, Takashi ARAMAKI
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Publication number: 20180021836Abstract: There is provided a method of manufacturing a tooth-shaped component including drawing process of draw-forming a workpiece so as to obtain a cylindrical container which has a bottom surface portion and a side surface portion; diameter-reducing process of reducing a diameter of a particular part in which a tooth tip portion is to be formed in the side surface portion of the cylindrical container, so as to increase a thickness of a corner portion such that an external shape of the corner portion between the bottom surface portion and the side surface portion satisfies the following conditional expression (1); and tooth shape-forming process of forming the tooth tip portion in the particular part of the cylindrical container reduced in diameter in the diameter-reducing process, so as to obtain a tooth-shaped component which has the bottom surface portion, the side surface portion, and the tooth tip portion.Type: ApplicationFiled: January 7, 2016Publication date: January 25, 2018Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Mitsuharu YAMAGATA, Shuji YAMAMOTO, Yasushi TSUKANO
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Patent number: 9840750Abstract: A medium carbon steel sheet for cold working that has a hardness of 500 HV to 900 HV when subjected to high-frequency quenching and a quick cooling to a room temperature is carried out. The medium carbon steel sheet includes, by mass %, C: 0.30 to 0.60%, Si: 0.06 to 0.30%, Mn: 0.3 to 2.0%, P: 0.03% or less, S: 0.0075% or less, Al: 0.005 to 0.10%, N: 0.001 to 0.01%, and Cr: 0.001 to 0.10%, the balance composed of Fe and inevitable impurities. An average diameter d of a carbide is 0.6 ?m or less, a spheroidizing ratio p of the carbide is equal to or more than 70% and less than 90%, and the average diameter d (?m) of the carbide and the spheroidizing ratio p % of the carbide satisfy the expression d?0.04×p?2.6.Type: GrantFiled: September 22, 2011Date of Patent: December 12, 2017Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Kengo Takeda, Masayuki Abe, Yasushi Tsukano, Takashi Aramaki, Shinichi Yamaguchi
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Publication number: 20170306434Abstract: A high-carbon steel sheet includes: a chemical composition represented by, in mass %, C: 0.30% to 0.70%, B: 0.0004% to 0.0035%, and others; and a structure represented by a spheroidized ratio of cementite: 80% or more; and an average diameter of cementite: 0.3 ?m to 2.2 ?m, wherein a coefficient of micro-friction of ferrite on a surface of the steel sheet is less than 0.5.Type: ApplicationFiled: October 16, 2014Publication date: October 26, 2017Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Kengo TAKEDA, Toshimasa TOMOKIYO, Yasushi TSUKANO, Takashi ARAMAKI
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Publication number: 20170067132Abstract: A middle/high carbon steel sheet according to an aspect of the present invention is a steel sheet, in which composition thereof contains, by mass %, C: 0.10% to 1.50%, Si: 0.01% to 1.00%, Mn: 0.01% to 3.00%, P: 0.0001% to 0.1000%, and S: 0.0001% to 0.1000%, and a remainder consisting of Fe and impurities, in which the steel sheet has a structure in which a total volume percentage of a martensite, a bainite, a pearlite, and a residual austenite is equal to or lower than 5.0%, and a remainder thereof is a ferrite and carbides, in which a spheroidizing ratio of carbide particles is 70% to 99%, and in which a proportion of a number of the carbide particles including a crystal interface at which an orientation difference is equal to or greater than 5° in the carbide particles is equal to or lower than 20% of a total number of the carbide particles.Type: ApplicationFiled: March 9, 2015Publication date: March 9, 2017Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Kengo TAKEDA, Toshimasa TOMOKIYO, Yasushi TSUKANO, Takashi ARAMAKI
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Publication number: 20160289787Abstract: A high-carbon steel sheet has a chemical composition represented by, in mass %, C: 0.60% to 0.90%, Mn: 0.30% to 1.50%, and Cr: 0.20% to 1.00%, and others, and has a structure represented by a concentration of Mn contained in cementite: 2% or more and 8% or less, a concentration of Cr contained in cementite: 2% or more and 8% or less, an average grain diameter of ferrite: 10 ?m or more and 50 ?m or less, an average particle diameter of cementite: 0.3 ?m or more and 1.5 ?m or less, and a spheroidized ratio of cementite: 85% or more.Type: ApplicationFiled: November 21, 2014Publication date: October 6, 2016Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Kengo TAKEDA, Toshimasa TOMOKIYO, Yasushi TSUKANO, Takashi ARAMAKI
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Patent number: 8992704Abstract: The present invention solves the problem of melting of Al in heating before hot-stamping, which had been a problem in the past in applying hot-stamping to Al-plated steel sheet, and provides Al-plated steel sheet for hot-stamping and a method of hot-stamping using that Al-plated steel sheet to solve the problem of delayed fracture due to residual hydrogen, and, furthermore, a method of a rapid heating hot-stamping using that Al-plated steel sheet. The Al-plated steel sheet of the present invention is produced by annealing the Al-plated steel sheet as coiled in a box-anneal furnace for the time and at the temperature indicated in FIG. 5, and alloying of a plated Al and a steel sheet. Further, a method of rapid heating hot-stamping in the present invention is characterized by cutting out a stamping blank of an Al-plated steel sheet, and heating that blank in heating before hot-stamping by an average temperature with a rising rate of 40° C./sec or more and a time of exposure to an environment of 700° C.Type: GrantFiled: July 13, 2009Date of Patent: March 31, 2015Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Jun Maki, Masayuki Abe, Kazuhisa Kusumi, Yasushi Tsukano
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Patent number: 8945719Abstract: This steel plate for cold forging includes a hot-rolled steel plate, wherein the hot-rolled steel plate includes: in terms of percent by mass, C: 0.13% to 0.20%; Si: 0.01% to 0.8%; Mn: 0.1% to 2.5%; P: 0.003% to 0.030%; S: 0.0001% to 0.008%; Al: 0.01% to 0.07%; N: 0.0001% to 0.02%; and O: 0.0001% to 0.0030%, with a remainder being Fe and inevitable impurities, an A value represented by the following formula (1) is in a range of 0.0080 or less, a thickness of the hot-rolled steel plate is in a range of 2 mm to 25 mm, and an area percentage of pearlite bands having lengths of 1 mm or more in a region of 4/10t to 6/10t when a plate thickness is indicated by t in a cross section of a plate thickness that is parallel to a rolling direction of the hot-rolled steel plate is in a range of not more than a K value represented by the following formula (2), A value=O%+S%+0.033Al%??(1) K value=25.5×C%+4.5×Mn%?6??(2).Type: GrantFiled: January 25, 2011Date of Patent: February 3, 2015Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Masayuki Abe, Kengo Takeda, Shuji Yamamoto, Yasushi Tsukano, Shinichi Yamaguchi
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Publication number: 20140212660Abstract: Disclosed is a medium carbon steel sheet for cold working that has a hardness of 500 HV to 900 HV when subjected to high-frequency quenching in which a temperature is raised at an average heating rate of 100° C./second, the temperature is held at 1,000° C. for 10 seconds, and a quick cooling to a room temperature is carried out at an average cooling rate of 200° C./second. The medium carbon steel sheet includes, by mass %, C: 0.30 to 0.60%, Si: 0.06 to 0.30%, Mn: 0.3 to 2.0%, P: 0.03% or less, S: 0.0075% or less, Al: 0.005 to 0.10%, N: 0.001 to 0.01%, and Cr: 0.001 to 0.10%, the balance composed of Fe and inevitable impurities. An average diameter d of a carbide is 0.6 ?m or less, a spheroidizing ratio p of the carbide is equal to or more than 70% and less than 90%, and the average diameter d (?m) of the carbide and the spheroidizing ratio p % of the carbide satisfy d?0.04×p?2.6.Type: ApplicationFiled: September 22, 2011Publication date: July 31, 2014Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Kengo Takeda, Masayuki Abe, Yasushi Tsukano, Takashi Aramaki, Shinichi Yamaguchi
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Publication number: 20120295123Abstract: This steel plate for cold forging includes a hot-rolled steel plate, wherein the hot-rolled steel plate includes: in terms of percent by mass, C: 0.13% to 0.20%; Si: 0.01% to 0.8%; Mn: 0.1% to 2.5%; P: 0.003% to 0.030%; S: 0.0001% to 0.008%; Al: 0.01% to 0.07%; N: 0.0001% to 0.02%; and O: 0.0001% to 0.0030%, with a remainder being Fe and inevitable impurities, an A value represented by the following formula (1) is in a range of 0.0080 or less, a thickness of the hot-rolled steel plate is in a range of 2 mm to 25 mm, and an area percentage of pearlite bands having lengths of 1 mm or more in a region of 4/10t to 6/10t when a plate thickness is indicated by t in a cross section of a plate thickness that is parallel to a rolling direction of the hot-rolled steel plate is in a range of not more than a K value represented by the following formula (2), A value=O%+S%+0.033Al%??(1) K value=25.5×C%+4.5×Mn%?6??(2).Type: ApplicationFiled: January 25, 2011Publication date: November 22, 2012Inventors: Masayuki Abe, Kengo Takeda, Shuji Yamamoto, Yasushi Tsukano, Shinichi Yamaguchi
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Publication number: 20110174418Abstract: The present invention solves the problem of melting of Al in heating before hot-stamping, which had been a problem in the past in applying hot-stamping to Al-plated steel sheet, and provides Al-plated steel sheet for hot-stamping and a method of hot-stamping using that Al-plated steel sheet to solve the problem of delayed fracture due to residual hydrogen, and, furthermore, a method of a rapid heating hot-stamping using that Al-plated steel sheet. The Al-plated steel sheet of the present invention is produced by annealing the Al-plated steel sheet as coiled in a box-anneal furnace for the time and at the temperature indicated in FIG. 5, and alloying of a plated Al and a steel sheet. Further, a method of rapid heating hot-stamping in the present invention is characterized by cutting out a stamping blank of an Al-plated steel sheet, and heating that blank in heating before hot-stamping by an average temperature with a rising rate of 40° C./sec or more and a time of exposure to an environment of 700° C.Type: ApplicationFiled: July 13, 2009Publication date: July 21, 2011Applicant: NIPPON STEEL CORPORATIONInventors: Jun Maki, Masayuki Abe, Kazuhisa Kusumi, Yasushi Tsukano