Patents by Inventor Elijah Kakiuchi
Elijah Kakiuchi 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: 10544489Abstract: A high-strength steel sheet has a chemical composition including 0.05% to 0.3% of C, 1% to 3% of Si, 0.5% to 3% of Mn, 0% to 0.1% of P, 0.001% to 0.1% of Al, and 0.002% to 0.03% of N, in mass percent; further includes iron and impurities; and has a structure including 50% to 90% of bainitic ferrite, 5% to 20% of retained austenite (?R), a total of 10% to 50% of martensite and the retained austenite, and 0% to 40% of polygonal ferrite, in area percent based on the entire structure. The retained austenite has a carbon content (C?R) of 0.5% to 1.2% by mass, an average equivalent circle diameter of 0.2 to 2 ?m, and an average aspect ratio (maximum diameter/minimum diameter) of less than 3.0. The high-strength steel sheet excels both in elongation and deep drawability while having a strength of 980 MPa or more.Type: GrantFiled: November 16, 2011Date of Patent: January 28, 2020Assignee: Kobe Steel, Ltd.Inventors: Elijah Kakiuchi, Toshio Murakami, Hideo Hata, Tatsuya Asai, Naoki Mizuta
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Publication number: 20190218640Abstract: Disclosed is a high-strength sheet including: C: 0.15% to 0.35% by mass, total of Si and Al: 0.5% to 3.0% by mass, Mn: 1.0% to 4.0% by mass, P: 0.05% by mass or less, and S: 0.01% by mass or less, with the balance being Fe and inevitable impurities, wherein the steel structure satisfies that: a ferrite fraction is 5% or less, the total fraction of tempered martensite and tempered bainite is 60% or more, the amount of retained austenite is 10% or more, MA has an average size of 1.0 ?m or less, retained austenite has an average size of 1.0 ?m or less, retained austenite having a size of 1.5 ?m or more accounts for 2% or more of the total amount of retained austenite, and a scattering intensity at the q value of 1 nm?1 in X-ray small angle scattering is 1.0 cm1 or less.Type: ApplicationFiled: July 21, 2017Publication date: July 18, 2019Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Elijah KAKIUCHI, Toshio MURAKAMI, Shigeo OTANI, Yuichi FUTAMURA, Tadao MURATA
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Patent number: 10329635Abstract: A high strength cold-rolled steel sheet has a component composition containing specific amounts of C, Si, Mn, P, S, N and Al, respectively with a remainder being iron and inevitable impurities. The steel sheet contains 95% or more of martensite in terms of area ratio, and contains 5% or less (inclusive of 0%) of residual austenite and ferrite in terms of a total area ratio. An average size of a carbide is 60 nm or less in terms of an equivalent circle diameter, and a number density of the carbide having the equivalent circle diameter of 25 nm or more is 5.0×105 pieces or less per mm2. The steel sheet has a yield strength of 1,180 MPa or more and a tensile strength of 1,470 MPa or more.Type: GrantFiled: February 13, 2014Date of Patent: June 25, 2019Assignee: Kobe Steel, Ltd.Inventors: Kosuke Shibata, Toshio Murakami, Elijah Kakiuchi, Katsura Kajihara
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Publication number: 20190185958Abstract: Disclosed is a high-strength sheet including: C: 0.15% by mass to 0.35% by mass, total of Si and Al: 0.5% by mass to 3.0% by mass, Mn: 1.0% by mass to 4.0% by mass, P: 0.05% by mass or less, and S: 0.01% by mass or less, with the balance being Fe and inevitable impurities, wherein the steel structure satisfies that: a ferrite fraction is 5% or less, the total fraction of tempered martensite and tempered bainite is 60% or more, the amount of retained austenite is 10% or more, MA has an average size of 1.0 ?m or less, a half-width of the concentration distribution of Mn in the carbon-concentrated region that is equal to the amount of retained austenite is 0.3% by mass or more, and a scattering intensity at the q value of 1 nm?1 in X-ray small angle scattering is 1.0 cm?1 or less.Type: ApplicationFiled: July 21, 2017Publication date: June 20, 2019Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Elijah KAKIUCHI, Toshio MURAKAMI, Shigeo OTANI, Yuichi FUTAMURA, Tadao MURATA
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Publication number: 20190071757Abstract: A high-strength steel sheet comprising, as component composition, by mass: C: 0.15 to 0.35%; total of Si and Al: 0.5 to 2.5%; Mn: 1.0 to 4.0%; P: more than 0% and 0.05% or less; and S: more than 0% and 0.01% or less, with the balance being Fe and inevitable impurities, wherein a steel structure satisfies, in ratio with respect to the whole structure: ferrite: more than 5 area % and 50 area % or less; total of tempered martensite and bainite: 30 area % or more; and retained austenite: 10 volume % or more, the steel structure further includes MA, and the steel structure satisfies: an average circle equivalent diameter of the MA: 1.0 ?m or less; an average circle equivalent diameter of the retained austenite: 1.0 ?m or less; and a volume ratio of retained austenite with a circle equivalent diameter of 1.5 ?m or more to the whole retained austenite: 5% or more.Type: ApplicationFiled: February 22, 2017Publication date: March 7, 2019Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Tadao MURATA, Toshio MURAKAMI, Elijah KAKIUCHI, Shigeo OTANI, Yuichi FUTAMURA
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Patent number: 9890437Abstract: This high-strength steel sheet contains, in mass %, 0.05 to 0.3% of C, 1 to 3% of Si, 0.5 to 3% of Mn, up to 0.1% (inclusive of 0%) of P, up to 0.01% (inclusive of 0%) of S, 0.001 to 0.1% of Al and 0.002 to 0.03% of N with the balance consisting of iron and unavoidable impurities, and has a microstructure which comprises, in area fraction relative to the microstructure, 40 to 85% of bainitic ferrite, 5 to 20% of retained austenite (?R), 10 to 50% (in total) of martensite and ?R, and 5 to 40% of ferrite. The retained austenite (?R) has a C concentration of 0.5 to 1.0 mass %, while the quantity of ?R present in the ferrite grains is 1% or more (in area fraction) relative to the microstructure.Type: GrantFiled: February 6, 2013Date of Patent: February 13, 2018Assignee: Kobe Steel, Ltd.Inventors: Elijah Kakiuchi, Toshio Murakami, Katsura Kajihara, Tatsuya Asai, Naoki Mizuta, Hideo Hata
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Patent number: 9863028Abstract: A hot-dip galvanized steel sheet contains specific amounts of C, Si, Mn, P, S, Ti, Al, and N with the remainder being iron and unavoidable impurities. Bainitic ferrite, martensite, retained ?, and ferrite (?) are present each in a specific area ratio. The remainder ? has a specific C concentration. Sub-grains in the recrystallized ? and un-recrystallized ? have a specific grain diameter. The surface area ratio of ? and worked ? having a grain diameter of 5 ?m or more is 5% or less. The average particle diameter of TiC particles inside ? grains is 10 nm or less.Type: GrantFiled: June 26, 2013Date of Patent: January 9, 2018Assignee: Kobe Steel, Ltd.Inventors: Elijah Kakiuchi, Toshio Murakami, Katsura Kajihara, Tatsuya Asai, Naoki Mizuta
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Patent number: 9657381Abstract: This high-strength steel plate has a component composition including, by mass %, C: 0.02-0.3%, Si: 1-3%, Mn: 1.8-3%, P: 0.1% or less, S: 0.01% or less, Al: 0.001-0.1%, N: 0.002-0.03%, the rest consisting of iron and impurities. Said steel plate has a microstructure including, in terms of area ratio relative to the entire microstructure, each of the following phases: bainitic ferrite: 50-85%; retained ?: 3% or greater; martensite+the aforementioned retained ?: 10-45%; and ferrite: 5-40%. The C concentration (C?R) in the aforementioned retained austenite is 0.3-1.2 mass %, part or all of the N in the aforementioned component composition is solid solution N, and the amount of said solid solution N is 30-100 ppm.Type: GrantFiled: August 15, 2012Date of Patent: May 23, 2017Assignee: Kobe Steel, Ltd.Inventors: Toshio Murakami, Elijah Kakiuchi, Hideo Hata, Naoki Mizuta, Tatsuya Asai
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Publication number: 20150368742Abstract: A high strength cold-rolled steel sheet has a component composition containing specific amounts of C, Si, Mn, P, S, N and Al, respectively with a remainder being iron and inevitable impurities. The steel sheet contains 95% or more of martensite in terms of area ratio, and contains 5% or less (inclusive of 0%) of residual austenite and ferrite in terms of a total area ratio. An average size of a carbide is 60 nm or less in terms of an equivalent circle diameter, and a number density of the carbide having the equivalent circle diameter of 25 nm or more is 5.0×105 pieces or less per mm2. The steel sheet has a yield strength of 1,180 MPa or more and a tensile strength of 1,470 MPa or more.Type: ApplicationFiled: February 13, 2014Publication date: December 24, 2015Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)Inventors: Kosuke SHIBATA, Toshio MURAKAMI, Elijah KAKIUCHI, Katsura KAJIHARA
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Patent number: 9194032Abstract: This high-strength steel sheet has a component composition containing, in mass %, 0.02 to 0.3% C, 1 to 3% Si, 1.8 to 3% Mn, 0.1% or less P, 0.01% or less S, 0.001 to 0.1% Al, and 0.002 to 0.03% N, the remainder being iron and impurities. The high-strength steel sheet has a structure containing, in terms of area ratio relative to the entire structure, each of the following phases: 50 to 85% bainitic ferrite; 3% or more retained austenite (?); 10 to 45% martensite and the aforementioned retained austenite (?); and 5 to 40% ferrite. The ratio between the Mn concentration (Mn?R) in the retained austenite (?) and the average Mn concentration (Mnav) in the entire structure is 1.2 or more (Mn?R/ Mnav) based on the Mn concentration distribution obtained by means of EPMA line analysis. As a consequence, the high-strength steel sheet exhibits strength of 980 MPa or more and exerts excellent deep drawability.Type: GrantFiled: February 27, 2012Date of Patent: November 24, 2015Assignee: Kobe Steel, Ltd.Inventors: Toshio Murakami, Elijah Kakiuchi, Hideo Hata, Tatsuya Asai, Naoki Mizuta
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Publication number: 20150184274Abstract: A hot-dip galvanized steel sheet contains specific amounts of C, Si, Mn, P, S, Ti, Al, and N with the remainder being iron and unavoidable impurities. Bainitic ferrite, martensite, retained ?, and ferrite (?) are present each in a specific area ratio. The remainder ? has a specific C concentration. Sub-grains in the recrystallized ? and un-recrystallized ? have a specific grain diameter. The surface area ratio of ? and worked ? having a grain diameter of 5 ?m or more is 5% or less. The average particle diameter of TiC particles inside a grains is 10 nm or less.Type: ApplicationFiled: June 26, 2013Publication date: July 2, 2015Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Elijah Kakiuchi, Toshio Murakami, Katsura Kajihara, Tatsuya Asai, Naoki Mizuta
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Publication number: 20150000796Abstract: This high-strength steel sheet contains, in mass %, 0.05 to 0.3% of C, 1 to 3% of Si, 0.5 to 3% of Mn, up to 0.1% (inclusive of 0%) of P, up to 0.01% (inclusive of 0%) of S, 0.001 to 0.1% of Al and 0.002 to 0.03% of N with the balance consisting of iron and unavoidable impurities, and has a microstructure which comprises, in area fraction relative to the microstructure, 40 to 85% of bainitic ferrite, 5 to 20% of retained austenite (?R), 10 to 50% (in total) of martensite and ?R, and 5 to 40% of ferrite. The retained austenite (?R) has a C concentration of 0.5 to 1.0 mass %, while the quantity of ?R present in the ferrite grains is 1% or more (in area fraction) relative to the microstructure.Type: ApplicationFiled: February 6, 2013Publication date: January 1, 2015Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (Kobe Steel, Ltd.)Inventors: Elijah Kakiuchi, Toshio Murakami, Katsura Kajihara, Tatsuya Asai, Naoki Mizuta, Hideo Hata
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Publication number: 20140271331Abstract: This high-strength steel plate has a component composition including, by mass %, C: 0.02-0.3%, Si: 1-3%, Mn: 1.8-3%, P: 0.1% or less, S: 0.01% or less, Al: 0.001-0.1%, N: 0.002-0.03%, the rest consisting of iron and impurities. Said steel plate has a microstructure including, in terms of area ratio relative to the entire microstructure, each of the following phases: bainitic ferrite: 50-85%; retained ?; 3% or greater; martensite+the aforementioned retained ?; 10-45%; and ferrite: 5-40%. The C concentration (C?R) in the aforementioned retained austenite is 0.3-1.2 mass %, part or all of the N in the aforementioned component composition is solid solution N, and the amount of said solid solution N is 30-100 ppm.Type: ApplicationFiled: August 15, 2012Publication date: September 18, 2014Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Toshio Murakami, Elijah Kakiuchi, Hideo Hata, Naoki Mizuta, Tatsuya Asai
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Publication number: 20130330226Abstract: This high-strength steel sheet has a component composition containing, in mass %, 0.02 to 0.3% C, 1 to 3% Si, 1.8 to 3% Mn, 0.1% or less P, 0.01% or less S, 0.001 to 0.1% Al, and 0.002 to 0.03% N, the remainder being iron and impurities. The high-strength steel sheet has a structure containing, in terms of area ratio relative to the entire structure, each of the following phases: 50 to 85% bainitic ferrite; 3% or more retained austenite (?); 10 to 45% martensite and the aforementioned retained austenite (?); and 5 to 40% ferrite. The ratio between the Mn concentration (Mn?R) in the retained austenite (?) and the average Mn concentration (Mnav) in the entire structure is 1.2 or more (Mn?R/ Mnav) based on the Mn concentration distribution obtained by means of EPMA line analysis. As a consequence, the high-strength steel sheet exhibits strength of 980 MPa or more and exerts excellent deep drawability.Type: ApplicationFiled: February 27, 2012Publication date: December 12, 2013Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Toshio Murakami, Elijah Kakiuchi, Hideo Hata, Tatsuya Asai, Naoki Mizuta
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Publication number: 20130259734Abstract: A high-strength steel sheet has a chemical composition including 0.05% to 0.3% of C, 1% to 3% of Si, 0.5% to 3% of Mn, 0% to 0.1% of P, 0% to 0.01% of S, 0.001% to 0.1% of Al, and 0.002% to 0.03% of N in mass percent; further includes iron and impurities; and has a structure including 50% to 90% of bainitic ferrite, 3% or more of retained austenite (?R), a total of 10% to 50% of martensite and the retained austenite, and 0% to 40% of polygonal ferrite in area percent based on the entire structure. The retained austenite has a carbon content (C?R) of 0.5% to 1.2% by mass. The steel sheet includes 0.3% or more of the retained austenite that is surrounded by martensite. The high-strength steel sheet has a strength of 980 MPa or more and exhibits better ductility.Type: ApplicationFiled: November 16, 2011Publication date: October 3, 2013Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Elijah Kakiuchi, Toshio Murakami, Hideo Hata, Tatsuya Asai, Naoki Mizuta
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Publication number: 20130236350Abstract: A high-strength steel sheet has a chemical composition including 0.05% to 0.3% of C, 1% to 3% of Si, 0.5% to 3% of Mn, 0% to 0.1% of P, 0.001% to 0.1% of Al, and 0.002% to 0.03% of N, in mass percent; further includes iron and impurities; and has a structure including 50% to 90% of bainitic ferrite, 5% to 20% of retained austenite (?R), a total of 10% to 50% of martensite and the retained austenite, and 0% to 40% of polygonal ferrite, in area percent based on the entire structure. The retained austenite has a carbon content (C?R) of 0.5% to 1.2% by mass, an average equivalent circle diameter of 0.2 to 2 ?m, and an average aspect ratio (maximum diameter/minimum diameter) of less than 3.0. The high-strength steel sheet excels both in elongation and deep drawability while having a strength of 980 MPa or more.Type: ApplicationFiled: November 16, 2011Publication date: September 12, 2013Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Elijah Kakiuchi, Toshio Murakami, Hideo Hata, Tatsuya Asai, Naoki Mizuta