Patents by Inventor Kaneharu Okuda
Kaneharu Okuda 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: 9039847Abstract: A multiphase steel sheet has a steel composition containing, in percent by mass, more than 0.015% to less than 0.100% of carbon, less than 0.40% of silicon, 1.0% to 1.9% of manganese, more than 0.015% to 0.05% of phosphorus, 0.03% or less of sulfur, 0.01% to 0.3% of soluble aluminum, 0.005% or less of nitrogen, less than 0.30% of chromium, 0.0050% or less of boron, less than 0.15% of molybdenum, 0.4% or less of vanadium, 0.02% or less of titanium, wherein [Mneq] is 2.0 to 2.8, the balance being iron and incidental impurities.Type: GrantFiled: July 27, 2010Date of Patent: May 26, 2015Assignee: JFE Steel CorporationInventors: Yoshihiko Ono, Kenji Takahashi, Kaneharu Okuda, Shoichiro Taira, Michitaka Sakurai, Yusuke Fushiwaki
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Patent number: 9028973Abstract: A high strength galvanized steel sheet is provided comprising steel containing C: 0.06% or more and 0.20% or less, Si: less than 0.50%, Mn: 0.5% or more and less than 2.0%, P: 0.05% or less, S: 0.02% or less, Al: 0.60% or more and 2.00% or less, N: less than 0.004%, Cr: 0.10% or more and 0.40% or less and B: 0.003% or less, satisfying the relationships 0.8?Mneq?2.0 and Mneq+1.3[% Al]?2.8, and a microstructure containing a ferrite phase and a second phase whose volume fraction is 15% or less, the second phase having a martensite phase whose volume fraction is 3% or more, a retained austenite phase whose volume fraction is 3% or more and a sum of the volume fractions of a pearlite phase and a bainite phase being equal to or less than the volume fraction of the martensite phase and the volume fraction of the retained austenite phase.Type: GrantFiled: November 10, 2011Date of Patent: May 12, 2015Assignee: JFE Steel CorporationInventors: Kenji Takahashi, Kaneharu Okuda, Yoshihiko Ono
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Publication number: 20150047751Abstract: A high strength steel sheet is formed of steel having the composition containing by mass % over 0.015% and less than 0.100% C, less than 0.50% Si, over 1.0% and less than 2.0% Mn, 0.05% or less P, 0.03% or less S, 0.01% or more and 0.3% or less sol. Al, 0.005% or less N, less than 0.35% Cr, 0.0010% or more and 0.0050% or less B, less than 0.15% Mo, less than 0.030% Ti, and iron and unavoidable impurities as a balance, wherein the steel satisfies 2.1?[Mneq]?3.1, the microstructure of the steel includes a ferrite and a second phase, a volume fraction of the second phase is set to 2.0 to 12.0%, a total ratio of a volume fraction of martensite and a volume fraction of retained ? to the volume fraction of second phase is 60% or more, and the number of carbides which are present within ferrite particles, have an aspect ratio of 3.0 or less and have a diameter of 0.25 to 0.90 ?m is set to 10000 pieces/mm2 or less.Type: ApplicationFiled: September 28, 2011Publication date: February 19, 2015Applicant: JFE Steel CorporationInventors: Yoshihiko Ono, Kenji Takahashi, Kaneharu Okuda, Yusuke Fushiwaki, Michitaka Sakurai
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Publication number: 20140363695Abstract: A high strength hot-dip galvanized steel sheet has TS of 440 MPa or more and an average r value of 1.30 or more, where the absolute value of the planar anisotropy of the r value (?r) is 0.20 or less. A chemical composition contains C: 0.010% or more and 0.04% or less, Si: more than 1.0% and 1.5% or less, Mn: 1.0% or more and 3.0% or less, P: 0.005% or more and 0.1% or less, S: 0.01% or less, sol. Al: 0.005% or more and 0.5% or less, N: 0.01% or less, Nb: 0.010% or more and less than 0.05%, Ti: 0.015% or more and 0.120% or less, and the remainder composed of Fe and incidental impurities, wherein (Nb/93)/(C/12)<0.20 and 0.005<C*?0.020 are satisfied, a steel sheet microstructure includes 80% or more of ferrite and 3% or more of martensite on an area ratio basis, and C*=C-(12/93)Nb-(12/48){Ti-(48/14)N-(48/32)S}.Type: ApplicationFiled: August 23, 2012Publication date: December 11, 2014Applicant: JFE Stell CorporationInventors: Hideyuki Kimura, Kaneharu Okuda, Yasunobu Nagataki, Kenji Kawamura
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Patent number: 8876987Abstract: A high strength pressed member has excellent ductility and stretch flangeability and tensile strength of 780-1400 MPa, with a predetermined steel composition and steel microstructure relative to the entire microstructure of steel sheet, where area ratio of martensite 5-70%, area ratio of retained austenite 5-40%, area ratio of bainitic ferrite in upper bainite 5% or more, and total thereof is 40% or more, 25% or more of martensite is tempered martensite, polygonal ferrite area ratio is above 10% and below 50% to the entire microstructure of steel sheet, and average grain size is 8 ?m or less, average diameter of a group of polygonal ferrite grains is 15 ?m or less, the group of polygonal ferrite grains represented by a group of ferrite grains of adjacent polygonal ferrite grains, and average carbon content in retained austenite is 0.70 mass % or more and tensile strength is 780 MPa or more.Type: GrantFiled: October 2, 2012Date of Patent: November 4, 2014Assignee: JFE Steel CorporationInventors: Hiroshi Matsuda, Yoshimasa Funakawa, Kaneharu Okuda, Kazuhiro Seto
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Publication number: 20140290810Abstract: A high strength cold rolled steel sheet includes a chemical composition containing, by mass %, C: 0.010% or more and 0.060% or less, Si: more than 0.5% and 1.5% or less, Mn: 1.0% or more and 3.0% or less, P: 0.005% or more and 0.100% or less, S: 0.010% or less, sol.Al: 0.005% or more and 0.500% or less, N: 0.0100% or less, Nb: 0.010% or more and 0.100% or less, Ti: 0.015% or more and 0.150% or less and the balance comprising Fe and inevitable impurities. The microstructure includes, in area fraction, 70% or more of a ferrite phase and 3% or more of a martensite phase. The tensile strength is 440 MPa or more and an average r value is 1.20 or more.Type: ApplicationFiled: August 23, 2012Publication date: October 2, 2014Applicant: JFE STEEL CORPORATIONInventors: Hideyuki Kimura, Yasunobu Nagataki, Kaneharu Okuda, Kenji Kawamura
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Publication number: 20140242416Abstract: A high strength pressed member has excellent ductility and stretch flangeability and tensile strength of 780-1400 MPa, with a predetermined steel composition and steel microstructure relative to the entire microstructure of steel sheet, where area ratio of martensite 5-70%, area ratio of retained austenite 5-40%, area ratio of bainitic ferrite in upper bainite 5% or more, and total thereof is 40% or more, 25% or more of martensite is tempered martensite, polygonal ferrite area ratio is above 10% and below 50% to the entire microstructure of steel sheet, and average grain size is 8 ?m or less, average diameter of a group of polygonal ferrite grains is 15 ?m or less, the group of polygonal ferrite grains represented by a group of ferrite grains of adjacent polygonal ferrite grains, and average carbon content in retained austenite is 0.70 mass % or more and tensile strength is 780 MPa or more.Type: ApplicationFiled: October 2, 2012Publication date: August 28, 2014Inventors: Hiroshi Matsuda, Yoshimasa Funakawa, Kaneharu Okuda, Kazuhiro Seto
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Publication number: 20140102596Abstract: A method of manufacturing a high strength cold rolled steel sheet includes hot-rolling and cold-rolling a steel slab annealing the steel sheet at an annealing temperature of 750° C. to 830° C.; subjecting the steel sheet to first cooling at an average cooling rate of 3° C./sec to 40° C./sec in a temperature range from the annealing temperature to 480° C.; subjecting the steel sheet to second cooling at an average cooling rate of 8° C./sec to 80° C./sec in a temperature range from 480° C. to Tc (° C.) given by formula (6): Tc=435?40×[% Mn]?30×[% Cr]?30×[% V](6) wherein [% A] is the content (% by mass) of alloying element A; and subjecting the steel sheet to third cooling at an average cooling rate of 0.3° C./sec to 30° C./sec in a temperature range from Tc (° C.) to 200° C.Type: ApplicationFiled: October 21, 2013Publication date: April 17, 2014Applicant: JFE Steel CorporationInventors: Yoshihiko Ono, Kenji Takahashi, Kaneharu Okuda, Shoichiro Taira, Michitaka Sakurai, Yusuke Fushiwaki
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Publication number: 20140103684Abstract: A vehicle collision energy absorbing member is excellent in collision energy absorbing performance in the axial direction upon collision. The vehicle collision energy absorbing member is formed of a high strength thin steel sheet having TS of at least 980 MPa and having an n-value and a limit bending radius Rc satisfying the following Formula: Rc/t?1.31×ln(n)+5.21.Type: ApplicationFiled: April 23, 2012Publication date: April 17, 2014Inventors: Shusaku Takagi, Kaneharu Okuda, Yoshikiyo Tamai, Takeshi Fujita, Yoshitaka Okitsu, Tadashi Naito, Naoki Takaki, Tomoaki Sugiura
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Publication number: 20140102597Abstract: The high strength galvanized steel sheet contains C: more than 0.015% and lower than 0.100%, Si: 0.3% or lower, Mn: lower than 1.90%, P: 0.015% or more and 0.05% or lower, S: 0.03% or lower, sol.Al: 0.01% or more and 0.5% or lower, N: 0.005% or lower, Cr: lower than 0.30%, B: 0.0003% or more and 0.005% or lower, and Ti: lower than 0.014% in terms of mass %, and satisfies 2.2?[Mneq]?3.1 and 0.42?8[% P]+150B*?0.73. The steel microstructure contains ferrite and a second phase, in which the second phase area ratio is 3 to 15%, the ratio of the area ratio of martensite and retained ? to the second phase area ratio is more than 70%, and 50% or more of the area ratio of the second phase exists in the grain boundary triple point.Type: ApplicationFiled: December 12, 2013Publication date: April 17, 2014Applicant: JFE STEEL CORPORATIONInventors: Yoshihiko Ono, Kenji Takahashi, Kaneharu Okuda, Shoichiro Taira
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Patent number: 8696832Abstract: A high-strength hot-rolled steel sheet has a tensile strength (TS) of 540 to 780 MPa, only small variations in strength, and excellent uniformity in strength using a general-purpose Ti-containing steel sheet, which is inexpensive. The high-strength hot-rolled steel sheet includes, on a mass percent basis, 0.05%-0.12% C, 0.5% or less Si, 0.8%-1.8% Mn, 0.030% or less P, 0.01% or less S, 0.005%-0.1% Al, 0.01% or less N, 0.030%-0.080% Ti, and the balance being Fe and incidental impurities. The microstructure have a bainitic ferrite fraction of 70% or more, and the amount of Ti present in a precipitate having a size of less than 20 nm is 50% or more of the value of Ti* calculated using formula (1): Ti*=[Ti]?48/14×[N] (1) where [Ti] and [N] represent a Ti content (percent by mass) and a N content (percent by mass), respectively, of the steel sheet.Type: GrantFiled: February 4, 2009Date of Patent: April 15, 2014Assignee: JFE Steel CorporationInventors: Shinjiro Kaneko, Kaneharu Okuda, Tetsuo Shimizu, Noriaki Moriyasu, Masahide Watabe
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Patent number: 8636852Abstract: The high strength galvanized steel sheet contains C: more than 0.015% and lower than 0.100%, Si: 0.3% or lower, Mn: lower than 1.90%, P: 0.015% or more and 0.05% or lower, S: 0.03% or lower, sol.Al: 0.01% or more and 0.5% or lower, N: 0.005% or lower, Cr: lower than 0.30%, B: 0.0003% or more and 0.005% or lower, and Ti: lower than 0.014% in terms of mass %, and satisfies 2.2?[Mneq]?3.1 and 0.42?8[% P]+150B*?0.73. The steel microstructure contains ferrite and a second phase, in which the second phase area ratio is 3 to 15%, the ratio of the area ratio of martensite and retained ? to the second phase area ratio is more than 70%, and 50% or more of the area ratio of the second phase exists in the grain boundary triple point.Type: GrantFiled: February 2, 2010Date of Patent: January 28, 2014Assignee: JFE Steel CorporationInventors: Yoshihiko Ono, Kenji Takahashi, Kaneharu Okuda, Shoichiro Taira
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Publication number: 20130295410Abstract: A high strength galvanized steel sheet is provided comprising steel containing C: 0.06% or more and 0.20% or less, Si: less than 0.50%, Mn: 0.5% or more and less than 2.0%, P: 0.05% or less, S: 0.02% or less, Al: 0.60% or more and 2.00% or less, N: less than 0.004%, Cr: 0.10% or more and 0.40% or less and B: 0.003% or less, satisfying the relationships 0.8?Mneq?2.0 and Mneq+1.3[% Al]?2.8, and a microstructure containing a ferrite phase and a second phase whose volume fraction is 15% or less, the second phase having a martensite phase whose volume fraction is 3% or more, a retained austenite phase whose volume fraction is 3% or more and a sum of the volume fractions of a pearlite phase and a bainite phase being equal to or less than the volume fraction of the martensite phase and the volume fraction of the retained austenite phase.Type: ApplicationFiled: November 10, 2011Publication date: November 7, 2013Applicant: JFE Steel CorporationInventors: Kenji Takahashi, Kaneharu Okuda, Yoshihiko Ono
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Publication number: 20130292010Abstract: A high-strength galvanized steel sheet contains C: 0.010% or more and 0.06% or less, Si: more than 0.5% and 1.5% or less, Mn: 1.0% or more and 3.0% or less, P: 0.005% or more and 0.1% or less, S: 0.01% or less, sol.Al: 0.005% or more and 0.5% or less, N: 0.01% or less, Nb: 0.010% or more and 0.090% or less, and Ti: 0.015% or more and 0.15% or less, on a mass percent basis. The Nb and C contents of the steel satisfy the relation of (Nb/93)/(C/12)<0.20. C* satisfies 0.005?C*?0.025. Ferrite constitutes 70% by area ratio or more of the steel sheet. Martensite constitutes 3% by area ratio or more of the steel sheet. C*=C?(12/93)Nb?(12/48){Ti?(48/14)N}, wherein C, Nb, Ti, and N denote the C, Nb, Ti, and N contents of the steel.Type: ApplicationFiled: September 15, 2011Publication date: November 7, 2013Applicant: JFE Steel CorporationInventors: Hideyuki Kimura, Kaneharu Okuda, Reiko Sugihara
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Publication number: 20130008571Abstract: A high-strength steel sheet has excellent deep drawability with a tensile strength of 390 to 700 MPa and an r-value of 1.1 or more in the orientation in which the r-value is lowest. A steel slab is subjected to finish rolling by hot rolling at a finish rolling delivery temperature of 800° C. or higher, coiling at 550° C. to 720° C., and cooling to form a hot-rolled steel sheet. The hot-rolled steel sheet is pickled and cold-rolled to a rolling reduction of 50% to 85% to form a cold-rolled steel sheet. The cold-rolled steel sheet is annealed at an annealing temperature of 760° C. to 950° C. In this step, a strain of 0.1% to 2.0% is applied in the temperature range of 700° C. to the annealing temperature.Type: ApplicationFiled: March 7, 2011Publication date: January 10, 2013Applicant: JFE STEEL CORPORATIONInventors: Kaneharu Okuda, Yasushi Tanaka
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Publication number: 20120180909Abstract: A multiphase steel sheet has a steel composition containing, in percent by mass, more than 0.015% to less than 0.100% of carbon, less than 0.40% of silicon, 1.0% to 1.9% of manganese, more than 0.015% to 0.05% of phosphorus, 0.03% or less of sulfur, 0.01% to 0.3% of soluble aluminum, 0.005% or less of nitrogen, less than 0.30% of chromium, 0.0050% or less of boron, less than 0.15% of molybdenum, 0.4% or less of vanadium, 0.02% or less of titanium, wherein [Mneq] is 2.0 to 2.8, the balance being iron and incidental impurities.Type: ApplicationFiled: July 27, 2010Publication date: July 19, 2012Applicant: JFE STEEL CORPORATIONInventors: Yoshihiko Ono, Kenji Takahashi, Kaneharu Okuda, Shoichiro Taira, Michitaka Sakurai, Yusuke Fushiwaki
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Publication number: 20120118439Abstract: A high-strength galvanized steel sheet has a low YP, good stretch flangeability, and excellent corrosion resistance and contains, on a percent by mass basis, more than 0.015% to less than 0.10% of C, 0.5% or less of Si, 1.0% to 1.9% of Mn, 0.015% to 0.050% of P, 0.03% or less of S, 0.01% to 0.5% of sol. Al, 0.005% or less of N, less than 0.40% of Cr, 0.005% or less of B, less than 0.15% of Mo, 0.4% or less of V, and less than 0.020% of Ti, in which 2.2?[Mneq]?3.1 and [% Mn]+3.3[% Mo]?1.9, and [% Mn]+3.3 [% Mo])/(1.3[% Cr]+8[% P]+150B*)<3.5 are satisfied.Type: ApplicationFiled: June 25, 2010Publication date: May 17, 2012Applicant: JFE STEEL CORPORATIONInventors: Yoshihiko Ono, Kenji Takahashi, Kaneharu Okuda, Shoichiro Taira, Michitaka Sakurai, Yusuke Fushiwaki
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Publication number: 20120037281Abstract: The high strength galvanized steel sheet contains C: more than 0.015% and lower than 0.100%, Si: 0.3% or lower, Mn: lower than 1.90%, P: 0.015% or more and 0.05% or lower, S: 0.03% or lower, sol.Al: 0.01% or more and 0.5% or lower, N: 0.005% or lower, Cr: lower than 0.30%, B: 0.0003% or more and 0.005% or lower, and Ti: lower than 0.014% in terms of mass %, and satisfies 2.2?[Mneq]?3.1 and 0.42?8[% P]+150B*?0.73. The steel microstructure contains ferrite and a second phase, in which the second phase area ratio is 3 to 15%, the ratio of the area ratio of martensite and retained ? to the second phase area ratio is more than 70%, and 50% or more of the area ratio of the second phase exists in the grain boundary triple point.Type: ApplicationFiled: February 2, 2010Publication date: February 16, 2012Applicant: JFE STEEL CORPORATIONInventors: Yoshihiko Ono, Kenji Takahashi, Kaneharu Okuda, Shoichiro Taira
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Publication number: 20100330392Abstract: A high-strength galvanized steel sheet has a steel composition which contains, by % by mass, 0.01 to 0.12% of C, 0.2% or less of Si, less than 2% of Mn, 0.04% or less of P, 0.02% or less of S, 0.3% or less of sol. Al, 0.01% or less of N, and over 0.3% to 2% of Cr, and which satisfies 2.1?[Mneq]?3 and 0.24?[% Cr]/[% Mn], the balance being composed of iron and inevitable impurities, and has a steel microstructures containing ferrite and a second phase.Type: ApplicationFiled: July 10, 2008Publication date: December 30, 2010Applicant: JFE STEEL CORPORATIONInventors: Yoshihiko Ono, Hideyuki Kimura, Kaneharu Okuda, Takeshi Fujita, Michitaka Sakurai
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Publication number: 20100326572Abstract: A method produces a high-strength cold-rolled steel sheet includes hot-rolling and cold-rolling steel having a composition which contains, by % by mass, over 0.01% to less than 0.08% of C, 0.2% or less of Si, 0.8% to less than 1.7% of Mn, 0.03% or less of P, 0.02% or less of S, 0.3% or less of sol. Al, 0.01% or less of N, and over 0.4% to 2% of Cr, and which satisfies 1.9<[Mneq]<3 and 0.34?[% Cr]/[% Mn], the balance being composed of iron and inevitable impurities; heating at an average heating rate of less than 3° C./sec in a temperature range of 680° C. to 740° C.; annealing at an annealing temperature of over 740° C. to less than 820° C.; cooling at an average cooling rate of 2 to 30° C./sec in a temperature range of the annealing temperature to 650° C.; cooling at an average cooling rate of 10° C./sec or more in the temperature range of 650° C. to Tc° C.Type: ApplicationFiled: July 10, 2008Publication date: December 30, 2010Applicant: JFE STEEL CORPORATIONInventors: Yoshihiko Ono, Hideyuki Kimura, Kaneharu Okuda, Takeshi Fujita, Michitaka Sakurai