Patents by Inventor Toru Inazumi
Toru Inazumi 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: 7879287Abstract: A hot-rolled steel sheet for high-strength ERW pipes contains about 0.02% to about 0.06% C; about 0.05% to about 0.50% Si; about 0.5% to about 1.5% Mn; about 0.010% or less P; about 0.0010% or less S; about 0.01% to about 0.10% Al; about 0.01% to about 0.10% Nb; about 0.001% to about 0.025% Ti; about 0.001% to about 0.005% Ca; about 0.003% or less 0; and about 0.005% or less N, and at least one element selected from the group consisting of about 0.01% to about 0.10% V; about 0.01% to about 0.50% Cu; about 0.01% to about 0.50% Ni; and about 0.01% to about 0.50% Mo on the basis of mass. The group of C, Si, Mn, Cu, Ni, Mo, and V and the group of Ca, 0, and S satisfy specific relationships, and the microstructure of the steel sheet is composed of about 95% by volume or more bainitic ferrite.Type: GrantFiled: February 3, 2005Date of Patent: February 1, 2011Assignee: JFE Steel CorporationInventors: Takashi Kobayashi, Hiroshi Nakata, Chikara Kami, Toru Inazumi, Shuji Kawamura
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Publication number: 20060065329Abstract: The present invention relates to a high strength steel sheet consisting essentially of 0.04 to 0.1% C, 0.5% or less Si, 0.5 to 2% Mn, 0.05% or less P, 0.005% or less O, 0.005% or less S, by weight, having 10 ?m or less of average ferritic grain size, and 20 mm/mm2 or less of generation frequency A, which generation frequency A is defined as the total length of a banded secondary phase structure observed per 1 mm2 of steel sheet cross section along the rolling direction thereof. The steel sheet is manufactured by, for example, a method comprising the steps of: hot-rolling a continuously cast slab having the composition described above at temperatures of Ar3 transformation point or above directly or after reheating thereof; and cooling the hot-rolled steel sheet within 2 seconds down to the temperatures of from 600 to 750° C. at cooling speeds of from 100 to 2,000° C./sec, followed by coiling the cooled steel sheet at temperatures of from 450 to 650° C.Type: ApplicationFiled: November 10, 2005Publication date: March 30, 2006Applicant: JFE STEEL CORPORATIONInventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroyasu Kikuchi, Sadanori Imada, Takayuki Odake, Yasunobu Nagataki, Toru Inazumi
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Publication number: 20050183798Abstract: A hot-rolled steel sheet for high-strength ERW pipes contains about 0.02% to about 0.06% C; about 0.05% to about 0.50% Si; about 0.5% to about 1.5% Mn; about 0.010% or less P; about 0.0010% or less S; about 0.01% to about 0.10% Al; about 0.01% to about 0.10% Nb; about 0.001% to about 0.025% Ti; about 0.001% to about 0.005% Ca; about 0.003% or less 0; and about 0.005% or less N, and at least one element selected from the group consisting of about 0.01% to about 0.10% V; about 0.01% to about 0.50% Cu; about 0.01% to about 0.50% Ni; and about 0.01% to about 0.50% Mo on the basis of mass. The group of C, Si, Mn, Cu, Ni, Mo, and V and the group of Ca, 0, and S satisfy specific relationships, and the microstructure of the steel sheet is composed of about 95% by volume or more bainitic ferrite.Type: ApplicationFiled: February 3, 2005Publication date: August 25, 2005Applicant: JFE Steel Corporation, a corporation of JapanInventors: Takashi Kobayashi, Hiroshi Nakata, Chikara Kami, Toru Inazumi, Shuji Kawamura
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Publication number: 20050000606Abstract: A method for manufacturing a steel sheet comprising rough-rolling a steel consisting essentially of 0.04 to 0.12 weight % C, 0.25 to 2 weight % Si, 0.5 to 2.5 weight % Mn, 0.1 weight % or less Al, and a balance of substantially Fe and inevitable impurities to form a sheet bar; finish-rolling the sheet bar at a rolling end temperature of the Ar3 transformation point or more; primary-cooling the finish-rolled steel sheet within 1 second after completing the finish-rolling at a cooling speed of higher than 200° C./sec through a cooling range where-the difference between the start temperature of the cooling and the end temperature of the cooling is 100° C. to below 250° C.; slowly cooling the primary-cooled steel at a cooling speed of 10° C./sec or less, for 2 seconds to less than 20 seconds, at a temperature of 580° C. to 720° C.; and coiling the slowly cooled steel sheet at a temperature of 400° C. to below 540° C.Type: ApplicationFiled: July 26, 2004Publication date: January 6, 2005Applicant: NKK CORPORATIONInventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroyasu Kikuchi, Yoshimasa Funakawa, Hiroshi Nakata, Sadanori Imada, Toru Inazumi
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Patent number: 6818079Abstract: A method for manufacturing a steel sheet comprising continuously casting a steel containing 0.04 to 0.2 wt. % C, 0.25 to 2 wt. % Si, 0.5 to 2.5 wt. % Mn, and 0.1 wt. % or less Al to form a slab; hot-rolling by rough-rolling the slab to form a sheet bar and finish-rolling the sheet bar with a reduction in thickness at the final stand of less than 30%, the finish-rolling being completed at a temperature from the Ar3 transformation point to the Ar3 transformation point +60° C.; primary-cooling the hot-rolled steel sheet, the primary cooling being started within 1 second after the completion of hot-rolling and conducting the cooling at a cooling speed of higher than 200° C./sec down to a temperature of Ar3 −30° C. to the Ar1 transformation point; slow cooling or air-cooling the primary-cooled steel sheet at a temperature of the Ar3 transformation point to the Ar1 transformation point at 10° C.Type: GrantFiled: May 27, 2003Date of Patent: November 16, 2004Assignee: NKK CorporationInventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroyasu Kikuchi, Yoshimasa Funakawa, Hiroshi Nakata, Sadanori Imada, Toru Inazumi
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Publication number: 20040118489Abstract: The present invention provides a process of producing a family of hot rolled dual phase steel sheets having excellent formability and stretch flangeability, with yield strengths of from about 500 MPa to about 900 MPa from a single steel chemistry consisting of, by weight percent, 0.02-0.15% of C, 0.3-2.5% of Mn, 0.1-2.0% of Cr, 0.01-0.2% Al, 0.001-0.01% Ca, not more than 0.1% P, not more than 0.03% S, not more than 0.2% Ti, not more than 0.2% V, not more than 0.2% Nb, not more than 0.5% Mo, not more than 0.5% Cu, not more than 0.5% Ni, the balance being Fe and unavoidable impurities. A slab or ingot of this composition is reheated to a temperature of between 1050° C. and 1350° C. and held at this temperature for at least 10 minutes, then hot rolled, completing the hot rolling at between 800° C. and 1000° C. The sheet is cooled, immediately after completion of hot rolling, at a rate of not lower than 10 C/sec.Type: ApplicationFiled: December 18, 2002Publication date: June 24, 2004Inventors: Weiping Sun, Toru Inazumi, Yasuhiro Matsuki, Yoshimasa Funakawa
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Publication number: 20040112482Abstract: The present invention relates to a high strength steel sheet consisting essentially of 0.04 to 0.1% C, 0.5% or less Si, 0.5 to 2% Mn, 0.05% or less P, 0.005% or less O, 0.005% or less S, by weight, having 10 &mgr;m or less of average ferritic grain size, and 20 mm/mm2 or less of generation frequency A, which generation frequency A is defined as the total length of a banded secondary phase structure observed per 1 mm2 of steel sheet cross section along the rolling direction thereof. The steel sheet is manufactured by, for example, a method comprising the steps of: hot-rolling a continuously cast slab having the composition described above at temperatures of Ar3 transformation point or above directly or after reheating thereof; and cooling the hot-rolled steel sheet within 2 seconds down to the temperatures of from 600 to 750° C. at cooling speeds of from 100 to 2,000° C./sec, followed by coiling the cooled steel sheet at temperatures of from 450 to 650° C.Type: ApplicationFiled: July 23, 2003Publication date: June 17, 2004Applicant: NKK CORPORATIONInventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroyasu Kikuchi, Sadanori Imada, Yasunobu Nagataki, Toru Inazumi
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Publication number: 20040047756Abstract: A method of producing cold rolled and annealed dual phase high strength steel sheets, and sheets produced by the method, including hot dip galvanized and galvannealed steel sheets having a tensile strength of at least about 750 MPa and a superior balance of strength and ductility using conventional thermomechanical processing parameters robust to the processing conditions. The synergistic effect on hardenability of Cr and V, within a controlled range, facilitates production using robust processing conditions, enabling production of a high strength product having a very low yield ratio.Type: ApplicationFiled: September 6, 2002Publication date: March 11, 2004Inventors: Jayanta Shantaram Rege, Toru Inazumi, Toshiake Urabe, Yasunobu Nagataki
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Patent number: 6689229Abstract: A high strength cold rolled steel sheet consists essentially of 0.0040 to 0.01% C, not more than 0.05% Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, not more than 0.02% S, 0.01 to 0.1% sol.Al, not more than 0.004% N, 0.01 to 0.14% Nb, by weight, and a balance of substantially Fe and inevitable impurities, and having an n value of not less than 0.21 calculated from two points (1% and 10%) of nominal strain determined by the uniaxial tensile test, and a method for manufacturing the cold rolled steel sheet. The high strength cold rolled steel sheet has excellent combined formability, resistance to embrittlement during secondary operation, formability at welded portions, and anti-burring performance, and has a desirable surface appearance and uniformity of material in a coil, and thus can be desirably used for automobile exterior panels.Type: GrantFiled: April 15, 2002Date of Patent: February 10, 2004Assignee: NKK CorporationInventors: Takeshi Fujita, Fusato Kitano, Yoshihiro Hosoya, Toru Inazumi, Yuji Yamasaki, Masaya Morita, Yasunobu Nagataki, Kohei Hasegawa, Hiroshi Matsuda, Moriaki Ono
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Publication number: 20040020570Abstract: A high strength cold rolled steel sheet consists essentially of 0.0040 to 0.01% C, 0.05% or less Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, 0.02% or less S, 0.01 to 0.1% sol.Al, 0.004% or less N, 0.01 to 0.14% Nb, optionally 0.05% or less Ti, optionally 0.Type: ApplicationFiled: July 29, 2003Publication date: February 5, 2004Applicant: NKK CORPORATIONInventors: Takeshi Fujita, Fusato Kitano, Yoshihiro Hosoya, Toru Inazumi, Yuji Yamasaki, Masaya Morita, Yasunobu Nagataki, Kohei Hasegawa, Hiroshi Matsuda, Moriaki Ono
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Patent number: 6652670Abstract: The method for manufacturing steel sheet comprises the steps of: rough-rolling to form a sheet bar; finish-rolling the sheet bar to form a steel strip; applying primary cooling and secondary cooling to the finish-rolled steel strip; and coiling the secondary-cooled steel strip. The primary cooling is conducted at cooling speeds of 120° C./sec or more down to the temperatures of from 500 to 800° C. The secondary cooling is conducted at cooling speeds of less than 60° C./sec.Type: GrantFiled: April 18, 2001Date of Patent: November 25, 2003Inventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroyasu Kikuchi, Yasuhide Ishiguro, Sadanori Imada, Toru Inazumi
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Publication number: 20030205302Abstract: A method for manufacturing a steel sheet comprising continuously casting a steel containing 0.04 to 0.2 wt. % C, 0.25 to 2 wt. % Si, 0.5 to 2.5 wt. % Mn, and 0.1 wt. % or less Al to form a slab; hot-rolling by rough-rolling the slab to form a sheet bar and finish-rolling the sheet bar with a reduction in thickness at the final stand of less than 30%, the finish-rolling being completed at a temperature from the Ar3 transformation point to the Ar3 transformation point +60° C.; primary-cooling the hot-rolled steel sheet, the primary cooling being started within 1 second after the completion of hot-rolling and conducting the cooling at a cooling speed of higher than 200° C./sec down to a temperature of Ar3 −30° C. to the Ar1 transformation point; slow cooling or air-cooling the primary-cooled steel sheet at a temperature of the Ar3 transformation point to the Ar1 transformation point at 10° C.Type: ApplicationFiled: May 27, 2003Publication date: November 6, 2003Applicant: NKK CORPORATIONInventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroyasu Kikuchi, Yoshimasa Funakawa, Hiroshi Nakata, Sadanori Imada, Toru Inazumi
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Publication number: 20030196731Abstract: The method for manufacturing steel sheet comprises the steps of: rough-rolling to form a sheet bar; finish-rolling the sheet bar to form a steel strip; applying primary cooling and secondary cooling to the finish-rolled steel strip; and coiling the secondary-cooled steel strip. The primary cooling is conducted at cooling speeds of 120° C./sec or more down to the temperatures of from 500 to 800° C. The secondary cooling is conducted at cooling speeds of less than 60° C./sec.Type: ApplicationFiled: May 30, 2003Publication date: October 23, 2003Applicant: NKK CORPORATIONInventors: Tadashi Inoue, Yoichi Motoyashiki, Hiroshi Nakata, Takayuki Odake, Toru Inazumi
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Patent number: 6632295Abstract: A high tensile strength hot-rolled steel sheet comprises 0.04 to 0.09% C, 0.1% or less Si, 0.5 to 1.5% Mn, 0.02% or less P, 0.01% or less S, 0.1% or less Al, 0.001 to 0.008% N, and 0.01 to 0.15% Ti, by mass %, the content of ingredient there each satisfying the equation (1), and the ferritic grain size &agr; (&mgr;m) satisfying the equation (2): [C]+7×[Si]+0.1×[Mn]+[P]+14×[S]+1.75×[Al] +23×[N]+[Ti]+18×[O]+7×[Cu]+18×[Sn]+7×[Mo]+ 1.7×[Cr]+70×[B]+7×[Ca]+14×[Zr]+14×[V]+7×[Nb] ≦2 (1) 3≦&agr;≦60×[Ti]+8 (2) where, [X] denotes the content (mass %) of element X.Type: GrantFiled: May 24, 2001Date of Patent: October 14, 2003Assignee: NKK CorporationInventors: Hiroshi Nakata, Tadashi Inoue, Hiroyasu Kikuchi, Sadanori Imada, Akira Hiura, Takeshi Nakahara, Satoshi Ishijima, Yoshimasa Funakawa, Toru Inazumi
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Patent number: 6554925Abstract: The method for manufacturing cold-rolled steel sheet comprises the steps of: rough-rolling a slab using a rough-rolling unit; finish-rolling the sheet bar using a continuous hot finishing-rolling mill; cooling the hot-rolled steel strip on a runout table; coiling thus cooled hot-rolled steel strip; and applying picking, cold-rolling the hot-rolled steel strip, and final annealing to the cold-rolled steel strip.Type: GrantFiled: March 29, 2001Date of Patent: April 29, 2003Assignee: NKK CorporationInventors: Tadashi Inoue, Yasuhide Ishiguro, Yoichi Motoyashiki, Sadanori Imada, Toru Inazumi
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Patent number: 6494969Abstract: The present invention relates to a very low C—Nb cold rolled steel sheet giving 340 to 440 MPa of tensile strength. For example, the cold rolled steel sheet consists essentially of 0.0040 to 0.01% C, not more than 0.05% Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, not more than 0.02% S, 0.01 to 0.1% sol.Al, not more than 0.004% N, 0.01 to 0.14% Nb, by weight, and balance of substantially Fe and inevitable impurities, and has not less than 0.21 of n value calculated from two points (1% and 10%) of nominal strain determined by the uniaxial tensile test, and relates to a method for manufacturing the cold rolled steel sheet. The present invention provides a high strength cold rolled steel sheet for automobile exterior panels having excellent combined formability, resistance to embrittlement during secondary operation, formability at welded portions, anti-burring performance, good surface appearance, and uniformity of material in a coil.Type: GrantFiled: August 3, 2000Date of Patent: December 17, 2002Assignee: NKK CorporationInventors: Takeshi Fujita, Fusato Kitano, Yoshihiro Hosoya, Toru Inazumi, Yuji Yamasaki, Masaya Morita, Yasunobu Nagataki, Kohei Hasegawa, Hiroshi Matsuda, Moriaki Ono
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Publication number: 20020179206Abstract: The present invention relates to a very low C-Nb cold rolled steel sheet giving 340 to 440 MPa of tensile strength. For example, the cold rolled steel sheet consists essentially of 0.0040 to 0.01% C, not more than 0.05% Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, not more than 0.02% S, 0.01 to 0.1% sol.Al, not more than 0.004% N, 0.01 to 0.14% Nb, by weight, and balance of substantially Fe and inevitable impurities, and has not less than 0.21 of n value calculated from two points (1% and 10%) of nominal strain determined by the uniaxial tensile test, and relates to a method for manufacturing the cold rolled steel sheet. The present invention provides a high strength cold rolled steel sheet for automobile exterior panels having excellent combined formability, resistance to embrittlement during secondary operation, formability at welded portions, anti-burring performance, good surface appearance, and uniformity of material in a coil.Type: ApplicationFiled: April 15, 2002Publication date: December 5, 2002Applicant: NKK CORPORATIONInventors: Takeshi Fujita, Fusato Kitano, Yoshihiro Hosoya, Toru Inazumi, Yuji Yamasaki, Masaya Morita, Yasunobu Nagataki, Kohei Hasegawa, Hiroshi Matsuda, Moriaki Ono
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Patent number: 6440584Abstract: A hot-dip galvanized steel sheet is produced by rough rolling a steel, finish rolling the rough rolled steel at a temperature of Ar3 point or more, coiling the finish rolled steel at a temperature of 700° C. or less, and hot-dip galvanizing the coiled steel at a pre-plating heating temperature of Ac1 to Ac3. A continuous hot-dip galvanizing operation is performed by soaking a pickled strip at a temperature of 750 to 850° C., cooling the soaked strip to a temperature range of 600° C. or less at a cooling rate of 1 to 50° C. per second, hot-dip galvanizing the cooled strip, and cooling the galvanized strip so that the residence time at 400 to 600° C. is within 200 seconds. The steel sheet has a structure consisting essentially of ferrite and martensite.Type: GrantFiled: September 17, 2001Date of Patent: August 27, 2002Assignee: NKK CorporationInventors: Yasunobu Nagataki, Toshiaki Urabe, Fusato Kitano, Akio Kobayashi, Kunikazu Tomita, Shunsaku Node, Kozo Harada, Shogo Sato, Toru Inazumi
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Publication number: 20020088510Abstract: A hot-dip galvanized steel sheet is produced by rough rolling a steel, finish rolling the rough rolled steel at a temperature of Ar3 point or more, coiling the finish rolled steel at a temperature of 700° C. or less, and hot-dip galvanizing the coiled steel at a pre-plating heating temperature of Ac1 to Ac3. A continuous hot-dip galvanizing operation is performed by soaking a pickled strip at a temperature of 750 to 850° C., cooling the soaked strip to a temperature range of 600° C. or less at a cooling rate of 1 to 50° C. per second, hot-dip galvanizing the cooled strip, and cooling the galvanized strip so that the residence time at 400 to 600° C. is within 200 seconds. The steel sheet has a structure consisting essentially of ferrite and martensite.Type: ApplicationFiled: September 17, 2001Publication date: July 11, 2002Applicant: NKK CORPORATIONInventors: Yasunobu Nagataki, Toshiaki Urabe, Fusato Kitano, Akio Kobayashi, Kunikazu Tomita, Shunsaku Node, Kozo Harada, Shogo Sato, Toru Inazumi
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Publication number: 20020029828Abstract: A high tensile strength hot-rolled steel sheet comprises 0.04 to 0.09% C, 0.1% or less Si, 0.5 to 1.5% Mn, 0.02% or less P, 0.01% or less S, 0.1% or less Al, 0.001 to 0.008% N, and 0.01 to 0.Type: ApplicationFiled: May 24, 2001Publication date: March 14, 2002Applicant: NKK CORPORATIONInventors: Hiroshi Nakata, Tadashi Inoue, Hiroyasu Kikuchi, Sadanori Imada, Akira Hiura, Takeshi Nakahara, Satoshi Ishijima, Yoshimasa Funakawa, Toru Inazumi