Patents by Inventor Minoru Suwa
Minoru Suwa 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).
-
Patent number: 9945015Abstract: A high-tensile steel plate has a chemical composition containing, by mass, specific amounts of C, Mn, Si, P, S, Al, Ni, B, N, one or more elements selected from Cr, Mo, V, Cu, Ti, and Ca as needed, Ceq?0.80, and a center-segregation zone hardness index HCS satisfying 5.5[C]4/3+15[P]+0.90[Mn]+0.12[Ni]+0.53[Mo]?2.5. The hardness of a center-segregation zone satisfies HVmax/HVave?1.35+0.006/C?t/750. A steel having the above-described chemical composition is subjected to hot rolling at a specific slab-heating temperature at a specific rolling reduction ratio, subsequently reheated, cooled at a cooling rate of 0.3° C./s or more until the temperature of a central portion in a plate-thickness direction reaches 350° C. or less, and tempered to a specific temperature range.Type: GrantFiled: October 1, 2012Date of Patent: April 17, 2018Assignee: JFE Steel CorporationInventors: Masao Yuga, Shigeki Kitsuya, Kenji Hayashi, Minoru Suwa
-
Patent number: 9790579Abstract: The present invention provides a high tensile strength steel plate having a chemical composition containing, in percent by mass, 0.03% to 0.12% of C, 0.01% to 0.30% of Si, 0.5% to 1.95% of Mn, 0.008% or less of P, 0.005% or less of S, 0.015% to 0.06% of Al, 0.011% to 0.05% of Nb, 0.005% to 0.02% of Ti, 0.001% to 0.006% of N, 0.0005% to 0.003% of Ca, optionally, one or two or more of Cr, Mo, V, Cu, and Ni, in which Ceq is 0.44 or less, Ti/N is 1.5 to 3.5, and parameter formulas composed of specific elements for controlling the sulfide morphology and the degree of center segregation in the steel are satisfied, and the balance being Fe and incidental impurities, in which the hardness of the center segregation area of the steel sheet is further specified.Type: GrantFiled: March 1, 2012Date of Patent: October 17, 2017Assignee: JFE Steel CorporationInventors: Masao Yuga, Shigeki Kitsuya, Yusuke Terazawa, Minoru Suwa, Kenji Hayashi
-
Publication number: 20150075682Abstract: The present invention provides a high tensile strength steel plate having a chemical composition containing, in percent by mass, 0.03% to 0.12% of C, 0.01% to 0.30% of Si, 0.5% to 1.95% of Mn, 0.008% or less of P, 0.005% or less of S, 0.015% to 0.06% of Al, 0.011% to 0.05% of Nb, 0.005% to 0.02% of Ti, 0.001% to 0.006% of N, 0.0005% to 0.003% of Ca, optionally, one or two or more of Cr, Mo, V, Cu, and Ni, in which Ceq is 0.44 or less, Ti/N is 1.5 to 3.5, and parameter formulas composed of specific elements for controlling the sulfide morphology and the degree of center segregation in the steel are satisfied, and the balance being Fe and incidental impurities, in which the hardness of the center segregation area of the steel sheet is further specified.Type: ApplicationFiled: March 1, 2012Publication date: March 19, 2015Applicant: JFE Steel CorporationInventors: Masao Yuga, Shigeki Kitsuya, Yusuke Terazawa, Minoru Suwa, Kenji Hayashi
-
Publication number: 20140246131Abstract: A high-tensile steel plate has a chemical composition containing, by mass, specific amounts of C, Mn, Si, P, S, Al, Ni, B, N, one or more elements selected from Cr, Mo, V, Cu, Ti, and Ca as needed, Ceq?0.80, and a center-segregation zone hardness index HCS satisfying 5.5[C]4/3+15[P]+0.90[Mn]+0.12[Ni]+0.53[Mo]?2.5. The hardness of a center-segregation zone satisfies HVmax/HVave?1.35+0.006/C?t/750. A steel having the above-described chemical composition is subjected to hot rolling at a specific slab-heating temperature at a specific rolling reduction ratio, subsequently reheated, cooled at a cooling rate of 0.3° C./s or more until the temperature of a central portion in a plate-thickness direction reaches 350° C. or less, and tempered to a specific temperature range.Type: ApplicationFiled: October 1, 2012Publication date: September 4, 2014Applicant: JFE STEEL CORPORATIONInventors: Masao Yuga, Shigeki Kitsuya, Kenji Hayashi, Minoru Suwa
-
Patent number: 8147626Abstract: A high strength steel plate containing 0.02 to 0.08% C, by mass, and has substantially a two phase microstructure of ferrite and bainite. The ferrite contains precipitates having a particle size of 30 nm or smaller grain size. The steel plate has a yield strength of 448 MPa or higher. A method for manufacturing the high strength steel plate which comprises hot rolling, accelerated cooling and reheating. The accelerated cooling is conducted down to a temperature of 300 to 600° C. at a cooling rate of 5° C./s or higher. The reheating is conducted up to a temperature of 550 to 700° C. at a heating rate of 0.5° C./s or higher.Type: GrantFiled: March 22, 2011Date of Patent: April 3, 2012Assignee: JFE Steel CorporationInventors: Nobuyuki Ishikawa, Toyohisa Shinmiya, Minoru Suwa, Shigeru Endo
-
Publication number: 20110253267Abstract: A high-strength steel pipe having a strength of API X65 grade or higher consisting essentially of, by mass %, 0.02 to 0.08% of C, 0.01 to 0.5% of Si, 0.5 to 1.8% of Mn, 0.01% or less of P, 0.002% or less of S, 0.01 to 0.7% of Al, 0.005 to 0.04% of Ti, 0.05 to 0.50% Mo, at least one element selected from 0.005 to 0.05% of Nb and 0.005 to 0.10% of V, and the balance being Fe, in which the volume percentage of the ferritic phase is 90% or higher, and complex carbides containing Ti, Mo, and at least one element selected from the group consisting of Nb and V are precipitated in the ferritic phase. The high-strength steel pipe has excellent HIC resistance and good toughness of a heat-affected zone, and can be manufactured stably at a low cost.Type: ApplicationFiled: May 9, 2011Publication date: October 20, 2011Applicant: JFE Steel CorporationInventors: Nobuyuki Ishikawa, Toyohisa Shinmiya, Shigeru Endo, Minoru Suwa
-
Publication number: 20110168304Abstract: A high strength steel plate containing 0.02 to 0.08% C, by mass, and has substantially a two phase microstructure of ferrite and bainite. The ferrite contains precipitates having a particle size of 30 nm or smaller grain size. The steel plate has a yield strength of 448 MPa or higher. A method for manufacturing the high strength steel plate which comprises hot rolling, accelerated cooling and reheating. The accelerated cooling is conducted down to a temperature of 300 to 600° C. at a cooling rate of 5° C./s or higher. The reheating is conducted up to a temperature of 550 to 700° C. at a heating rate of 0.5° C./s or higher.Type: ApplicationFiled: March 22, 2011Publication date: July 14, 2011Applicant: JFE STEEL CORPORATIONInventors: Nobuyuki ISHIKAWA, Toyohisa SHINMIYA, Minoru SUWA, Shigeru ENDO
-
Patent number: 7959745Abstract: A high-strength steel pipe having a strength of API X65 grade or higher consisting essentially of, by mass %, 0.02 to 0.08% of C, 0.01 to 0.5% of Si, 0.5 to 1.8% of Mn, 0.01% or less of P, 0.002% or less of S, 0.01 to 0.7% of Al, 0.005 to 0.04% of Ti, 0.05 to 0.50% Mo, at least one element selected from 0.005 to 0.05% of Nb and 0.005 to 0.10% of V, and the balance being Fe, in which the volume percentage of the ferritic phase is 90% or higher, and complex carbides containing Ti, Mo, and at least one element selected from the group consisting of Nb and V are precipitated in the ferritic phase. The high-strength steel pipe has excellent HIC resistance and good toughness of a heat-affected zone, and can be manufactured stably at a low cost.Type: GrantFiled: May 15, 2006Date of Patent: June 14, 2011Assignee: JFE Steel CorporationInventors: Nobuyuki Ishikawa, Toyohisa Shinmiya, Shigeru Endo, Minoru Suwa
-
Patent number: 7935197Abstract: A high strength steel plate containing 0.02 to 0.08% C, by mass, and has substantially a two phase microstructure of ferrite and bainite. The ferrite contains precipitates having a particle size of 30 nm or smaller grain size. The steel plate has a yield strength of 448 MPa or higher. A method for manufacturing the high strength steel plate which comprises hot rolling, accelerated cooling and reheating. The accelerated cooling is conducted down to a temperature of 300 to 600° C. at a cooling rate of 5° C./s or higher. The reheating is conducted up to a temperature of 550 to 700° C. at a heating rate of 0.5° C./s or higher.Type: GrantFiled: September 19, 2006Date of Patent: May 3, 2011Assignee: JFE Steel CorporationInventors: Nobuyuki Ishikawa, Toyohisa Shinmiya, Minoru Suwa, Shigeru Endo
-
Publication number: 20070012386Abstract: A high strength steel plate containing 0.02 to 0.08% C, by mass, and has substantially a two phase microstructure of ferrite and bainite. The ferrite contains precipitates having a particle size of 30 nm or smaller grain size. The steel plate has a yield strength of 448 MPa or higher. A method for manufacturing the high strength steel plate which comprises hot rolling, accelerated cooling and reheating. The accelerated cooling is conducted down to a temperature of 300 to 600° C. at a cooling rate of 5° C./s or higher. The reheating is conducted up to a temperature of 550 to 700° C. at a heating rate of 0.5° C./s or higher.Type: ApplicationFiled: September 19, 2006Publication date: January 18, 2007Applicant: JFE STEEL CORPORATIONInventors: Nobuyuki Ishikawa, Toyohisa Shinmiya, Minoru Suwa, Shigeru Endo
-
Publication number: 20060201592Abstract: A high-strength steel pipe having a strength of API X65 grade or higher consisting essentially of, by mass %, 0.02 to 0.08% of C, 0.01 to 0.5% of Si, 0.5 to 1.8% of Mn, 0.01% or less of P, 0.002% or less of S, 0.01 to 0.7% of Al, 0.005 to 0.04% of Ti, 0.05 to 0.50% Mo, at least one element selected from 0.005 to 0.05% of Nb and 0.005 to 0.10% of V, and the balance being Fe, in which the volume percentage of the ferritic phase is 90% or higher, and complex carbides containing Ti, Mo, and at least one element selected from the group consisting of Nb and V are precipitated in the ferritic phase. The high-strength steel pipe has excellent HIC resistance and good toughness of a heat-affected zone, and can be manufactured stably at a low cost.Type: ApplicationFiled: May 15, 2006Publication date: September 14, 2006Applicant: JFE STEEL CORPORATIONInventors: Nobuyuki Ishikawa, Toyohisa Shinmiya, Shigeru Endo, Minoru Suwa
-
Publication number: 20050106411Abstract: The high strength steel plate according to the present invention contains 0.02 to 0.08% C, by mass, and has substantially a two phase microstructure of ferrite and bainite. The ferrite contains precipitates having particle size of 30 nm or smaller grain size. The steel plate has yield strength of 448 MPa or higher. The method for manufacturing the high strength steel plate comprises the steps of hot rolling, accelerated cooling, and reheating. The accelerated cooling is conducted down to the temperature of 300 to 600° C. at a cooling rate of 5° C./s or higher. The reheating is conducted up to temperature of 550 to 700° C. at a heating rate of 0.5° C./s or higher.Type: ApplicationFiled: February 4, 2003Publication date: May 19, 2005Applicant: JFE STEEL CORPORATIONInventors: Nobuyuki Ishikawa, Toyohisa Shinmiya, Minoru Suwa, Shigeru Endo
-
Publication number: 20040074573Abstract: The present invention relates to a high strength hot rolled steel sheet containing 0.15% or less C, 0.02 to 0.35% Ti, and 0.05 to 0.7% Mo by weight percentage and consisting essentially of a matrix of ferrite structure single phase and fine precipitates with a grain size of smaller than 10 nm dispersed in the matrix, for example, a high strength hot rolled steel sheet which consists essentially of 0.06% or less C, 0.5% or less Si, 0.5 to 2.0% Mn, 0.06% or less P, 0.005% or less S, 0.1% or less Al, 0.006% or less N, 0.02 to 0.10% Ti, 0.05 to 0.6% Mo by weight percentage, and the balance being Fe, wherein fine precipitates with a grain size of smaller than 10 nm are dispersed in a matrix of ferrite structure single phase at a number per unit volume of 5×104/&mgr;m3 or higher. This steel sheet, which has tensile strength of not lower than 550 MPa, high elongation and excellent stretch flangeability, is suitable for intricately shaped automotive chassis parts such as a suspension arm.Type: ApplicationFiled: October 14, 2003Publication date: April 22, 2004Applicant: NKK CORPORATIONInventors: Yoshimasa Funakawa, Tsuyoshi Shiozaki, Kunikazu Tomita, Takanobu Saito, Hiroshi Nakata, Kaoru Sato, Minoru Suwa, Tetsuo Yamamoto, Yasuhiro Murao, Eiji Maeda
-
Patent number: 6666932Abstract: The present invention relates to a high strength hot rolled steel sheet containing 0.15% or less C, 0.02 to 0.35% Ti, and 0.05 to 0.7% Mo by weight percentage and consisting essentially of a matrix of ferrite structure single phase and fine precipitates with a grain size of smaller than 10 nm dispersed in the matrix, for example, a high strength hot rolled steel sheet which consists essentially of 0.06% or less C, 0.5% or less Si, 0.5 to 2.0% Mn, 0.06% or less P, 0.005% or less S, 0.1% or less Al, 0.006% or less N, 0.02 to 0.10% Ti, 0.05 to 0.6% Mo by weight percentage, and the balance being Fe, wherein fine precipitates with a grain size of smaller than 10 nm are dispersed in a matrix of ferrite structure single phase at a number per unit volume of 5×104/&mgr;m3 or higher. This steel sheet, which has tensile strength of not lower than 550 MPa, high elongation and excellent stretch flangeability, is suitable for intricately shaped automotive chassis parts such as a suspension arm.Type: GrantFiled: March 28, 2002Date of Patent: December 23, 2003Assignee: NKK CorporationInventors: Yoshimasa Funakawa, Tsuyoshi Shiozaki, Kunikazu Tomita, Takanobu Saito, Hiroshi Nakata, Kaoru Sato, Minoru Suwa, Tetsuo Yamamoto, Yasuhiro Murao, Eiji Maeda
-
Publication number: 20030180174Abstract: The present invention provides a high-strength steel pipe of API X65 grade or higher consisting essentially of, by mass %, 0.02 to 0.08% of C, 0.01 to 0.5% of Si, 0.5 to 1.8% of Mn, 0.01% or less of P, 0.002% or less of S, 0.01 to 0.07% of Al, 0.005 to 0.04% of Ti, 0.05 to 0.50% Mo, at least one element selected from 0.005 to 0.05% of Nb and 0.005 to 0.10% of V, and the balance being Fe, in which the volume percentage of ferritic phase is 90% or higher, and complex carbides containing Ti, Mo, and at least one element selected from Nb and V are precipitated in the ferritic phase. The high-strength steel pipe in accordance with the present invention has excellent HIC resistance and good toughness of heat-affected zone, and can be manufactured stably at a low cost.Type: ApplicationFiled: March 10, 2003Publication date: September 25, 2003Applicant: JFE STEEL CORPORATIONInventors: Nobuyuki Ishikawa, Toyohisa Shinmiya, Shigeru Endo, Minoru Suwa
-
Publication number: 20030063996Abstract: The present invention relates to a high strength hot rolled steel sheet containing 0.15% or less C, 0.02 to 0.35% Ti, and 0.05 to 0.7% Mo by weight percentage and consisting essentially of a matrix of ferrite structure single phase and fine precipitates with a grain size of smaller than 10 nm dispersed in the matrix, for example, a high strength hot rolled steel sheet which consists essentially of 0.06% or less C, 0.5% or less Si, 0.5 to 2.0% Mn, 0.06% or less P, 0.005% or less S, 0.1% or less Al, 0.006% or less N, 0.02 to 0.10% Ti, 0.05 to 0.6% Mo by weight percentage, and the balance being Fe, wherein fine precipitates with a grain size of smaller than 10 nm are dispersed in a matrix of ferrite structure single phase at a number per unit volume of 5×104/&mgr;m3 or higher. This steel sheet, which has tensile strength of not lower than 550 MPa, high elongation and excellent stretch flangeability, is suitable for intricately shaped automotive chassis parts such as a suspension arm.Type: ApplicationFiled: March 28, 2002Publication date: April 3, 2003Applicant: NKK CORPORATIONInventors: Yoshimasa Funakawa, Tsuyoshi Shiozaki, Kunikazu Tomita, Takanobu Saito, Hiroshi Nakata, Kaoru Sato, Minoru Suwa, Tetsuo Yawamoto, Yasuhiro Murao, Eiji Maeda