Patents by Inventor Taizo Makino
Taizo Makino 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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Publication number: 20240093324Abstract: A steel pipe for pressure piping subjected to autofrettage has an average hardness at its outer layer region of 1.20 times or more of an average hardness at its inner layer region. When an outer diameter is D, and an inner diameter is d, a measured value of a residual stress at an outer surface is denoted by ?o1, a measured value of a residual stress at an outer surface after halving is denoted by ?o2, and a measured value of a residual stress at an inner surface after the halving is denoted by ?i2, an estimated value ?i1 of a residual stress at the inner surface of the steel pipe is determined by [?i1=(??i2)/(A×(t/T)2?1)], [t/T=((?o2??o1)/(A×(?o2??o1)?C×?i2))1/2], [A=3.9829× exp(0.1071×(D/d)2)], and [C=?3.3966×exp(0.0452×(D/d)2)] is ?150 MPa or less.Type: ApplicationFiled: January 7, 2022Publication date: March 21, 2024Inventors: Taizo MAKINO, Masahiro YAMAZAKI
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Publication number: 20230271635Abstract: The railway axle according to this disclosure has a pair of fitting portions and which each include a fitting portion hardened layer and a base metal portion, and a center parallel portion which includes a center parallel portion hardened layer and the base metal portion. The base metal portion has the chemical composition described in the description. In a region having the Vickers hardness of 480 HV or more in the center parallel portion hardened layer, a dislocation density p obtained based on a CoK? characteristic X-ray diffraction result is 2.5×1016 m?2 or less, a half-value width B of the (211) diffraction plane is 1.34 degrees or less, and the dislocation density p and the half-value width B of the (211) plane obtained by X-ray diffraction satisfy Formula (1). (?4.8×1016×B+8.5×1016)/??1.Type: ApplicationFiled: September 28, 2021Publication date: August 31, 2023Inventors: Taizo MAKINO, Chihiro KOZUKA, Yuichiro YAMAMOTO, Toshiyuki HATA, Akihito YAMANE
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Publication number: 20230140650Abstract: A steel pipe for pressure piping can be subjected to autofrettage. When an outer diameter of the pipe is D, an inner diameter is d, and a yield stress is ?y, and when a measured value of an outer surface residual stress is ?o1, a measured value of an outer surface residual stress after halving is ?o2, and a measured value of an inner surface residual stress after the halving is ?i2, D/d is 1.2 or more, an estimated value ?i1 of inner surface residual stress is [?i1=(??i2)/(A×(t/T)2?1)], where [t/T=((?o2??o1)/(A×(?o2??o1)?C×?i2))1/2], [A=3.9829×exp(0.1071×(D/d)2)], and [C=?3.3966×Exp(0.0452×(D/d)2)] satisfies [1.1×F×?y??i1?0.8×F×?y], and (F=(0.3×(3?D/d)2?1) when 1.2?D/d?3.0, and F=?1 when D/d>3.0).Type: ApplicationFiled: April 5, 2021Publication date: May 4, 2023Inventors: Taizo MAKINO, Masahiro YAMAZAKI
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Publication number: 20220136469Abstract: A steel pipe for a fuel injection pipe has a chemical composition consisting of, by mass %: C: 0.17 to 0.27%, Si: 0.05 to 0.40%, Mn: 0.30 to 2.00%, P: 0.020% or less, S: 0.0100% or less, O: 0.0040% or less, Ca: 0.0010% or less, Al: 0.005 to 0.060%, N: 0.0020 to 0.0080%, Ti: 0.005 to 0.015%, Nb: 0.015 to 0.045%, Cr: 0 to 1.00%, Mo: 0 to 1.00%, Cu: 0 to 0.50%, Ni: 0 to 0.50%, V: 0 to 0.15%, and the balance: Fe and impurities. The metal micro-structure consists substantially of tempered martensite, or tempered martensite and tempered bainite. The hardness is within the range of 350 to 460 HV1. A lattice spacing of a (211) diffraction plane measured by CoK? characteristic X-ray diffraction is 1.1716 ? or less, and a half-value width of the (211) diffraction plane is 1.200° or less. The number density of cementite having a diameter of 50 nm or more is 20/?m2 or less.Type: ApplicationFiled: February 13, 2020Publication date: May 5, 2022Inventors: Taizo MAKINO, Masahiro YAMAZAKI, Tomohiko OMURA, Yuji ARAI, Osamu ENDO, Naoki SERIZAWA, Tatsuya MASUDA
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Publication number: 20220112572Abstract: A steel pipe for a fuel injection pipe has a chemical composition consisting of, by mass %: C: 0.17 to 0.27%, Si: 0.05 to 0.40%, Mn: 0.30 to 2.00%, P: 0.020% or less, S: 0.0100% or less, O: 0.0040% or less, Ca: 0.0010% or less, Al: 0.005 to 0.060%, N: 0.0020 to 0.0080%, Ti: 0.005 to 0.015%, Nb: 0.015 to 0.045%, Cr: 0 to 1.00%, Mo: 0 to 1.00%, Cu: 0 to 0.50%, Ni: 0 to 0.50%, V: 0 to 0.15%, and the balance: Fe and impurities. The metal micro-structure consists substantially of tempered martensite, or tempered martensite and tempered bainite. A prior-austenite grain size number is 9.0 or more. The hardness is within the range of 350 to 460 HV1. When a maximum value of a square root of an area of inclusions observed in a cross section perpendicular to a longitudinal direction of the steel pipe is taken as an (n=1 to 20), a maximum value amax of an is 30.0 ?m or less, and an average value aav of an is 40% or more of amax.Type: ApplicationFiled: February 13, 2020Publication date: April 14, 2022Inventors: Taizo MAKINO, Masahiro YAMAZAKI, Yuji ARAI, Osamu ENDO, Naoki SERIZAWA, Tatsuya MASUDA
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Patent number: 11203793Abstract: A steel pipe for fuel injection pipe has a tensile strength of 500 to 900 MPa and a yield ratio of 0.50 to 0.85, and has a critical internal pressure (IP) satisfying [IP?0.41×TS×?] (?=[(D/d)2?1]/[0.776×(D/d)2], where TS: tensile strength (MPa) of the steel pipe, D: steel pipe outer diameter (mm), and d: steel pipe inner diameter (mm)), wherein a circumferential-direction residual stress on an inner surface of the pipe is ?20 MPa or lower after the steel pipe is split in half in a pipe axis direction.Type: GrantFiled: May 26, 2016Date of Patent: December 21, 2021Assignees: USUI CO., LTD., NIPPON STEEL CORPORATIONInventors: Tatsuya Masuda, Tsugumi Yamazaki, Hiroaki Kondo, Taizo Makino, Masahiro Yamazaki, Katsunori Nagao
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Patent number: 10392683Abstract: Provided is a rail vehicle axle having an excellent fatigue limit and notch factor. A rail vehicle axle according to the present embodiment has a chemical composition consisting of, in mass %, C: 0.20 to 0.35%, Si: 0.20 to 0.65%, Mn: 0.40 to 1.20%, P: 0.020% or less, S: 0.020% or less, Cu: 0 to 0.30%, Ni: 0 to 0.30%, Cr: 0 to 0.30%, Mo: 0 to 0.08%, Al: 0 to 0.100%, N: 0.0200% or less, V: 0 to 0.060%, and Ti: 0 to 0.020%, with the balance being Fe and impurities, and satisfying Formulae (1) and (2): 0.58?C+Si/8+Mn/5+Cu/10+Cr/4+V?0.67??(1) Si+0.9Cr?0.50??(2) where, each element symbol in Formulae (1) and (2) is substituted by the content (mass %) of a corresponding element.Type: GrantFiled: February 25, 2015Date of Patent: August 27, 2019Assignee: NIPPON STEEL CORPORATIONInventors: Taizo Makino, Yukiteru Takeshita, Naomitsu Mizui, Yutaka Wakasu
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Patent number: 10066281Abstract: An age-hardenable steel having a composition consisting of: C: 0.05 to 0.20%, Si: 0.01 to 0.50%, Mn: 1.5 to 2.5%, S: 0.005 to 0.08%, Cr: more than 0.50% and not more than 1.6%, Al: 0.005 to 0.05%, V: 0.25 to 0.50%, Mo: 0 to 1.0%, Cu: 0 to 0.3%, Ni: 0 to 0.3%, Ca: 0 to 0.005%, and Bi: 0 to 0.4%, the balance being Fe and impurities. Within the impurities, P?0.03%, Ti<0.005%, and N<0.0080%, and [C+0.3Mn+0.25Cr+0.6Mo?0.68], [C+0.1Si+0.2Mn+0.15Cr+0.35V+0.2Mo?1.05], and [?4.5C+Mn+Cr?3.5V?0.8Mo?0.12]. The steel has hardness before aging of not more than 310 HV. After aging, the fatigue strength is not less than 480 MPa and absorbed energy at 20° C. is not less than 12 J.Type: GrantFiled: October 1, 2014Date of Patent: September 4, 2018Assignees: NIPPON STEEL & SUMITOMO METAL CORPORATION, DENSO CORPORATIONInventors: Masashi Higashida, Masato Yuya, Hitoshi Matsumoto, Tatsuya Hasegawa, Yutaka Neishi, Taizo Makino, Kouji Morita, Yoshihiro Tanimura, Toshimasa Ito, Tomomitsu Fukuoka, Tadashi Nishiwaki
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Publication number: 20180245172Abstract: Age hardenable steel is low in hardness after hot forging, providing a machine part with the desired fatigue strength and yield strength by aging treatment, and high in toughness after aging treatment, comprising C: 0.09 to 0.20%, Si: 0.01 to 0.40%, Mn: 1.5 to 2.5%, S: 0.001 to 0.045%, Cr: over 1.00% to 2.00%, Al: 0.001 to 0.060%, V: 0.22 to 0.55%, N: over 0.0080 to 0.0170%, and a balance of Fe and impurities, where an area rate of bainite structures is 80% or more, an effective V ratio (amount of dissolved V/total amount of V) is 0.9 or more, a P and Ti in the impurities is P: 0.03% or less and Ti: less than 0.005%, and the chemical composition is one where the following F1 is 1.00 or less and the F2 is 0.30 or more: F1=C+0.1×Si+0.2×Mn+0.15×Cr+0.35×V F2=?4.5×C+Mn+Cr?3.Type: ApplicationFiled: March 16, 2016Publication date: August 30, 2018Applicants: Nippon Steel & Sumitomo Metal Corporation, Denso CorporationInventors: Masato YUYA, Motoki TAKASUGA, Taizo MAKINO, Masashi HIGASHIDA, Tatsuya HASEGAWA, Kouji MORITA, Toshimasa ITO, Tomomitsu FUKUOKA, Tadashi NISHIWAKI, Yoshihiro TANIMURA
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Publication number: 20180245189Abstract: Provided is a rail vehicle axle having an excellent fatigue limit and notch factor. A rail vehicle axle according to the present embodiment has a chemical composition consisting of, in mass %, C: 0.20 to 0.35%, Si: 0.20 to 0.65%, Mn: 0.40 to 1.20%, P: 0.020% or less, S: 0.020% or less, Sn: 0.07 to 0.40%, N: 0.0200% or less, Cu: 0 to 0.30%, Ni: 0 to 0.30%, Cr: 0 to 0.30%, Mo: 0 to 0.08%, Al: 0 to 0.100%, V: 0 to 0.060%, and Ti: 0 to 0.020%, with the balance being Fe and impurities, and satisfying Formulae (1) and (2): 0.58?C+Si/8+Mn/5+Cu/10+Cr/4+V?0.67??(1) Si+0.9Cr?0.50??(2) where, each element symbol in Formulae (1) and (2) is substituted by the content (mass %) of a corresponding element.Type: ApplicationFiled: August 17, 2016Publication date: August 30, 2018Applicant: Nippon Steel & Sumitomo Metal CorporationInventors: Taizo MAKINO, Takayuki KAMIMURA, Yuichiro YAMAMOTO, Yutaka WAKASU, Kiyonobu SUGAE, Yukiteru TAKESHITA, Naomitsu MIZUI
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Publication number: 20180171426Abstract: A steel pipe for fuel injection pipe has a tensile strength of 500 to 900 MPa and a yield ratio of 0.50 to 0.85, and has a critical internal pressure (IP) satisfying [IP?0.41×TS×?] (?=[(D/d)2?1]/[0.776×(D/d)2], where TS: tensile strength (MPa) of the steel pipe, D: steel pipe outer diameter (mm), and d: steel pipe inner diameter (mm)), wherein a circumferential-direction residual stress on an inner surface of the pipe is ?20 MPa or lower after the steel pipe is split in half in a pipe axis direction.Type: ApplicationFiled: May 26, 2016Publication date: June 21, 2018Inventors: Tatsuya MASUDA, Tsugumi YAMAZAKI, Hiroaki KONDO, Taizo MAKINO, Masahiro YAMAZAKI, Katsunori NAGAO
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Patent number: 9994943Abstract: Rolled steel bar for hot forging consisting, by mass percent, of C: 0.25-0.50%, Si: 0.40-1.0%, Mn: 1.0-1.6%, S: 0.005-0.035%, Al: 0.005-0.050%, V: 0.10-0.30%, N: 0.005-0.030% with the balance being Fe and impurities, i.e., P: 0.035% or less and O: 0.0030% or less, wherein Fn1=C+Si/10+Mn/5+5Cr/22+1.65V?5S/7 is 0.90 to 1.20. The predicted maximum width of nonmetallic inclusions at the time when a cumulative distribution function obtained by extreme value statistical processing by taking the width of nonmetallic inclusion in an R1/2 part of a longitudinal cross section of the steel bar as W (mm) is 99.99% is 100 ?m or narrower. The number density of sulfides each having a circle-equivalent diameter of 0.3 to 1.0 ?m observed per unit area of the R1/2 part of a transverse cross section of the steel bar is 500 pieces/mm2 or higher.Type: GrantFiled: July 11, 2017Date of Patent: June 12, 2018Assignees: NIPPON STEEL & SUMITOMO METAL CORPORATION, DENSO CORPORATIONInventors: Naoki Matsui, Masashi Higashida, Hitoshi Matsumoto, Yutaka Neishi, Taizo Makino, Kouji Morita, Yoshihiro Tanimura, Naoyuki Sashima, Toshimasa Itou
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Patent number: 9951403Abstract: A rolled steel bar for hot forging consisting, by mass percent, of C: 0.25-0.50%, Si: 0.40-1.0%, Mn: 1.0-1.6%, S: 0.005-0.035%, Al: 0.005-0.050%, V: 0.10-0.30%, and N: 0.005-0.030%, and the balance of Fe and impurities, i.e., P: 0.035% or less and O: 0.0030% or less, wherein Fn1=C+Si/10+Mn/5+5Cr/22+1.65V?5S/7 is 0.90 to 1.20. The predicted maximum width of nonmetallic inclusions at the time when a cumulative distribution function obtained by extreme value statistical processing by taking the width of nonmetallic inclusion in an R1/2 part of a longitudinal cross section of the steel bar as W (?m) is 99.99% is 100 ?m or narrower. The number density of sulfides each having a circle-equivalent diameter of 0.3 to 1.0 ?m observed per unit area of the R1/2 part of a transverse cross section of the steel bar is 500 pieces/mm2 or higher.Type: GrantFiled: February 5, 2013Date of Patent: April 24, 2018Assignees: NIPPON STEEL & SUMITOMO METAL CORPORATION, DENSO CORPORATIONInventors: Naoki Matsui, Masashi Higashida, Hitoshi Matsumoto, Yutaka Neishi, Taizo Makino, Kouji Morita, Yoshihiro Tanimura, Naoyuki Sashima, Toshimasa Itou
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Publication number: 20180057917Abstract: A rolled steel bar for hot forging consisting, by mass percent, of C: 0.25-0.50%, Si: 0.40-1.0%, Mn: 1.0-1.6%, S: 0.005-0.035%, Al: 0.005-0.050%, V: 0.10-0.30%, and N: 0.005-0.030%, and the balance of Fe and impurities, i.e., P: 0.035% or less and O: 0.0030% or less, wherein Fn1=C+Si/10+Mn/5+5Cr/22+1.65V?5S/7 is 0.90 to 1.20. The predicted maximum width of nonmetallic inclusions at the time when a cumulative distribution function obtained by extreme value statistical processing by taking the width of nonmetallic inclusion in an R1/2 part of a longitudinal cross section of the steel bar as W (mm) is 99.99% is 100 mm or narrower. The number density of sulfides each having a circle-equivalent diameter of 0.3 to 1.0 mm observed per unit area of the R1/2 part of a transverse cross section of the steel bar is 500 pieces/mm2 or higher.Type: ApplicationFiled: July 11, 2017Publication date: March 1, 2018Inventors: Naoki MATSUI, Masashi HIGASHIDA, Hitoshi MATSUMOTO, Yutaka NEISHI, Taizo MAKINO, Kouji MORITA, Yoshihiro TANIMURA, Naoyuki SASHIMA, Toshimasa ITOU
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Publication number: 20180044757Abstract: Age hardening steel excellent in machinability before aging treatment and excellent in fatigue characteristics, toughness, and low cycle fatigue characteristics after aging treatment, that is, age hardening steel containing predetermined amounts of C, Si, Mn, S, Cr, Al, V, Nb, Ca, and REM, limiting contents of P, Ti, and N to predetermined amounts or less, having a balance of Fe and impurities, having an area ratio of bainite structures of 70% or more, and, furthermore, having a chemical composition where F1 expressed by C+0.3×Mn+0.25×Cr is 0.68 or more, F2 expressed by C+0.1×Si+0.2×Mn+0.15×Cr+0.35×V is 0.85 or less, F3 expressed by ?4.5×C+Mn+Cr?3.5×V is 0.00 or more, and F4 expressed by 10×Ca+REM is 0.012 to 0.08, is provided. Note that, the symbols of elements in the formulas showing F1 to F4 mean the contents by mass % of those elements.Type: ApplicationFiled: March 17, 2016Publication date: February 15, 2018Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Yutaka NEISHI, Masato YUYA, Tatsuya HASEGAWA, Motoki TAKASUGA, Masashi HIGASHIDA, Hitoshi MATSUMOTO, Taizo MAKINO
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Patent number: 9574255Abstract: A rolled steel bar has a composition consisting, by mass percent, of C: 0.27 to 0.37%, Si: 0.30 to 0.75%, Mn: 1.00 to 1.45%, S: 0.008% or more and less than 0.030%, Cr: 0.05 to 0.30%, Al: 0.005 to 0.050%, V: 0.200 to 0.320%, and N: 0.0080 to 0.0200%, the balance being Fe and impurities. The contents of P, Ti and O in the impurities are, by mass percent, P: 0.030% or less, Ti: 0.0040% or less, and O: 0.0020% or less. Y1 expressed by the formula <1> is 1.05 to 1.18. Y1=C+(1/10)Si+(1/5)Mn+(5/22)Cr+1.65V?(5/7)S??<1>. C, Si, Mn, Cr, V, and S in the formula represent mass percent of the elements. A hot-forged part having a tensile strength of 900 MPa or higher and a transverse endurance ratio of 0.47 can be obtained by the rolled steel bar.Type: GrantFiled: November 7, 2012Date of Patent: February 21, 2017Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masashi Higashida, Hitoshi Matsumoto, Naoki Matsui, Yutaka Neishi, Taizo Makino
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Publication number: 20160369759Abstract: A steel pipe has a composition consisting, by mass percent, of, C: 0.12 to 0.27%, Si: 0.05 to 0.40%, Mn: 0.3 to 2.0%, Al: 0.005 to 0.060%, N: 0.0020 to 0.0080%, Ti: 0.005 to 0.015%, Nb: 0.015 to 0.045%, Cr 0 to 1.0%, Mo: 0 to 1.0%, Cu: 0 to 0.5%, Ni: 0 to 0.5%, V: 0 to 0.15%, and B: 0 to 0.005%, the balance being Fe and impurities. As impurities, contents are Ca: 0.001% or less, P: 0.02% or less, S: 0.01% or less, and O: 0.0040% or less. The micro-structure is tempered martensitic or tempered martensite and tempered bainite, in which a prior-austenite grain size number is 10.0 or more. Tensile strength is TS 800 MPa or higher. Critical internal pressure is [0.3·TS·a] or more, a=[(D/d)2?1]/[0.776 ·(D/d)2], D: pipe outer diameter (mm), d: pipe inner diameter (mm).Type: ApplicationFiled: February 23, 2015Publication date: December 22, 2016Inventors: Tatsuya MASUDA, Tsugumi YAMAZAKI, Taizo MAKINO, Katsunori NAGAO, Tsutomu OKUYAMA
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Publication number: 20160355910Abstract: Provided is a rail vehicle axle having an excellent fatigue limit and notch factor. A rail vehicle axle according to the present embodiment has a chemical composition consisting of, in mass %, C: 0.20 to 0.35%, Si: 0.20 to 0.65%, Mn: 0.40 to 1.20%, P: 0.020% or less, S: 0.020% or less, Cu: 0 to 0.30%, Ni: 0 to 0.30%, Cr: 0 to 0.30%, Mo: 0 to 0.08%, Al: 0 to 0.100%, N: 0.0200% or less, V: 0 to 0.060%, and Ti: 0 to 0.020%, with the balance being Fe and impurities, and satisfying Formulae (1) and (2): 0.58?C+Si/8+Mn/5+Cu/10+Cr/4+V?0.67??(1) Si+0.9Cr?0.50??(2) where, each element symbol in Formulae (1) and (2) is substituted by the content (mass %) of a corresponding element.Type: ApplicationFiled: February 25, 2015Publication date: December 8, 2016Inventors: Taizo MAKINO, Yukitru TAKESHITA, Naomitsu MIZUI, Yutaka WAKASU
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Publication number: 20160265092Abstract: An age-hardenable steel having a composition consisting of: C: 0.05 to 0.20%, Si: 0.01 to 0.50%, Mn: 1.5 to 2.5%, S: 0.005 to 0.08%, Cr: more than 0.50% and not more than 1.6%, Al: 0.005 to 0.05%, V: 0.25 to 0.50%, Mo: 0 to 1.0%, Cu: 0 to 0.3%, Ni: 0 to 0.3%, Ca: 0 to 0.005%, and Bi: 0 to 0.4%, the balance being Fe and impurities. Within the impurities, P?0.03%, Ti<0.005%, and N<0.0080%, and [C+0.3Mn+0.25Cr+0.6Mo?0.68], [C+0.1Si+0.2Mn+0.15Cr+0.35V+0.2Mo?1.05], and [?4.5C+Mn+Cr?3.5V?0.8Mo?0.12]. The steel has hardness before aging of not more than 310 HV. After aging, the fatigue strength is not less than 480 MPa and absorbed energy at 20° C. is not less than 12 J.Type: ApplicationFiled: October 1, 2014Publication date: September 15, 2016Inventors: Masashi HIGASHIDA, Masato YUYA, Hitoshi MATSUMOTO, Tatsuya HASEGAWA, Yutaka NEISHI, Taizo MAKINO
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Publication number: 20160201175Abstract: An age-hardenable steel consists of: C: 0.05 to 0.20%, Si: 0.01 to 0.50%, Mn: 1.5 to 2.5%, S: 0.005 to 0.08%, Cr: 0.03 to 0.50%, Al: 0.005 to 0.05%, V: 0.25 to 0.50%, Mo: 0 to 1.0%, Cu: 0 to 0.3%, Ni: 0 to 0.3%, Ca: 0 to 0.005%, and Bi: 0 to 0.4%, the balance being Fe and impurities. Within impurities, P £ 0.03%, Ti<0.005%, and N<0.0080%, and [C+0.3Mn+0.25Cr+0.6Mo3 0.68], [C+0.1Si+0.2Mn+0.15Cr+0.35V+0.2Mo £ 0.85], and [?4.5C+Mn+Cr?3.5V?0.8Mo3 0.00]. The hardness before aging is not more than 290 HV, a quantity of hardening by aging being not less than 25 HV, fatigue strength is not less than 350 MPa, and absorbed energy at 20° C. after aging is not less than 16 J.Type: ApplicationFiled: October 1, 2014Publication date: July 14, 2016Inventors: Masato YUYA, Masashi HIGASHIDA, Hitoshi MATSUMOTO, Tatsuya HASEGAWA, Yutaka NEISHI, Taizo MAKINO