Patents by Inventor Mitsuru Yoshizawa
Mitsuru Yoshizawa 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: 20240318289Abstract: Provided is a heat-resistant ferritic steel having a chemical composition containing, by mass %, C: 0.07 to 0.14%, Si: 0.15 to 0.35%, Mn: 0.30 to 0.55%, P: 0.0250% or less, S: 0.0030% or less, Ni: 0.15 to 0.35%, Cr: 8.0 to 9.7%, Mo: 0.20 to 0.60%, W: 1.50 to 2.30%, V: 0.16 to 0.25%, Nb: 0.020 to 0.120%, B: 0.0010 to 0.0050%, N: 0.010 to 0.080%, Al: 0.020% or less, and O: 0.020% or less, with the balance Fe and impurities, wherein VER, i.e., the V content (mass %) in precipitates obtained by extracted residue analysis satisfies [?0.2×C+0.060?VER??0.1×C+0.160].Type: ApplicationFiled: July 14, 2021Publication date: September 26, 2024Applicant: NIPPON STEEL CORPORATIONInventors: Hiroyuki HIRATA, Katsuki TANAKA, Masayuki TAKIGUCHI, Mitsuru YOSHIZAWA, Junichi HIGUCHI, Takahiro OSUKI
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Patent number: 12054818Abstract: There is provided a duplex stainless steel tube including a chemical composition consisting of, in mass %, C: 0.008 to 0.030%, Si: 0.10 to 0.70%, Mn: 0.80 to 2.60%, P: 0.030% or less, S: 0.0001 to 0.0050%, O: 0.0004 to 0.0150%, Sn: 0.0001% or more to less than 0.0100%, Cu: 0.10 to 2.50%, Ni: more than 2.50 to 5.50% or less, Cr: 21.5 to 25.5%, Mo: 0.10 to 0.50%, N: 0.050 to 0.200%, Al: 0.200% or less, and optional elements, with the balance: Fe and impurities, wherein 4S+8O+Sn is 0.0040 to 0.0900, and 4S+Sn is 0.0180 or less.Type: GrantFiled: June 23, 2021Date of Patent: August 6, 2024Assignee: NIPPON STEEL CORPORATIONInventors: Hiroyuki Hirata, Shohgo Aota, Mitsuru Yoshizawa, Takahiro Osuki
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Publication number: 20240240295Abstract: A composite tube is provided that includes a first tube and a second tube. A chemical composition of the first tube includes, in mass %, C: more than 0.060% to 0.400% or less, Si: 0.01 to 1.00%, Mn: 0.01 to 1.20%, P: 0.0350% or less, S: 0.0150% or less, Sn: 0.0005 to 0.0400%, Al: 0.040% or less, N: 0.050% or less, O: 0.030% or less, and the balance: Fe and impurities. A chemical composition of the second tube includes, in mass %, C: 0.003 to 0.100%, Si: 0.01 to 1.50%, Mn: 0.01 to 2.20%, P: 0.0400% or less, S: 0.0100% or less, Sn: 0.0005 to 0.0300%, Ni: 7.0 to 52.0%, Cr: 15.0 to 27.0%, Al: 0.001 to 0.600%, N: 0.001 to 0.150%, O: 0.030% or less, and the balance: Fe and impurities. The composite tube satisfies formulas [Siave+6×Pave+20×Save+2×Snave?1.1000] and [0.0015?4×Save+Snave].Type: ApplicationFiled: August 6, 2021Publication date: July 18, 2024Inventors: Hiroyuki HIRATA, Mitsuru YOSHIZAWA, Katsuki TANAKA, Takahiro OSUKI
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Publication number: 20230220508Abstract: A method for producing an austenitic heat resistant steel in which a difference between a content of Nb and an amount of Nb analyzed as extraction residues satisfies [0.170?Nb?NbER?0.480], the method including: a forming step of machining and forming a steel having a predetermined chemical composition into a product shape; a solution heat treatment step of performing, after the forming step, heat treatment under conditions including a heat treatment temperature satisfying [?250Nb+1200?T??100Nb+1290] and a soaking time satisfying [405?0.3T?t?2475?1.5T]; and a cooling step of performing cooling after the solution heat treatment step.Type: ApplicationFiled: April 21, 2021Publication date: July 13, 2023Inventors: Hiroyuki HIRATA, Masahiro SETO, Mitsuru YOSHIZAWA, Junichi HIGUCHI, Takahiro OSUKI
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Publication number: 20230212724Abstract: There is provided a duplex stainless steel tube including a chemical composition consisting of, in mass %, C: 0.008 to 0.030%, Si: 0.10 to 0.70%, Mn: 0.80 to 2.60%, P: 0.030% or less, S: 0.0001 to 0.0050%, O: 0.0004 to 0.0150%, Sn: 0.0001% or more to less than 0.0100%, Cu: 0.10 to 2.50%, Ni: more than 2.50 to 5.50% or less, Cr: 21.5 to 25.5%, Mo: 0.10 to 0.50%, N: 0.050 to 0.200%, Al: 0.200% or less, and optional elements, with the balance: Fe and impurities, wherein 4S+8O+Sn is 0.0040 to 0.0900, and 4S+Sn is 0.0180 or less.Type: ApplicationFiled: June 23, 2021Publication date: July 6, 2023Inventors: Hiroyuki HIRATA, Shohgo AOTA, Mitsuru YOSHIZAWA, Takahiro OSUKI
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Publication number: 20230203629Abstract: There is provided an austenitic heat resistant steel including a chemical composition that consists of, in mass %, C: 0.04 to 0.12%, Si: 0.01 to 0.30%, Mn: 0.50 to 1.50%, P: 0.001 to 0.040%, S: less than 0.0050%, Cu: 2.2 to 3.8%, Ni: 8.0 to 11.0%, Cr: 17.7 to 19.3%, Mo: 0.01 to 0.55%, Nb: 0.400 to 0.650%, B: 0.0010 to 0.0060%, N: 0.050 to 0.160%, Al: 0.025% or less, and O: 0.020% or less, with the balance: Fe and impurities and that satisfies [0.170?Nb?NbER?0.480].Type: ApplicationFiled: April 21, 2021Publication date: June 29, 2023Inventors: Masahiro SETO, Hiroyuki HIRATA, Mitsuru YOSHIZAWA, Junichi HIGUCHI, Takahiro OSUKI
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Publication number: 20220325394Abstract: An austenitic heat resisting steel includes, as a chemical composition, by mass %: C: 0.04% to 0.12%; Si: 0.10% to 0.30%; Mn: 0.20% to 0.80%; P: 0% to 0.030%; S: 0.0001% to 0.0020%: Sn: 0.0005% to 0.0230%; Cu: 2.3% to 3.8%; Co: 0.90% to 2.40%; Ni: 22.0% to 28.0%; Cr: 20.0% to 25.0%; Mo: 0.01% to 0.40%; W: 2.8% to 4.2%; Nb: 0.20% to 0.80%; B: 0.0010% to 0.0050%; and N: 0.16% to 0.30%, and a remainder of Fe and impurities, optionally further includes one or more selected from Al, O, V, Ti, Ta, C, Mg, and REM, in which 0.0012%?[% S]+[% Sn]?2.5×[% B]+0.0125% is satisfied.Type: ApplicationFiled: July 30, 2020Publication date: October 13, 2022Applicant: NIPPON STEEL CORPORATIONInventors: Hiroyuki HIRATA, Mitsuru YOSHIZAWA, Junichi HIGUCHI, Katsuki TANAKA
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Publication number: 20220235445Abstract: A ferritic heat-resistant steel includes, by mass: from 0.06 to 0.11% of C; from 0.15 to 0.35% of Si; from 0.35 to 0.65% of Mn; from 0 to 0.02% of P; from 0 to 0.003% of S; from 0.005 to 0.25% of Ni; from 0.005 to 0.25% of Cu; from 2.7 to 3.3% of Co; from 8.3 to 9.7% of Cr; from 2.5 to 3.5% of W; from 0.15 to 0.25% of V; from 0.03 to 0.08% of Nb; from 0.002 to 0.04% of Ta; from 0.01 to 0.06% of Nd; from 0.006 to 0.016% of B; from 0.005 to 0.015% of N; from 0 to 0.02% of Al; and from 0 to 0.02% of O, with a balance consisting of Fe and impurities, and an amount of W, which is analyzed as an electrolytically extracted residue, [% W]ER, satisfying: ?10×[% B]+0.26?[% W]ER?10×[% B]+0.54.Type: ApplicationFiled: March 19, 2020Publication date: July 28, 2022Inventors: Hiroyuki HIRATA, Mitsuru YOSHIZAWA, Junichi HIGUCHI, Katsuki TANAKA
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Publication number: 20200232081Abstract: Provided is an austenitic heat resistant alloy having a chemical composition consisting of, in mass %: C: 0.02 to 0.12%; Si: 2.0% or less; Mn: 3.0% or less; P: 0.030% or less; S: 0.015% or less; Cr: 20.0% or more and less than 28.0%; Ni: more than 35.0% and 55.0% or less; Co: 0 to 20.0%; W: 4.0 to 10.0%; Ti: 0.01 to 0.50%; Nb: 0.01 to 1.0%; Mo: less than 0.50%; Cu: less than 0.50%; Al: 0.30% or less; N: less than 0.10%; Mg: 0 to 0.05%; Ca: 0 to 0.05%; REM: 0 to 0.50%; V: 0 to 1.5%; B: 0 to 0.01%; Zr: 0 to 0.10%; Hf: 0 to 1.0%; Ta: 0 to 8.0%; Re: 0 to 8.0%; and the balance: Fe and impurities, wherein a shortest distance from a center portion to an outer surface portion of a cross section of the alloy is 40 mm or more, the cross section being perpendicular to a longitudinal direction of the alloy, an austenite grain size number at the outer surface portion is ?2.0 to 4.0, an amount of Cr which is present as a precipitate satisfies [CrPB/CrPS?10.0], and [YSS/YSB?1.5] and [TSS/TSB?1.Type: ApplicationFiled: February 9, 2017Publication date: July 23, 2020Inventors: Hiroyuki Semba, Hirokazu Okada, Mitsuru Yoshizawa, Toshihide Ono
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Patent number: 9328403Abstract: A Ni-based heat resistant alloy as pipe, plate, rod, forgings and the like consists of C?0.15%, Si?2%, Mn?3%, P?0.03%, S?0.01%, Cr: 15% or more and less than 28%, Mo: 3 to 15%, Co: more than 5% and not more than 25%, Al: 0.2 to 2%, Ti: 0.2% to 3%, Nd: fn to 0.08%, and O?0.4Nd, further containing, as necessary, at least one kind of Nb, W, B, Zr, Hf, Mg, Ca, Y, La, Ce, Ta, Re and Fe of specific amounts, the balance being Ni and impurities, wherein, fn=1.7×10?5d+0.05{(Al/26.98)+(Ti/47.88)+(Nb/92.91)}. In the formula, d denotes an average grain size (?m), and each element symbol denotes the content (mass %) of that element. If the alloy contains W, Mo+(W/2)?15% holds. The alloy has improved ductility after long-term use at high temperatures, and cracking due to welding can be avoided.Type: GrantFiled: July 31, 2012Date of Patent: May 3, 2016Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Hiroyuki Semba, Hirokazu Okada, Hiroyuki Hirata, Mitsuru Yoshizawa, Atsuro Iseda
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Patent number: 8852362Abstract: There is provided an austenitic stainless steel pipe excellent in steam oxidation resistance. The austenitic stainless steel pipe excellent in steam oxidation resistance contains, by mass percent, 14 to 28% of Cr and 6 to 30% of Ni, and is configured so that a region satisfying the following Formula exists in a metal structure at a depth of 5 to 20 ?m from the inner surface of the steel pipe: (?/?)×?/?×100?0.3 where the meanings of symbols in the above Formula are as follows: ?: sum total of the number of pixels of digital image in region in which orientation difference of adjacent crystals detected by electron backscattering pattern is 5 to 50 degrees ?: the number of total pixels of digital image in region of measurement using electron backscattering pattern ?: analysis pitch width of electron backscattering pattern (?m) ?: grain boundary width (?m).Type: GrantFiled: June 1, 2012Date of Patent: October 7, 2014Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Yoshitaka Nishiyama, Mitsuru Yoshizawa, Masahiro Seto, Katsuki Tanaka
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Publication number: 20140234155Abstract: A Ni-based heat resistant alloy as pipe, plate, rod, forgings and the like consists of C?0.15%, Si?2%, Mn?3%, P?0.03%, S?0.01%, Cr: 15% or more and less than 28%, Mo: 3 to 15%, Co: more than 5% and not more than 25%, Al: 0.2 to 2%, Ti: 0.2% to 3%, Nd: fn to 0.08%, and O?0.4Nd, further containing, as necessary, at least one kind of Nb, W, B, Zr, Hf, Mg, Ca, Y, La, Ce, Ta, Re and Fe of specific amounts, the balance being Ni and impurities, wherein, fn=1.7×10?5d+0.05{(Al/26.98)+(Ti/47.88)+(Nb/92.91)}. In the formula, d denotes an average grain size (?m), and each element symbol denotes the content (mass %) of that element. If the alloy contains W, Mo+(W/2)?15% holds. The alloy has improved ductility after long-term use at high temperatures, and cracking due to welding can be avoided.Type: ApplicationFiled: July 31, 2012Publication date: August 21, 2014Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Hiroyuki Semba, Hirokazu Okada, Hiroyuki Hirata, Mitsuru Yoshizawa, Atsuro Iseda
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Patent number: 8808473Abstract: An austenitic heat resistant alloy includes, by mass percent, C: 0.15% or less, Si: 2% or less, Mn: 3% or less, Ni: 40 to 60%, Co: 10.14 to 25%, Cr: 15% or more and less than 28%, either one or both of Mo: 12% or less and W: less than 0.05%, the total content thereof being 0.1 to 12%, Nd: 0.001 to 0.1%, B: 0.0005 to 0.006%, N: 0.03% or less, O: 0.03% or less, at least one selected from Al: 1.36% or less, Ti: 3% or less, and Nb: 3% or less, and the balance being Fe and impurities. The contents of P and S in the impurities are P: 0.03% or less and S: 0.01% or less. The alloy satisfies 1?4×Al+2×Ti+Nb?12 and P+0.2×Cr×B?0.035, where an element in the Formulas represents the content by mass percent.Type: GrantFiled: May 16, 2012Date of Patent: August 19, 2014Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Hiroyuki Hirata, Hirokazu Okada, Hiroyuki Semba, Kazuhiro Ogawa, Atsuro Iseda, Mitsuru Yoshizawa
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Publication number: 20130130058Abstract: To provide an austenitic stainless steel which has an excellent high-temperature corrosion thermal fatigue cracking resistance. An austenitic stainless steel containing, by mass %, Cr: 15.0 to 23.0%, and Ni: 6.0 to 20.0%, wherein a near-surface portion is covered with a worked layer with high energy density having an average thickness of 5 to 30 ?m.Type: ApplicationFiled: March 26, 2012Publication date: May 23, 2013Applicant: SUMITOMO METAL INDUSTRIES, LTD.Inventors: Atsuro ISEDA, Yoshitaka Nishiyama, Masahiro Seto, Satomi Yamamoto, Hiroyuki Hirata, Yasutaka Noguchi, Mitsuru Yoshizawa, Hiroshi Matsuo
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Publication number: 20120288400Abstract: An austenitic heat resistant alloy consisting of, by mass percent, C: 0.15% or less, Si: 2% or less, Mn: 3% or less, Ni: 40 to 60%, Co: 0.03 to 25%, Cr: 15% or more and less than 28%, either one or both of Mo: 12% or less and W: less than 4%, the total content thereof being 0.1 to 12%, Nd: 0.001 to 0.1%, B: 0.0005 to 0.006%, N: 0.03% or less, O: 0.03% or less, at least one selected from Al: 3% or less, Ti: 3% or less, and Nb: 3% or less, the balance being Fe and impurities. The contents of P and S in the impurities being P: 0.03% or less and S: 0.01% or less. The alloy satisfies 1?4×Al+2×Ti+Nb?12 and P+0.2×Cr×B?0.035, is excellent in weld crack resistance and toughness of HAZ, and is further excellent in creep strength at high temperatures.Type: ApplicationFiled: May 16, 2012Publication date: November 15, 2012Applicant: SUMITOMO METAL INDUSTRIES., LTD.Inventors: Hiroyuki Hirata, Hirokazu Okada, Hiroyuki Semba, Kazuhiro Ogawa, Atsuro Iseda, Mitsuru Yoshizawa
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Publication number: 20120279607Abstract: There is provided an austenitic stainless steel pipe excellent in steam oxidation resistance. The austenitic stainless steel pipe excellent in steam oxidation resistance contains, by mass percent, 14 to 28% of Cr and 6 to 30% of Ni, and is configured so that a region satisfying the following Formula exists in a metal structure at a depth of 5 to 20 ?m from the inner surface of the steel pipe: (?/?)×?/?×100?0.3 where the meanings of symbols in the above Formula are as follows: ?: sum total of the number of pixels of digital image in region in which orientation difference of adjacent crystals detected by electron backscattering pattern is 5 to 50 degrees ?: the number of total pixels of digital image in region of measurement using electron backscattering pattern ?: analysis pitch width of electron backscattering pattern (?m) ?: grain boundary width (?m).Type: ApplicationFiled: June 1, 2012Publication date: November 8, 2012Applicant: SUMITOMO METAL INDUSTRIES, LTD.Inventors: Yoshitaka NISHIYAMA, Mitsuru YOSHIZAWA, Masahiro SETO, Katsuki TANAKA
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Patent number: 8065901Abstract: A method for surface treating a mandrel bar used for hot rolling of high-alloy seamless steel pipe is provided. The method includes heat treating the mandrel bar to develop a scale, and after heat treatment, rolling ordinary steel comprising 8% or less of chromium for at least 50 passes. This achieves a mandrel bar for rolling high-alloy steel possessing both durability and superior resistance to seizure.Type: GrantFiled: September 24, 2008Date of Patent: November 29, 2011Assignee: Sumitomo Metal Industries, Ltd.Inventors: Sumio Iida, Yasuyoshi Hidaka, Mitsuru Yoshizawa, Koji Nakaike
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Publication number: 20100086430Abstract: There is provided a heat resistant ferritic steel, excellent in the weld crack resistance of the HAZ and creep strength. A high-Cr heat resistant ferritic steel is characterized by consisting of, by mass %, Si: more than 0.1% and not more than 1.0%, Mn: 2.0% or less, Co: 1 to 8%, Cr: 7 to 13%, V: 0.05 to 0.4%, Nb: 0.01 to 0.09%, either one or both of Mo and W: 0.5 to 4% as a total, B: 0.005 to 0.025%, Al: 0.03% or less, and N: 0.003 to 0.06%, and containing C in an amount satisfying Expression (1), the balance being Fe and impurities, and O, P and S as impurities being such that O: 0.02% or less, P: 0.03% or less, and S: 0.02% or less, respectively, 0.005?C?(?5/3)×B+0.085??(1) in which C and B represent the content of each element (mass %). Furthermore, the high-Cr heat resistant ferritic steel may contain one or more kinds selected from the group consisting of Nd, Ta, Ca and Mg.Type: ApplicationFiled: December 4, 2009Publication date: April 8, 2010Inventors: Hiroyuki Hirata, Mitsuru Yoshizawa, Kazuhiro Ogawa, Masaaki Igarashi
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Patent number: 7662244Abstract: A martensitic stainless steel provided includes C: 0.01-0.1% and Cr: 9-15%, and the retained austenite phase has a thickness not more than 100 nm in such a manner that the X-ray integral intensities of 111? and 110? satisfy the following formula (a): 0.005?111?/(111?+110?)?0.05??(a) Such a metal structure can be obtained by the following procedure: the steel is heated at a temperature of the Ac3 point or more, and then cooled from 800° C. to 400° C. at a cooling rate of not less than 0.08° C./sec and further cooled down to 150° C. at a cooling rate of not more than 1° C./sec. The martensitic stainless steel according to the present invention has a relatively high carbon content and a greater toughness in spite of a high mechanical strength, and further exhibits an excellent corrosion resistance, so that it is particularly effective as the material for constructing a deep oil well.Type: GrantFiled: May 23, 2003Date of Patent: February 16, 2010Assignee: Sumitomo Metal Industries, Ltd.Inventors: Mitsuru Yoshizawa, Kunio Kondo, Masaaki Igarashi, Yuichi Komizo
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Publication number: 20090071221Abstract: A method for surface treating a mandrel bar used for hot rolling of high-alloy seamless steel pipe is provided. The method includes heat treating the mandrel bar to develop a scale, and after heat treatment, rolling ordinary steel comprising 8% or less of chromium for at least 50 passes.Type: ApplicationFiled: September 24, 2008Publication date: March 19, 2009Applicant: SUMITOMO METAL INDUSTRIES, LTD.Inventors: Sumio Iida, Yasuyoshi Hidaka, Mitsuru Yoshizawa, Koji Nakaike