Patents by Inventor Ayako Ta
Ayako Ta 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: 20230212705Abstract: Provided is a stainless steel sheet having a predetermined chemical composition, in which a total volume fraction of Cr-based carbides with a grain size of 2.0 ?m or more is 10% or less.Type: ApplicationFiled: April 7, 2021Publication date: July 6, 2023Applicant: JFE STEEL CORPORATIONInventors: Masataka YOSHINO, Shino HIROTA, Takuya MATSUMOTO, Ayako TA
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Patent number: 10968499Abstract: Ferritic stainless steel that has excellent formability and ridging resistance and can be produced with high productivity is provided. The ferritic stainless steel has: a predetermined chemical composition; a microstructure containing ferrite crystal grains which satisfy at least one of a C concentration of 2CC or more and an N concentration of 2CN or more, the ferrite crystal grains having a volume fraction with respect to a whole volume of the microstructure of 5% or more and 50% or less, where CC and CN are respectively C content and N content in the steel in mass %; and a Vickers hardness of 180 or less.Type: GrantFiled: July 2, 2015Date of Patent: April 6, 2021Assignee: JFE STEEL CORPORATIONInventors: Akito Mizutani, Masataka Yoshino, Mitsuyuki Fujisawa, Ayako Ta
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Patent number: 10633730Abstract: Provided is a material for a cold-rolled stainless steel sheet having a chemical composition containing, by mass %, C: 0.01% to 0.05%, Si: 0.02% to 0.75%, Mn: 0.1% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 16.0% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06% and the balance being Fe and inevitable impurities. The material has a metallographic structure including a martensite phase having an area ratio of 5% to 50% and the balance being a ferrite phase. A ferrite phase in portions extending from surface layers of front and back surfaces of a steel sheet has an average grain diameter of 20 ?m or more and 50 ?m or less, and a ferrite phase in a central portion of the sheet includes an unrecrystallized ferrite phase.Type: GrantFiled: July 2, 2015Date of Patent: April 28, 2020Assignee: JFE Steel CorporationInventors: Ayako Ta, Yukihiro Matsubara, Yukio Kimura, Masataka Yoshino, Keisuke Nakazono, Sumio Kaiho, Saiichi Murata, Nobukazu Kitagawa
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Patent number: 10626486Abstract: Stainless steel that has excellent formability and ridging resistance and can be produced with high productivity is provided. The stainless steel comprises: a chemical composition containing, in mass %, C: 0.005% to 0.050%, Si: 0.01% to 1.00%, Mn: 0.01% to 1.0%, P: 0.040% or less, S: 0.010% or less, Cr: 15.5% to 18.0%, Ni: 0.01% to 1.0%, Al: 0.001% to 0.10%, and N: 0.005% to 0.06%, with a balance being Fe and incidental impurities; and a microstructure containing a martensite phase of 1% to 10% in volume fraction with respect to a whole volume of the microstructure.Type: GrantFiled: July 2, 2015Date of Patent: April 21, 2020Assignee: JFE STEEL CORPORATIONInventors: Akito Mizutani, Masataka Yoshino, Mitsuyuki Fujisawa, Ayako Ta
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Patent number: 10550454Abstract: Provided is a cold-rolled ferritic stainless steel sheet having a chemical composition that contains, by mass %, C: 0.01% or more and 0.05% or less, Si: 0.02% or more and 0.75% or less, Mn: 0.1% or more and 1.0% or less, P: 0.04% or less, S: 0.01% or less, Al: 0.001% or more and 0.10% or less, N: 0.01% or more and 0.06% or less, Cr: 16.0% or more and 18.0% or less, and the balance being Fe and inevitable impurities. The metallographic structure includes a ferrite phase, in which the average grain diameter is 10 ?m or less, in which the proportion of ferrite grains having a grain diameter of 10 ?m or more and less than 40 ?m is 60% or more, and in which the proportion of ferrite grains having a grain diameter of less than 5 ?m is less than 20%.Type: GrantFiled: July 2, 2015Date of Patent: February 4, 2020Assignee: JFE Steel CorporationInventors: Ayako Ta, Yukihiro Matsubara, Yukio Kimura, Keisuke Nakazono, Masataka Yoshino
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Publication number: 20180265951Abstract: A ferritic stainless steel having sufficient corrosion resistance and excellent formability and ridging resistance. The ferritic stainless steel having a chemical composition comprising, by mass %, C: 0.005% or more and 0.035% or less, Si: 0.25% or more and less than 0.40%, Mn: 0.05% or more and 0.35% or less, P: 0.040% or less, S: 0.01% or less, Cr: 15.5% or more and 18.0% or less, Al: 0.001% or more and 0.10% or less, N: 0.01% or more and 0.06% or less, and the balance being Fe and inevitable impurities. Si and Mn satisfy the relational expression 29.5×Si?50×Mn+6?0, where Si and Mn in the relational expression respectively denote the content, by mass %, of the corresponding chemical element.Type: ApplicationFiled: October 2, 2014Publication date: September 20, 2018Applicant: JFE STEEL CORPORATIONInventors: Masataka YOSHINO, Akito MIZUTANI, Mitsuyuki FUJISAWA, Ayako TA
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Patent number: 10000824Abstract: A material for stainless steel cold rolling suitable for producing a cold-rolled stainless steel sheet that has sufficient corrosion resistance and ridging resistance as well as excellent formability and surface properties is provided. The material for stainless steel cold rolling according to the present invention contains, in terms of % by mass, C: 0.007% to 0.05%, Si: 0.02% to 0.50%, Mn: 0.05% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 15.5% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06%, and the balance being Fe and unavoidable impurities, wherein the material has a microstructure that includes 10% to 60% of a martensite phase in terms of area fraction, with the remainder being a ferrite phase, and the martensite phase has a hardness of HV500 or less.Type: GrantFiled: January 20, 2015Date of Patent: June 19, 2018Assignee: JFE STEEL CORPORATIONInventors: Masataka Yoshino, Hiroki Ota, Ayako Ta, Yukihiro Matsubara, Akito Mizutani, Mitsuyuki Fujisawa
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Publication number: 20170349984Abstract: Stainless steel that has excellent formability and ridging resistance and can be produced with high productivity is provided. The stainless steel comprises: a chemical composition containing, in mass %, C: 0.005% to 0.050%, Si: 0.01% to 1.00%, Mn: 0.01% to 1.0%, P: 0.040% or less, S: 0.010% or less, Cr: 15.5% to 18.0%, Ni: 0.01% to 1.0%, Al: 0.001% to 0.10%, and N: 0.005% to 0.06%, with a balance being Fe and incidental impurities; and a microstructure containing a martensite phase of 1% to 10% in volume fraction with respect to a whole volume of the microstructure.Type: ApplicationFiled: July 2, 2015Publication date: December 7, 2017Applicant: JFE STEEL CORPORATIONInventors: Akito MIZUTANI, Masataka YOSHINO, Mitsuyuki FUJISAWA, Ayako TA
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Publication number: 20170327921Abstract: Ferritic stainless steel that has excellent formability and ridging resistance and can be produced with high productivity is provided. The ferritic stainless steel has: a predetermined chemical composition; a microstructure containing ferrite crystal grains which satisfy at least one of a C concentration of 2CC or more and an N concentration of 2CN or more, the ferrite crystal grains having a volume fraction with respect to a whole volume of the microstructure of 5% or more and 50% or less, where CC and CN are respectively C content and N content in the steel in mass %; and a Vickers hardness of 180 or less.Type: ApplicationFiled: July 2, 2015Publication date: November 16, 2017Applicant: JFE STEEL CORPORATIONInventors: Akito MIZUTANI, Masataka YOSHINO, Mitsuyuki FUJISAWA, Ayako TA
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Publication number: 20170283923Abstract: Provided is a cold-rolled ferritic stainless steel sheet having a chemical composition that contains, by mass %, C: 0.01% or more and 0.05% or less, Si: 0.02% or more and 0.75% or less, Mn: 0.1% or more and 1.0% or less, P: 0.04% or less, S: 0.01% or less, Al: 0.001% or more and 0.10% or less, N: 0.01% or more and 0.06% or less, Cr: 16.0% or more and 18.0% or less, and the balance being Fe and inevitable impurities. The metallographic structure includes a ferrite phase, in which the average grain diameter is 10 ?m or less, in which the proportion of ferrite grains having a grain diameter of 10 ?m or more and less than 40 ?m is 60% or more, and in which the proportion of ferrite grains having a grain diameter of less than 5 ?m is less than 20%.Type: ApplicationFiled: July 2, 2015Publication date: October 5, 2017Applicant: JFE STEEL CORPORATIONInventors: Ayako Ta, Yukihiro Matsubara, Yukio Kimura, Keisuke Nakazono, Masataka Yoshino
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Publication number: 20170275744Abstract: Provided is a material for a cold-rolled stainless steel sheet having a chemical composition containing, by mass %, C: 0.01% to 0.05%, Si: 0.02% to 0.75%, Mn: 0.1% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 16.0% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06% and the balance being Fe and inevitable impurities. The material has a metallographic structure including a martensite phase having an area ratio of 5% to 50% and the balance being a ferrite phase. A ferrite phase in portions extending from surface layers of front and back surfaces of a steel sheet has an average grain diameter of 20 ?m or more and 50 ?m or less, and a ferrite phase in a central portion of the sheet includes an unrecrystallized ferrite phase.Type: ApplicationFiled: July 2, 2015Publication date: September 28, 2017Applicant: JFE STEEL CORPORATIONInventors: Ayako Ta, Yukihiro Matsubara, Yukio Kimura, Masataka Yoshino, Keisuke Nakazono, Sumio Kaiho, Saiichi Murata, Nobukazu Kitagawa
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Publication number: 20160369368Abstract: A material for stainless steel cold rolling suitable for producing a cold-rolled stainless steel sheet that has sufficient corrosion resistance and ridging resistance as well as excellent formability and surface properties is provided. The material for stainless steel cold rolling according to the present invention contains, in terms of % by mass, C: 0.007% to 0.05%, Si: 0.02% to 0.50%, Mn: 0.05% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 15.5% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06%, and the balance being Fe and unavoidable impurities, wherein the material has a microstructure that includes 10% to 60% of a martensite phase in terms of area fraction, with the remainder being a ferrite phase, and the martensite phase has a hardness of HV500 or less.Type: ApplicationFiled: January 20, 2015Publication date: December 22, 2016Applicant: JFE STEEL CORPORATIONInventors: Masataka Yoshino, Hiroki Ota, Ayako Ta, Yukihiro Matsubara, Akito Mizutani, Mitsuyuki Fujisawa
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Publication number: 20160333439Abstract: Provided are a ferritic stainless steel and a method for producing the ferritic stainless steel. A ferritic stainless steel of the present invention contains, in terms of % by mass, C: 0.005% to 0.05%, Si: 0.02% to 0.50%, Mn: 0.05% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 15.5% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06%, V: 0.01% to 0.25%, Ti: 0.001% to 0.020%, Nb: 0.001% to 0.030%, and the balance being Fe and unavoidable impurities, in which V/(Ti+Nb)?2.0 is satisfied.Type: ApplicationFiled: January 7, 2015Publication date: November 17, 2016Applicant: JFE STEEL CORPORATIONInventors: Masataka Yoshino, Hiroki Ota, Ayako Ta, Yukihiro Matsubara, Akito Mizutani, Mitsuyuki Fujisawa