Patents by Inventor Katsufumi KURODA
Katsufumi KURODA 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: 10844456Abstract: Provided are: a cold work tool having excellent wear resistance; and a method for manufacturing the cold work tool. A cold work tool which has an ingredient composition that can be prepared into a martensite structure by quenching and which has a martensite structure, wherein the hardness of the cold work tool is 58 HRC or more, the area ratio of a carbide having an equivalent circle diameter of 5 ?m or more in the cross-sectional structure of the cold work tool is 4.0% by area or more, and the carbon solid solution fraction, which is expressed by the ratio of the mass ratio of the amount of carbon that is present in the form of a solid solution in the structure of the cold work tool to the mass ratio of the amount of carbon that is contained in the whole of the cold work tool, is 75.0% or more. A method for manufacturing a cold work tool, which is suitable for manufacturing the aforementioned cold work tool.Type: GrantFiled: March 1, 2016Date of Patent: November 24, 2020Assignee: HITACHI METALS, LTD.Inventors: Tatsuya Shouji, Yukio Shinji, Katsufumi Kuroda
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Patent number: 10407747Abstract: Provided are a cold working tool material with which high hardness can be obtained in a broad range of tempering temperatures, and a cold working tool manufacturing method using same. The present invention is a cold working tool material comprising a steel component composition that contains, in mass %, C: 0.65-2.40%, Cr: 5.0-15.0%, Mo and W alone or combined (Mo+½W): 0.50-4.00%, V: 0.10-1.50%, and N: greater than 0.0300% to 0.0800%, in which martensitic structure can be adjusted by quenching, and in which, in a 90 ?m long 90 ?m wide region of a cross-sectional structure that does not contain carbides with equivalent circle diameters exceeding 5.0 ?m, the number density of carbides A with equivalent circle diameters greater than 0.1 ?m to 2.0 ?m is at least 9.0×105/mm2 and the number density of carbides B with equivalent circle diameters greater than 0.1 ?m to 0.4 ?m is at least 7.5×105/mm2.Type: GrantFiled: December 27, 2016Date of Patent: September 10, 2019Assignee: HITACHI METALS, LTD.Inventors: Tatsuya Shouji, Setsuo Mishima, Yukio Shinji, Katsufumi Kuroda
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Patent number: 9994925Abstract: Provided is a cold work tool material capable of reducing dimensional changes which occur, due to heat treatment, in the longitudinal direction of the material during quenching and tempering. This cold work tool material is drawn through hot working, has an annealed structure including carbides, and is used after being quenched and tempered, wherein, in the annealed structure which is formed in a cross section parallel to a drawing direction due to the hot working of the cold work tool material, the standard deviation in the degree of orientation of carbides Oc, as determined by equation (1) below, is 6.0 or more for carbides having a circle equivalent diameter of 5.0 ?m or greater as observed in the annealed structure in the cross section at right angle to a direction perpendicular to the drawing direction. Oc=D×? . . .Type: GrantFiled: January 7, 2016Date of Patent: June 12, 2018Assignee: HITACHI METALS, LTD.Inventors: Tatsuya Shouji, Yukio Shinji, Katsufumi Kuroda
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Publication number: 20180135144Abstract: Provided are a cold working tool material with which high hardness can be obtained in a broad range of tempering temperatures, and a cold working tool manufacturing method using same. The present invention is a cold working tool material comprising a steel component composition that contains, in mass %, C: 0.65-2.40%, Cr: 5.0-15.0%, Mo and W alone or combined (Mo+½W): 0.50-4.00%, V: 0.10-1.50%, and N: greater than 0.0300% to 0.0800%, in which martensitic structure can be adjusted by quenching, and in which, in a 90 ?m long 90 ?m wide region of a cross-sectional structure that does not contain carbides with equivalent circle diameters exceeding 5.0 ?m, the number density of carbides A with equivalent circle diameters greater than 0.1 ?m to 2.0 ?m is at least 9.0×105/mm2 and the number density of carbides B with equivalent circle diameters greater than 0.1 ?m to 0.4 ?m is at least 7.5×105/mm2.Type: ApplicationFiled: December 27, 2016Publication date: May 17, 2018Applicant: HITACHI METALS, LTD.Inventors: Tatsuya SHOUJI, Setsuo MISHIMA, Yukio SHINJI, Katsufumi KURODA
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Patent number: 9890435Abstract: A cold work tool material has an annealed structure including carbides, and a composition including, in mass %, C: 0.80% to 2.40%, Cr: 5.0% to 15.0%, Mo and W contained alone or in combination in an amount of (Mo+½W): 0.50% to 3.00%, and V: 0.10 to 1.50%, and adjusted such that the material has a martensitic structure by quenching. The material includes a cross sectional region of an annealed structure and a length of 90 ?m and a width of 90 ?m and including no carbides having a circle equivalent diameter exceeding 5.0 ?m. In the cross sectional region, a proportion of a number of carbides B having a circle equivalent diameter of more than 0.1 ?m and not more than 0.4 ?m to a number of carbides A having a circle equivalent diameter of exceeds 0.1 ?m and not more than 2.0 ?m is greater than 80.0%.Type: GrantFiled: September 2, 2015Date of Patent: February 13, 2018Assignee: HITACHI METALS, LTD.Inventors: Tatsuya Shouji, Setsuo Mishima, Toru Taniguchi, Katsufumi Kuroda
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Publication number: 20170327920Abstract: Provided are: a cold work tool having excellent wear resistance; and a method for manufacturing the cold work tool. A cold work tool which has an ingredient composition that can be prepared into a martensite structure by quenching and which has a martensite structure, wherein the hardness of the cold work tool is 58 HRC or more, the area ratio of a carbide having an equivalent circle diameter of 5 ?m or more in the cross-sectional structure of the cold work tool is 4.0% by area or more, and the carbon solid solution fraction, which is expressed by the ratio of the mass ratio of the amount of carbon that is present in the form of a solid solution in the structure of the cold work tool to the mass ratio of the amount of carbon that is contained in the whole of the cold work tool, is 75.0% or more. A method for manufacturing a cold work tool, which is suitable for manufacturing the aforementioned cold work tool.Type: ApplicationFiled: March 1, 2016Publication date: November 16, 2017Applicant: HITACHI METALS, LTD.Inventors: Tatsuya SHOUJI, Yukio SHINJI, Katsufumi KURODA
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Publication number: 20170314086Abstract: Provided is a cold work tool material capable of reducing dimensional changes which occur, due to heat treatment, in the longitudinal direction of the material during quenching and tempering. This cold work tool material is drawn through hot working, has an annealed structure including carbides, and is used after being quenched and tempered, wherein, in the annealed structure which is formed in a cross section parallel to a drawing direction due to the hot working of the cold work tool material, the standard deviation in the degree of orientation of carbides Oc, as determined by equation (1) below, is 6.0 or more for carbides having a circle equivalent diameter of 5.0 ?m or greater as observed in the annealed structure in the cross section at right angle to a direction perpendicular to the drawing direction. Oc=D×? . . .Type: ApplicationFiled: January 7, 2016Publication date: November 2, 2017Applicant: HITACHI METALS, LTD.Inventors: Tatsuya SHOUJI, Yukio SHINJI, Katsufumi KURODA
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Publication number: 20170204486Abstract: A cold work tool material has an annealed structure including carbides, and a composition including, in mass %, C: 0.80% to 2.40%, Cr: 5.0% to 15.0%, Mo and W contained alone or in combination in an amount of (Mo+½W): 0.50% to 3.00%, and V: 0.10 to 1.50%, and adjusted such that the material has a martensitic structure by quenching. The material includes a cross sectional region of an annealed structure and a length of 90 ?m and a width of 90 ?m and including no carbides having a circle equivalent diameter exceeding 5.0 ?m. In the cross sectional region, a proportion of a number of carbides B having a circle equivalent diameter of more than 0.1 ?m and not more than 0.4 ?m to a number of carbides A having a circle equivalent diameter of exceeds 0.1 ?m and not more than 2.0 ?m is greater than 80.0%.Type: ApplicationFiled: September 2, 2015Publication date: July 20, 2017Applicant: HITACHI METALS, LTD.Inventors: Tatsuya SHOUJI, Setsuo MISHIMA, Toru TANIGUCHI, Katsufumi KURODA