Patents by Inventor Shiro Torizuka
Shiro Torizuka 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: 10100383Abstract: Provided is martensitic steel which is used in structures such as buildings and bridges, and automotive underbody, and mechanical parts such as gears and is more suitably used for steel products such as thick steel sheets, shape steel, a deformed steel bar, steel bars, or steel wires. The martensitic steel has a microstructure of a martensite structure containing a chemical composition, by mass %, of Si: 1.0 to 3.5%, Mn: 4.5 to 5.5%, Al: 0.001 to 0.080%, Nb: 0.045% or less, and C having an amount in which the following regression equation (1) is satisfied and the maximum stress (TS) becomes 1800 to 2160 MPa, a balance being Fe and inevitable impurities of: P: 0.030% or less, S: 0.020% or less, and N: 0.010% or less, the martensitic steel having total elongation of 13 to 15%. TS(maximum stress) [MPa]=4000×C[mass %]+1050??(1).Type: GrantFiled: July 9, 2014Date of Patent: October 16, 2018Assignee: NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Toshihiro Hanamura, Shiro Torizuka
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Publication number: 20160369365Abstract: Provided is martensitic steel which is used in structures such as buildings and bridges, and automotive underbody, and mechanical parts such as gears and is more suitably used for steel products such as thick steel sheets, shape steel, a deformed steel bar, steel bars, or steel wires. The martensitic steel has a microstructure of a martensite structure containing a chemical composition, by mass %, of Si: 1.0 to 3.5%, Mn: 4.5 to 5.5%, Al: 0.001 to 0.080%, Nb: 0.045% or less, and C having an amount in which the following regression equation (1) is satisfied and the maximum stress (TS) becomes 1800 to 2160 MPa, a balance being Fe and inevitable impurities of: P: 0.030% or less, S: 0.020% or less, and N: 0.010% or less, the martensitic steel having total elongation of 13 to 15%.Type: ApplicationFiled: July 9, 2014Publication date: December 22, 2016Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Toshihiro HANAMURA, Shiro TORIZUKA
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Patent number: 9366211Abstract: An orifice plate for liquid injection made of plate-shaped stainless steel, wherein an orifice is formed by shearing, is characterized in that the average crystal grain size of the stainless steel is 3 ?m or less. The thickness of the plate-shaped stainless steel is 1.2 mm or less, and preferably 0.1 mm or less. The aspect ratio of the orifices is 0.8 or lower. The orifices are formed orthogonal to the plate surface, or slanted by 50° or at smaller angles. The plate-shaped stainless steel has a composition containing C, Mn, and Si.Type: GrantFiled: May 14, 2010Date of Patent: June 14, 2016Assignees: NATIONAL INSTITUTE FOR MATERIALS SCIENCE, KOMATSU SEIKI KOSAKUSHO CO., LTD., TOKUSHU KINZOKU EXCEL CO., LTD.Inventors: Shiro Torizuka, Eijiro Muramatsu, Takafumi Komatsu, Hitoshi Kobayashi, Shin-ichi Nagayama, Mitsuyuki Tanaka
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Publication number: 20120125067Abstract: An orifice plate for liquid injection made of plate-shaped stainless steel, wherein an orifice is formed by shearing, is characterized in that the average crystal grain size of the stainless steel is 3 ?m or less. The thickness of the plate-shaped stainless steel is 1.2 mm or less, and preferably 0.1 mm or less. The aspect ratio of the orifices is 0.8 or lower. The orifices are formed orthogonal to the plate surface, or slanted by 50° or at smaller angles. The plate-shaped stainless steel has a composition containing C, Mn, and Si.Type: ApplicationFiled: May 14, 2010Publication date: May 24, 2012Applicants: NATIONAL INSTITUTE FOR MATERIALS SCIENCE, TOKUSHU KINZOKU EXCEL CO., LTD., KOMATSU SEIKI KOSAKUSHO CO., LTD.Inventors: Shiro Torizuka, Eijiro Muramatsu, Takafumi Komatsu, Hitoshi Kobayashi, Shin-ichi Nagayama, Mitsuyuki Tanaka
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Patent number: 8070888Abstract: A wire rod or a steel wire of a bamboo nano-structure, whose mean grain diameter in a C-direction section is 200 nm or smaller, is prepared by applying a hot or warm working and additionally applying a cold working to a steel and next, by performing a forging, by a tool or a die such as cold pressure production, to a section, of a desired, limited site, other than a section parallel to an L-direction, an equiaxed nano-structure, whose mean grain diameter is 200 nm or smaller, is formed in this site. As a typical example of a formed article, there is enumerated a high strength micro screw in which a shaft outer diameter is 1.6 mm or smaller, a surface layer part of a head part recess has equiaxed nano-structure and a hardness Hv?300, and a screw main body portion has bamboo nano-structure and a hardness Hv?250.Type: GrantFiled: February 28, 2006Date of Patent: December 6, 2011Assignee: National Institute for Materials ScienceInventors: Shiro Torizuka, Eijrio Muramatsu, Kotobu Nagai
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Publication number: 20110083775Abstract: A tough high strength heavy wall steel material having superior weldability is provided, said steel material has a diameter or a side 5 mm or more in length, and comprises oxides 1 ?m or less in particle diameter homogeneously dispersed at a dispersion density in a range of from 10,000 to 100,000 particles/mm2 and uniform ferrite grains 2 ?m or less in grain diameter formed over the entire plane making a right angle with respect to the rolling direction.Type: ApplicationFiled: December 15, 2010Publication date: April 14, 2011Inventors: Hiroshi Nakajima, Shiro Torizuka, Kaneaki Tsuzaki, Kotobu Nagai
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Publication number: 20100173716Abstract: A formed product, characterized in that it is produced by using, as a material, a steel having an ultra fine structure comprising ferrite grains having an average grain diameter of 3 ?m or less and by a method comprising only a forming step and including none of refining steps; and a method for producting the above formed product with ease. The formed product contains no alloying element and has been subjected to no refining step, and has been imparted with high strength and high toughness by the above ultra fine structure.Type: ApplicationFiled: July 21, 2009Publication date: July 8, 2010Inventors: Shiro Torizuka, Kotobu Nagai, Eijiro Muramatsu, Yoshiyuki Suzuki
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Patent number: 7727343Abstract: The invention presents a new warm control rolling method, in consideration of processing heat generation, as a method of stably manufacturing ultrafine crystal steel of 3 microns to 1 micron or less, without any limitation in pass interval or strain speed, being a rolling method of manufacturing steel mainly composed of fine ferrite particle texture with average ferrite grain size of 3 ?m or less, in which, in the rolling process of one pass or more wherein the rolling temperature range is a temperature region of 350° C. to 800° C., the material temperature upon start of rolling of each rolling process does not exceed the maximum temperature of 800° C., and the material temperature during rolling and right after final rolling (within 1 second) is not lower than 350° C., temperature Tx-out right after rolling in each rolling process (within 1 second) is not higher than the temperature that is higher than rolling entry temperature Tx-in by 100° C.Type: GrantFiled: May 20, 2004Date of Patent: June 1, 2010Assignee: National Institute for Materials ScienceInventors: Shiro Torizuka, Kotobu Nagai
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Publication number: 20100051144Abstract: There are provided an excellent cold-workability exhibiting high-strength steel wire or steel bar, or high-strength shaped article and a process for producing them. In particular, there is provided a process comprising carrying out hot working at 350 to 800° C. of a steel ingot, cast slab, steel slab or steel semifinished product having a C content of not greater than the solid solution limit of carbon of ferrite phase at Ae1 point and not greater than 0.010 mass % and being free of any cementite, or having a C content of >0.01 to 0.45 mass % to thereby obtain a material whose average crystal grain diameter in a cross section perpendicular to the longitudinal direction is ?3 ?m, and thereafter carrying out cold working of the material to thereby attain formation of a ferrite structure whose average crystal grain diameter in a cross section perpendicular to the longitudinal direction is ?500 nm.Type: ApplicationFiled: September 9, 2009Publication date: March 4, 2010Inventors: Shiro Torizuka, Eijiro Muramatsu, Kotobu Nagai
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Patent number: 7647804Abstract: A method of rolling a material in two more continuous passes is disclosed. The method includes rolling the material with a flattened-shaped caliber in a first pass, and subsequently rolling with a square-shaped caliber in a second pass. The rolling is performed with a first pass caliber having a flattened shape, wherein the ratio of the length (2A01) of minor axis of the first pass caliber to an initial width (2A0) is (A01/A0)?0.75; and a second pass caliber, wherein the ratio of a diagonal dimension (2AS1) of the second pass caliber to the length (2B1) of the major axis of the material after the first pass is (AS1/B1)?0.75 to introduce the large strain into the material.Type: GrantFiled: May 20, 2004Date of Patent: January 19, 2010Assignee: National Institute for Materials ScienceInventors: Tadanobu Inoue, Shiro Torizuka, Eijiro Muramatsu, Kotobu Nagai
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Publication number: 20080210351Abstract: A formed product, characterized in that it is produced by using, as a material, a steel having an ultra fine structure comprising ferrite grains having an average grain diameter of 3 ?m or less and by a method comprising only a forming step and including none of refining steps; and a method for producting the above formed product with ease. The formed product contains no alloying element and has been subjected to no refining step, and has been imparted with high strength and high toughness by the above ultra fine structure.Type: ApplicationFiled: April 8, 2008Publication date: September 4, 2008Inventors: Shiro TORIZUKA, Kotobu NAGAI, Eijiro MURAMATSU, Yoshiyuki SUZUKI
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Publication number: 20080135140Abstract: A wire rod or a steel wire of a bamboonano-stricture, whose mean grain diameter in a C-direction section is 200 nm or smaller, is prepared by applying a hot or warm working and additionally applying a cold working to a steel and next, by performing a forging, by a tool or a die such as cold pressure production, to a section, of a desired, limited site, other than a section parallel to an L-direction, an equiaxed nano-structure, whose mean grain diameter is 200 nm or smaller, is formed in this site. As a typical example of a formed article, there is enumerated a screw, and there is enumerated a high strength micro screw in which a shaft outer diameter is 1.6 mm or smaller, a surface layer part of a head part recess is the equiaxed nano-structure and a hardness HV?300, and a screw main body portion is the bamboo nano-structure and a hardness Hv?250. A constituent composition is a carbon steel of C<0.02%, and a strengthening element may not be added especially.Type: ApplicationFiled: February 28, 2006Publication date: June 12, 2008Inventors: Shiro Torizuka, Eijrio Muramatsu, Kotobu Nagai
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Publication number: 20080041503Abstract: There are provided an excellent cold-workability exhibiting high-strength steel wire or steel bar, or high-strength shaped article and a process for producing them. In particular, there is provided a process comprising carrying out hot working at 350 to 800° C. of a steel ingot, cast slab, steel slab or steel semifinished product having a C content of not greater than the solid solution limit of carbon of ferrite phase at Ael point and not greater than 0.010 mass % and being free of any cementite, or having a C content of >0.01 to 0.45 mass % to thereby obtain a material whose average crystal grain diameter in a cross section perpendicular to the longitudinal direction is ?3 ?m, and thereafter carrying out cold working of the material to thereby attain formation of a ferrite structure whose average crystal grain diameter in a cross section perpendicular to the longitudinal direction is ?500 nm.Type: ApplicationFiled: April 11, 2005Publication date: February 21, 2008Inventors: Shiro Torizuka, Eijiro Muramatsu, Kotobu Nagai
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Publication number: 20070119527Abstract: A tough high strength heavy wall steel material having superior weldability is provided, said steel material has a diameter or a side 5 mm or more in length, and comprises oxides 1 ?m or less in particle diameter homogeneously dispersed at a dispersion density in a range of from 10,000 to 100,000 particles/mm2 and uniform ferrite grains 2 ?m or less in grain diameter formed over the entire plane making a right angle with respect to the rolling direction.Type: ApplicationFiled: January 26, 2007Publication date: May 31, 2007Inventors: Hiroshi Nakajima, Shiro Torizuka, Kaneaki Tsuzaki, Kotobu Nagai
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Publication number: 20060260375Abstract: A method of rolling with a flattened-shaped caliber in a 1st pass and subsequently roiling with a square-shaped caliber in a 2nd pass In a caliber rolling of two or more continuous passes. The rolling is performed with a caliber which sets the ratio of the minor axis (2A01) of a 1st pass flattened to a material opposite side dimension (2A0) to A01/A0?0.75 and the ratio of a 2nd pass vertical diagonal dimension 2As1 to the major axis 2B1 of a material after the 1st pass to As1/B1?0.75 to introduce the large strain into the material. Thus, the effect of the distribution of strain introduced into the material in the 1st pass on the distribution of strain and the shape of the next pass is made clear so that the large strain can be introduced into the entire cross sectional are of the material, particularly at the center of the material.Type: ApplicationFiled: May 20, 2004Publication date: November 23, 2006Inventors: Tadanobu Inoue, Shiro Torizuka, Eijiro Muramatsu, Kotobu Nagai
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Publication number: 20060191613Abstract: A multi-directional warm-rolling method for manufacturing an ultrafine grain steel material with an ultrafine grain structure of 3 ?m or smaller in average grain size. When roiling of two passes or more is performed for a steel material in the rolling temperature range of 350 to 800° C., a rolling by an oval shape caliber and a rolling by the other shape caliber an performed at leas one time so that a large amount of strain can be introduced into the material by a simple means with less section reduction ratio and less number of passes. Steel materials having the ultrafine grain structure and excellent strength and ductility can be manufactured by this method.Type: ApplicationFiled: May 20, 2004Publication date: August 31, 2006Inventors: Shiro Torizuka, Eijiro Muramatsu, Tadanobu Inoue, Kotobu Nagai
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Publication number: 20060147296Abstract: A screw or a tapping screw, comprising an ultra fine structure steel having ferrite grains of 3 ?m or smaller in average grain size and a nitrided layer on a surface part, wherein a strength is increased, a surface hardness is increased, and the surface hardness and an inside hardness are kept in balance, whereby a novel tapping screw and novel general screws can be provided.Type: ApplicationFiled: October 17, 2003Publication date: July 6, 2006Inventors: Shiro Torizuka, Kotobu Nagal, Takafumi Komatsu, Naohisa Miyashita, Fumito Takagi, Masaaki Matsuzawa, Yoshimasa Miyasaka, Yoshiki Hatnato, Chiaki Fujimori, Masayoshi Osaka, Masaaki Uematsu, Hajime Hama
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Publication number: 20060054255Abstract: The invention presents a new warm control rolling method, in consideration of processing heat generation, as a method of stably manufacturing ultrafine crystal steel of 3 microns to 1 micron or less, without any limitation in pass interval or strain speed, being a rolling method of manufacturing steel mainly composed of fine ferrite particle texture with average ferrite grain size of 3 ?m or less, in which, in the rolling process of one pass or more wherein the rolling temperature range is a temperature region of 350° C. to 800° C., the material temperature upon start of rolling of each rolling process does not exceed the maximum temperature of 800° C., and the material temperature during rolling and right after final rolling (within 1 second) is not lower than 350° C., temperature Tx-out right after rolling in each rolling process (within 1 second) is not higher than the temperature that is higher than rolling entry temperature Tx-in by 100° C.Type: ApplicationFiled: May 20, 2004Publication date: March 16, 2006Inventors: Shiro Torizuka, Kotobu Nagai
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Publication number: 20050271496Abstract: A formed product, characterized in that it is produced by using, as a material, a steel having an ultra fine structure comprising ferrite grains having an average grain diameter of 3 ?m or less and by a method comprising only a forming step and including none of refining steps; and a method for producting the above formed product with ease. The formed product contains no alloying element and has been subjected to no refining step, and has been imparted with high strength and high toughness by the above ultra fine structure.Type: ApplicationFiled: October 17, 2003Publication date: December 8, 2005Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Shiro Torizuka, Kotobu Nagai, Eijiro Muramatsu, Yoshiyuki Suzuki
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Publication number: 20050241733Abstract: An ultra fine grain steel has a ferrite grain structure having an average grain size of 3 ?m or less and has a nitride layer formed on a surface of the steel. The nitride layer is formed without adding an alloy element such as Cr or Mo that is expensive and detrimental to recycling. Fatigue strength is enhanced by the nitride layer.Type: ApplicationFiled: October 17, 2003Publication date: November 3, 2005Applicant: National Institute for Materials ScienceInventors: Saburo Matsuoka, Yoshiyuki Furuya, Hisashi Hirukawa, Shiro Torizuka