Patents by Inventor Koichi Makii
Koichi Makii 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: 9459058Abstract: This heat sink has bonded on one surface a member to be bonded, and has a cooling member in contact with the other surface. The heat sink is provided with a metal plate having a thermal expansion coefficient larger than that of the member to be bonded, and the metal plate is provided with a center portion where the member to be bonded is bonded, and a plurality of linear peripheral slits formed in a whirl-like radial manner such that the linear peripheral slits surround the center portion.Type: GrantFiled: July 26, 2012Date of Patent: October 4, 2016Assignee: Kobe Steel, Ltd.Inventors: Yoshihiro Yokota, Kenichi Inoue, Koji Inoue, Kyoji Zaitsu, Koichi Makii
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Patent number: 9194015Abstract: A dual phase steel sheet with good bake-hardening properties is provided. The steel sheet is characterized in containing (in terms of percent by mass) C: no less than 0.06% and less than 0.25%; Si+Al: 0.5 to 3%; Mn: 0.5 to 3%; P: no more than 0.15%; and S: no more than 0.02%; and also meeting the following condition (in terms of space factor) that retained austenite is at least 3%, bainite is at least 30%, and ferrite is no more than 50%, and further characterized in differing in stress larger than 50 MPa before and after application of 2% pre-strain and ensuing heat treatment for paint baking at 170° C. for 20 minutes. The steel sheet has well-balanced strength and workability, exhibits good bake-hardening properties at the time of paint baking, and offers good resistance to natural aging.Type: GrantFiled: June 3, 2009Date of Patent: November 24, 2015Assignee: Kobe Steel, Ltd.Inventors: Shushi Ikeda, Koichi Makii, Hiroshi Akamizu
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Publication number: 20140224467Abstract: This heat sink has bonded on one surface a member to be bonded, and has a cooling member in contact with the other surface. The heat sink is provided with a metal plate having a thermal expansion coefficient larger than that of the member to be bonded, and the metal plate is provided with a center portion where the member to be bonded is bonded, and a plurality of linear peripheral slits formed in a whirl-like radial manner such that the linear peripheral slits surround the center portion.Type: ApplicationFiled: July 26, 2012Publication date: August 14, 2014Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)Inventors: Yoshihiro Yokota, Kenichi Inoue, Koji Inoue, Kyoji Zaitsu, Koichi Makii
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Patent number: 8597439Abstract: A high-strength cold rolled steel sheet contains: 0.10 to 0.28% of C, 1.0 to 2.0% of Si, 1.0 to 3.0% of Mn, and 0.03 to 0.10% of Nb in terms of % by mass, Al is controlled to 0.5 or less, P is controlled to 0.15% or less, and S is controlled to 0.02% or less, and residual austenite accounts for 5 to 20%, bainitic ferrite accounts for 50% or more, and polygonal ferrite accounts for 30% or less (containing 0%), of the entire structure, and a mean number of residual austenite blocks is 20 or more as determined when the random area (15 ?m×15 ?m) is observed by EBSP (electron back scatter diffraction pattern).Type: GrantFiled: December 17, 2009Date of Patent: December 3, 2013Assignee: Kobe Steel, Ltd.Inventors: Shushi Ikeda, Yoichi Mukai, Hiroshi Akamizu, Koichi Makii, Koichi Sugimoto, Shunichi Hashimoto, Kenji Saito
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Patent number: 7833363Abstract: A high-strength forged part is disclosed which comprises a base phase structure, comprising 30% or more of ferrite in terms of a space factor, and a second phase structure, comprising bainite and/or martensite, and retained austenite having an average gain diameter of 5 ?m or less and a content represented by 50X[C]<[V?R]<150x[C], wherein [V?R] represents a space factor of the retained austenite (?R) and [C] represents the mass % of C in the forged part. Furthermore, a high-strength forged part is disclosed which comprises a base phase structure, comprising 50% or more of tempered bainite or tempered martensite in terms of a space factor, and a second phase structure, comprising martensite and 3% to 30% retained austenite in terms of a space factor, wherein the portion of the retained austenite and martensite having an aspect ratio of 2 or less is 25% or less in terms of a space factor.Type: GrantFiled: October 18, 2007Date of Patent: November 16, 2010Assignee: Kobe Steel, Ltd.Inventors: Shushi Ikeda, Koichi Makii, Hiroshi Akamizu, Yoichi Mukai, Koh-ichi Sugimoto
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Publication number: 20100092332Abstract: To provide a high-strength cold rolled steel sheet that has well-balanced tensile strength and elongation as well as well-balanced tensile strength and stretch-flangeability, and a plated steel sheet manufactured by plating the steel sheet. The high-strength cold rolled steel sheet contains: 0.10 to 0.28% of C, 1.0 to 2.0% of Si, 1.0 to 3.0% of Mn, and 0.03 to 0.10% of Nb in terms of % by mass, wherein the content of Al is controlled to 0.5 or less, the content of P is controlled to 0.15% or less, and the content of S is controlled to 0.02% or less, and wherein residual austenite accounts for 5 to 20%, bainitic ferrite accounts for 50% or more, and polygonal ferrite accounts for 30% or less (containing 0%), of the entire structure, and wherein a mean number of residual austenite blocks is 20 or more as determined when the random area (15 ?m×15 ?m) is observed by EBSP (electron back scatter diffraction pattern).Type: ApplicationFiled: December 17, 2009Publication date: April 15, 2010Applicant: Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.)Inventors: Shushi IKEDA, Yoichi Mukai, Hiroshi Akamizu, Koichi Makii, Koichi Sugimoto, Shunichi Hashimoto, Kenji Saito
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Publication number: 20090242085Abstract: A dual phase steel sheet with good bake-hardening properties is provided. The steel sheet is characterized in containing (in terms of percent by mass) C: no less than 0.06% and less than 0.25%; Si+Al: 0.5 to 3%; Mn: 0.5 to 3%; P: no more than 0.15%; and S: no more than 0.02%; and also meeting the following condition (in terms of space factor) that retained austenite is at least 3%, bainite is at least 30%, and ferrite is no more than 50%, and further characterized in differing in stress larger than 50 MPa before and after application of 2% pre-strain and ensuing heat treatment for paint baking at 170° C. for 20 minutes. The steel sheet has well-balanced strength and workability, exhibits good bake-hardening properties at the time of paint baking, and offers good resistance to natural aging.Type: ApplicationFiled: June 3, 2009Publication date: October 1, 2009Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd)Inventors: Shushi IKEDA, Koichi Makii, Hiroshi Akamizu
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Patent number: 7591977Abstract: To provide a high strength and low yield ratio cold rolled steel sheet having high elongation property and high flange drawing property, or a plated steel sheet made by plating the same. The high strength and low yield ratio cold rolled steel sheet or the plated steel sheet made by plating the same has such a constitution as 0.10 to 0.25% of C, 1.0 to 2.0% of Si and 1.5 to 3.0% of Mn, are contained in terms of weight percentage, while other elements are controlled such as Al within 0.2%, P within 0.15% and S within 0.02%, with residual austenite occupying at least 5%, bainitic ferrite occupying at least 60% (preferably 80% or more), and polygonal ferrite within 20% (containing 0%), so that a tensile strength is 980 MPa or higher, while an elongation (El in %), a flange drawing property (?in %), a tensile strength (TS in MPa) and a yield strength (YP in MPa) satisfy the following inequality (1): [(El ×?×TS)/YP]?645.Type: GrantFiled: January 28, 2005Date of Patent: September 22, 2009Assignee: Kabuhsiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Shushi Ikeda, Hiroshi Akamizu, Koichi Makii, Yoichi Mukai, Koichi Sugimoto
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Publication number: 20080196796Abstract: A Zn—Al alloy excellent in static deformability as well as dynamic deformability and applicable to large-sized structures, and a method for production thereof. The alloy contains 30-99% Zn, with the remainder being Al and inevitable impurities, and has a metallographic structure in which the ? phase or ?? phase having an average grain size no larger than 5 ?m contains the ? phase finely dispersed therein, the Al inclusions have a maximum equivalent circle diameter no larger than 50 ?m and are free of pores no smaller than 0.5 mm in terms of equivalent circle diameter, and the macrosegregation of Al is less than 3.0% and the microsegregation of Al is less than 2.0%. (% means mass %.Type: ApplicationFiled: June 1, 2005Publication date: August 21, 2008Inventors: Koichi Makii, Seiya Furuta, Toshiaki Takagi
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Publication number: 20080178972Abstract: The present invention relates to A high strength steel sheet having a structure which is mainly composed of MD structure (Micro Duplex structure) comprising a ferrite matrix, and as a secondary phase, martensite or martensite and retained austenite, finely dispersed in said matrix, wherein the proportion that the MD structure occupies in the whole structure is 90% or more, wherein the proportion that the secondary phase present in the whole structure occupies in the whole structure is from 10 to 60%, wherein the secondary phase in the MD structure is present in ferrite grains and at grain boundary, in which the proportion of the secondary phase present in the ferrite grains is 50% or more, and wherein the average grain size of the secondary phase in the whole structure is 3 ?m or less. The secondary phase is constituted of martensite, or martensite and retained austenite.Type: ApplicationFiled: October 16, 2007Publication date: July 31, 2008Applicants: KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD), National University Corporation Kagawa UniversityInventors: Kenji SAITO, Tomokazu MASUDA, Toshio MURAKAMI, Koichi MAKII, Kazutoshi KUNISHIGE, Rintaro UEJI
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Publication number: 20080092996Abstract: A high-strength forged part is disclosed which comprises a base phase structure, comprising 30% or more of ferrite in terms of a space factor, and a second phase structure, comprising bainite and/or martensite, and retained austenite having an average grain diameter of 5 ?m or less and a content represented by 50X[C]<[V?R]<150x[C], wherein [V?R] represents a space factor of the retained austenite (?R) and [C] represents the mass % of C in the forged part. Furthermore, a high-strength forged part is disclosed which comprises a base phase structure, comprising 50% or more of tempered bainite or tempered martensite in terms of a space factor, and a second phase structure, comprising martensite and 3% to 30% retained austenite in terms of a space factor, wherein the portion of the retained austenite and martensite having an aspect ratio of 2 or less is 25% or less in terms of a space factor.Type: ApplicationFiled: October 18, 2007Publication date: April 24, 2008Applicant: KABUSHIKI KAISHA KOBE SEIKO SHOInventors: Shushi Ikeda, Koichi Makii, Hiroshi Akamizu, Yoichi Mukai, Koh-ichi Sugimoto
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Patent number: 7314532Abstract: A high-strength forged part is disclosed which comprises a base phase structure, comprising 30% or more of ferrite in terms of a space factor, and a second phase structure, comprising bainite and/or martensite, and retained austenite having an average grain diameter of 5 ?m or less and a content represented by 50×[C]<[V?R]<150×[C], wherein [V?R] represents a space factor of the retained austenite (?R) and [C] represents the mass % of C in the forged part. Furthermore, a high-strength forged part is disclosed which comprises a base phase structure, comprising 50% or more of tempered bainite or tempered martensite in terms of a space factor, and a second phase structure, comprising martensite and 3% to 30% retained austenite in terms of a space factor, wherein the portion of the retained austenite and martensite having an aspect ratio of 2 or less is 25% or less in terms of a space factor.Type: GrantFiled: February 25, 2004Date of Patent: January 1, 2008Assignee: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Shushi Ikeda, Koichi Makii, Hiroshi Akamizu, Yoichi Mukai, Koh-ichi Sugimoto
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Publication number: 20070107813Abstract: A Zn—Al alloy excellent in elongation, and a method for producing the same are provided. The Zn—Al alloy comprises Zn in a range of 68 to 88% by mass and the remainder including Al and unavoidable impurities, and has a structure with ? phases finely dispersed in respective ? phases or respective ?? phases, not more than 5 ?m in average grain size, a macrosegregation value of Al in the structure being less than 3%, wherein lamellar structures at a central part of the structure is at not higher than 30% by volume, and a difference in average hardness between the central part and a surface layer zone of the structure is not more than 15%, so that the Zn—Al alloy is improved in respect of elongation and uniformity.Type: ApplicationFiled: October 16, 2006Publication date: May 17, 2007Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Toshiaki Takagi, Koichi Makii, Seiya Furuta
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Patent number: 7008488Abstract: A high-strength steel sheet comprises carbon: 0.06 to 0.25 mass %, Si: 0.5 to 3.5 mass % and Mn: 0.7 to 4 mass %. Its mother structure is ferrite, its second phase structure comprises martensite and the residual austenite and the second phase structure measured by image analysis has an area fraction of 25% or less based on the total structure. The steel sheet satisfies the following requirements (1) to (3): (1) the volume fraction (Vt?hd R) of the residual austenite is 5% or more; (2) the ratio (SF?R/Vt?R) of the area fraction (SF?R) of the residual austenite within ferrite to Vt?R is 0.65 or more; and (3) the ratio [?2/(?1+?R)] of the space factor (?2) of martensite to the second phase structure (?1+?R) is 0.25 to 0.60. The steel sheet has excellent balance between strength and local elongation, and a low yield ratio.Type: GrantFiled: July 9, 2003Date of Patent: March 7, 2006Assignee: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Hiroshi Akamizu, Shushi Ikeda, Koichi Makii
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Publication number: 20050247378Abstract: To provide a high-strength cold rolled steel sheet that has well-balanced tensile strength and elongation as well as well-balanced tensile strength and stretch-flangeability, and a plated steel sheet manufactured by plating the steel sheet. The high-strength cold rolled steel sheet contains: 0.10 to 0.28% of C, 1.0 to 2.0% of Si, 1.0 to 3.0% of Mn, and 0.03 to 0.10% of Nb in terms of % by mass, wherein the content of Al is controlled to 0.5 or less, the content of P is controlled to 0.15% or less, and the content of S is controlled to 0.02% or less, and wherein residual austenite accounts for 5 to 20%, bainitic ferrite accounts for 50% or more, and polygonal ferrite accounts for 30% or less (containing 0%), of the entire structure, and wherein a mean number of residual austenite blocks is 20 or more as determined when the random area (15 ?m×15 ??m) is observed by EBSP (electron back scatter diffraction pattern).Type: ApplicationFiled: April 21, 2005Publication date: November 10, 2005Applicants: Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.), SHINSHU TLO CO., LTD.Inventors: Shushi Ikeda, Yoichi Mukai, Hiroshi Akamizu, Koichi Makii, Koichi Sugimoto, Shunichi Hashimoto, Kenji Saito
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Publication number: 20050161134Abstract: To provide a high strength and low yield ratio cold rolled steel sheet having high elongation property and high flange drawing property, or a plated steel sheet made by plating the same. The high strength and low yield ratio cold rolled steel sheet or the plated steel sheet made by plating the same has such a constitution as 0.10 to 0.25% of C, 1.0 to 2.0% of Si and 1.5 to 3.0% of Mn, are contained in terms of weight percentage, while other elements are controlled such as Al within 0.2%, P within 0.15% and S within 0.02%, with residual austenite occupying at least 5%, bainitic ferrite occupying at least 60% (preferably 80% or more), and polygonal ferrite within 20% (containing 0%), so that a tensile strength is 980 MPa or higher, while an elongation (El in %), a flange drawing property (? in %), a tensile strength (TS in MPa) and a yield strength (YP in MPa) satisfy the following inequality (1): [(El×?×TS)/YP]?645.Type: ApplicationFiled: January 28, 2005Publication date: July 28, 2005Applicants: SHINSHU TLO CO., LTD., KABUSHIKI KAISHA KOBE SEIKO SHOInventors: Shushi Ikeda, Hiroshi Akamizu, Koichi Makii, Yoichi Mukai, Koichi Sugimoto
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Publication number: 20050150580Abstract: The present invention provides an ultra-high strength steel sheet having excellent hydrogen embrittlement resistance, which includes: 0.06 to 0.6% of C; 0.5 to 3% of Si+Al; 0.5 to 3% of Mn; 0.15% or lower of P; and 0.02% or lower of S in terms of mass percentage, and also includes 3% or higher of residual austenite structure, 30% or higher of bainitic ferrite structure, and preferably 50% or lower of polygonal ferrite in terms of an areal ratio to the entire structure, wherein a mean grain size of bainite blocks is smaller than 20 ?m as determined by comparing observations of the same region of the bainitic ferrite structure by EBSP (electron back scatter diffraction pattern) and SEM.Type: ApplicationFiled: January 7, 2005Publication date: July 14, 2005Applicants: Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.), SHINSHU TLO CO., LTD.Inventors: Hiroshi Akamizu, Shushi Ikeda, Koichi Makii, Yoichi Mukai, Koichi Sugimoto
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Publication number: 20040226635Abstract: A high-strength forged part is disclosed which comprises a base phase structure, comprising 30% or more of ferrite in terms of a space factor, and a second phase structure, comprising bainite and/or martensite, and retained austenite having an average grain diameter of 5 &mgr;m or less and a content represented by 50×[C]<[V&ggr;R]<150×[C], wherein [V&ggr;R] represents a space factor of the retained austenite (&ggr;R) and [C] represents the mass % of C in the forged part. Furthermore, a high-strength forged part is disclosed which comprises a base phase structure, comprising 50% or more of tempered bainite or tempered martensite in terms of a space factor, and a second phase structure, comprising martensite and 3% to 30% retained austenite in terms of a space factor, wherein the portion of the retained austenite and martensite having an aspect ratio of 2 or less is 25% or less in terms of a space factor.Type: ApplicationFiled: February 25, 2004Publication date: November 18, 2004Applicant: KABUSHIKI KAISHA KOBE SEIKO SHOInventors: Shushi Ikeda, Koichi Makii, Hiroshi Akamizu, Yoichi Mukai, Koh-ichi Sugimoto
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Publication number: 20040159373Abstract: A steel sheet with excellent bendability in which the main structure is composed of retained austenite (5-30 area %) and ferrite (no less than 50 area %) such that there exist no more than 40 carbide grains per 2000 &mgr;m2 between the retained austenite and the ferrite. The steel sheet is suitable for automobiles which exhibits bending properties (bendability and tight bendability) even though its strength is as high as 600 to 1400 MPa.Type: ApplicationFiled: July 25, 2003Publication date: August 19, 2004Applicant: Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.)Inventors: Shushi Ikeda, Koichi Makii, Hiroshi Akamizu
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Publication number: 20040035500Abstract: A dual phase steel sheet with good bake-hardening properties is provided. The steel sheet is characterized in containing (in terms of percent by mass) C: no less than 0.06% and less than 0.25%; Si+Al: 0.5 to 3%; Mn: 0.5 to 3%; P: no more than 0.15%; and S: no more than 0.02%; and also meeting the following condition (in terms of space factor) that retained austenite is at least 3%, bainite is at least 30%, and ferrite is no more than 50%, and further characterized in differing in stress larger than 50 MPa before and after application of 2% pre-strain and ensuing heat treatment for paint baking at 170° C. for 20 minutes. The steel sheet has well-balanced strength and workability, exhibits good bake-hardening properties at the time of paint baking, and offers good resistance to natural aging.Type: ApplicationFiled: August 13, 2003Publication date: February 26, 2004Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd)Inventors: Shushi Ikeda, Koichi Makii, Hiroshi Akamizu