Patents by Inventor Nobusato Kojima

Nobusato Kojima 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).

  • Patent number: 8828153
    Abstract: A high-strength cold-rolled steel sheet providing a product with a good surface condition after press forming, having excellent bake hardenability and anti room temperature aging property, and having a dual phase structure with a tensile strength of at least 340 MPa is provided. A high-strength cold-rolled steel sheet has a structure comprising a main phase which is a ferrite and a secondary phase which is a low temperature transformation product including a martensite and has a hardness distribution of the ferrite phase in an arbitrary cross section having a length of 10 mm in the widthwise 10 direction of the sheet which satisfies the relationship prescribed by (HV(max)?HV(ave))<0.5×(Hv(ave). HV(max) is the maximum Vickers hardness of ferrite grains in a region at a distance of from (?)t to (¼)t in the thickness direction from the surface when the thickness of the high-strength cold-rolled steel sheet is t, and Hv(ave) is the average Vickers hardness of ferrite grains in this region.
    Type: Grant
    Filed: December 8, 2010
    Date of Patent: September 9, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Jun Haga, Nobusato Kojima
  • Publication number: 20140008937
    Abstract: A side structure for an automobile body has an A-pillar having a first portion which has a closed cross section and which is connected to a side sill and extends upwards, and a second portion which has a closed cross section and which is continuous with the first portion and extends along a slope therefrom, and a roof rail side member which has a closed cross section and which is continuous with the A-pillar and is connected to a B-pillar. The side reinforcing member having a closed cross section and a shape which is bent three-dimensionally and which is constituted by a single member in the axial direction and has undergone high frequency quenching is disposed so a to extend at least inside the second portion and inside the roof rail side member to be positioned to the rear of the connection with the B-pillar.
    Type: Application
    Filed: May 1, 2013
    Publication date: January 9, 2014
    Inventors: Michitaka YOSHIDA, Nobusato Kojima, Atsushi Tomizawa, Naoaki Shimada
  • Publication number: 20130280548
    Abstract: A bent metal member has a body formed from a tubular metal material and has a shape which is bent two-dimensionally or three-dimensionally. The surface of the body has a Zn-based coating which contains an ? phase and which satisfies the following condition: coating weight: at most 90 g/m2 per side, Fe content: 8-35 mass %, and a surface roughness Ra prescribed by WS B 0601: at most 2.0 ?m. The bent metal member can have a closed cross section, an open cross section, or a shaped cross section.
    Type: Application
    Filed: June 19, 2013
    Publication date: October 24, 2013
    Inventors: Toyomitsu NAKAMURA, Atsushi Tomizawa, Naoaki Shimada, Nobusato Kojima, Kazuya Ishii, Kazuhito Imai, Tamotsu Toki
  • Publication number: 20130213534
    Abstract: A steel material which is suitable for hot press working or hot three-dimensional bending and direct quench and which can be used to manufacture a high-strength formed article with sufficient quench hardening even by short time heating at a low temperature has a chemical composition comprising, in mass percent, C: 0.05-0.35%, Si: at most 0.5%, Mn: 0.5-2.5%, P: at most 0.03%, S: at most 0.01%, sol. Al: at most 0.1%, N: at most 0.01%, and optionally at least one element selected from the group consisting of B: 0.0001-0.005%, Ti: 0.01-0.1%, Cr: 0.18-0.5%, Nb: 0.03-0.1%, Ni: 0.18-1.0%, and Mo: 0.03-0.5% and has a steel structure in which the spheroidization ratio of carbides is 0.60-0.90.
    Type: Application
    Filed: August 22, 2012
    Publication date: August 22, 2013
    Applicant: SUMITOMO METAL INDUSTRIES, LTD.
    Inventors: Kazuo HIKITA, Nobusato KOJIMA
  • Patent number: 8490457
    Abstract: A method of manufacturing a bent metal member comprises supporting the outer surface of a tubular metal material having a Zn-Fe alloy coating layer at two locations spaced in the axial direction of the metal material. The metal material is fed in its axial direction and heated at a position between the two locations to a temperature range of at least the Ac3 point at a heating speed such that the rate of temperature increase is at least 3.0×102° C. per second, held so that the time for which the surface of the metal material is at a temperature of 8.0×102° C. or higher is at most 2 seconds, and then rapid cooled. A bending moment is imparted to the healed portion in two or three dimensions to manufacture a bent metal member having on its surface a Zn-based layer which contains an ?, phase.
    Type: Grant
    Filed: July 19, 2011
    Date of Patent: July 23, 2013
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Toyomitsu Nakamura, Atsushi Tomizawa, Naoaki Shimada, Nobusato Kojima, Kazuya Ishii, Kazuhito Imai, Tamotsu Toki
  • Patent number: 8454079
    Abstract: A front side member having a single body formed from a tubular body having a closed cross section has a front portion which extends in the fore and aft direction of a vehicle body, a sloping portion which is continuous with the front portion and slopes downwards along a dash panel, and a rear portion continuous with the sloping portion and extending along the bottom surface of a floor panel joined to the dash panel. A portion of the front portion is an unquenched portion which has not undergone quenching treatment and the remainder is a high frequency quenched portion which has undergone high frequency quenching. The sloping portion is a high frequency quenched portion. A portion of the rear portion is an unquenched portion which has not undergone quenching and the remainder other than that portion is a high frequency quenched portion which has undergone high frequency quenching.
    Type: Grant
    Filed: February 15, 2012
    Date of Patent: June 4, 2013
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Michitaka Yoshida, Nobusato Kojima, Atsushi Tomizawa, Naoaki Shimada
  • Publication number: 20120267919
    Abstract: A front side member having a single body formed from a tubular body having a closed cross section has a front portion which extends in the fore and aft direction of a vehicle body, a sloping portion which is continuous with the front portion and slopes downwards along a dash panel, and a rear portion continuous with the sloping portion and extending along the bottom surface of a floor panel joined to the dash panel. A portion of the front portion is an unquenched portion which has not undergone quenching treatment and the remainder is a high frequency quenched portion which has undergone high frequency quenching. The sloping portion is a high frequency quenched portion. A portion of the rear portion is an unquenched portion which has not undergone quenching and the remainder other than that portion is a high frequency quenched portion which has undergone high frequency quenching.
    Type: Application
    Filed: February 15, 2012
    Publication date: October 25, 2012
    Applicant: SUMITOMO METAL INDUSTRIES, LTD.
    Inventors: Michitaka YOSHIDA, Nobusato Kojima, Atsushi Tomizawa, Naoaki Shimada
  • Patent number: 8136871
    Abstract: A strength member for an automobile body such as a side member or a pillar which has a bent portion which is bent two-dimensionally or three-dimensionally and which has an ultrahigh strength with a tensile strength exceeding 1100 MPa is provided. The strength member for an automobile body has a tubular body which has a closed cross section which does not have an outwardly-extending flange and which has a bent portion which is bent two-dimensionally or three-dimensionally, a portion to be cut or punched, and a portion to be welded.
    Type: Grant
    Filed: October 2, 2009
    Date of Patent: March 20, 2012
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Michitaka Yoshida, Nobusato Kojima, Atsushi Tomizawa, Naoaki Shimada
  • Publication number: 20120009435
    Abstract: A bent metal member which is obtained by bending accompanied by heat treatment of a zinc-based coated metal material and which is suitable for use in components of automobiles due to having a high strength and excellent post-painting corrosion resistance is manufactured. The outer surface of a tubular metal material having on its surface a Zn—Fe alloy coating layer with a coating weight of 30-90 g/m2 per side, an Fe content of 8-20%, and a surface roughness Ra of at most 0.8 ?m is supported at two locations spaced in the axial direction of the metal material so that the material can move in its axial direction, the metal material is heated between the two locations to a temperature range of at least the Ac3 point at a heating speed such that the rate of temperature increase is at least 3.0×102° C. per second while feeding the metal material in its axial direction, holding so that the length of time for which the surface of the metal material is at 8.0×102° C.
    Type: Application
    Filed: July 19, 2011
    Publication date: January 12, 2012
    Applicant: SUMITOMO METAL INDUSTRIES, LTD.
    Inventors: Toyomitsu NAKAMURA, Atsushi TOMIZAWA, Naoaki SHIMADA, Nobusato KOJIMA, Kazuya ISHII, Kazuhito IMAI, Tamotsu TOKI
  • Publication number: 20110073218
    Abstract: A high-strength cold-rolled steel sheet providing a product with a good surface condition after press forming, having excellent bake hardenability and anti room temperature aging property, and having a dual phase structure with a tensile strength of at least 340 MPa is provided. A high-strength cold-rolled steel sheet has a structure comprising a main phase which is a ferrite and a secondary phase which is a low temperature transformation product including a martensite and has a hardness distribution of the ferrite phase in an arbitrary cross section having a length of 10 mm in the widthwise direction of the sheet which satisfies the relationship prescribed by (Hv(max)?Hv(ave))<0.5×(Hv(ave). Hv(max) is the maximum Vickers hardness of ferrite grains in a region at a distance of from (?)t to (¼)t in the thickness direction from the surface when the thickness of the high-strength cold-rolled steel sheet is t, and Hv(ave) is the average Vickers hardness of ferrite grains in this region.
    Type: Application
    Filed: December 8, 2010
    Publication date: March 31, 2011
    Applicant: SUMITOMO METAL INDUSTRIES, LTD.
    Inventors: Jun HAGA, Nobusato KOJIMA
  • Publication number: 20110048585
    Abstract: A heat treated galvannealed steel material having excellent post-painting corrosion resistance and a high strength which is suitable for use as an automotive part and a method for its manufacture are provided. A galvannealed steel material having a galvannealed coating on at least one side thereof is heat treated by heating at least a portion thereof to a temperature range in which hardening is possible. The coating remaining on the surface of at least a part of the portion which underwent heat treatment has a coating weight of at least 20 g/m2 and at most 80 g/m2 per side and an Fe content of at least 15% and at most 35%, an ? phase is present in the coating, and the centerline average roughness Ra of the surface of the coating is at most 1.5 ?m.
    Type: Application
    Filed: July 23, 2010
    Publication date: March 3, 2011
    Inventors: Tamotsu Toki, Atsushi Tomizawa, Nobusato Kojima, Kazuya Ishii, Kazuhito Imai, Toyomitsu Nakamura, Naoaki Shimada
  • Publication number: 20100084892
    Abstract: A strength member for an automobile body such as a side member or a pillar which has a bent portion which is bent two-dimensionally or three-dimensionally and which has an ultrahigh strength with a tensile strength exceeding 1100 MPa is provided. The strength member for an automobile body has a tubular body which has a closed cross section which does not have an outwardly-extending flange and which has a bent portion which is bent two-dimensionally or three-dimensionally, a portion to be cut or punched, and a portion to be welded.
    Type: Application
    Filed: October 2, 2009
    Publication date: April 8, 2010
    Inventors: Michitaka Yoshida, Nobusato Kojima, Atsushi Tomizawa, Naoaki Shimada
  • Patent number: 7673485
    Abstract: Hot press forming of a steel material is made possible by coating the surface of the steel material with a plated layer of zinc or a zinc alloy and forming thereon a barrier layer which prevents the vaporization of zinc even when heated to 700-1000° C. Corrosion resistance can also be guaranteed without requiring post treatment, and hot press forming of high tensile steel sheet and stainless steel sheet is made possible. The barrier layer is formed by forming an upper plated layer, by surface oxidation, by contact with an oxidizing agent, by contact with Zn and an oxidizing agent, by anodic electrolysis, by cathodic electrolysis, or by coating with a ZnO sol.
    Type: Grant
    Filed: July 22, 2005
    Date of Patent: March 9, 2010
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Kazuhito Imai, Tamotsu Toki, Yukihiro Yoshikawa, Masaru Takahashi, Toshinobu Nishibata, Nobusato Kojima
  • Publication number: 20080202638
    Abstract: A high-strength cold-rolled steel sheet providing a product with a good surface condition after press forming, having excellent bake hardenability and anti room temperature aging property, and having a dual phase structure with a tensile strength of at least 340 MPa is provided. A high-strength cold-rolled steel sheet has a structure comprising a main phase which is a ferrite and a secondary phase which is a low temperature transformation product including a martensite and has a hardness distribution of the ferrite phase in an arbitrary cross section having a length of 10 mm in the widthwise direction of the sheet which satisfies the relationship prescribed by (Hv(max)?Hv(ave))<0.5×(Hv(ave). Hv(max) is the maximum Vickers hardness of ferrite grains in a region at a distance of from (?)t to (¼)t in the thickness direction from the surface when the thickness of the high-strength cold-rolled steel sheet is t, and Hv(ave) is the average Vickers hardness of ferrite grains in this region.
    Type: Application
    Filed: January 3, 2008
    Publication date: August 28, 2008
    Inventors: Jun Haga, Nobusato Kojima
  • Publication number: 20050252262
    Abstract: Hot press forming of a steel material is made possible by coating the surface of the steel material with a plated layer of zinc or a zinc alloy and forming thereon a barrier layer which prevents the vaporization of zinc even when heated to 700-1000° C. Corrosion resistance can also be guaranteed without requiring post treatment, and hot press forming of high tensile steel sheet and stainless steel sheet is made possible. The barrier layer is formed by forming an upper plated layer, by surface oxidation, by contact with an oxidizing agent, by contact with Zn and an oxidizing agent, by anodic electrolysis, by cathodic electrolysis, or by coating with a ZnO sol.
    Type: Application
    Filed: July 22, 2005
    Publication date: November 17, 2005
    Inventors: Kazuhito Imai, Tamotsu Toki, Yukihiro Yoshikawa, Masaru Takahashi, Toshinobu Nishibata, Nobusato Kojima
  • Publication number: 20040166360
    Abstract: Hot press forming of a steel material is made possible by coating the surface of the steel material with a plated layer of zinc or a zinc alloy and forming thereon a barrier layer which prevents the vaporization of zinc even when heated to 700-1000° C. Corrosion resistance can also be guaranteed without requiring post treatment, and hot press forming of high tensile steel sheet and stainless steel sheet is made possible. The barrier layer is formed by forming an upper plated layer, by surface oxidation, by contact with an oxidizing agent, by contact with Zn and an oxidizing agent, by anodic electrolysis, by cathodic electrolysis, or by coating with a ZnO sol.
    Type: Application
    Filed: December 10, 2003
    Publication date: August 26, 2004
    Inventors: Kazuhito Imai, Tamotsu Toki, Yukihiro Yoshikawa, Masaru Takahashi, Toshinobu Nishibata, Nobusato Kojima