公开(公告)号：ZA201207927B

公开(公告)日：2013-06-26

申请号：ZA201207927

申请日：2012-10-22

Applicant: JFE STEEL CORP

Inventor： HASEGAWA KOHEI

IPC: C22C20060101

公开(公告)号：AT506458T

公开(公告)日：2011-05-15

申请号：AT09002195

申请日：2009-02-17

Applicant: JFE STEEL CORP ,  THYSSENKRUPP STEEL EUROPE AG

Inventor： KAWAMURA KENJI ,  KIZU TARO ,  TAKAGI SHUSAKU ,  HASEGAWA KOHEI ,  MATSUDA HIROSHI ,  KOBAYASHI AKIO ,  NAGATAKI YASUNOBU ,  TANAKA YASUSHI ,  HELLER THOMAS ,  HAMMER BRIGITTE ,  BIAN JIAN ,  STICH GUENTER ,  BODE ROLF

IPC: C21D8/04 ,  C21D9/46 ,  C21D9/48 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14

Abstract: A high strength steel sheet and a method for manufacturing the same are proposed, the high strength steel sheet having superior phosphatability properties and hot-dip galvannealed properties besides a tensile strength of 950 MPa or more and a high ductility, and also having a small variation in mechanical properties with the change in annealing conditions. The high strength steel sheet described above has a component composition which includes 0.05 to 0.20 mass percent of C, 0.5 mass percent or less of Si, 1.5 to 3.0 mass percent of Mn, 0.06 mass percent or less of P, 0.01 mass percent or less of S, 0.3 to 1.5 mass percent of Al, 0.02 mass percent or less of N, 0.01 to 0.1 mass percent of Ti, and 0.0005 to 0.0030 mass percent of B; at least one of 0.1 to 1.5 mass percent of Cr and 0.01 to 2.0 mass percent of Mo; and the balance being Fe and inevitable impurities, and in addition, this high strength steel sheet is composed of a microstructure including ferrite and martensite and has a tensile strength of 950 MPa or more.

公开(公告)号：DE60335624D1

公开(公告)日：2011-02-17

申请号：DE60335624

申请日：2003-06-06

Applicant: JFE STEEL CORP

Inventor： HASEGAWA KOHEI ,  NAKAMURA NOBUYUKI ,  URABE TOSHIAKI

IPC: C21D9/46 ,  C21D1/19 ,  C21D8/02 ,  C21D9/52 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14

公开(公告)号：DE60138204D1

公开(公告)日：2009-05-14

申请号：DE60138204

申请日：2001-09-10

Applicant: JFE STEEL CORP

Inventor： HASEGAWA KOHEI ,  URABE TOSHIAKI ,  YOSHITAKE AKIHIDE ,  TSURUMARU HIDEYUKI

IPC: C22C38/00 ,  C21D1/19 ,  C21D8/02 ,  C21D9/46 ,  C21D9/52 ,  C22C38/06 ,  C22C38/38

Abstract: The present invention relates to an ultra-high strength cold rolled steel sheet having 880 to 1170 MPa of tensile strength, that consists essentially of 0.01 to 0.07% C, 0.3% or less Si, 0.1% or less P, 0.01% or less S, 0.01 to 0.1% sol.Al, 0.0050% or less N. 1.6 to 2.5% of sum of at least one element selected from the group consisting of Mn, Cr, and Mo, by mass, and balance of Fe, and that has an inner zone deeper than 10 mum from the surface of the steel sheet being substantially martensitic single phase structure. Since the steel sheet has hole expansion ratio of 75% or more, specified by the Standard of Japan Iron and Steel Federation, JFST1001-1996, tensile strength in a range of from 880 to 1170 MPa, and excellent mechanically joining property, it is suitable for automobile seat frames.

公开(公告)号：DE69938265T2

公开(公告)日：2009-02-26

申请号：DE69938265

申请日：1999-12-03

Applicant: JFE STEEL CORP

Inventor： FUJITA TAKESHI ,  KITANO FUSATO ,  HOSOYA YOSHIHIRO ,  INAZUMI TORU ,  YAMASAKI YUJI ,  MORITA MASAYA ,  NAGATAKI YASUNOBU ,  HASEGAWA KOHEI ,  MATSUDA HIROSHI ,  ONO MORIAKI

IPC: C22C38/12 ,  C21D8/02 ,  C21D8/04 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06

Abstract: The present invention relates to a very low C-Nb cold rolled steel sheet giving 340 to 440 MPa of tensile strength. For example, the cold rolled steel sheet consists of 0.0040 to 0.01% C, not more than 0.05% Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, not more than 0.02% S, 0.01 to 0.1% sol.Al, not more than 0.004% N, 0.01 to 0.14% Nb, by weight, and balance of Fe and inevitable impurities, and has not less than 0.21 of n value calculated from two points (1% and 10%) of nominal strain determined by the uniaxial tensile test, and relates to a method for manufacturing the cold rolled steel sheet. The present invention provides a high strength cold rolled steel sheet for automobile exterior panels having excellent combined formability, resistance to embrittlement during secondary operation, formability at welded portions, anti-burring performance, good surface appearance, and uniformity of material in a coil.

公开(公告)号：DE69938265D1

公开(公告)日：2008-04-10

申请号：DE69938265

申请日：1999-12-03

Applicant: JFE STEEL CORP

Inventor： FUJITA TAKESHI ,  KITANO FUSATO ,  HOSOYA YOSHIHIRO ,  INAZUMI TORU ,  YAMASAKI YUJI ,  MORITA MASAYA ,  NAGATAKI YASUNOBU ,  HASEGAWA KOHEI ,  MATSUDA HIROSHI ,  ONO MORIAKI

IPC: C22C38/12 ,  C21D8/02 ,  C21D8/04 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06

Abstract: The present invention relates to a very low C-Nb cold rolled steel sheet giving 340 to 440 MPa of tensile strength. For example, the cold rolled steel sheet consists of 0.0040 to 0.01% C, not more than 0.05% Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, not more than 0.02% S, 0.01 to 0.1% sol.Al, not more than 0.004% N, 0.01 to 0.14% Nb, by weight, and balance of Fe and inevitable impurities, and has not less than 0.21 of n value calculated from two points (1% and 10%) of nominal strain determined by the uniaxial tensile test, and relates to a method for manufacturing the cold rolled steel sheet. The present invention provides a high strength cold rolled steel sheet for automobile exterior panels having excellent combined formability, resistance to embrittlement during secondary operation, formability at welded portions, anti-burring performance, good surface appearance, and uniformity of material in a coil.

公开(公告)号：DE69935125D1

公开(公告)日：2007-03-29

申请号：DE69935125

申请日：1999-12-03

Applicant: JFE STEEL CORP

Inventor： FUJITA TAKESHI ,  KITANO FUSATO ,  HOSOYA YOSHIHIRO ,  INAZUMI TORU ,  YAMASAKI YUJI ,  MORITA MASAYA ,  NAGATAKI YASUNOBU ,  HASEGAWA KOHEI ,  MATSUDA HIROSHI ,  ONO MORIAKI

IPC: C22C38/12 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14

Abstract: The present invention relates to a very low C-Nb cold rolled steel sheet giving 340 to 440 MPa of tensile strength. For example, the cold rolled steel sheet consists of 0.0040 to 0.01% C, not more than 0.05% Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, not more than 0.02% S, 0.01 to 0.1% sol.Al, not more than 0.004% N, 0.01 to 0.14% Nb, by weight, and balance of Fe and inevitable impurities, and has not less than 0.21 of n value calculated from two points (1% and 10%) of nominal strain determined by the uniaxial tensile test, and relates to a method for manufacturing the cold rolled steel sheet. The present invention provides a high strength cold rolled steel sheet for automobile exterior panels having excellent combined formability, resistance to embrittlement during secondary operation, formability at welded portions, anti-burring performance, good surface appearance, and uniformity of material in a coil.

公开(公告)号：AT353985T

公开(公告)日：2007-03-15

申请号：AT99973310

申请日：1999-12-03

Applicant: JFE STEEL CORP

Inventor： FUJITA TAKESHI ,  KITANO FUSATO ,  HOSOYA YOSHIHIRO ,  INAZUMI TORU ,  YAMASAKI YUJI ,  MORITA MASAYA ,  NAGATAKI YASUNOBU ,  HASEGAWA KOHEI ,  MATSUDA HIROSHI ,  ONO MORIAKI

IPC: C21D8/02 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C21D9/46

Abstract: The present invention relates to a very low C-Nb cold rolled steel sheet giving 340 to 440 MPa of tensile strength. For example, the cold rolled steel sheet consists of 0.0040 to 0.01% C, not more than 0.05% Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, not more than 0.02% S, 0.01 to 0.1% sol.Al, not more than 0.004% N, 0.01 to 0.14% Nb, by weight, and balance of Fe and inevitable impurities, and has not less than 0.21 of n value calculated from two points (1% and 10%) of nominal strain determined by the uniaxial tensile test, and relates to a method for manufacturing the cold rolled steel sheet. The present invention provides a high strength cold rolled steel sheet for automobile exterior panels having excellent combined formability, resistance to embrittlement during secondary operation, formability at welded portions, anti-burring performance, good surface appearance, and uniformity of material in a coil.

公开(公告)号：EP3009527A4

公开(公告)日：2016-07-06

申请号：EP14834577

申请日：2014-07-18

Applicant: JFE STEEL CORP

Inventor： TAKASHIMA KATSUTOSHI ,  ONO YOSHIHIKO ,  HASEGAWA KOHEI

IPC: C22C38/00 ,  C21D8/12 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/38 ,  C22C38/58

CPC classification number: C21D9/46 ,  C21D1/25 ,  C21D1/84 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0278 ,  C21D8/0473 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/38

Abstract: Provided are a high-strength cold-rolled steel sheet having excellent elongation, excellent stretch flangeability, and high yield ratio and a method for manufacturing the same. The high-strength cold-rolled steel sheet has a composition and a microstructure. The composition contains 0.15% to 0.27% C, 0.8% to 2.4% Si, 2.3% to 3.5% Mn, 0.08% or less P, 0.005% or less S, 0.01% to 0.08% Al, and 0.010% or less N on a mass basis, the remainder being Fe and inevitable impurities. The microstructure comprises: ferrite having an average grain size of 5 µm or less and a volume fraction of 3% to 20%, retained austenite having a volume fraction of 5% to 20%, and martensite having a volume fraction of 5% to 20%, the remainder being bainite and/or tempered martensite. The total number of retained austenite with a grain size of 2 µm or less, martensite with a grain size of 2 µm or less, or a mixed phase thereof is 150 or more per 2,000 µm 2 of a thickness cross section parallel to the rolling direction of the steel sheet.

公开(公告)号：EP2762580A4

公开(公告)日：2015-06-03

申请号：EP12835327

申请日：2012-09-27

Applicant: JFE STEEL CORP

Inventor： TAKASHIMA KATSUTOSHI ,  TOJI YUKI ,  KARIYA NOBUSUKE ,  HASEGAWA KOHEI

IPC: C22C38/00 ,  B32B15/01 ,  C21D8/02 ,  C21D8/04 ,  C21D9/46 ,  C21D9/48 ,  C22C18/04 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/26 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28

CPC classification number: C23C2/02 ,  B32B15/013 ,  C21D8/0226 ,  C21D8/0263 ,  C21D8/0426 ,  C21D8/0463 ,  C21D9/46 ,  C21D9/48 ,  C21D2211/005 ,  C22C18/04 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/26 ,  C23C2/06 ,  C23C2/28 ,  Y10T428/12799

Abstract: Provided is a high-strength hot-dip galvanized steel sheet having excellent workability, namely, excellent ductility and hole expansion formability, and high yield ratio. The steel sheet has a chemical composition containing by mass %: C: 0.05-0.15 %; Si: 0.10-0.90 %; Mn: 1.0-1.9 %; P: 0.005-0.10 %; S: 0.0050 % or less; Al: 0.01-0.10 %; N: 0.0050 % or less; Nb: 0.010-0.100 %; and the balance being Fe and incidental impurities, in which: the steel sheet has a complex phase that includes: ferrite having an average crystal grain size of 15 µm or less to at least 90 % in volume fraction; martensite having an average crystal grain size of 3.0 µm or less to 0.5 % or more and less than 5.0 % in volume fraction; pearlite to 5.0 % or less in volume fraction; and the balance being a phase generated at low temperature.