公开(公告)号：US20190085426A1

公开(公告)日：2019-03-21

申请号：US16080571

申请日：2017-02-08

申请人： Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

发明人： Muneaki IKEDA ,  Koji KASUYA ,  Tadao MURATA ,  Kenji SAITO ,  Toshio MURAKAMI ,  Yuichi FUTAMURA

IPC分类号： C21D9/46 ,  C22C38/00 ,  C22C38/04 ,  C22C38/02 ,  C22C38/06 ,  C23C2/02 ,  C23C2/06 ,  C23C2/40

摘要： One aspect of the present invention is a high strength steel sheet having a specific component composition, wherein a metal structure of the steel sheet comprises polygonal ferrite, bainite, tempered martensite, and retained austenite; when the metal structure is observed with a scanning electron microscope, the metal structure satisfies polygonal ferrite: 10 to 50 area %, bainite: 10 to 50 area %, and tempered martensite: 10 to 80 area % with respect to the metal structure overall; and when the metal structure is measured by X-ray diffractometry, the metal structure satisfies retained austenite: 5.0 volume % or more, retained austenite with a carbon concentration of 1.0 mass % or less: 3.5 volume % or more, and retained austenite with a carbon concentration of 0.8 mass % or less: 2.4 volume % or less with respect to the metal structure overall.

公开(公告)号：US20180044752A1

公开(公告)日：2018-02-15

申请号：US15554875

申请日：2016-03-01

申请人： Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

发明人： Tadao MURATA ,  Yuichi FUTAMURA ,  Koji KASUYA

IPC分类号： C21D9/46 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C25D3/22 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D6/00 ,  C23C2/28 ,  C23C2/40 ,  C22C38/38 ,  C22C38/06

CPC分类号： C21D9/46 ,  C21D6/001 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/02 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0247 ,  C21D2211/001 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/38 ,  C22C38/60 ,  C23C2/28 ,  C23C2/40 ,  C25D3/22

摘要： Disclosed herein is a high-strength cold-rolled steel sheet, in which the metal structure at a position of ¼ of the sheet thickness satisfies (1) to (4): (1) an area ratio of ferrite is more than 10% to 65% or less, with a balance being a hard phase including quenched martensite and retained austenite and including at least one selected from the group consisting of bainitic ferrite, bainite, and tempered martensite; (2) a volume ratio Vγ of retained austenite is 5% to 30%; (3) an area ratio VMA of an MA structure in which quenched martensite and retained austenite are combined is 3% to 25%, and an average circle-equivalent diameter of the MA structure is 2.0 μm or less; and (4) a ratio VMA/Vγ of the area ratio VMA of the MA structure to the volume ratio Vγ of the retained austenite is 0.50 to 1.50.

公开(公告)号：US20180037964A1

公开(公告)日：2018-02-08

申请号：US15554843

申请日：2016-03-01

申请人： Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

发明人： Tadao MURATA ,  Yuichi FUTAMURA ,  Koji KASUYA

IPC分类号： C21D8/02 ,  C22C38/04 ,  C23C2/06 ,  C22C38/06 ,  C22C38/00 ,  C23C2/02 ,  C21D9/46 ,  C22C38/02

CPC分类号： C21D8/0236 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0273 ,  C21D9/46 ,  C21D2211/001 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/20 ,  C22C38/34 ,  C22C38/38 ,  C23C2/02 ,  C23C2/06 ,  C23C2/26 ,  C23C2/28 ,  C23C2/40

摘要： A high-strength cold-rolled steel sheet, in which the metal structure at a position of ¼ of the sheet thickness satisfies (1) to (4) below. (1) The area ratio of ferrite is 0% or more and 10% or less, with the balance being a hard phase including quenched martensite and retained austenite and including at least one selected from the group consisting of bainitic ferrite, bainite, and tempered martensite. (2) The volume ratio Vγ of retained austenite is 5% to 30%. (3) The area ratio VMA of an MA structure in which quenched martensite and retained austenite are combined is 3% to 25%, and the average circle-equivalent diameter of the MA structure is 2.0 μm or less. (4) The ratio VMA/Vγ of the area ratio VMA of the MA structure to the volume ratio Vγ of the retained austenite is 0.50 to 1.50.

公开(公告)号：US20160208359A1

公开(公告)日：2016-07-21

申请号：US15023520

申请日：2014-09-25

申请人： KABUSHIKI KAISHA KOBE SEIKO SHO(KOBE STEEL, LTD.)

发明人： Koji KASUYA ,  Tadao MURATA ,  Sae MIZUTA ,  Yuichi FUTAMURA

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

CPC分类号： C21D9/46 ,  C21D8/0205 ,  C21D8/0247 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/38 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28

摘要： A high-strength steel sheet of the present invention is a steel sheet satisfying a predetermined component composition. A metal structure of the steel sheet is composed of polygonal ferrite, high-temperature region generated bainite, low-temperature region generated bainite and retained austenite each having a predetermined area percent, and a distribution using each average IQ of predetermined crystal grains determined by electron backscatter diffraction satisfies Equations (1) and (2) below. According to the present invention, a high-strength steel sheet having excellent ductility and low-temperature toughness can be realized even at a tensile strength of 780 MPa or more. (IQave−IQmin)/(IQmax−IQmin)≧0.40  (1) (σIQ)/(IQmax−IQmin)≦0.25  (2)

摘要翻译： 本发明的高强度钢板是满足规定成分组成的钢板。 钢板的金属结构由多边形铁素体，高温区域生成的贝氏体，低温区域生成贝氏体和各自具有预定面积百分比的残留奥氏体组成，并且使用由电子测定的预定晶粒的平均IQ的分布 反向散射衍射满足下面的等式（1）和（2）。 根据本发明，即使在780MPa以上的拉伸强度下也能够实现延展性和低温韧性优异的高强度钢板。 （IQave-IQmin）/（IQmax-IQmin）≥0.40（1）（＆sgr; IQ）/（IQmax-IQmin）＆nlE; 0.25（2）

公开(公告)号：US20170096723A1

公开(公告)日：2017-04-06

申请号：US15126936

申请日：2014-12-25

申请人： Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

发明人： Koji KASUYA ,  Sae MIZUTA ,  Yuichi FUTAMURA

IPC分类号： C21D9/46 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C23C2/06 ,  C22C38/14 ,  C22C38/28 ,  C22C38/22 ,  C22C38/08 ,  C23C2/28 ,  C21D8/02 ,  C22C38/12

CPC分类号： C21D9/46 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C21D8/0278 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/22 ,  C22C38/28 ,  C22C38/60 ,  C23C2/06 ,  C23C2/28

摘要： Provided is a high strength cold rolled steel sheet having a tensile strength of 980 MPa or higher and excellent ductility and bendability. The high strength cold rolled steel sheet has a specified component composition. The structures at a position of ¼ sheet thickness in the steel sheet has certain area ratio of ferrite relative to the entire structure, certain area ratio of a mixed structure of fresh martensite and retained austenite relative to the entire structure, certain region in which the concentration of Mn is enriched, certain standard deviation of the fraction of a region in which the concentration of Mn is enriched, and certain concentration of Mn in a ferrite phase.

公开(公告)号：US20160237520A1

公开(公告)日：2016-08-18

申请号：US15024423

申请日：2014-09-25

申请人： KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)

发明人： Tadao MURATA ,  Koji KASUYA ,  Sae MIZUTA ,  Yuichi FUTAMURA

IPC分类号： C21D9/46 ,  C23C2/28 ,  C23C2/36 ,  C25D3/22 ,  C25D7/00 ,  C22C38/38 ,  C22C38/34 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D6/00 ,  C21D1/19 ,  B32B15/01 ,  C23C2/06

CPC分类号： C21D9/46 ,  B32B15/013 ,  C21D1/19 ,  C21D1/20 ,  C21D1/22 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0236 ,  C21D8/0247 ,  C21D8/0284 ,  C21D9/573 ,  C21D2201/05 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/34 ,  C22C38/38 ,  C22C38/60 ,  C23C2/06 ,  C23C2/285 ,  C23C2/36 ,  C25D3/22 ,  C25D7/00

摘要： A high-strength steel sheet of the present invention is a steel sheet satisfying a predetermined component composition. A metal structure of the steel sheet is composed of polygonal ferrite, high-temperature region generated bainite, low-temperature region generated bainite and retained austenite each having a predetermined area percent, and a distribution using each average IQ of predetermined crystal grains determined by electron backscatter diffraction satisfies Equations (1) and (2) below. According to the present invention, a high-strength steel sheet having excellent formability and low-temperature toughness can be realized even at a tensile strength of 590 MPa or more. (IQave−IQmin)/(IQmax−IQmin)≧0.40  (1) (σIQ)/(IQmax−IQmin)≦0.25  (2)

摘要翻译： 本发明的高强度钢板是满足规定成分组成的钢板。 钢板的金属结构由多边形铁素体，高温区域生成的贝氏体，低温区域生成贝氏体和各自具有预定面积百分比的残留奥氏体组成，并且使用由电子测定的预定晶粒的平均IQ的分布 反向散射衍射满足下面的等式（1）和（2）。 根据本发明，即使在590MPa以上的拉伸强度下也能够得到成形性和低温韧性优异的高强度钢板。 （IQave-IQmin）/（IQmax-IQmin）≥0.40（1）（σIQ）/（IQmax-IQmin）≤0.25（2）