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：US20190218640A1

公开(公告)日：2019-07-18

申请号：US16321544

申请日：2017-07-21

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

发明人： Elijah KAKIUCHI ,  Toshio MURAKAMI ,  Shigeo OTANI ,  Yuichi FUTAMURA ,  Tadao MURATA

IPC分类号： C21D9/46 ,  C21D6/00 ,  C21D1/34 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00 ,  C22C38/02

CPC分类号： C21D9/46 ,  C21D1/18 ,  C21D1/34 ,  C21D6/005 ,  C21D6/008 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06

摘要： Disclosed is a high-strength sheet including: C: 0.15% to 0.35% by mass, total of Si and Al: 0.5% to 3.0% by mass, Mn: 1.0% to 4.0% by mass, P: 0.05% by mass or less, and S: 0.01% by mass or less, with the balance being Fe and inevitable impurities, wherein the steel structure satisfies that: a ferrite fraction is 5% or less, the total fraction of tempered martensite and tempered bainite is 60% or more, the amount of retained austenite is 10% or more, MA has an average size of 1.0 μm or less, retained austenite has an average size of 1.0 μm or less, retained austenite having a size of 1.5 μm or more accounts for 2% or more of the total amount of retained austenite, and a scattering intensity at the q value of 1 nm−1 in X-ray small angle scattering is 1.0 cm1 or less.

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）

公开(公告)号：US20220349020A1

公开(公告)日：2022-11-03

申请号：US17760969

申请日：2020-09-14

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

发明人： Tadao MURATA ,  Muneaki IKEDA ,  Toshio MURAKAMI

IPC分类号： C21D9/46 ,  C22C38/14 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D6/00 ,  B32B15/01 ,  C23C2/40

摘要： The present invention provides a high-strength steel sheet, which can be used in various applications including automobile parts and exhibits excellent collision safety and excellent moldability, and a method for manufacturing the high-strength steel sheet. The high-strength steel sheet according to an aspect of the present invention satisfies a predetermined chemical composition and has a metallographic microstructure having ferrite fraction: 0% to 10%, MA fraction: 0% to 30%, hard phase other than ferrite and MA: 70% to 100% in terms of area proportion and retained austenite fraction: 5% to 30% in terms of volume proportion, and in the high-strength steel sheet, the skewness of IQ as analyzed by the EBRD method is −1.2 to −0.3 when the skewness is expressed by a predetermined relational expression in a case where crystal grains having a bcc structure and a bct structure are regarded as an aggregation of regions having an area of 0.05 μm2.

公开(公告)号：US20200071787A1

公开(公告)日：2020-03-05

申请号：US16615462

申请日：2018-05-14

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

发明人： Hirokazu NATSUMEDA ,  Toshio MURAKAMI ,  Kenji SAITO ,  Tadao MURATA

IPC分类号： C21D9/48 ,  C21D8/02 ,  C22C38/14 ,  C22C38/58 ,  C22C38/02 ,  C22C38/06

摘要： Disclosed is a high-strength sheet containing: C: 0.15% by mass to 0.35% by mass, a total of Si and Al: 0.5% by mass to 3.0% by mass, Mn: 1.0% by mass to 4.0% by mass, P: 0.05% by mass or less (including 0% by mass), S: 0.01% by mass or less (including 0% by mass), and Ti: 0.01% by mass to 0.2% by mass, with the balance being Fe and inevitable impurities, wherein the steel structure satisfies that: a ferrite fraction is 5% or less, a total fraction of tempered martensite and tempered bainite is 60% or more, a retained austenite fraction is 10% or more, a fresh martensite fraction is 5% or less, retained austenite has an average grain size of 0.5 μm or less, retained austenite having a grain size of 1.0 μm or more accounts for 2% or more of the total amount of retained austenite, and a prior austenite grain size is 10 μm or less.

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：US20190185958A1

公开(公告)日：2019-06-20

申请号：US16321157

申请日：2017-07-21

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

发明人： Elijah KAKIUCHI ,  Toshio MURAKAMI ,  Shigeo OTANI ,  Yuichi FUTAMURA ,  Tadao MURATA

IPC分类号： C21D9/46 ,  C21D6/00 ,  C21D1/18 ,  C22C38/06 ,  C22C38/02 ,  C22C38/04 ,  C22C38/00

CPC分类号： C21D9/46 ,  C21D1/18 ,  C21D6/005 ,  C21D6/008 ,  C22C38/00 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06

摘要： Disclosed is a high-strength sheet including: C: 0.15% by mass to 0.35% by mass, total of Si and Al: 0.5% by mass to 3.0% by mass, Mn: 1.0% by mass to 4.0% by mass, P: 0.05% by mass or less, and S: 0.01% by mass or less, with the balance being Fe and inevitable impurities, wherein the steel structure satisfies that: a ferrite fraction is 5% or less, the total fraction of tempered martensite and tempered bainite is 60% or more, the amount of retained austenite is 10% or more, MA has an average size of 1.0 μm or less, a half-width of the concentration distribution of Mn in the carbon-concentrated region that is equal to the amount of retained austenite is 0.3% by mass or more, and a scattering intensity at the q value of 1 nm−1 in X-ray small angle scattering is 1.0 cm−1 or less.

公开(公告)号：US20190071757A1

公开(公告)日：2019-03-07

申请号：US16082519

申请日：2017-02-22

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

发明人： Tadao MURATA ,  Toshio MURAKAMI ,  Elijah KAKIUCHI ,  Shigeo OTANI ,  Yuichi FUTAMURA

IPC分类号： C22C38/04 ,  C21D6/00 ,  C21D9/46 ,  C21D11/00 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/32 ,  C22C38/42 ,  C22C38/44 ,  C22C38/48 ,  C22C38/54

摘要： A high-strength steel sheet comprising, as component composition, by mass: C: 0.15 to 0.35%; total of Si and Al: 0.5 to 2.5%; Mn: 1.0 to 4.0%; P: more than 0% and 0.05% or less; and S: more than 0% and 0.01% or less, with the balance being Fe and inevitable impurities, wherein a steel structure satisfies, in ratio with respect to the whole structure: ferrite: more than 5 area % and 50 area % or less; total of tempered martensite and bainite: 30 area % or more; and retained austenite: 10 volume % or more, the steel structure further includes MA, and the steel structure satisfies: an average circle equivalent diameter of the MA: 1.0 μm or less; an average circle equivalent diameter of the retained austenite: 1.0 μm or less; and a volume ratio of retained austenite with a circle equivalent diameter of 1.5 μm or more to the whole retained austenite: 5% or more.

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.