公开(公告)号：US09828648B2

公开(公告)日：2017-11-28

申请号：US14363977

申请日：2012-12-10

Applicant: JFE STEEL CORPORATION

Inventor： Taro Kizu ,  Koichiro Fujita

IPC: C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/14 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/60

CPC classification number: C21D8/0263 ,  C21D8/0205 ,  C21D8/0236 ,  C21D9/46 ,  C21D2211/004 ,  C21D2211/005 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/60

Abstract: A steel sheet and a method for producing the same are disclosed. The steel sheet has a composition containing 0.015% to 0.05% C, less than 0.10% Si, 0.1% to 2.0% Mn, 0.20% or less P, 0.1% or less S, 0.01% to 0.10% Al, 0.005% or less N, and 0.06% to 0.5% Ti in percent by mass, C and Ti satisfying the inequality Ti*/C≧4, where Ti* (mass percent)=Ti−3.4N and Ti, C, and N represent the content (mass percent) of each element. The steel sheet has a microstructure which contains a ferrite phase as a base, in which the average grain diameter of the ferrite phase is 7 μm or more, and in which the ratio of the rolling-direction average grain diameter to thickness-wise average grain diameter of the ferrite phase is 1.1 or more.

公开(公告)号：US20170218474A1

公开(公告)日：2017-08-03

申请号：US15484171

申请日：2017-04-11

Applicant: JFE Steel Corporation

Inventor： Yoshimasa Funakawa ,  Tetsuo Yamamoto ,  Hiroshi Uchomae ,  Hiroshi Nakano ,  Taro Kizu

IPC: C21D9/46 ,  C22C38/60 ,  C22C38/28 ,  C22C38/22 ,  C22C38/16 ,  C22C38/00 ,  C22C38/12 ,  C22C38/10 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C21D8/02 ,  C22C38/14

Abstract: A method of manufacturing a high-strength hot rolled steel sheet by hot rolling a steel having a chemical composition including, by mass %: C: more than 0.010% and not more than 0.06%, Si: not more than 0.3%, Mn: not more than 0.8%, P: not more than 0.03%, S: not more than 0.02%, Al: not more than 0.1%, N: not more than 0.01% and Ti: 0.05 to 0.10%, the balance including Fe and inevitable impurities, including: after the steel is heated to an austenite single phase region, the steel is finish rolled at a finishing delivery temperature of 860° C. to 1050° C., the steel sheet is cooled at an average cooling rate of not less than 30° C/s in a temperature range of from a temperature after the completion of the finish rolling to 750° C., and the steel sheet is coiled into a coil at a coiling temperature of 580° C. to 700° C.

公开(公告)号：US20150252456A1

公开(公告)日：2015-09-10

申请号：US14433869

申请日：2012-10-11

Applicant: JFE STEEL CORPORATION

Inventor： Taro Kizu ,  Koichiro Fujita ,  Hideharu Koga ,  Masahide Morikawa ,  Kenji Tahara

IPC: C22C38/32 ,  C21D9/46 ,  C21D1/26 ,  C21D6/00 ,  C22C38/00 ,  C22C38/26 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C21D8/02 ,  C22C38/28

CPC classification number: C22C38/32 ,  C21D1/26 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0273 ,  C21D9/46 ,  C21D2211/005 ,  C22C38/001 ,  C22C38/002 ,  C22C38/004 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/18 ,  C22C38/26 ,  C22C38/28

Abstract: A steel material having a chemical composition contains 0.0010% to 0.0030% C, 0.05% or less Si, 0.1% to 0.5% Mn, 0.021% to 0.060% Ti, and 0.0005% to 0.0050% B on a mass basis such that B/C satisfies 0.5 or more, whereby a resulting cold-rolled steel sheet has a microstructure dominated by ferrite with an average grain size of 10 μm to 30 μm, a proportional limit of 100 MPa or less, and excellent shape fixability.

Abstract translation: 具有化学成分的钢材以质量计含有C：0.0010〜0.0030％，Si：0.05％以下，Mn：0.1〜0.5％，Ti：0.021〜0.060％，B：0.0005〜0.0050％ C满足0.5以上，由此所得到的冷轧钢板具有平均粒径为10μm〜30μm，比例极限为100MPa以下，铁素体为主的显微结构，形状定形性优异。

公开(公告)号：US11208712B2

公开(公告)日：2021-12-28

申请号：US16483500

申请日：2018-02-01

Applicant: JFE STEEL CORPORATION

Inventor： Taro Kizu ,  Noriaki Moriyasu ,  Shigeyuki Nabeshima ,  Kazunori Tahara ,  Kana Sasaki

IPC: C23C2/06 ,  C22C38/12

Abstract: There is provided a galvanized steel sheet more highly excellent in terms of punchability. The steel sheet has a specified chemical composition and a microstructure including a ferrite phase and a tempered bainite phase in a total amount of 95% or more in terms of area ratio, in which the average grain diameter of the microstructure is 5.0 μm or less, the amount of Fe precipitated is 0.10 mass % or more, the amount of Ti, Nb, and V precipitated in the form of precipitates having a grain diameter of less than 20 nm is 0.025 mass % or more in terms of precipitate C equivalent, and half or more of precipitates having a grain diameter of less than 20 nm are formed at random.

公开(公告)号：US20190078172A1

公开(公告)日：2019-03-14

申请号：US16083725

申请日：2017-03-02

Applicant: JFE Steel Corporation

Inventor： Taro Kizu

IPC: C21D8/02 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/00 ,  C22C38/60 ,  C23C2/06 ,  C23C2/02 ,  C23C2/28 ,  C23C2/40

Abstract: A high-strength thin steel sheet having a high yield ratio and excellent formability and a manufacturing method therefor are provided. The steel sheet contains C: 0.04 to 0.25%, Si: 0.5 to 2.0%, Mn: 0.1 to 2.0%, P: 0.05% or less, S: 0.030% or less, Al: 0.10% or less, and N: 0.010% or less, with the balance being iron and incidental impurities; and has a microstructure containing, in area fraction, 90% or more of ferrite and bainite in total, where ferrite and bainite each have an aspect ratio of 3.0 or higher.

公开(公告)号：US20150056468A1

公开(公告)日：2015-02-26

申请号：US14396924

申请日：2013-04-18

Applicant: JFE Steel Corporation

Inventor： Taro Kizu ,  Yoshimasa Funakawa ,  Hidekazu Ookubo ,  Tokunori Kanemura ,  Masato Shigemi ,  Shoji Kasai ,  Shinji Yamazaki ,  Yusuke Yasufuku

IPC: C22C38/60 ,  C22C38/24 ,  C22C38/54 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C23C2/02 ,  C23C2/06 ,  C22C38/28

CPC classification number: C22C38/60 ,  C21D8/0263 ,  C21D8/0284 ,  C21D8/0463 ,  C21D8/0478 ,  C21D9/46 ,  C21D2211/004 ,  C21D2211/005 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/24 ,  C22C38/28 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C23C2/02 ,  C23C2/06 ,  Y10T428/12799

Abstract: The high strength steel sheet has a chemical composition including 0.08% to 0.20% of C, 0.3% or less of Si, 0.1% to 3.0% of Mn, 0.10% or less of P, 0.030% or less of S, 0.10% or less of Al, 0.010% or less of N, 0.20% to 0.80% of V, and the remainder composed of Fe and incidental impurities on a percent by mass basis, and a microstructure which includes 95% or more of ferrite phase on an area percentage basis, in which fine precipitates are dispersed having a distribution in such a way that the number density of precipitates having a particle size of less than 10 nm is 1.0×105/μm3 or more and the standard deviation of natural logarithm values of precipitate particle sizes with respect to precipitates having a particle size of less than 10 nm is 1.5 or less.

Abstract translation: 高强度钢板具有C：0.08〜0.20％，Si：0.3％以下，Mn：0.1〜3.0％，P：0.10％以下，S：0.030％以下，0.10％以下 较少的Al，0.010％以下的N，0.20〜0.80％的V，剩余部分由Fe和偶然杂质构成，以及在区域上含有95％以上的铁素体相的组织 百分数，其中分散有细小析出物的分布方式使得粒径小于10nm的析出物的数量密度为1.0×10 5 /μm3以上，析出物粒子的自然对数值的标准偏差 相对于粒径小于10nm的析出物的尺寸为1.5以下。

公开(公告)号：US11085107B2

公开(公告)日：2021-08-10

申请号：US16063728

申请日：2016-12-13

Applicant: JFE Steel Corporation

Inventor： Taro Kizu ,  Akimasa Kido ,  Tetsushi Tadani

IPC: C22C38/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C23C2/02 ,  C25D5/48 ,  C22C38/60 ,  C23C2/28 ,  C23C2/06 ,  C23C2/40 ,  B21B45/08 ,  C21D9/68

Abstract: A steel sheet has a composition containing, by mass %, C: 0.04% to 0.20%, Si: 0.6% to 1.5%, Mn: 1.0% to 3.0%, P: 0.10% or less, S: 0.030% or less, Al: 0.10% or less, N: 0.010% or less, one, two, or all of Ti, Nb, and V in an amount of 0.01% to 1.0% each, and the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 50% or more of ferrite, in which an average grain diameter at a position located 50 μm from a surface of the steel sheet in a thickness direction is 3000×(tensile strength TS (MPa))−0.85 μm or less, C precipitates having a grain diameter of less than 20 nm formed in steel is 0.010 mass % or more, and a amount of precipitated Fe is 0.03 mass % to 1.0 mass %, and a roughness Ra of 3.0 μm or less.

公开(公告)号：US20210129491A1

公开(公告)日：2021-05-06

申请号：US16491717

申请日：2018-02-26

Applicant: JFE Steel Corporation

Inventor： Sota Goto ,  Kazuhiko Yamazaki ,  Taro Kizu ,  Shunsuke Toyoda

IPC: B32B15/01 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C22C38/22 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00 ,  C21D9/46 ,  C21D8/02 ,  C21D6/00

Abstract: Provided is a high-strength hot-rolled coated steel sheet with excellent formability,
A high-strength hot-rolled coated steel sheet has a constituent composition containing, in a mass percent, C: 0.03% to 0.15%, Si: 0.4% or less, Mn: 1.2% to 1.9%, Ti: 0.05% to 0.25%, B: 0.0005% to 0.0050%, P: 0.03% or less, S: 0.005% or less, Al: 0.005% to 0.4%, and N: 0.01% or less, the balance being Fe and incidental impurities. The total area fraction of one or more of ferrite and tempered bainite is 90% or more. The steel sheet has a structure in which the volume fraction of Ti carbides having particle sizes of 20 nm or less is 0.05 vol % or more.

公开(公告)号：US10815547B2

公开(公告)日：2020-10-27

申请号：US15554821

申请日：2016-03-01

Applicant: JFE STEEL CORPORATION

Inventor： Taro Kizu ,  Shunsuke Toyoda ,  Akimasa Kido ,  Tetsushi Tadani

IPC: C21D9/46 ,  C22C38/14 ,  C22C38/60 ,  C22C38/00 ,  C21D8/02 ,  C22C38/06 ,  C22C38/12 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/58

Abstract: A high strength steel sheet having high strength such as a tensile strength of 780 MPa or more and having excellent blanking workability and stretch flangeability and a manufacturing method therefor are provided. A high strength steel sheet comprises: a chemical composition containing, in mass %, C: 0.05% to 0.30%, Si: 0.6% to 2.0%, Mn: 1.3% to 3.0%, P: 0.10% or less, S: 0.030% or less, Al: 2.0% or less, N: 0.010% or less, and one or more of Ti, Nb, and V: 0.01% to 1.0% each, with a balance being Fe and incidental impurities; a ferrite microstructure of 50% or more in area ratio; an amount of precipitated Fe of 0.04 mass % or more; and a precipitate with a particle size of less than 20 nm, wherein C* and C*p satisfy specific conditions.

公开(公告)号：US20190055621A1

公开(公告)日：2019-02-21

申请号：US16084313

申请日：2017-03-21

Applicant: JFE Steel Corporation

Inventor： Taro Kizu ,  Imanuel Tarigan ,  Minoru Utake ,  Yuichi Ozawa

IPC: C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C23C2/06 ,  C23C2/02 ,  C23C2/40 ,  C22C38/60 ,  C22C38/58 ,  C22C38/54 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00 ,  B32B15/01

Abstract: A steel sheet and a method for producing the steel sheet are provided. The steel sheet is provided having a composition including C: 0.05% to 0.15%, Si: 0.1% or less, Mn: 1.0% to 2.0%, P: 0.10% or less, S: 0.030% or less, Al: 0.10% or less, and N: 0.010% or less, and including one or two or more of Ti, Nb, and V, the remainder being iron and incidental impurities. The steel sheet has a microstructure containing, on an area percent basis, ferrite: 80% or more, and bainite and martensite: 1% to 20% in total. The ferrite has an average grain size of 10.0 μm or less, and a phase containing bainite and martensite has an average grain size of 3.0 μm or less. The ratio of the average grain size of the phase containing bainite and martensite to the average grain size of the ferrite is 0.3 or less.