公开(公告)号：US11566301B2

公开(公告)日：2023-01-31

申请号：US16325572

申请日：2017-08-22

申请人： JFE Steel Corporation

发明人： Yusuke Yoshimura ,  Hiroki Ota ,  Masao Yuga ,  Yuichi Kamo ,  Kenichiro Eguchi

IPC分类号： C21D9/08 ,  C21D6/00 ,  C22C38/60 ,  C22C38/52 ,  C22C38/54 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/10

摘要： Provided herein is a dual-phase stainless steel having excellent carbon dioxide corrosion resistance, excellent sulfide stress corrosion cracking resistance, and excellent sulfide stress cracking resistance. The dual-phase stainless steel contains, in mass %, C: 0.03% or less, Si: 1.0% or less, Mn: 0.10 to 1.5%, P: 0.030% or less, S: 0.005% or less, Cr: 20.0 to 30.0%, Ni: 5.0 to 10.0%, Mo: 2.0 to 5.0%, Cu: 2.0 to 6.0%, N: less than 0.07%, and the balance Fe and unavoidable impurities, and has a structure that is 20 to 70% austenite phase, and 30 to 80% ferrite phase in terms of a volume fraction.

公开(公告)号：US11313007B2

公开(公告)日：2022-04-26

申请号：US16333029

申请日：2017-09-13

申请人： JFE Steel Corporation

发明人： Masao Yuga ,  Mitsuhiro Okatsu

IPC分类号： C21D6/02 ,  C21D8/10 ,  C21D9/08 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/32 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/54 ,  C22C38/20 ,  C22C38/28 ,  C22C38/42 ,  C22C38/50

摘要： Provided herein is a high-strength seamless steel pipe containing a particular chemical composition. The volume fraction of tempered martensite is 90% or more in terms of a volume fraction. The number of nitride inclusions with a particle diameter of 4 μm or more is 50 or less per 100 mm2, the number of nitride inclusions with a particle diameter of less than 4 μm is 500 or less per 100 mm2, the number of oxide inclusions with a particle diameter of 4 μm or more is 40 or less per 100 mm2, and the number of oxide inclusions with a particle diameter of less than 4 μm is 400 or less per 100 mm2 in a cross section perpendicular to a rolling direction.

公开(公告)号：US11186885B2

公开(公告)日：2021-11-30

申请号：US16064086

申请日：2016-10-18

申请人： JFE Steel Corporation

发明人： Masao Yuga ,  Mitsuhiro Okatsu ,  Hiroki Ota

IPC分类号： C21D8/10 ,  C22C38/32 ,  C22C38/54 ,  C21D9/08 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C21D1/18

摘要： The high-strength seamless steel pipe has a volume fraction of tempered martensite of 95% or more, and a prior austenite size number of 8.5 or more, and contains nitride inclusions having a size of 4 μm or more and whose number is 100 or less per 100 mm2, nitride inclusions having a size of less than 4 μm and whose number is 700 or less per 100 mm2, oxide inclusions having a size of 4 μm or more and whose number is 60 or less per 100 mm2, and oxide inclusions having a size of less than 4 μm and whose number is 500 or less per 100 mm2, in a cross section perpendicular to a rolling direction.

公开(公告)号：US20210071275A1

公开(公告)日：2021-03-11

申请号：US16956805

申请日：2018-12-06

申请人： JFE Steel Corporation

发明人： Mitsuhiro Okatsu ,  Masao Yuga ,  Yoichi Ito

IPC分类号： C21D8/10 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32

摘要： Provided herein is a low-alloy high-strength seamless steel pipe. The steel pipe of the present invention has a composition that contains, in mass %, C: 0.25 to 0.50%, Si: 0.01 to 0.40%, Mn: 0.3 to 1.5%, P: 0.010% or less, S: 0.001% or less, O: 0.0015% or less, Al: 0.015 to 0.080%, Cu: 0.02 to 0.09%, Cr: 0.5 to 0.8%, Mo: 0.5 to 1.3%, Nb: 0.005 to 0.05%, B: 0.0005 to 0.0040%, Ca: 0.0010 to 0.0020%, Mg: 0.001% or less, and N: 0.005% or less, and in which the balance is Fe and incidental impurities. The steel pipe has a microstructure in which the number of oxide-base nonmetallic inclusions satisfying the composition ratios represented by predefined formulae is 10 or less per 100 mm2, and in which the number of oxide-base nonmetallic inclusions satisfying the composition ratios represented by other predefined formulae is 30 or less per 100 mm2.

公开(公告)号：US10300564B2

公开(公告)日：2019-05-28

申请号：US15129932

申请日：2015-03-31

申请人： JFE STEEL CORPORATION

发明人： Katsuyuki Ichimiya ,  Masao Yuga ,  Kazukuni Hase ,  Shigeru Endo

IPC分类号： B23K35/30 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/14 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C21D9/18 ,  C21D9/30 ,  C21D9/50 ,  F16B5/08 ,  B23K9/23 ,  B23K9/18 ,  B23K103/04

摘要： A weld joint with an excellent CTOD property is produced with a weld metal, using a steel plate as a base metal. The steel plate has a chemical composition including C: 0.03% to 0.09%, Si: 0.01% to 0.35%, Mn: 1.3% to 2.0%, P: 0.012% or less, S: 0.0035% or less, Al: 0.01% to 0.06%, Ni: less than 0.3%, Mo: less than 0.10%, Nb: 0.005% to 0.023%, Ti: 0.005% to 0.025%, B: less than 0.0003%, N: 0.002% to 0.005%, Ca: 0.0005% to 0.0050%, and O: 0.0030% or less, with the components additionally satisfying a predetermined relationship. The weld metal has a chemical composition including C: 0.040% to 0.090%, Si: 0.1% to 0.8%, Mn: 1.0% to 2.5%, Al: 0.020% or less, Ni: 0.1% to 1.0%, Mo: 0.05% to 0.50%, Ti: 0.005% to 0.050%, and B: 0.0015% or less, the balance being Fe and incidental impurities.

公开(公告)号：US20190048443A1

公开(公告)日：2019-02-14

申请号：US16078919

申请日：2016-11-18

申请人： JFE Steel Corporation

发明人： Mitsuhiro Okatsu ,  Masao Yuga ,  Hiroki Ota ,  Kazuki Fujimura

IPC分类号： C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/20 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D9/08 ,  C21D8/10 ,  C21D6/00 ,  C21D6/02 ,  E21B17/00

摘要： The steel pipe of the present invention is a low alloy high strength seamless steel pipe for oil country tubular goods including a composition containing, in terms of mass %, C: 0.23 to 0.27%, Si: 0.01 to 0.35%, Mn: 0.45 to 0.70%, P: 0.010% or less, S: 0.001% or less, O: 0.0015% or less, Al: 0.015 to 0.080%, Cu: 0.02 to 0.09%, Cr: 0.8 to 1.5%, Mo: 0.5 to 1.0%, Nb: 0.02 to 0.05%, B: 0.0015 to 0.0030%, Ti: 0.005 to 0.020%, and N: 0.005% or less, and having a value of a ratio of the Ti content to the N content (Ti/N) of 3.0 to 4.0, with the balance being Fe and inevitable impurities, the steel pipe having a ratio of a stress at a strain of 0.7% to a stress at a strain of 0.4% in a stress-strain curve; of 1.02 or less and a yield strength of 655 MPa or more.

公开(公告)号：US11505842B2

公开(公告)日：2022-11-22

申请号：US16956800

申请日：2018-12-06

申请人： JFE Steel Corporation

发明人： Mitsuhiro Okatsu ,  Masao Yuga ,  Yoichi Ito

IPC分类号： B22D11/00 ,  C21D8/10 ,  C21C7/06 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/32

摘要： Provided herein is a low-alloy high-strength seamless steel pipe. The steel pipe of the present invention has a composition that contains, in mass %, C: 0.20 to 0.50%, Si: 0.01 to 0.35%, Mn: 0.45 to 1.5%, P: 0.020% or less, S: 0.002% or less, 0: 0.003% or less, Al: 0.01 to 0.08%, Cu: 0.02 to 0.09%, Cr: 0.35 to 1.1%, Mo: 0.05 to 0.35%, B: 0.0010 to 0.0030%, Ca: 0.0010 to 0.0030%, Mg: 0.001% or less, and N: 0.005% or less, and in which the balance is Fe and incidental impurities. The steel pipe has a microstructure in which the number of oxide-base nonmetallic inclusions satisfying the composition ratios represented by predefined formulae is 20 or less per 100 mm2, and in which the number of oxide-base nonmetallic inclusions satisfying the composition ratios represented by other predefined formulae is 50 or less per 100 mm2.

公开(公告)号：US11111566B2

公开(公告)日：2021-09-07

申请号：US16078919

申请日：2018-08-22

申请人： JFE Steel Corporation

发明人： Mitsuhiro Okatsu ,  Masao Yuga ,  Hiroki Ota ,  Kazuki Fujimura

IPC分类号： C22C38/32 ,  C21D8/10 ,  C22C38/00 ,  C21D6/00 ,  C21D6/02 ,  C21D9/08 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  E21B17/00

摘要： The steel pipe of the present invention is a low alloy high strength seamless steel pipe for oil country tubular goods including a composition containing, in terms of mass %, C: 0.23 to 0.27%, Si: 0.01 to 0.35%, Mn: 0.45 to 0.70%, P: 0.010% or less, S: 0.001% or less, O: 0.0015% or less, Al: 0.015 to 0.080%, Cu: 0.02 to 0.09%, Cr: 0.8 to 1.5%, Mo: 0.5 to 1.0%, Nb: 0.02 to 0.05%, B: 0.0015 to 0.0030%, Ti: 0.005 to 0.020%, and N: 0.005% or less, and having a ratio of the Ti content to the N content (Ti/N) of 3.0 to 4.0, with the balance being Fe and inevitable impurities, the steel pipe having a ratio of a stress at a strain of 0.7% to a stress at a strain of 0.4% in a stress-strain curve of 1.02 or less and a yield strength of 655 MPa or more.

公开(公告)号：US10920297B2

公开(公告)日：2021-02-16

申请号：US15527893

申请日：2015-08-20

申请人： JFE STEEL CORPORATION

发明人： Masao Yuga ,  Yasuhide Ishiguro ,  Mitsuhiro Okatsu ,  Seiji Nabeshima ,  Hiroki Ota

IPC分类号： C22C38/02 ,  C21D1/18 ,  C21D8/10 ,  C21D9/08 ,  C21D9/46 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C22C38/18 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/32 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C21D6/02 ,  C22C38/20 ,  C22C38/28 ,  C22C38/08 ,  C22C38/40

摘要： A seamless steel pipe having a specific chemical composition. A ratio of Ti to N is in a range of 2.0 to 5.0. The steel pipe has a microstructure including tempered martensite having a volume ratio of 95% or more, and prior austenite grains having a grain size number of 8.5 or more. In a cross-section perpendicular to a rolling direction of the steel pipe a number of nitride-based inclusions having a particle size of 4 μm or more is 100 or less per 100 mm2, a number of nitride-based inclusions having a particle size of less than 4 μm is 1000 or less per 100 mm2, a number of oxide-based inclusions having a particle size of 4 μm or more is 40 or less per 100 mm2, and a number of oxide-based inclusions having a particle size of less than 4 μm is 400 or less per 100 mm2.

公开(公告)号：US20200325553A1

公开(公告)日：2020-10-15

申请号：US16956800

申请日：2018-12-06

申请人： JFE Steel Corporation

发明人： Mitsuhiro Okatsu ,  Masao Yuga ,  Yoichi Ito

IPC分类号： C21D8/10 ,  C21C7/06 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/32

摘要： Provided herein is a low-alloy high-strength seamless steel pipe. The steel pipe of the present invention has a composition that contains, in mass %, C: 0.20 to 0.50%, Si: 0.01 to 0.35%, Mn: 0.45 to 1.5%, P: 0.020% or less, S: 0.002% or less, O: 0.003% or less, Al: 0.01 to 0.08%, Cu: 0.02 to 0.09%, Cr: 0.35 to 1.1%, Mo: 0.05 to 0.35%, B: 0.0010 to 0.0030%, Ca: 0.0010 to 0.0030%, Mg: 0.001% or less, and N: 0.005% or less, and in which the balance is Fe and incidental impurities. The steel pipe has a microstructure in which the number of oxide-base nonmetallic inclusions satisfying the composition ratios represented by predefined formulae is 20 or less per 100 mm2, and in which the number of oxide-base nonmetallic inclusions satisfying the composition ratios represented by other predefined formulae is 50 or less per 100 mm2.