公开(公告)号：US11473177B2

公开(公告)日：2022-10-18

申请号：US16975318

申请日：2019-02-26

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinji Yoshida ,  Yuji Arai

IPC: C22C38/14 ,  C22C38/02 ,  C22C38/04 ,  C22C38/20 ,  C22C38/32 ,  C22C38/28 ,  C22C38/24 ,  C21D9/08

Abstract: The steel material according to the present disclosure has a chemical composition consisting of, in mass %, C: 0.10 to 0.60%, Si: 0.05 to 1.00%, Mn: 0.05 to 1.00%, P: 0.025% or less, S: 0.0100% or less, Al: 0.005 to 0.100%, Cr: 0.20 to 1.50%, Mo: 0.25 to 1.50%, V: 0.01 to 0.60%, Ti: 0.002 to 0.050%, B: 0.0001 to 0.0050%, N: 0.0020 to 0.0100%, and O: 0.0100% or less, with the balance being Fe and impurities. A dislocation density ρ is 3.5×1015 m−2 or less. Among fine precipitates, the numerical proportion of precipitates for which a ratio of the Mo content is not more than 50% is 15% or more. The yield strength is in a range of 655 to 1172 MPa.

公开(公告)号：US11332813B2

公开(公告)日：2022-05-17

申请号：US17043096

申请日：2019-03-22

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinji Yoshida ,  Yuji Arai ,  Atsushi Soma ,  Hiroki Kamitani

IPC: C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/22 ,  C22C38/32 ,  C21D1/18 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/20 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/30

Abstract: The steel material according to the present disclosure contains a chemical composition consisting of, in mass %, C: more than 0.50 to 0.80%, Si: 0.05 to 1.00%, Mn: 0.05 to 1.00%, P: 0.025% or less, S: 0.0100% or less, Al: 0.005 to 0.100%, Cr: 0.20 to 1.50%, Mo: 0.25 to 1.50%, Ti: 0.002 to 0.050%, B: 0.0001 to 0.0050%, N: 0.0100% or less and O: 0.0100% or less, with the balance being Fe and impurities. The steel material contains an amount of dissolved C within a range of 0.010 to 0.060 mass %. The steel material also has a yield strength within a range of 862 to less than 965 MPa, and a yield ratio of the steel material is 90% or more.

公开(公告)号：US12054798B2

公开(公告)日：2024-08-06

申请号：US17265614

申请日：2019-10-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Yuji Arai ,  Shinji Yoshida ,  Hiroki Kamitani ,  Yohei Otome

IPC: C21D8/10 ,  C21D6/00 ,  C21D9/00 ,  C21D9/08 ,  C22C38/00 ,  C22C38/44 ,  C22C38/46 ,  C22C38/54

CPC classification number: C21D8/105 ,  C21D6/004 ,  C21D6/005 ,  C21D6/007 ,  C21D6/008 ,  C21D9/085 ,  C22C38/001 ,  C22C38/44 ,  C22C38/46 ,  C22C38/54

Abstract: The steel material according to the present disclosure has a chemical composition consisting of, in mass %, C: 0.15 to 0.45%, Si: 0.05 to 1.00%, Mn: 0.01 to 1.00%, P: 0.030% or less, S: 0.0050% or less, Al: 0.005 to 0.100%, Cr 0.60 to 1.80%, Mo: 0.80 to 2.30%, Ti: 0.002 to 0.020%, V: 0.05 to 0.30%, Nb: 0.002 to 0.100%, B: 0.0005 to 0.0040%, Cu: 0.01 to 0.50%, Ni: 0.01 to 0.50%, N: 0.0020 to 0.0100% and O: 0.0020% or less, with the balance being Fe and impurities. The number density of BN in the steel material is 10 to 100 particles/100 μm2. The yield strength of the steel material is 758 MPa or more.

公开(公告)号：US11905580B2

公开(公告)日：2024-02-20

申请号：US17259651

申请日：2019-09-26

Applicant: NIPPON STEEL CORPORATION

Inventor： Hiroki Kamitani ,  Nobuaki Komatsubara ,  Seiya Okada ,  Atsushi Soma ,  Yuji Arai ,  Shinji Yoshida

IPC: C22C38/32 ,  C21D9/08 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/26 ,  C22C38/28

CPC classification number: C22C38/32 ,  C21D9/085 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/26 ,  C22C38/28

Abstract: The seamless steel pipe according to the present disclosure has a chemical composition consisting of, in mass %, C: 0.15 to 0.45%, Si: 0.05 to 1.00%, Mn: 0.01 to 1.00%, P: 0.030% or less, S: 0.0050% or less, Al: 0.005 to 0.070%, Cr: 0.30 to 1.50%, Mo: 0.25 to 2.00%, Ti: 0.002 to 0.020%, Nb: 0.002 to 0.100%, B: 0.0005 to 0.0040%, rare earth metal: 0.0001 to 0.0015%, Ca: 0.0001 to 0.0100%, N: 0.0100% or less and O: 0.0020% or less, with the balance being Fe and impurities, and satisfying Formula (1) described in the description. A predicted maximum major axis of inclusions is 150 μm or less, the predicted maximum major axis being predicted by means of extreme value statistical processing. The yield strength is within a range of 758 to 862 MPa.

公开(公告)号：US11773460B2

公开(公告)日：2023-10-03

申请号：US17044601

申请日：2019-03-22

Applicant: NIPPON STEEL CORPORATION

Inventor： Yuji Arai ,  Shinji Yoshida ,  Atsushi Soma ,  Hiroki Kamitani

IPC: C21D9/00 ,  C21D6/04 ,  C21D6/00 ,  C22C38/00 ,  C21D9/08 ,  C21D8/10 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/30 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54

CPC classification number: C21D9/085 ,  C21D6/004 ,  C21D6/005 ,  C21D6/007 ,  C21D6/008 ,  C21D8/105 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/30 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54

Abstract: The steel pipe according to the present disclosure contains a chemical composition consisting of, in mass %, C: 0.25 to 0.50%, Si: 0.05 to 0.50%, Mn: 0.05 to 1.00%, P: 0.025% or less, S: 0.0050% or less, Al: 0.005 to 0.100%, Cr: 0.30 to 1.50%, Mo: 0.25 to 3.00%, Ti: 0.002 to 0.050%, N: 0.0010 to 0.0100% and O: 0.0030% or less, with the balance being Fe and impurities. The steel pipe contains an amount of dissolved C within a range of 0.010 to 0.050 mass %. The tensile yield strength in the axial direction and the circumferential direction is 862 to 965 MPa, and the yield ratio in the axial direction is 90% or more. The tensile yield strength in the circumferential direction is 30 to 80 MPa higher than the compressive yield strength in the circumferential direction.

公开(公告)号：US11643712B2

公开(公告)日：2023-05-09

申请号：US17043306

申请日：2019-03-22

Applicant: NIPPON STEEL CORPORATION

Inventor： Yuji Arai ,  Shinji Yoshida ,  Atsushi Soma ,  Hiroki Kamitani

IPC: C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  F16L9/02 ,  C22C38/54 ,  C21D8/10 ,  C21D9/08 ,  C22C38/00 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/52

CPC classification number: C22C38/54 ,  C21D8/10 ,  C21D9/08 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/52 ,  F16L9/02

Abstract: The steel pipe according to the present disclosure contains a chemical composition consisting of, in mass %, C: more than 0.50 to 0.65%, Si: 0.05 to 0.50%, Mn: 0.05 to 1.00%, P: 0.025% or less, S: 0.0050% or less, Al: 0.005 to 0.100%, Cr: 0.30 to 1.50%, Mo: 0.25 to 3.00%, Ti: 0.002 to 0.050%, N: 0.0010 to 0.0100% and O: 0.0030% or less, with the balance being Fe and impurities. The steel pipe contains an amount of dissolved C within a range of 0.010 to 0.060 mass %. The tensile yield strength in the axial direction and the circumferential direction is 862 to 1069 MPa, and the yield ratio in the axial direction is 90% or more. The tensile yield strength in the circumferential direction is 30 to 80 MPa higher than the compressive yield strength in the circumferential direction.

公开(公告)号：US11471923B2

公开(公告)日：2022-10-18

申请号：US16761640

申请日：2018-11-28

Applicant: NIPPON STEEL CORPORATION

Inventor： Kouji Yamane ,  Kazuhiro Shimoda ,  Yuji Arai ,  Akihiro Sakamoto ,  Yasuhiko Daimon ,  Haruka Obe

IPC: B21B19/04 ,  C21D9/08 ,  C22C38/32 ,  C21D6/00 ,  C21D8/10

Abstract: The production method of a seamless steel pipe includes a heating step of heating an Nb-containing steel material to 800 to 1030° C., a pipe-making step of producing a hollow shell by performing piercing-rolling or elongation-rolling on the Nb-containing steel material, by using a piercing mill including a plurality of skewed rolls, a plug disposed between the plurality of skewed rolls, and a mandrel bar, and a cooling step immediately after rolling, of carrying out cooling using a cooling liquid on a hollow shell portion that passes between rear ends of the plurality of skewed rolls, in the hollow shell, so as to reduce an outer surface temperature of the hollow shell portion to 700 to 1000° C. within 15.0 seconds after the hollow shell portion passes between the rear ends of the plurality of skewed rolls.

公开(公告)号：US11155893B2

公开(公告)日：2021-10-26

申请号：US16977881

申请日：2019-03-22

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinji Yoshida ,  Yuji Arai ,  Atsushi Soma ,  Hiroki Kamitani

IPC: C22C38/00 ,  C21D9/46 ,  C21D6/00 ,  C21D8/02 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/24 ,  C22C38/26 ,  C22C38/30 ,  C22C38/44 ,  C22C38/50 ,  C22C38/54

Abstract: The steel material according to the present disclosure contains a chemical composition consisting of, in mass %, C: 0.20 to 0.50%, Si: 0.05 to 1.00%, Mn: 0.05 to 1.00%, P: 0.025% or less, S: 0.0100% or less, Al: 0.005 to 0.100%, Cr: 0.20 to 1.50%, Mo: 0.25 to 1.50%, Ti: 0.002 to 0.050%, B: 0.0001 to 0.0050%, N: 0.0100% or less and O: 0.0100% or less, with the balance being Fe and impurities. The steel material contains an amount of dissolved C within a range of 0.010 to 0.050 mass %. The steel material also has a yield strength within a range of 965 to 1069 MPa, and a yield ratio of the steel material is 90% or more.

公开(公告)号：US20200040436A1

公开(公告)日：2020-02-06

申请号：US16339577

申请日：2017-10-06

Applicant: Nippon Steel Corporation

Inventor： Yuji Arai ,  Shinji Yoshida ,  Atsushi Soma ,  Hiroki Kamitani

IPC: C22C38/42 ,  C22C38/44 ,  C22C38/52 ,  C22C38/50 ,  C22C38/46 ,  C22C38/48 ,  C22C38/54 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00 ,  C22C38/02 ,  C21D9/08 ,  C21D7/13

Abstract: The steel material according to the present invention contains a chemical composition consisting of, in mass %, C: 0.25 to 0.50%, Si: 0.05 to 0.50%, Mn: 0.05 to 1.00%, P: 0.025% or less, S: 0.0100% or less, Al: 0.005 to 0.100%, Cr: 0.30 to 1.50%, Mo: 0.25 to 1.50%, Ti: 0.002 to 0.050%, B: 0.0001 to 0.0050%, N: 0.002 to 0.010% and O: 0.0100% or less, with the balance being Fe and impurities. The steel material also contains an amount of dissolved C within a range of 0.010 to 0.050 mass %. The steel material also contains an yield strength is in a range of 862 to less than 965 MPa, and an yield ratio is 90% or more.

公开(公告)号：US12188110B2

公开(公告)日：2025-01-07

申请号：US17596474

申请日：2020-08-13

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinji Yoshida ,  Yuji Arai ,  Kuniaki Itoh ,  Takuya Okamura

IPC: C22C38/42 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/44 ,  C22C38/54

Abstract: The steel material according to the present disclosure has a chemical composition consisting of, in mass %, C: more than 0.20 to 0.35%, Si: 0.05 to 1.00%, Mn: 0.02 to 1.00%, P: 0.025% or less, S: 0.0100% or less, Al: 0.005 to 0.100%, Cr: 0.40 to 1.50%, Mo: 0.30 to 1.50%, Ti: 0.002 to 0.050%, B: 0.0001 to 0.0050%, N: 0.0100% or less and O: 0.0100% or less, with the balance being Fe and impurities, and satisfies Formula (1) and Formula (2) described in the description. The yield strength is 862 MPa or more. A numerical proportion of precipitates having an equivalent circular diameter within a range of 20 to 300 nm among precipitates having an equivalent circular diameter of 20 nm or more in the steel material is 0.85 or more.