公开(公告)号：US20210025021A1

公开(公告)日：2021-01-28

申请号：US16981435

申请日：2019-03-26

Applicant: NIPPON STEEL CORPORATION

Inventor： Hiroki KAMITANI ,  Takanori TANAKA ,  Atsushi SOMA ,  Keiichi KONDO ,  Hideki MITSUNARI ,  Seiya OKADA ,  Takuya MATSUMOTO ,  Shinji YOSHIDA ,  Yuji ARAI

IPC: C21D9/08 ,  B21D41/04 ,  C21D8/10

Abstract: A seamless steel pipe heat-treatment-finishing-treatment continuous facility includes: a heat treatment apparatus; a steel pipe inspection apparatus which performs a test for a surface defect and/or an inner defect of the seamless steel pipe, the steel pipe inspection apparatus being disposed downstream of the heat treatment apparatus; a main transfer mechanism which forms a main transfer path MT for transferring the seamless steel pipe, discharged from the heat treatment apparatus, to the steel pipe inspection apparatus disposed downstream of the heat treatment apparatus; and a first forced steel pipe-temperature reduction apparatus which forcibly reduces a temperature of the seamless steel pipe on the main transfer path MT, the first forced steel pipe-temperature reduction apparatus being disposed on the main transfer path MT at a position downstream of the heat treatment apparatus and upstream of the steel pipe inspection apparatus.

公开(公告)号：US20250066891A1

公开(公告)日：2025-02-27

申请号：US18724764

申请日：2023-02-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Hiroki KAMITANI ,  Yuji ARAI ,  Jin KAWASAKI ,  Keiichi KONDO

IPC: C22C38/32 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28

Abstract: A steel material according to the present disclosure consists of, in mass %, C: 0.15 to 0.45%, Si: 0.05 to 1.00%, Mn: 0.05 to 0.30%, P: 0.030% or less, S: 0.0050% or less, Al: 0.005 to 0.100%, Cr: 0.30 to 1.10%, Mo: 0.40 to 2.00%, Ti: 0.002 to 0.020%, Nb: 0.002 to 0.100%, B: 0.0005 to 0.0040%, N: 0.0100% or less, and O: less than 0.0040%, with the balance being Fe and impurities, and has a yield strength of 862 MPa or more. In the steel material, a number density of Si oxides which have a major axis of 5.0 μm or more is 5/100 mm2 or less, and in a case where the yield strength is 931 MPa or more, the number density of the Si oxides is 5/200 mm2 or less.

公开(公告)号：US20210017635A1

公开(公告)日：2021-01-21

申请号：US16980671

申请日：2019-03-25

Applicant: NIPPON STEEL CORPORATION

Inventor： Hiroki KAMITANI ,  Atsushi SOMA ,  Shinji YOSHIDA ,  Yuji ARAI ,  Seiya OKADA

IPC: C22C38/54 ,  C22C38/52 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/42 ,  C22C38/22 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00

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 0.50%, Mn: 0.05 to 1.00%, P: 0.030% or less, S: 0.0100% or less, Al: 0.005 to 0.100%, Cr: 0.10 to 1.50%, Mo: 0.25 to 1.50%, Ti: 0.002 to 0.050%, 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 655 to less than 862 MPa, and a yield ratio of the steel material is 85% or more.

公开(公告)号：US20230203631A1

公开(公告)日：2023-06-29

申请号：US17995368

申请日：2021-04-15

Applicant: NIPPON STEEL CORPORATION

Inventor： Keiichi KONDO ,  Yuji ARAI ,  Keiichi NAKAMURA ,  Taro OE ,  Takenori KURAMOTO ,  Yosuke TAKEDA ,  Hiroki KAMITANI

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

CPC classification number: C22C38/54 ,  C21D9/08 ,  C22C38/001 ,  C22C38/02 ,  C22C38/002 ,  C22C38/04 ,  C22C38/005 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C21D2211/001

Abstract: The steel material according to the present disclosure consists of, in mass%, C: 0.15 to 0.45%, Si: 0.05 to 1.00%, Mn: 0.05 to less than 0.80%, P: 0.030% or less, S: 0.0100% or less, Al: 0.100% or less, Cr: 0.30 to 1.50%, Mo: 0.25 to 2.00%, Ti: 0.001 to 0.015%, N: 0.0100% or less, O: 0.0050% or less, V: 0 to 0.05%, Nb: 0 to 0.010%, B: 0 to less than 0.0005%, Ca: 0 to 0.0100%, Mg: 0 to 0.0100%, and rare earth metal: 0 to 0.0100%, with the balance being Fe and impurities. In the steel material, the grain size number of prior-austenite grains is less than 7.0, Formula (1) to Formula (4) described in the specification are satisfied, the yield strength is 896 MPa or more, and the absorbed energy at -10° C. is 95 J or more.

公开(公告)号：US20210180149A1

公开(公告)日：2021-06-17

申请号：US17044601

申请日：2019-03-22

Applicant: NIPPON STEEL CORPORATION

Inventor： Yuji ARAI ,  Shinji YOSHIDA ,  Atsushi SOMA ,  Hiroki KAMITANI

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

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：US20210032734A1

公开(公告)日：2021-02-04

申请号：US17043306

申请日：2019-03-22

Applicant: NIPPON STEEL CORPORATION

Inventor： Yuji ARAI ,  Shinji YOSHIDA ,  Atsushi SOMA ,  Hiroki KAMITANI

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

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：US20220186350A1

公开(公告)日：2022-06-16

申请号：US17432146

申请日：2020-03-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Seiya OKADA ,  Hiroki KAMITANI ,  Nobuaki KOMATSUBARA ,  Yusaku TOMIO ,  Shohei IKEDA ,  Naoya SHIRASAWA

IPC: C22C38/32 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/24 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C21D3/04 ,  C22C38/00

Abstract: The seamless steel pipe according to the present disclosure includes a base material and a decarburized layer formed on the surface of the base material. The chemical composition of the base material consists of, in mass %, C: 0.20 to 0.50%, Si: 0.05 to 0.50%, Mn: 0.01 to 1.00%, P: 0.0300% or less, S: 0.0100% or less, Al: 0.005 to 0.100%, Cr: 0.30 to 1.20%, Mo: 0.30 to 1.50%, Ti: 0.002 to 0.050%, V: 0.01 to 0.30%, Nb: 0.002 to 0.100%, B: 0.0001 to 0.0050%, N: 0.0100% or less, O: 0.0050% or less, and with the balance being Fe and impurities. The base material has a yield strength of 655 MPa or more, and a yield ratio of 85.0% or more. The decarburized layer has a depth of 150 μm or less.

公开(公告)号：US20220098712A1

公开(公告)日：2022-03-31

申请号：US17422870

申请日：2020-02-13

Applicant: NIPPON STEEL CORPORATION

Inventor： Hiroki KAMITANI ,  Yohei OTOME ,  Atsushi SOMA ,  Taro OE ,  Nobuaki KOMATSUBARA ,  Shinji YOSHIDA ,  Yuji ARAI

IPC: C22C38/54 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/30 ,  C22C38/20 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00

Abstract: A steel material according to the present disclosure has a chemical composition consisting of, in mass %: C: 0.20 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 1.50%, Mo: more than 1.00 to 2.00%, Ti: 0.002 to 0.020%, V: 0.05 to 0.30%, Nb: 0.005 to 0.100%, B: 0.0005 to 0.0040%, N: 0.0100% or less, O: less than 0.0020%, and the balance being Fe and impurities, and satisfying Formula (1) described in the specification. A grain diameter of a prior-austenite grain is 11.0 μm or less, and an average area of precipitate which is precipitated in a prior-austenite grain boundary is 10.0×10−3 μm2 or less. A yield strength is 758 to 862 MPa.

公开(公告)号：US20210317553A1

公开(公告)日：2021-10-14

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 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/00 ,  C22C38/26 ,  C22C38/28 ,  C21D9/08

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：US20210262051A1

公开(公告)日：2021-08-26

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 ,  C21D9/08 ,  C21D6/00 ,  C22C38/54 ,  C22C38/44 ,  C22C38/46 ,  C22C38/00

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.