公开(公告)号：US20220112572A1

公开(公告)日：2022-04-14

申请号：US17427864

申请日：2020-02-13

Applicant: NIPPON STEEL CORPORATION ,  USUI CO., LTD.

Inventor： Taizo MAKINO ,  Masahiro YAMAZAKI ,  Yuji ARAI ,  Osamu ENDO ,  Naoki SERIZAWA ,  Tatsuya MASUDA

IPC: C21D9/08 ,  F16L9/02 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/10 ,  C21D6/00

Abstract: A steel pipe for a fuel injection pipe has a chemical composition consisting of, by mass %: C: 0.17 to 0.27%, Si: 0.05 to 0.40%, Mn: 0.30 to 2.00%, P: 0.020% or less, S: 0.0100% or less, O: 0.0040% or less, Ca: 0.0010% or less, Al: 0.005 to 0.060%, N: 0.0020 to 0.0080%, Ti: 0.005 to 0.015%, Nb: 0.015 to 0.045%, Cr: 0 to 1.00%, Mo: 0 to 1.00%, Cu: 0 to 0.50%, Ni: 0 to 0.50%, V: 0 to 0.15%, and the balance: Fe and impurities. The metal micro-structure consists substantially of tempered martensite, or tempered martensite and tempered bainite. A prior-austenite grain size number is 9.0 or more. The hardness is within the range of 350 to 460 HV1. When a maximum value of a square root of an area of inclusions observed in a cross section perpendicular to a longitudinal direction of the steel pipe is taken as an (n=1 to 20), a maximum value amax of an is 30.0 μm or less, and an average value aav of an is 40% or more of amax.

公开(公告)号：US20210269902A1

公开(公告)日：2021-09-02

申请号：US17253229

申请日：2019-09-26

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinji YOSHIDA ,  Yuji ARAI

IPC: C22C38/32 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/22 ,  C22C38/28 ,  C21D8/10

Abstract: The steel material according to the present disclosure has a chemical composition consisting of, in mass %, C: 0.20 to 0.35%, Si: 0.05 to 1.00%, Mn: 0.01 to 1.00%, P: 0.025% or less, S: 0.0100% or less, Al: 0.005 to 0.100%, Cr 0.25 to 0.80%, Mo: 0.20 to 2.00%, 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, and satisfying Formula (1). A number density of precipitates having an equivalent circular diameter of 400 nm or more is 0.150 particles/μm2 or less. The yield strength is within a range of 655 to 965 MPa. A dislocation density ρ is 7.0×1014 m−2 or less. 5×Cr—Mo-2×(V+Ti)≤3.00  (1)

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：US20250137110A1

公开(公告)日：2025-05-01

申请号：US18691204

申请日：2022-09-29

Applicant: NIPPON STEEL CORPORATION

Inventor： Seiya OKADA ,  Yuji ARAI ,  Daisuke MATSUO

IPC: C22C38/60 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/52 ,  C22C38/54 ,  C22C38/58 ,  F16L9/02

Abstract: The duplex stainless steel pipe according to the present disclosure consists of, by mass %, C: 0.030% or less, Si: 1.00% or less, Mn: 0.10 to 7.00%, P: 0.040% or less, S: 0.0050% or less, Cr: 20.0 to 30.0%, Ni: 4.2 to 10.0%, Mo: 0.5 to 5.0%, Cu: 0.5 to 6.0%, N: less than 0.350%, O: 0.0005 to 0.0100%, and Ca: 0.0005 to 0.0100%, with the balance being Fe and impurities. A microstructure consists of, in volume ratio, ferrite in an amount of 30 to 80% with the balance being austenite. A yield strength is 552 MPa or more. A number density of Ca oxides having an equivalent circular diameter of 2.0 μm or more is 500/100 mm2 or more.

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：US20230366070A1

公开(公告)日：2023-11-16

申请号：US18044249

申请日：2021-10-29

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinji YOSHIDA ,  Yuji ARAI ,  Hiroyuki FUJI

IPC: C22C38/34 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06 ,  C22C38/22 ,  C22C38/24 ,  C22C38/28 ,  C22C38/32 ,  C21D9/08

CPC classification number: C22C38/34 ,  C22C38/001 ,  C22C38/002 ,  C22C38/04 ,  C22C38/06 ,  C22C38/22 ,  C22C38/24 ,  C22C38/28 ,  C22C38/32 ,  C21D9/08

Abstract: The steel material according to the present disclosure contains, in mass %, C: 0.20 to 0.45%, Si: 1.36 to 3.20%, Mn: 0.02 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: 0.36 to 1.50%, V: 0.01 to 0.90%, Ti: 0.002 to 0.050%, B: 0.0001 to 0.0050%, N: 0.0100% or less, and O: 0.0100% or less, and satisfies Formula (1). A yield strength σYS is 758 MPa or more. The yield strength σYS and a dislocation density ρ satisfy Formula (2).


27×Mn+9×Cr−14×Mo−770×C2+760×C−11×Si2+4×Si>85   (1)



691

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.

公开(公告)号：US20210198775A1

公开(公告)日：2021-07-01

申请号：US17044616

申请日：2019-03-22

Applicant: NIPPON STEEL CORPORATION

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

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

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: less than 0.0050%, Al: 0.005 to 0.050%, Cr: 0.10 to 1.50%, Mo: 0.25 to 1.80%, Ti: 0.002 to 0.050%, Nb: 0.002 to 0.100%, B: 0.0001 to 0.0050%, N: 0.0070% or less and O: less than 0.0050% with the balance being Fe and impurities. A yield strength is within a range of 655 to 1069 MPa, and a yield ratio is 85% or more. A proportion of KAM values of 1° or less is 30 area % or more.