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.

公开(公告)号：US20210047714A1

公开(公告)日：2021-02-18

申请号：US17043096

申请日：2019-03-22

Applicant: NIPPON STEEL CORPORATION

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

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

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：US20210010099A1

公开(公告)日：2021-01-14

申请号：US16977881

申请日：2019-03-22

Applicant: NIPPON STEEL CORPORATION

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

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

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 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.