公开(公告)号：US11898216B2

公开(公告)日：2024-02-13

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

CPC classification number: C21D9/085 ,  B21D41/04 ,  C21D8/105

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：US11174539B2

公开(公告)日：2021-11-16

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

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：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.