公开(公告)号：US20240093324A1

公开(公告)日：2024-03-21

申请号：US18256577

申请日：2022-01-07

Applicant: NIPPON STEEL CORPORATION

Inventor： Taizo MAKINO ,  Masahiro YAMAZAKI

IPC: C21D9/14 ,  C21D7/12 ,  C21D8/10 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/50 ,  F16L9/02

CPC classification number: C21D9/14 ,  C21D7/12 ,  C21D8/105 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/50 ,  F16L9/02

Abstract: A steel pipe for pressure piping subjected to autofrettage has an average hardness at its outer layer region of 1.20 times or more of an average hardness at its inner layer region. When an outer diameter is D, and an inner diameter is d, a measured value of a residual stress at an outer surface is denoted by σo1, a measured value of a residual stress at an outer surface after halving is denoted by σo2, and a measured value of a residual stress at an inner surface after the halving is denoted by σi2, an estimated value σi1 of a residual stress at the inner surface of the steel pipe is determined by [σi1=(−σi2)/(A×(t/T)2−1)], [t/T=((σo2−σo1)/(A×(σo2−σo1)−C×σi2))1/2], [A=3.9829× exp(0.1071×(D/d)2)], and [C=−3.3966×exp(0.0452×(D/d)2)] is −150 MPa or less.

公开(公告)号：US20240084432A1

公开(公告)日：2024-03-14

申请号：US17908264

申请日：2021-11-03

Applicant: Jiangsu University

Inventor： Yulin JU ,  Xiaonong CHENG ,  Zhizhong YUAN ,  Shun GUO ,  Rui LUO ,  Fuyang CAO ,  Hao HUANG

IPC: C23C8/22 ,  C21D1/18 ,  C21D1/58 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/28 ,  C22C38/32 ,  C23C8/80

CPC classification number: C23C8/22 ,  C21D1/18 ,  C21D1/58 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/28 ,  C22C38/32 ,  C23C8/80 ,  C21D2211/001 ,  C21D2211/008

Abstract: The disclosure provides a method for heat-treating a boron steel, which includes: carburizing a boron steel on a surface thereof to obtain a carburized boron steel; austenitizing the carburized boron steel at a temperature of 885-895° C. for 25-35 min, to obtain an austenitized boron steel; sequentially subjecting the austenitized boron steel to an oil quenching and a tempering, wherein the oil quenching is performed at a temperature of 55-65° C. for 29-31 min.

公开(公告)号：US20240084427A1

公开(公告)日：2024-03-14

申请号：US18274364

申请日：2022-02-18

Applicant: NIPPON STEEL CORPORATION

Inventor： Yuya SUZUKI

IPC: C22C38/60 ,  B32B15/01 ,  C21D1/18 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/10 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/38 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/52 ,  C22C38/54 ,  C22C38/58

CPC classification number: C22C38/60 ,  B32B15/013 ,  C21D1/18 ,  C21D6/001 ,  C21D6/002 ,  C21D6/004 ,  C21D6/005 ,  C21D6/007 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/021 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0278 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/10 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/38 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/52 ,  C22C38/54 ,  C22C38/58 ,  C21D2211/001 ,  C21D2211/008 ,  C23C2/28

Abstract: A steel sheet has a predetermined chemical composition, when a sheet thickness is denoted by t, a metallographic structure at a t/4-position, which is a position t/4 away from a surface, in a cross section in a sheet thickness direction includes, by volume percentage, martensite: 70% or greater and residual austenite: 10% or greater, the maximum grain diameter of the residual austenite is less than 5.0 μm when a Mn concentration is measured at a plurality of measurement points at intervals of 1 μm in a square region with a side length of t/4 centered at the t/4-position in the cross section in the sheet thickness direction, a proportion of measurement points at which the Mn concentration is 1.1 times or greater than the average of the Mn concentrations at all of the plurality of measurement points is less than 10.0%, and the tensile strength is 1,470 MPa or greater.

公开(公告)号：US20240084415A1

公开(公告)日：2024-03-14

申请号：US18284765

申请日：2022-03-31

Applicant: NIPPON STEEL CORPORATION

Inventor： Hiroyoshi YASHIKI ,  Yoshiaki NATORI ,  Kazutoshi TAKEDA ,  Ichiro TANAKA ,  Yoshihiro ARITA ,  Hiroki HORI ,  Wataru OHASHI

IPC: C21D9/46 ,  C21D6/00 ,  C21D8/12 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/60 ,  H01F1/147

CPC classification number: C21D9/46 ,  C21D6/001 ,  C21D6/005 ,  C21D6/008 ,  C21D8/1222 ,  C21D8/1233 ,  C21D8/1261 ,  C21D8/1266 ,  C21D8/1283 ,  C22C38/001 ,  C22C38/002 ,  C22C38/004 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/60 ,  H01F1/14775

Abstract: This non-oriented electrical steel sheet includes a base material having a chemical composition including Si: 3.7 to 4.8%, wherein a recrystallization rate is less than 100% in terms of an area fraction, the following Formula (i) and Formula (ii) are satisfied, and the tensile strength is more than 700 MPa.


4.3≤Si+sol. Al+0.5×Mn≤4.9  (i)



(B50(0°)+2×B50(45°)+B50(90°))/4≥1.57  (ii)

公开(公告)号：US11926888B2

公开(公告)日：2024-03-12

申请号：US17417113

申请日：2019-12-26

Applicant: JFE STEEL CORPORATION

Inventor： Takashi Terashima ,  Makoto Watanabe ,  Toshito Takamiya ,  Karin Kokufu

IPC: C22C38/18 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04

CPC classification number: C22C38/18 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04

Abstract: Provided is an annealing separator with which a grain-oriented electrical steel sheet having a forsterite film with excellent appearance uniformity and adhesion can be obtained. The annealing separator for grain-oriented electrical steel sheet comprises: magnesia that contains 0.05 mass % or more and 0.20 mass % or less of B, a phosphate in 0.1 parts by mass or more and 1.0 part by mass or less in terms of P per 100 parts by mass of the magnesia, and titanium oxide in 1.0 part by mass or more and 10.0 parts by mass or less per 100 parts by mass of the magnesia where the titanium oxide contains one or more types of alkali metals in a total amount of 0.050 mass % or more and 1.0 mass % or less, where an amount of P adsorbed on per 1 g of the titanium oxide is 1.0×10−4 g or less.

公开(公告)号：US11923115B2

公开(公告)日：2024-03-05

申请号：US16967945

申请日：2019-01-21

Applicant: JFE STEEL CORPORATION

Inventor： Takashi Terashima ,  Masahiro Suemune ,  Karin Kokufu ,  Toshito Takamiya

IPC: B32B15/04 ,  B32B17/06 ,  C23C22/82 ,  C23C28/04 ,  H01F1/147 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/16 ,  C23C18/12

CPC classification number: H01F1/147 ,  C23C22/82 ,  C23C28/04 ,  C22C38/001 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/16 ,  C22C2202/02 ,  C23C18/1212 ,  C23C18/1241 ,  C23C18/127

Abstract: An insulating coating-attached electrical steel sheet has, on at least one surface, an insulating coating including an insulating tensile coating layer A. A tension applied to the steel sheet by an insulating tensile coating layer having a coating weight of M/2 from a surface of the insulating tensile coating layer A is 0.80×σA or more, where M is a weight of the insulating tensile coating layer A, and σA is the tension applied to the steel sheet by the insulating tensile coating layer A. The insulating coating-attached electrical steel sheet has excellent adhesion of the insulating coating. A method for manufacturing the insulating coating-attached electrical steel sheet is also provided.

公开(公告)号：US11920209B2

公开(公告)日：2024-03-05

申请号：US16969318

申请日：2019-03-08

Applicant: NORTHWESTERN UNIVERSITY

Inventor： Kazuhiko Nishioka ,  Gregory B. Olson

IPC: C21D9/46 ,  C21D1/19 ,  C21D1/84 ,  C21D6/00 ,  C21D8/02 ,  C22C38/02 ,  C22C38/04 ,  C22C38/12

CPC classification number: C21D9/46 ,  C21D1/19 ,  C21D1/84 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C22C38/02 ,  C22C38/04 ,  C22C38/12 ,  C21D2211/001 ,  C21D2211/002

Abstract: One aspect, this invention relates to a carbide-free bainite and retained austenite steel including a composition designed and processed such that the carbide-free bainite and retained austenite steel meets property objectives comprising a yield strength in a range of about 1000-2000 MPa, a uniform ductility, a desired total elongation and hole-expansion ratio, a desired level of weldability and an austenite stability designed to have an austenite start temperature Msσ to be equal to an application temperature in range from about 50° C. to −50° C. The property objectives are design specifications of the carbide-free bainite and retained austenite steel.

公开(公告)号：US11920206B2

公开(公告)日：2024-03-05

申请号：US17958603

申请日：2022-10-03

Applicant: thyssenkrupp Rasselstein GmbH

Inventor： Burkhard Kaup ,  Peter Kirchesch ,  Manuel Köhl ,  Dimitrios Nouskalis ,  Alexander Gossen ,  Björn Ehmke

IPC: C21D8/02 ,  C21D9/46 ,  C21D9/573 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06

CPC classification number: C21D8/0236 ,  C21D8/0226 ,  C21D8/0263 ,  C21D8/0273 ,  C21D9/46 ,  C21D9/573 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C21D2211/005

Abstract: A cold rolled steel flat product for packaging made of a low carbon steel having a thickness of less than 0.49 mm and a method of making. The steel flat product has a martensite-free microstructure and represents a standard grade for packaging with tensile strengths from 300 to 550 MPa, which can be produced from a cold-rolled steel sheet with a carbon content from 0.01% to 0.1% by weight by inductive annealing of the steel sheet and subsequent water cooling for quenching the recrystallization-annealed steel sheet. To achieve flatness of 5 I-units or less, the induction annealed steel sheet is first primarily cooled in the manufacturing process to a take-off temperature at a rate of less than 1000 K/s, with the take-off temperature being below the transformation temperature of 723° C., and thereafter a secondary cooling by water cooling with a water temperature of less than 80° C. at a rate of more than 1000 K/s.

公开(公告)号：US20240068080A1

公开(公告)日：2024-02-29

申请号：US18261885

申请日：2022-03-14

Applicant: NIPPON STEEL CORPORATION

Inventor： Takashi DOI ,  Kenji KOBAYASHI ,  Naomi INATOMI ,  Yuki SUZUKI ,  Soshi FUJITA ,  Masahiro FUDA

IPC: C23C2/12 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C23C2/28 ,  C23C2/40

CPC classification number: C23C2/12 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C23C2/28 ,  C23C2/40

Abstract: A hot-stamped product with improved delayed-fracture resistance is provided. The hot-stamped product 1 includes: a steel substrate 10; and an Al film 20 formed on the steel substrate 10, the Al film 20 including: an interface layer 21 located at the interface with the steel substrate 10 and with part of the αFe substituted by Al and Si; an intermediate layer 22 formed on the interface layer 21; and an oxide layer formed on the intermediate layer, the intermediate layer 22 including an Fe—Al—Si phase 22a with part of the αFe substituted by Al and Si, the Fe—Al—Si phase 22a including one or more elements selected from the group consisting of Zr, Ce, Y, Ta, Ni, Cu, Nb, Cr, Co, V and Ti, the oxide layer 23 including one or more elements selected from the group consisting of Be, Mg, Ca, Sr, Ba, Sc and Zn.

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.