公开(公告)号：US11970759B2

公开(公告)日：2024-04-30

申请号：US17277794

申请日：2019-10-01

Applicant: NIPPON STEEL CORPORATION

Inventor： Kyohei Kanki ,  Masayuki Sagara ,  Yusaku Tomio ,  Daisuke Matsuo

IPC: C22C38/52 ,  C21D6/00 ,  C21D8/10 ,  C21D9/14 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/22 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50

CPC classification number: C22C38/52 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/105 ,  C21D9/14 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C21D2211/008

Abstract: The seamless steel pipe according to the present disclosure includes a chemical composition consisting of, in mass %, C: 0.030% or less, Si: 1.00% or less, Mn: 1.00% or less, P: 0.030% or less, S: 0.0050% or less, Al: 0.001 to 0.100%, N: 0.0500% or less, O: 0.050% or less, Ni: 5.00 to 6.50%, Cr: more than 10.00 to 13.40%, Cu: more than 1.50 to 3.50%, Mo: 1.00 to 4.00%, V: 0.01 to 1.00%, Ti: 0.050 to 0.300%, and Co: 0.010 to 0.300%, with the balance being Fe and impurities, and satisfying Formula (1), wherein a depassivation pH of an inner surface is 3.00 or less.

Cr+2.0 Mo+0.5 Ni+2.0 Cu+0.5 Co≥20.0  (1)

公开(公告)号：US11970758B2

公开(公告)日：2024-04-30

申请号：US17285428

申请日：2019-10-21

Applicant: NIPPON STEEL CORPORATION

Inventor： Hiroshi Shuto ,  Akifumi Sakakibara ,  Shinsuke Kai ,  Koutarou Hayashi ,  Hiroshi Kaido

IPC: C21D9/46 ,  C21D6/00 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/10 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/26 ,  C22C38/34 ,  C22C38/38

CPC classification number: C22C38/38 ,  C21D6/001 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  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 ,  C22C38/26 ,  C22C38/34 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C21D2211/009

Abstract: This hot-rolled steel sheet has a predetermined chemical composition. The metallographic structure at a sheet thickness ¼ depth from a surface and at a center position in a sheet width direction in a sheet width cross section parallel to a rolling direction contains, by area %, 77.0% to 97.0% of bainite and tempered martensite in total, 0% to 5.0% of ferrite, 0% to 5.0% of pearlite, 3.0% or more of residual austenite, and 0% to 10.0% of martensite. The average grain size of the metallographic structure excluding the residual austenite is 7.0 μm or less. The C concentration in the residual austenite is 0.5 mass % or more. The number density of iron-based carbides having a diameter of 20 nm or more is 1.0×106 carbides/mm2 or more.

公开(公告)号：US11970749B2

公开(公告)日：2024-04-30

申请号：US18171305

申请日：2023-02-17

Applicant: POSCO CO., LTD

Inventor： Tae-Jin Song ,  Jeong-Eun Kim ,  Chang-Sik Choi

IPC: C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14

CPC classification number: C21D8/0226 ,  C21D8/0205 ,  C21D8/0215 ,  C21D8/0247 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C21D2211/001

Abstract: Provided is a method of manufacturing a hot rolled steel sheet having excellent formability and fatigue properties, including: preparing a slab including, by weight %, 0.3 to 0.8% of carbon C, 13 to 25% of manganese (Mn), 0.1 to 1.0% of vanadium (V), 0.005 to 2.0% of silicon (Si), 0.01 to 2.5% of aluminum (Al), 0.03% or less of phosphorus (P), 0.03% or less of sulfur (S), 0.04% or less (excluding 0%) of nitrogen (N), and a remainder of iron (Fe) and inevitable impurities; heating the slab to 1050 to 1250° C.; finish rolling, the slab heated in the heating, at a temperature of not lower than a recrystallization temperature of a region having an average V concentration and not higher than a recrystallization temperature of a region having twice the average V concentration, to obtain a hot rolled steel sheet; and coiling the hot-rolled steel sheet at 50 to 700° C.

公开(公告)号：US20240133007A1

公开(公告)日：2024-04-25

申请号：US18569882

申请日：2022-09-19

Applicant: NIPPON STEEL CORPORATION

Inventor： Shingo FUJINAKA ,  Hitomi NISHIBATA

IPC: C22C38/60 ,  C21D1/18 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/30 ,  C22C38/32 ,  C22C38/38 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54

CPC classification number: C22C38/60 ,  C21D1/18 ,  C21D6/002 ,  C21D6/004 ,  C21D6/005 ,  C21D6/007 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/30 ,  C22C38/32 ,  C22C38/38 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C21D2211/001

Abstract: A hot-stamp formed body has a predetermined chemical composition and has a microstructure including, by area ratio, martensite: 90% to 100% and a remainder in the microstructure: 0% to 10%. The percentage of martensite having a GAIQ value of 40000 or less in all of the martensite is less than 5.0%, an average grain size of prior austenite grains is 6.0 μm or less, and a standard deviation of grain sizes of the prior austenite grains is 2.6 μm or less.

公开(公告)号：US20240133003A1

公开(公告)日：2024-04-25

申请号：US18547692

申请日：2022-03-02

Applicant: JFE STEEL CORPORATION

Inventor： Shigehiro TAKAJO ,  Hiroi YAMAGUCHI

IPC: C22C38/02 ,  C21D8/02 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06 ,  C22C38/60

CPC classification number: C22C38/02 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0273 ,  C22C38/001 ,  C22C38/04 ,  C22C38/06 ,  C22C38/60

Abstract: The method includes slab-heating a steel slab to a temperature of higher than a γ-phase precipitation temperature and 1380° C. or lower, subjecting the steel slab to rough rolling including at least two passes of rolling at a predetermined temperature with an introduced sheet thickness true strain εt of 0.50 or more and to finish rolling with a rolling finish temperature of 900° C. or higher to obtain a hot-rolled sheet, cooling the sheet for 1 second or longer at a cooling rate of 70° C./s or higher within 2 seconds after finish rolling, coiling the sheet at a coiling temperature of 600° C. or lower, performing hot-rolled sheet annealing for soaking at a predetermined soaking temperature, and then performing cold rolling, primary recrystallization annealing, and secondary recrystallization annealing.

公开(公告)号：US11965231B2

公开(公告)日：2024-04-23

申请号：US17417735

申请日：2019-12-27

Applicant: NIPPON STEEL CORPORATION ,  JTEKT CORPORATION

Inventor： Yutaka Neishi ,  Tomohiro Yamashita ,  Daisuke Hirakami ,  Takahisa Suzuki ,  Tatsuya Koyama ,  Takashi Sada ,  Kohei Kanetani

IPC: C22C38/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/44

CPC classification number: C22C38/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/44

Abstract: The steel material includes a chemical composition containing, in mass %, C: 0.15 to 0.45%, Si: 0.50% or less, Mn: 0.20 to 0.60%, P: 0.015% or less, S: 0.005% or less, Cr: 0.80 to 1.50%, Mo: 0.17 to 0.30%, V: 0.24 to 0.40%, Al: 0.005 to 0.100%, N: 0.0300% or less, O: 0.0015% or less, and the balance being Fe and impurities, and satisfying Formula (1) to Formula (4) described in Embodiment, wherein, in its microstructure, a total area fraction of ferrite and pearlite is 10.0% or more, and a proportion of a content of V (mass %) in electrolytic extraction residue to the content of V (mass %) in the chemical composition is 10.0% or less.

公开(公告)号：US11959158B2

公开(公告)日：2024-04-16

申请号：US17501193

申请日：2021-10-14

Applicant: University of Science & Technology Beijing

Inventor： Jinfeng Huang ,  Jin Zhang ,  Chao Zhao ,  Cheng Zhang

IPC: C22C38/46 ,  C21D1/18 ,  C21D1/26 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/44 ,  C22C38/48 ,  C22C38/50 ,  C22C38/52 ,  C22C38/54

CPC classification number: C22C38/46 ,  C21D1/18 ,  C21D1/26 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/44 ,  C22C38/48 ,  C22C38/50 ,  C22C38/52 ,  C22C38/54

Abstract: A low-carbon and low alloy hot-work die steel with a high toughness at low temperatures and a high strength at high temperatures and a high hardenability, comprises the following components: C: 0.15-0.35%, Si: 0.40-0.90%, Mn: ≤0.80%, Cr: 1.50-2.40%, Ni: 2.50-4.50%, Mo: 1.00-1.60%, V: 0.10-0.40%, W: 0.20-0.90%, P: ≤0.02%, S≤0.02%, and a balance of Fe matrix and other inevitable impurities. The above percentages are mass percentages. The material of the present invention can have a V notch impact energy of 30 J or more than 30 J at −40° C., a high temperature strength of 380 MPa or more at 700° C., and a hardenability of 200 mm or more to ensure the consistency of internal and external microstructures. The materials of the present invention can be applied to hot-work molds used in special working conditions that require high toughness at low temperatures, high strength at high temperatures and high hardenability.

公开(公告)号：US11959149B2

公开(公告)日：2024-04-16

申请号：US17426729

申请日：2020-01-30

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi Imamura ,  Makoto Watanabe

IPC: C21D9/46 ,  C21D8/12 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/12 ,  C22C38/42 ,  C22C38/48 ,  C22C38/60

CPC classification number: C21D9/46 ,  C21D8/1222 ,  C21D8/1233 ,  C21D8/1255 ,  C21D8/1272 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/12 ,  C22C38/42 ,  C22C38/48 ,  C22C38/60 ,  C21D2201/05

Abstract: Provided are a grain-oriented electrical steel sheet having excellent iron loss property without using magnetic domain refining treatment and an iron core produced using the same. The steel sheet comprises: a predetermined chemical composition; and a steel microstructure in which: crystal grains are made up of coarse secondary recrystallized grains of 5.0 mm or more, fine grains of more than 2.0 mm and less than 5.0 mm contained at a frequency of 0.2 to 5 grains per cm2, and very fine grains of 2.0 mm or less; for each coarse secondary recrystallized grain extending through the sheet in a thickness direction, an area ratio of a region in which projected surfaces of exposed areas of the coarse secondary recrystallized grain on a front side and a back side of the sheet coincide with each other to each of the exposed areas is 95% or more.

公开(公告)号：US11958139B2

公开(公告)日：2024-04-16

申请号：US16959475

申请日：2019-01-16

Applicant: Kobe Steel, Ltd.

Inventor： Yoshimasa Muranishi

IPC: B23K35/02 ,  B23K35/30 ,  B23K35/368 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/18 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/32

CPC classification number: B23K35/0266 ,  B23K35/30 ,  B23K35/3086 ,  B23K35/3093 ,  B23K35/368 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/32 ,  C22C38/18

Abstract: A flux-cored wire for gas shielded arc welding may contain, based on total mass of the wire: Fe: 78 mass % or more; TiO2: 4 mass % to 13 mass %; Mn: 1.0 mass % to 2.4 mass %; Cr: 1.0 mass % to 3.0 mass %; Mo: 0.2 mass % to 1.2 mass %; Si: 0.1 mass % to 0.8 mass %; Mg: 0.1 mass % to 1.0 mass %; fluoride (F conversion value): 0.05 mass % to 0.25 mass %; C: 0.01 mass % to 0.10 mass %; V: 0.003 mass % to 0.020 mass %; Nb: 0.003 mass % to 0.020 mass %; and B: less than 100 ppm (including 0 ppm). The contents of Mn, C, and V based on total mass of the wire may satisfy a relationship of 28×Mn/(390×C+2370×V)≥0.82.

公开(公告)号：US20240117459A1

公开(公告)日：2024-04-11

申请号：US18267237

申请日：2021-11-18

Applicant: POSCO CO., LTD.

Inventor： Choongyeol LEE

IPC: C21D9/52 ,  C21D1/84 ,  C21D8/06 ,  C22C38/02 ,  C22C38/04

CPC classification number: C21D9/525 ,  C21D1/84 ,  C21D8/065 ,  C22C38/02 ,  C22C38/04 ,  C21D2211/003 ,  C21D2211/009

Abstract: A steel wire with improved drawability, and a manufacturing method therefor are disclosed. A steel wire according to the present invention comprises, by wt %, 0.52-0.69% of C, 0.3-0.8% of Mn, 0.1-0.5% of Si, and the balance of Fe and inevitable impurities, wherein the carbon content of cementite in pearlite is 7 at. % or more, and the following formula (1) is satsified.


[TS]+exp(ε)*10