公开(公告)号：US20240360538A1

公开(公告)日：2024-10-31

申请号：US18287864

申请日：2022-04-19

Applicant: BAOSHAN IRON & STEEL CO., LTD.

Inventor： Sixin Zhao ,  Jiaqiang Gao ,  Zongze Huang

IPC: C22C38/26 ,  C21D1/18 ,  C21D1/26 ,  C21D7/13 ,  C21D9/28 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/24 ,  C22C38/28

CPC classification number: C22C38/26 ,  C21D1/18 ,  C21D1/26 ,  C21D7/13 ,  C21D9/28 ,  C22C38/001 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/24 ,  C22C38/28

Abstract: Disclosed are a steel for a high-temperature carburized gear shaft and a manufacturing method for the steel. The steel for the high-temperature carburized gear shaft comprises the following chemical components in percentage by mass: 0.17-0.22% of C, 0.05-0.35% of Si, 0.80-1.40% of Mn, 0.010-0.035% of S, 0.80-1.40% of Cr, 0.020-0.046% of Al, 0.006-0.020% of N, 0.002-0.030% of Nb, V≤0.02%, and Ti≤0.01%. Also disclosed is a manufacturing method for the steel for the high-temperature carburized gear shaft, comprising the steps of: smelting and casting; heating; forging or rolling; and finishing. By reasonably controlling chemical element compositions of the steel, the steel for the gear shaft in the present invention can maintain proper austenite grain size and stability at high temperature, maintains 5-8 grades of the austenite grain size before and after the high-temperature vacuum carburizing at 940-1050° C., can be effectively applied to high-end parts such as a gearbox for a vehicle or a speed reducer and a differential of a new energy vehicle, and has good application prospects and value.

公开(公告)号：US20240360531A1

公开(公告)日：2024-10-31

申请号：US18579903

申请日：2022-06-22

Applicant: JFE Steel Corporation

Inventor： Taiyo Asakawa ,  Shimpei Yoshioka ,  Shinjiro Kaneko

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

CPC classification number: C21D9/46 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0242 ,  C21D8/0273 ,  C21D8/0278 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C21D2211/001 ,  C21D2211/008

Abstract: A steel sheet contains, in mass %, C: 0.15 to 0.45%, Si: 1.5% or less, Mn: 1.7% or less, P: 0.03% or less, S: less than 0.0020%, sol. Al: 0.20% or less, N: 0.005% or less, B: 0.0015 to 0.0100%, and at least one of Nb and Ti in a total amount of 0.005 to 0.080%, with the balance being Fe and incidental impurities. The area fraction of martensite with respect to the total area of the microstructure is 95 to 100%, and the diameter of prior γ grains is less than 11.0 μm. The number density A of precipitates having an equivalent circular diameter of 500 nm or more satisfies the formula: A (particles/mm2)≤8.5×105×[B].

公开(公告)号：US12129534B2

公开(公告)日：2024-10-29

申请号：US17801134

申请日：2021-05-07

Applicant: NIPPON STEEL CORPORATION

Inventor： Yuri Toda ,  Daisuke Maeda ,  Shingo Fujinaka

IPC: C22C38/02 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18

CPC classification number: C22C38/18 ,  C21D6/001 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C21D2211/002 ,  C21D2211/005

Abstract: This hot-stamping formed body has a predetermined chemical composition and has a metallographic structure consisting of, by area ratio, a total of 10% to 30% of ferrite and granular bainite and a remainder in microstructure consisting of one or more of martensite, bainite, and tempered martensite, and, in textures of a surface layer region and an inside region, ratios between a pole density of an orientation group consisting of {001} to {001} and a pole density of an orientation group consisting of {111} to {111} are controlled.

公开(公告)号：US12129526B2

公开(公告)日：2024-10-29

申请号：US17413781

申请日：2019-12-27

Applicant: BAOSHAN IRON & STEEL CO., LTD.

Inventor： Suoquan Zhang ,  Sihai Jiao ,  Jianhua Ding ,  Xiaojun Liang

IPC: C21D8/02 ,  C22C38/02 ,  C22C38/04

CPC classification number: C21D8/0247 ,  C21D8/0205 ,  C22C38/02 ,  C22C38/04 ,  C21D2211/005 ,  C21D2211/009

Abstract: Provided are a gradient steel material having a surface layer with ferrite and an inner layer with ferrite+pearlite, and a manufacturing method, the weight percentages of the components are: C≤0.15%, Si≤1%, Mn≤1.5%, the balance of Fe and inevitable impurities, and the surface layer of the steel material is ferrite, the inner layer is ferrite+pearlite. The manufacturing method thereof includes: smelting, casting, rolling, heat treatment; wherein, in the heat treatment step, the steel material is heated above the austenitizing temperature Ac3, and hold at the temperature more than 3 min to ensure that the material is completely austenitized; subsequently, it is cooled to a temperature below Ar1 at a cooling rate lower than 0.5° C./s. The present steel material does not need to be obtained by means of the compound preparation of different materials, and is only processed and prepared by a single material, the process is short, the procedure is simple, and the cost is low.

公开(公告)号：US20240352566A1

公开(公告)日：2024-10-24

申请号：US18687374

申请日：2022-09-22

Applicant: NIPPON STEEL CORPORATION

Inventor： Kei MIYANISHI ,  Toshiharu AISO

IPC: C22C38/60 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/30 ,  C22C38/32 ,  C22C38/38 ,  C22C38/40

CPC classification number: C22C38/60 ,  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 ,  C22C38/40

Abstract: A steel material which is excellent in machinability, in which occurrence of cracks during hot working and melting cracks during induction hardening can be suppressed, and which has excellent fatigue strength when formed into a component for machine structural use is provided. A steel material of the present embodiment contains, in percent by mass, C: 0.05 to 0.30%, Si: 0.05 to 0.45%, Mn: 0.30 to 2.00%, P: 0.030% or less, S: 0.010 to 0.095%, Cr: 0.01 to 2.00%, Bi: 0.0051 to 0.1500%, and N: 0.0030 to 0.0250%, and satisfies the following Formula (1). In the steel material, a number density of fine Bi particles is 80 to 8000 pieces/mm2 and a number density of coarse Bi particles is 10 pieces/mm2 or less.







0.25
≤

C
+

(

Si
/
10

)

+

(

Mn
/
5

)

-

(

5
⁢
S
/
7

)

+

(

5
⁢
Cr
/
22

)

+

1.65
V


≤
1.




(
1
)

公开(公告)号：US12123069B2

公开(公告)日：2024-10-22

申请号：US17286148

申请日：2019-10-16

Applicant: JFE STEEL CORPORATION

Inventor： Yoshihiko Ono ,  Junya Tobata ,  Hiroyuki Akimoto ,  Yoichiro Matsui ,  Shinjiro Kaneko

IPC: C21D9/46 ,  C21D1/20 ,  C21D6/00 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/42 ,  C22C38/44 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C22C38/60

CPC classification number: C21D9/46 ,  C21D1/20 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/42 ,  C22C38/44 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C22C38/60 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008

Abstract: A steel sheet having a specified chemical composition and a method for producing the steel sheet. The steel sheet has a microstructure comprising ferrite: 5% or less, and at least one of upper bainite, fresh martensite, tempered martensite, lower bainite, and retained γ: 95% to 100% by area percentage, and retained γ: 4% to 15% by volume percentage. Retained γUB has a specified area percentage SγUB, retained γLB has a specified distribution number NγLB, and at least one of (i) fresh martensite has a specified equivalent circular grain diameter and aspect ratio and (ii) retained γ grains has a specified equivalent circular grain diameter and aspect ratio.

公开(公告)号：US12123068B2

公开(公告)日：2024-10-22

申请号：US17258968

申请日：2018-07-13

Applicant: NIPPON STEEL CORPORATION

Inventor： Takashi Kataoka ,  Yoshiyuki Ushigami ,  Shuichi Nakamura ,  Hiroyasu Fujii ,  Shunsuke Okumura

IPC: C21D9/46 ,  C21D6/00 ,  C21D8/12 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/16 ,  C22C38/18 ,  H01F1/14

CPC classification number: C21D9/46 ,  C21D6/008 ,  C21D8/1283 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/16 ,  C22C38/18 ,  H01F1/14 ,  C21D2201/05 ,  C22C2202/02

Abstract: A grain oriented electrical steel sheet includes: by mass %, 0.010% or less of C; 2.50 to 4.00% of Si; 0.010% or less of acid soluble Al; 0.012% or less of N; 1.00% or less of Mn; 0.020% or less of S; and a balance comprising Fe and impurities, and has a tension-insulation coating at steel sheet surface and a SiO2 intermediate oxide film layer with an average thickness of 1.0 nm to 1.0 μm at an interface between the tension-insulation coating and the steel sheet surface. In the grain oriented electrical steel, when a surface of the intermediate oxide film layer is analyzed by an infrared reflection spectroscopy, a peak intensity IA at 1250 cm−1 and a peak intensity IB at 1200 cm−1 satisfy IB/IA≥0.010.

公开(公告)号：US12123064B2

公开(公告)日：2024-10-22

申请号：US17422406

申请日：2020-01-30

Applicant: NIPPON STEEL CORPORATION

Inventor： Hiroshi Shuto ,  Koutarou Hayashi ,  Hiroshi Kaido ,  Akifumi Sakakibara ,  Jun Ando ,  Tetsu Asato

IPC: C21D9/46 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C21D1/02

CPC classification number: C21D8/0226 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C21D1/02 ,  C21D2211/001

Abstract: This hot-rolled steel sheet has a predetermined chemical composition, in which a metal microstructure contains, by area %, 3.0% or more of residual austenite, has a ratio L52/L7 of a length L52 of a grain boundary having a crystal orientation difference of 52° to a length L7 of a grain boundary having a crystal orientation difference of 7° about a direction of 0.10 or more and 0.18 or less, has a standard deviation of a Mn concentration of 0.60 mass % or less, and has a tensile strength of 980 MPa or more.

公开(公告)号：US20240344164A1

公开(公告)日：2024-10-17

申请号：US18646241

申请日：2024-04-25

Applicant: POSCO CO., LTD

Inventor： Ki-Cheol Kang ,  Chung-Hwan Lee ,  Yong-Joo Kim ,  Kang-Min Lee ,  Kyoo-Young Lee

IPC: C21D9/46 ,  B32B15/01 ,  B32B15/04 ,  B32B15/18 ,  C21D1/19 ,  C21D1/25 ,  C21D1/76 ,  C21D1/84 ,  C21D3/04 ,  C21D6/00 ,  C21D8/02 ,  C21D9/56 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/18 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/38 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/58 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  C23C28/00 ,  C23C28/02 ,  C23C30/00

CPC classification number: C21D9/46 ,  B32B15/01 ,  B32B15/013 ,  B32B15/04 ,  B32B15/043 ,  B32B15/18 ,  C21D1/19 ,  C21D1/25 ,  C21D1/76 ,  C21D1/84 ,  C21D3/04 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0257 ,  C21D8/0263 ,  C21D8/0273 ,  C21D8/0278 ,  C21D9/562 ,  C22C38/001 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/18 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/38 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/58 ,  C23C2/02 ,  C23C2/022 ,  C23C2/0224 ,  C23C2/024 ,  C23C2/06 ,  C23C2/28 ,  C23C2/29 ,  C23C2/40 ,  C23C28/025 ,  C23C28/3225 ,  C23C28/345 ,  C23C30/00 ,  C23C30/005 ,  B32B2307/732 ,  Y10T428/12583 ,  Y10T428/1259 ,  Y10T428/12597 ,  Y10T428/12611 ,  Y10T428/12618 ,  Y10T428/1266 ,  Y10T428/12667 ,  Y10T428/12799 ,  Y10T428/12958 ,  Y10T428/12965 ,  Y10T428/12972 ,  Y10T428/12993 ,  Y10T428/24942 ,  Y10T428/2495 ,  Y10T428/24967 ,  Y10T428/24983 ,  Y10T428/26 ,  Y10T428/27 ,  Y10T428/273

Abstract: The present disclosure relates to a high-strength hot-dip galvanized steel sheet having excellent surface quality and electrical resistance spot weldability, and a method for manufacturing the same. A galvanized steel sheet according to an aspect of the present disclosure is a galvanized steel sheet including a base steel sheet and a zinc-based plating layer formed on a surface of the base steel sheet, wherein a ratio (a/b) of a hardness of a surface layer portion (a) to a hardness of an internal portion (b) of the base steel sheet may be less than 0.95.

公开(公告)号：US20240344161A1

公开(公告)日：2024-10-17

申请号：US18682465

申请日：2022-10-11

Applicant: NIPPON STEEL CORPORATION

Inventor： Arisa HASEGAWA

IPC: C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C23C2/06 ,  C23C2/12 ,  C23C2/40

CPC classification number: C21D8/0236 ,  C21D8/0226 ,  C21D8/0273 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C23C2/06 ,  C23C2/12 ,  C23C2/40 ,  C21D2211/001 ,  C21D2211/008

Abstract: This cold-rolled steel sheet has a predetermined chemical composition, in which a metallographic structure at a position of ¼ to ¾ of a sheet thickness in a sheet thickness direction from a surface contains, by volume percentage, 0% or more and 10.0% or less of retained austenite and 90.0% or more and 100% or less of one or two of martensite and tempered martensite, in the metallographic structure at the position, a P content at prior γ grain boundaries is 10.0 mass % or less, and a Mn content at the prior γ grain boundaries is 10.0 mass % or less, and a tensile strength is 1,310 MPa or more.