公开(公告)号：US20250065432A1

公开(公告)日：2025-02-27

申请号：US18293892

申请日：2022-08-29

Applicant: JFE STEEL CORPORATION

Inventor： Akiyoshi ANDO ,  Atsushi TAKADA ,  Kazufumi WATANABE ,  Takatoshi OKABE ,  Keiji UEDA ,  Masamichi SUZUKI ,  Peng HAN

IPC: B23K9/18 ,  B23K35/30 ,  B23K103/04

Abstract: Provided is a submerged arc welding method that produces little fume, has good weldability, and is suitable for welding high-Mn-containing steel materials to be used in cryogenic environments. The method includes welding with a combination of a wire having a predetermined chemical composition and flux having a basicity [BL] of 1.5 to 2.4, while adjusting a welding heat input according to a groove cross-sectional area. In this way, a weld metal with high strength and excellent cryogenic impact toughness where the 0.2% proof stress at room temperature is 400 MPa or more and an absorbed energy (vE−196) in the Charpy impact test is 28 J or more can be easily manufactured.

公开(公告)号：US20220275489A1

公开(公告)日：2022-09-01

申请号：US17635377

申请日：2020-08-18

Applicant: JFE STEEL CORPORATION

Inventor： Daichi IZUMI ,  Koichi NAKASHIMA ,  Keiji UEDA

IPC: C22C38/04 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/26 ,  C22C38/28

Abstract: The steel of the present disclosure contains, in mass %, C: 0.100% to 0.700%, Si: 0.05% to 1.00%, Mn: 20.0% to 40.0%, P: ≤0.030%, S: ≤0.0050%, Al: 0.01% to 5.00%, Cr: 0.5% to 7.0%, N: 0.0050% to 0.0500%, O: ≤0.0050%, Ti: ≤0.005%, Nb: ≤0.005%, and at least one selected from Ca: 0.0005% to 0.0100%, Mg: 0.0005% to 0.0100%, and REM: 0.0010% to 0.0200%, and has a microstructure with austenite as matrix, where an average grain size is 50 μm or less, a cleanliness of sulfide inclusion is less than 1.0%, a yield strength is 400 MPa or more, and a percent brittle fracture after a Charpy impact test at −269° C. is less than 5%.

公开(公告)号：US20240131632A1

公开(公告)日：2024-04-25

申请号：US18277837

申请日：2022-02-28

Applicant: JFE STEEL CORPORATION

Inventor： Kazufumi WATANABE ,  Atsushi TAKADA ,  Akiyoshi ANDO ,  Takatoshi OKABE ,  Keiji UEDA

IPC: B23K35/30 ,  B23K9/167 ,  B23K35/00 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/38

CPC classification number: B23K35/3073 ,  B23K9/167 ,  B23K35/004 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/06 ,  C22C38/38

Abstract: A TIG welded joint in a high-Mn content steel material that can be formed with reduced occurrence of hot cracking during the welding process and has high strength and excellent cryogenic impact toughness. In the TIG welded joint, the high-Mn content steel material has a chemical composition including, by mass %, C: 0.10 to 0.80%, Si: 0.05 to 1.00%, Mn: 18.0 to 30.0%, P: 0.030% or less, S: 0.0070% or less, Al: 0.010 to 0.070%, Cr: 2.5 to 7.0%, N: 0.0050 to 0.0500%, and O: 0.0050% or less, the balance being Fe and incidental impurities, and a weld metal has a chemical composition including C: 0.10 to 0.80%, Si: 0.05 to 1.00%, Mn: 15.0 to 30.0%, P: 0.030% or less, S: 0.030% or less, Al: 0.100% or less, Cr: 6.0 to 14.0%, and N: 0.100% or less, the balance being Fe and incidental impurities.

公开(公告)号：US20180057916A1

公开(公告)日：2018-03-01

申请号：US15551301

申请日：2016-01-25

Applicant: JFE Steel Corporation

Inventor： Yoshie OBATA ,  Yoshiyasu KAWASAKI ,  Keiji UEDA ,  Shinjiro KANEKO ,  Takeshi YOKOTA ,  Kazuhiro SETO

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

CPC classification number: C22C38/14 ,  C21D8/0236 ,  C21D8/0268 ,  C21D9/46 ,  C21D2211/001 ,  C21D2211/004 ,  C21D2211/005 ,  C21D2211/008 ,  C21D2211/009 ,  C22C38/00 ,  C22C38/001 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/16 ,  C22C38/18 ,  C22C38/60 ,  C23C2/02 ,  C23C2/06 ,  C23C2/40

Abstract: A steel having a composition containing C: more than 0.20% and 0.45% or less, Si: 0.50% to 2.50%, Mn: 2.00% or more and less than 3.50%, and one or two selected from Ti: 0.005% to 0.100% and Nb: 0.005% to 0.100% is hot-rolled and cold-rolled. The steel sheet is heated to 800° C. to 950° C. and cooled to a cooling-end temperature of 350° C. to 500° C. at a cooling rate of 5° C./s or more to form a steel sheet having a microstructure including martensite and bainite phases such that the total proportion of the martensite and bainite phases is 80% or more by volume. The steel sheet is heated to 700° C. to 840° C. and maintained at 700° C. to 840° C., cooled to a cooling-end temperature of 350° C. to 500° C. at a cooling rate of 5 to 50° C./s, and maintained within the above temperature range for 10 to 1800 s.

公开(公告)号：US20240227088A9

公开(公告)日：2024-07-11

申请号：US18277837

申请日：2022-02-28

Applicant: JFE STEEL CORPORATION

Inventor： Kazufumi WATANABE ,  Atsushi TAKADA ,  Akiyoshi ANDO ,  Takatoshi OKABE ,  Keiji UEDA

IPC: B23K35/30 ,  B23K9/167 ,  B23K35/00 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/38

CPC classification number: B23K35/3073 ,  B23K9/167 ,  B23K35/004 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/06 ,  C22C38/38

Abstract: A TIG welded joint in a high-Mn content steel material that can be formed with reduced occurrence of hot cracking during the welding process and has high strength and excellent cryogenic impact toughness. In the TIG welded joint, the high-Mn content steel material has a chemical composition including, by mass %, C: 0.10 to 0.80%, Si: 0.05 to 1.00%, Mn: 18.0 to 30.0%, P: 0.030% or less, S: 0.0070% or less, Al: 0.010 to 0.070%, Cr: 2.5 to 7.0%, N: 0.0050 to 0.0500%, and O: 0.0050% or less, the balance being Fe and incidental impurities, and a weld metal has a chemical composition including C: 0.10 to 0.80%, Si: 0.05 to 1.00%, Mn: 15.0 to 30.0%, P: 0.030% or less, S: 0.030% or less, Al: 0.100% or less, Cr: 6.0 to 14.0%, and N: 0.100% or less, the balance being Fe and incidental impurities.

公开(公告)号：US20210301378A1

公开(公告)日：2021-09-30

申请号：US17264295

申请日：2019-07-31

Applicant: JFE STEEL CORPORATION

Inventor： Daichi IZUMI ,  Shigeki KITSUYA ,  Keiji UEDA ,  Koichi NAKASHIMA

IPC: C22C38/38 ,  C22C38/02 ,  C22C38/00 ,  C22C38/06 ,  C22C38/26 ,  C22C38/28 ,  C21D8/02

Abstract: Provided is a high-Mn steel having excellent low-temperature toughness and excellent surface characteristics. A high-Mn steel comprises: a chemical composition containing, in mass %, C: 0.100 to 0.700%, Si: 0.05 to 1.00%, Mn: 20.0 to 35.0%, P: ≤0.030%, S: ≤0.0070%, Al: 0.010 to 0.070%, Cr: 0.50 to 5.00%, N: 0.0050 to 0.0500%, O: ≤0.0050%, Ti: ≤0.005%, and Nb: ≤0.005%, with a balance consisting of Fe and inevitable impurities; and a microstructure having austenite as a matrix, wherein in the microstructure, a Mn concentration of a Mn-concentrated portion is 38.0% or less, and an average KAM value is 0.3 or more, yield stress is 400 MPa or more, absorbed energy vE−196 in a Charpy impact test at −196° C. is 100 J or more, and percent brittle fracture is less than 10%.

公开(公告)号：US20210164067A1

公开(公告)日：2021-06-03

申请号：US16768884

申请日：2018-12-06

Applicant: JFE STEEL CORPORATION

Inventor： Koichi NAKASHIMA ,  Keiji UEDA ,  Shigeki KITSUYA ,  Ryo ARAO ,  Daichi IZUMI ,  Satoshi IGI ,  Tomohiro ONO

IPC: C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/58 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00

Abstract: Provided is a high-Mn steel which not only has high strength and excellent low-temperature toughness but also has excellent CTOD property at low temperatures. The high-Mn steel has a chemical composition containing, in mass %, C: 0.10-0.70%, Si: 0.05-0.50%, Mn: 20-30%, P: 0.030% or less, S: 0.0070% or less, Al: 0.01-0.07%, Cr: 0.5-7.0%, Ni: 0.01% or more and less than 0.1%, Ca: 0.0005-0.0050%, N: 0.0050-0.0500%, O: 0.0050% or less, Ti: less than 0.0050%, and Nb: less than 0.0050%, the balance consisting of Fe and inevitable impurities, and a microstructure having austenite as a base phase, where the austenite has a grain size of 1 μm or more and a standard deviation of 9 μm or less.

公开(公告)号：US20240051070A1

公开(公告)日：2024-02-15

申请号：US18277833

申请日：2022-02-28

Applicant: JFE STEEL CORPORATION

Inventor： Kazufumi WATANABE ,  Atsushi TAKADA ,  Akiyoshi ANDO ,  Takatoshi OKABE ,  Keiji UEDA

IPC: B23K35/30 ,  B23K9/18

CPC classification number: B23K35/3073 ,  B23K9/18 ,  B23K2103/04

Abstract: A submerged arc welded joint in a high-Mn content steel material that can be formed with reduced occurrence of hot cracking during the welding process and has high strength and excellent cryogenic impact toughness. In the welded joint, the high-Mn content steel material has a chemical composition including, by mass %, C: 0.10 to 0.80%, Si: 0.05 to 1.00%, Mn: 18.0 to 30.0%, P: 0.030% or less, S: 0.0070% or less, Al: 0.010 to 0.070%, Cr: 2.5 to 7.0%, N: 0.0050 to 0.0500%, and O: 0.0050% or less, the balance being Fe and incidental impurities, and a weld metal has a chemical composition including C: 0.10 to 0.80%, Si: 0.05 to 1.00%, Mn: 15.0 to 30.0%, P: 0.030% or less, S: 0.030% or less, Al: 0.100% or less, Cr: 6.0 to 14.0%, and N: 0.100% or less, the balance being Fe and incidental impurities.

公开(公告)号：US20210323101A1

公开(公告)日：2021-10-21

申请号：US17270045

申请日：2019-04-01

Applicant: JFE STEEL CORPORATION ,  Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

Inventor： Atsushi TAKADA ,  Daichi IZUMI ,  Ryo ARAO ,  Shohei KOZUKI ,  Keiji UEDA ,  Naoya HAYAKAWA ,  Ken YAMASHITA ,  Peng HAN

IPC: B23K35/30 ,  B23K35/02 ,  C22C38/58 ,  C22C38/44 ,  C22C38/02

Abstract: Provided is a solid wire for gas metal arc welding, which has a small amount of fume during welding and is suitable as a welding material for high Mn steel materials. The wire has a chemical composition containing, in mass %, C: 0.2% to 0.8%, Si: 0.15% to 0.90%, Mn: 17.0% to 28.0%, P: 0.03% or less, S: 0.03% or less, Ni: 0.01% to 10.00%, Cr: 0.4% to 4.0%, Mo: 0.01% to 3.50%, B: less than 0.0010%, and N: 0.12% or less, with the balance consisting of Fe and inevitable impurities. It may contain at least one selected from V, Ti, Nb, Cu, Al, Ca and REM, if necessary. The wire has excellent manufacturability, can significantly suppress the amount of fume generated during gas metal arc welding, and can easily manufacture a weld joint having high strength and excellent impact toughness at cryogenic temperatures.

公开(公告)号：US20170204492A1

公开(公告)日：2017-07-20

申请号：US15329026

申请日：2015-07-31

Applicant: JFE STEEL CORPORATION

Inventor： Keiji UEDA ,  Shinjiro KANEKO ,  Masami IWASAKI ,  Reiko SUGIHARA ,  Takeshi YOKOTA ,  Kazuhiro SETO

IPC: C21D9/46 ,  C21D1/26 ,  C22C38/58 ,  C22C38/50 ,  C22C38/48 ,  C22C38/42 ,  C22C38/38 ,  C22C38/28 ,  C22C38/26 ,  C22C38/22 ,  C22C38/20 ,  C22C38/24 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02

CPC classification number: C21D9/46 ,  C21D1/26 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/38 ,  C22C38/42 ,  C22C38/48 ,  C22C38/50 ,  C22C38/58

Abstract: A cold-rolled steel sheet having excellent spot weldability suitable for use in vehicles, electric appliances, etc. is provided. The cold-rolled steel sheet has a steel composition containing, in mass%: C: 0.05% to 0.13%; Si: 0.05% to 2.0%; Mn: 1.5% to 4.0%; P: 0.05% or less; S: 0.005% or less; Al: 0.01% to 0.10%; Cr: 0.05% to 1.0%; Nb: 0.010% to 0.070%; Ti: 0.005% to 0.040%; and N: 0.0005% to 0.0065%, with a mass ratio Ti/N of Ti and N being 2.5 or more and 7.5 or less, and a balance being Fe and incidental impurities, wherein 70 mass % or more of Ti in steel exists as a precipitate, and 15 mass % or more of Nb in the steel exists as solute Nb, and a tensile strength is 980 MPa or more.