公开(公告)号：US20220118508A1

公开(公告)日：2022-04-21

申请号：US17423557

申请日：2020-01-22

Applicant: JFE Steel Corporation

Inventor： Yoichi Ito ,  Norichika Aramaki ,  Koichi Nakashima ,  Shigeki Kitsuya

IPC: B22D11/16 ,  C21D8/02 ,  C22C38/02 ,  C22C38/06 ,  C22C38/58

Abstract: The method for manufacturing a high-manganese steel cast slab according to the present invention includes manufacturing a cast slab by continuously casting a molten high-manganese steel having a specific chemical composition. In the manufacture, in a continuous-casting machine or during transportation before subsequent charging into a heating furnace for hot rolling, a processing strain is applied to the cast slab having a surface temperature of 600° C. or higher and 1100° C. or lower in such an amount that a processing strain amount calculated by a certain formula is 3.0% or more and 10.0% or less.

公开(公告)号：US11959157B2

公开(公告)日：2024-04-16

申请号：US17264295

申请日：2019-07-31

Applicant: JFE STEEL CORPORATION

Inventor： Daichi Izumi ,  Shigeki Kitsuya ,  Keiji Ueda ,  Koichi Nakashima

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

CPC classification number: C22C38/38 ,  C21D8/0226 ,  C21D8/0263 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/06 ,  C22C38/26 ,  C22C38/28 ,  C21D2211/001

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：US11819909B2

公开(公告)日：2023-11-21

申请号：US17423557

申请日：2020-01-22

Applicant: JFE Steel Corporation

Inventor： Yoichi Ito ,  Norichika Aramaki ,  Koichi Nakashima ,  Shigeki Kitsuya

IPC: B22D11/16 ,  C21D8/02 ,  C22C38/02 ,  C22C38/06 ,  C22C38/58

CPC classification number: B22D11/16 ,  C21D8/0226 ,  C22C38/02 ,  C22C38/06 ,  C22C38/58

Abstract: The method for manufacturing a high-manganese steel cast slab according to the present invention includes manufacturing a cast slab by continuously casting a molten high-manganese steel having a specific chemical composition. In the manufacture, in a continuous-casting machine or during transportation before subsequent charging into a heating furnace for hot rolling, a processing strain is applied to the cast slab having a surface temperature of 600° C. or higher and 1100° C. or lower in such an amount that a processing strain amount calculated by a certain formula is 3.0% or more and 10.0% or less.

公开(公告)号：US11326238B2

公开(公告)日：2022-05-10

申请号：US16074184

申请日：2017-01-30

Applicant: JFE Steel Corporation

Inventor： Yuki Toji ,  Akio Ohmori ,  Koichi Nakashima ,  Ryo Arao ,  Katsuyuki Ichimiya ,  Kazukuni Hase

IPC: C22C38/54 ,  B23K35/30 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  B23K103/04

Abstract: Provided is a steel material for high heat input welding having excellent welding heat affected zone low-temperature toughness at −55° C. in the case that the steel material is welded by high heat input welding with a heat input of more than 80 kJ/cm. The steel material may be used in low-temperature storage tanks, for example. The steel material for high heat input welding includes, in mass %, C: 0.04 to 0.09%, Si: 0.15 to 0.25%, Mn: 1.40 to 2.00%, P: 0.015% or less, S: 0.0005 to 0.0040%, Al: 0.030 to 0.080%, Ti: 0.005 to 0.025%, B: 0.0003 to 0.0020%, Ca: 0.0005 to 0.0030%, N: 0.0030 to 0.0060%, O: 0.0040% or less, Nb: 0.005% or less, and Mo: 0.005% or less, the balance being Fe and incidental impurities.

公开(公告)号：US20210140023A1

公开(公告)日：2021-05-13

申请号：US16074184

申请日：2017-01-30

Applicant: JFE Steel Corporation

Inventor： Yuki Toji ,  Akio Ohmori ,  Koichi Nakashima ,  Ryo Arao ,  Katsuyuki Ichimiya ,  Kazukuni Hase

IPC: C22C38/54 ,  C22C38/00 ,  C22C38/04 ,  C22C38/46 ,  C22C38/42 ,  C22C38/48 ,  C22C38/50 ,  C22C38/06 ,  B23K35/30 ,  C22C38/44

Abstract: Provided is a steel material for high heat input welding having excellent welding heat affected zone low-temperature toughness at −55° C. in the case that the steel material is welded by high heat input welding with a heat input of more than 80 kJ/cm. The steel material may be used in low-temperature storage tanks, for example. The steel material for high heat input welding includes, in mass %, C: 0.04 to 0.09%, Si: 0.15 to 0.25%, Mn: 1.40 to 2.00%, P: 0.015% or less, S: 0.0005 to 0.0040%, Al: 0.030 to 0.080%, Ti: 0.005 to 0.025%, B: 0.0003 to 0.0020%, Ca: 0.0005 to 0.0030%, N: 0.0030 to 0.0060%, O: 0.0040% or less, Nb: 0.005% or less, and Mo: 0.005% or less, the balance being Fe and incidental impurities.