公开(公告)号：US20170369958A1

公开(公告)日：2017-12-28

申请号：US15543364

申请日：2016-01-15

Applicant: JFE STEEL CORPORATION

Inventor： Shigeki KITSUYA ,  Katsuyuki ICHIMIYA ,  Kazukuni HASE

IPC: C21D8/02 ,  C21D6/00 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/54 ,  C22C38/42 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C22C38/58 ,  C22C38/44

CPC classification number: C21D8/0263 ,  B21B1/024 ,  B21B1/026 ,  B21B3/00 ,  B21B3/02 ,  B21B2001/028 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D7/13 ,  C21D8/0205 ,  C21D8/0226 ,  C21D9/0081 ,  C21D9/46 ,  C21D2211/002 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/16 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58

Abstract: A thick-walled, high-toughness, high-strength steel plate manufactured from steel having a particular composition and casted under conditions where the cooling rate of a surface during solidification is 1° C./s or less. The surface of the steel plate has a toughness (vE-40) of 70 J or more, and the steel plate has a thickness of 100 mm or more.

公开(公告)号：US20230183845A1

公开(公告)日：2023-06-15

申请号：US17999214

申请日：2021-05-25

Applicant: JFE STEEL CORPORATION

Inventor： Shigeki KITSUYA ,  Naoki TAKAYAMA ,  Tomoyuki YOKOTA

IPC: C22C38/00 ,  C22C38/26 ,  C22C38/06 ,  C22C38/58 ,  C22C38/02 ,  C22C38/28 ,  C22C38/32 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/52 ,  C21D8/02 ,  C21D1/18

CPC classification number: C22C38/001 ,  C22C38/26 ,  C22C38/06 ,  C22C38/58 ,  C22C38/02 ,  C22C38/28 ,  C22C38/32 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/52 ,  C21D8/0226 ,  C21D1/18

Abstract: Provided is an abrasion-resistant steel plate excellent in both abrasion resistance and wide bending workability. An abrasion-resistant steel plate comprises a specific chemical composition, wherein a volume fraction of martensite at a depth of 1 mm from a surface of the abrasion-resistant steel plate is 90% or more, hardness at a depth of 1 mm from the surface is 420 HBW 10/3000 to 560 HBW 10/3000 in Brinell hardness, and a transverse direction hardness difference is 30Hv10 or less in Vickers hardness, the transverse direction hardness difference being defined as a difference in the hardness at a depth of 1 mm from the surface between two points adjacent at intervals of 10 mm in a transverse direction of the abrasion-resistant steel plate.

公开(公告)号：US20220154303A1

公开(公告)日：2022-05-19

申请号：US17437505

申请日：2020-02-25

Applicant: JFE STEEL CORPORATION

Inventor： Yuya SATO ,  Shigeki KITSUYA ,  Shusaku OTA ,  Tomoyuki YOKOTA

IPC: C21D9/46 ,  C22C38/22 ,  C22C38/16 ,  C22C38/14 ,  C22C38/10 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D6/00 ,  B21B3/02

Abstract: An object is to provide a steel plate having excellent deformability in the central portion in the thickness direction and a method for manufacturing the steel plate. A steel plate having a chemical composition containing, by mass %, C: 0.01% to 0.15%, Si: 0.01% to 1.00%, Mn: 0.10% to 2.00%, P: 0.010% or less, S: 0.0050% or less, Al: 0.002% to 0.100%, Ni: 5.0% to 10.0%, N: 0.0010% to 0.0080%, and with a balance being Fe and incidental impurities and a percentage reduction of area of 30% or more in a tensile test in the thickness direction performed on the central portion in the thickness direction.

公开(公告)号：US20230175091A1

公开(公告)日：2023-06-08

申请号：US17999047

申请日：2021-05-25

Applicant: JFE STEEL CORPORATION

Inventor： Shigeki KITSUYA ,  Hitoshi SUEYOSHI ,  Tomoyuki YOKOTA

IPC: C21D9/46 ,  C22C38/58 ,  C22C38/52 ,  C22C38/50 ,  C22C38/48 ,  C22C38/44 ,  C22C38/42 ,  C22C38/38 ,  C22C38/54 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D6/00 ,  C21D8/02 ,  C21D1/18

CPC classification number: C21D9/46 ,  C22C38/58 ,  C22C38/52 ,  C22C38/50 ,  C22C38/48 ,  C22C38/44 ,  C22C38/42 ,  C22C38/38 ,  C22C38/54 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/005 ,  C22C38/002 ,  C22C38/001 ,  C21D6/002 ,  C21D6/004 ,  C21D6/005 ,  C21D6/007 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0263 ,  C21D1/18 ,  C21D2211/008

Abstract: Provided is an abrasion-resistant steel plate excellent in both abrasion resistance and wide bending workability. An abrasion-resistant steel plate comprises a specific chemical composition, wherein a volume fraction of martensite at a depth of 1 mm from a surface of the abrasion-resistant steel plate is 90% or more, a number density of TiC precipitates of 0.5 μm or more in equivalent circular diameter at a depth of 1 mm from the surface is 400/mm2 or more, hardness at a depth of 1 mm from the surface is 360 HBW 10/3000 or more in Brinell hardness, and a transverse direction hardness difference is 30Hv10 or less in Vickers hardness, the transverse direction hardness difference being defined as a difference in the hardness at a depth of 1 mm from the surface between two points adjacent at intervals of 10 mm in a transverse direction of the abrasion-resistant steel plate.

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：US20230203614A1

公开(公告)日：2023-06-29

申请号：US17999585

申请日：2021-05-25

Applicant: JFE STEEL CORPORATION

Inventor： Shigeki KITSUYA ,  Hitoshi SUEYOSHI ,  Tomoyuki YOKOTA

IPC: C21D9/00 ,  C22C38/54 ,  C22C38/52 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/20 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D6/00 ,  C21D1/18 ,  C22C33/04

CPC classification number: C21D9/0081 ,  C21D1/18 ,  C21D6/002 ,  C21D6/004 ,  C21D6/005 ,  C21D6/007 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0263 ,  C22C33/04 ,  C22C38/001 ,  C22C38/02 ,  C22C38/002 ,  C22C38/04 ,  C22C38/005 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/52 ,  C22C38/54 ,  C21D2211/008

Abstract: Provided is an abrasion-resistant steel plate excellent in both abrasion resistance and wide bending workability. An abrasion-resistant steel plate comprises a specific chemical composition, wherein a volume fraction of martensite at a depth of 1 mm from a surface of the abrasion-resistant steel plate is 90 % or more, hardness at a depth of 1 mm from the surface is 500 HBW 10/3000 to 650 HBW 10/3000 in Brinell hardness, and a transverse direction hardness difference is 30Hv10 or less in Vickers hardness, the transverse direction hardness difference being defined as a difference in the hardness at a depth of 1 mm from the surface between two points adjacent at intervals of 10 mm in a transverse direction of the abrasion-resistant steel plate.

公开(公告)号：US20220333227A1

公开(公告)日：2022-10-20

申请号：US17753552

申请日：2020-08-17

Applicant: JFE STEEL CORPORATION

Inventor： Naoki TAKAYAMA ,  Shigeki KITSUYA ,  Yoshiaki MURAKAMI

IPC: C22C38/38 ,  C22C38/02 ,  C21D8/04

Abstract: The steel plate has a specific chemical composition, and a microstructure where a volume fraction of martensite at a depth of 1 mm from a surface of the steel plate is 95% or more, and at a depth of 1 mm from a surface of the steel plate, a Vickers hardness at 400° C. is 288 or more, and a Brinell hardness at 25° C. is 360 HBW10/3000 to 490 HBW10/3000.

公开(公告)号：US20180155805A1

公开(公告)日：2018-06-07

申请号：US15525672

申请日：2015-11-17

Applicant: JFE STEEL CORPORATION

Inventor： Yota KURONUMA ,  Hirofumi OHTSUBO ,  Shigeki KITSUYA ,  Katsuyuki ICHIMIYA ,  Kazukuni HASE

IPC: C21D9/46 ,  C22C38/58 ,  C22C38/54 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D8/00 ,  C21D6/00 ,  C21D1/18 ,  B21J5/02

CPC classification number: C21D9/46 ,  B21J1/02 ,  B21J5/025 ,  C21D1/18 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D7/13 ,  C21D8/005 ,  C21D8/0226 ,  C21D8/0263 ,  C21D9/0081 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  Y10T428/12458

Abstract: A thick steel plate is provided by heating a continuously-cast slab, hot forging the continuously-cast slab using opposing dies having respective short sides differing such that when a short side length of a die having a shorter one of the short sides is taken to be 1, a short side length of a die having a longer one of the short sides is 1.1 to 3.0, allowing cooling to obtain a steel raw material, reheating the steel raw material, performing hot rolling of the steel raw material including at least two passes carried out, allowing cooling to obtain a thick steel plate, reheating the thick steel plate to at least the Ac3 temperature and no higher than 1050° C., rapidly cooling the thick steel plate to 350° C. or lower, and tempering the thick steel plate at at least 550° C. and no higher than 700° C.