公开(公告)号：US12180572B2

公开(公告)日：2024-12-31

申请号：US17753552

申请日：2020-08-17

Applicant: JFE STEEL CORPORATION

Inventor： Naoki Takayama ,  Shigeki Kitsuya ,  Yoshiaki Murakami

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

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：US11731210B2

公开(公告)日：2023-08-22

申请号：US17279218

申请日：2019-09-24

Applicant: JFE Steel Corporation

Inventor： Teruki Sadasue ,  Tsunehisa Handa ,  Yoshiaki Murakami

IPC: F16L13/02 ,  B23K11/093 ,  F16L9/02 ,  B23K103/04 ,  B23K101/10 ,  F16L9/22

CPC classification number: B23K11/0935 ,  F16L9/02 ,  F16L13/02 ,  B23K2101/10 ,  B23K2103/04 ,  F16L9/22

Abstract: A long steel pipe for reel-lay installation formed of electric resistance welded (ERW) steel pipes and having high buckling resistance and a method for producing the long steel pipe for reel-lay installation are provided. The long steel pipe is formed by successively butt-joining longitudinal ends of the ERW steel pipes by girth welding so that girth welds are formed. The ERW steel pipes are successively butt-joined in the pipe longitudinal direction such that the 0 o'clock cross-sectional position or the 6 o'clock cross-sectional position of one of adjacent ERW steel pipes faces an area from the 2 o'clock cross-sectional position to the 4 o'clock cross-sectional position or an area from the 8 o'clock cross-sectional position to the 10 o'clock cross-sectional position of the other of the adjacent ERW steel pipes.

公开(公告)号：US11060172B2

公开(公告)日：2021-07-13

申请号：US16488701

申请日：2018-02-02

Applicant: JFE STEEL CORPORATION

Inventor： Naoki Takayama ,  Yusuke Terazawa ,  Yoshiaki Murakami ,  Kazukuni Hase ,  Yusaku Takemura ,  Yasuhiro Murota

IPC: C22C38/00 ,  C22C38/02 ,  C22C38/54 ,  C21D8/02 ,  C21D9/46 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/50 ,  C22C38/52

Abstract: Provided is an abrasion-resistant steel plate which has high hardness up to the mid-thickness part thereof although the steel plate is 50 mm or more, and can be manufactured at low cost. The abrasion-resistant steel plate has a specific chemical composition having DI* of 120 or more, where DI* is defined by the following Formula (1): DI*=33.85×(0.1×C)0.5×(0.7×Si+1)×(3.33×Mn+1)×(0.35×Cu+1)×(0.36×Ni+1)×(2.16×Cr+1)×(3×Mo+1)×(1.75×V+1)×(1.5×W+1) . . . (1), has HB1 of 360 HBW10/3000 to 490 HBW10/3000, HB1 being a Brinell hardness at a depth of 1 mm from a surface, has a hardness ratio, HB1/2 to HB1, of 75% or more, HB1/2 being a Brinell hardness at a mid-thickness position, and has a plate thickness of 50 mm or more.

公开(公告)号：US20220032391A1

公开(公告)日：2022-02-03

申请号：US17279218

申请日：2019-09-24

Applicant: JFE Steel Corporation

Inventor： Teruki Sadasue ,  Tsunehisa Handa ,  Yoshiaki Murakami

IPC: B23K11/093 ,  F16L9/02 ,  F16L13/02

Abstract: A long steel pipe for reel-lay installation formed of electric resistance welded (ERW) steel pipes and having high buckling resistance and a method for producing the long steel pipe for reel-lay installation are provided. The long steel pipe is formed by successively butt-joining longitudinal ends of the ERW steel pipes by girth welding so that girth welds are formed. The ERW steel pipes are successively butt-joined in the pipe longitudinal direction such that the 0 o'clock cross-sectional position or the 6 o'clock cross-sectional position of one of adjacent ERW steel pipes faces an area from the 2 o'clock cross-sectional position to the 4 o'clock cross-sectional position or an area from the 8 o'clock cross-sectional position to the 10 o'clock cross-sectional position of the other of the adjacent ERW steel pipes.