公开(公告)号：US20220025473A1

公开(公告)日：2022-01-27

申请号：US17021386

申请日：2020-09-15

Applicant: NORTHEASTERN UNIVERSITY

Inventor： Haijun LI ,  Yi HAN ,  Tianliang FU ,  Jiadong LI ,  Yong LI ,  Zhaodong WANG

IPC: C21D8/02 ,  B24C1/10 ,  C23G1/00

Abstract: An on-line solution heat treatment process for austenitic stainless steel plates is disclosed, which comprises continuous casting billet heating, high pressure water dephosphorization, rough rolling, finish rolling, softening process, ultra fast cooling, straightening, cutting to length, shot peening, pickling. The process of the present invention makes full use of the residual rolling temperature, without the need of reheating steel plates from the room temperature to the solid solution temperature. Compared with the conventional steel plate rolling process, the process needs to perform the softening process on the steel plates after rolling to ensure that the deformed austenite is fully softened before cooling. After the softening process, ultra fast cooling is performed to cool the steel plates from above 800° C. to below 430° C. so as to prevent intergranular chromium depletion caused by a large amount of precipitation of high chromium carbides from affecting the stain resistance of stainless steel.

公开(公告)号：US20220002849A1

公开(公告)日：2022-01-06

申请号：US17130785

申请日：2020-12-22

Applicant: NORTHEASTERN UNIVERSITY

Inventor： Qibin YE ,  Liye KAN ,  Cheng ZHOU ,  Qinghai WANG ,  Yimin WANG ,  Yong TIAN ,  Zhaodong WANG

IPC: C22C38/46 ,  C22C38/42 ,  C22C38/44 ,  C22C38/02 ,  C22C38/04 ,  C21D8/02 ,  C21D8/00 ,  C21D9/46

Abstract: The present invention discloses a low-yield-ratio ultra-high-strength high-toughness steel for pressure hulls and a preparation method therefor, wherein the chemical components by weight percentage are: 0.05%-0.10% of C, 0.15%-0.35% of Si, 0.60%-1.00% of Mn, 0.10%-0.50% of Cu, 0.10%-1.00% of Mo, 0.40%-0.70% of Cr, 0.05%-0.15% of V, 5.00%-10.00% of Ni, and the balance of Fe and unavoidable impurities. The technical solution of the present invention adopts secondary quenching heat treatment, the first quenching is performed to achieve complete austenitizing, and then the second quenching and tempering are performed to finally obtain complex phase structures such as tempered martensite, critical ferrite and retained austenite, so as to meet the performance index requirements of low yield ratio, ultra-high strength and high toughness, and thereby promoting application in practice.

公开(公告)号：US20210108279A1

公开(公告)日：2021-04-15

申请号：US16897950

申请日：2020-06-10

Applicant: Northeastern University

Inventor： Xiangtao DENG ,  Zhaodong WANG ,  Hao WU ,  Tianliang FU ,  Yong TIAN ,  Jiadong LI

IPC: C21D8/02 ,  C21D1/02 ,  C21D1/18 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/32

Abstract: An ultrahigh-strength ultrahigh-toughness and low-density dual-phase lamellar steel plate is disclosed. The steel plate comprises the following alloy components in percentage by mass: 0.200-0.320% of C, 0.600-2.000% of Mn, 0.200-0.600% of Si, 2.000-4.000% of Al, 0.300-1.200% of Ni, 0.001-0.005% of B, P not greater than 0.012%, S not greater than 0.005%, and the balance of Fe and inevitable impurities. The steel plate consists of dual phases of ferrites and martensites, the ferrites are high-temperature delta ferrites, the martensites are lath martensites, the delta ferrites are distributed in the lath martensites in a lamellar mode. The steel plate has excellent mechanical properties, for example, the yield strength in the rolling direction is not less than 1000 MPa, the tensile strength is not less than 1600 MPa, the elongation is not less than 8.0%, and the average value of Charpy V-Notch impact energy at −40° C. is not less than 350J.

公开(公告)号：US20220025474A1

公开(公告)日：2022-01-27

申请号：US17130354

申请日：2020-12-22

Applicant: Northeastern University

Inventor： Qibin YE ,  Qinghai WANG ,  Cheng ZHOU ,  Yong TIAN ,  Zhaodong WANG

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

Abstract: The present invention discloses a 785 MPa level extra-thick quenched and tempered rack steel plate for offshore platforms and a preparation method therefor, wherein chemical components of the steel plate by weight percentage are: 0.08%-0.15% of C, 0.60%-1.5% of Mn, 0.10%-0.50% of Si, 0.002%-0.005% of S, 0.005%-0.015% of P, 2.7%-4.0% of Ni, 0.40%-1.00% of Cr, 0.30%-0.70% of Mo, 0.10%-0.40% of Cu, 0%-0.080% of Nb, 0%-0.10% of V, 0%-0.08% of Ti, 0.02%-0.08% of Al, 0.0008%-0.0015% of B, and the balance of Fe and other unavoidable impurities. The present invention adopts a low C, high Ni—Cr—Mo alloying and Nb—V—Ti microalloying component system, has a yield strength of ≥795 MPa, a tensile strength of ≥865 MPa, a −60° C. Charpy V-notch impact energy of ≥140 J, a Z value of ≥35%, and a maximum thickness of 100 mm, and can be used to manufacture racks for offshore platforms.

公开(公告)号：US20160247613A1

公开(公告)日：2016-08-25

申请号：US15027368

申请日：2014-10-20

Applicant: NORTHEASTERN UNIVERSITY

Inventor： Guodong WANG ,  Yuanxiang ZHANG ,  Yang WANG ,  Xiang LU ,  Feng FANG ,  Guangming CAO ,  Chenggang LI ,  Guo YUAN ,  Yunbo XU ,  Zhenyu LIU ,  Zhaodong WANG

IPC: H01F1/147 ,  C22C38/06 ,  C22C38/04 ,  B22D11/041 ,  C22C38/00 ,  C21D9/52 ,  C21D8/04 ,  B22D11/00 ,  C22C38/12 ,  C22C38/02

CPC classification number: H01F1/14766 ,  B22D11/001 ,  B22D11/041 ,  B22D11/0622 ,  B22D11/1206 ,  C21D8/0405 ,  C21D8/0415 ,  C21D8/0426 ,  C21D8/0436 ,  C21D8/0463 ,  C21D8/0473 ,  C21D8/0478 ,  C21D8/12 ,  C21D8/1205 ,  C21D8/1211 ,  C21D8/1222 ,  C21D8/1233 ,  C21D8/1261 ,  C21D8/1272 ,  C21D8/1277 ,  C21D9/52 ,  C21D2201/05 ,  C22C38/001 ,  C22C38/002 ,  C22C38/004 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12

Abstract: The preparation method includes steps of (1) melting steel according to in weight percentage 0.001-0.003% of C, 5.0-6.6% of Si, 0.2-0.3% of Mn, 0.05-0.12% of Al, 0.01-0.04% of V, 0.03-0.06% of Nb, 0.02-0.03% of S, 0.009-0.020% of N, O which is less than or equal to 0.0020%, and the balance being Fe and unavoidable impurities; (2) forming cast strips after a thin-strip casting course; (3) hot-rolling the cast strips under inert atmosphere conditions; (4) cooling the hot-rolled cast strips to 550-600 DEG C, coiling and performing low-temperature hot rolling/warm rolling on the coiled cast strips under a nitrogen atmosphere condition; (5) removing oxidized scales though pickling, performing cold rolling multiple times; (6) performing recrystallization annealing, coating with an MgO layer, and coiling; (7) performing purification annealing under hydrogen circulation conditions; and (8) removing oxidized scales, coating with an insulating layer, performing flat stretch annealing, and air-cooled coiling.

Abstract translation: 该制备方法包括以下步骤：（1）将重量百分比分别为C，0.001-0.003％的C，5.0-6.6％的Si，0.2-0.3％的Mn，0.05-0.12％的Al，0.01-0.04％的V ，0.03-0.06％的Nb，0.02-0.03％的S，0.009-0.020％的N，O，小于或等于0.0020％，余量为Fe和不可避免的杂质; （2）在薄带铸造过程之后形成铸造带; （3）在惰性气氛条件下对铸造带进行热轧; （4）将热轧铸造带冷却至550〜600℃，在氮气氛下对卷取的铸造带进行卷取和低温热轧/热轧; （5）通过酸洗除去氧化鳞片，进行多次冷轧; （6）进行再结晶退火，用MgO层进行涂布和卷取; （7）在氢循环条件下进行纯化退火; 和（8）去除氧化鳞片，用绝缘层涂覆，进行平面拉伸退火和空气冷却卷取。