公开(公告)号：US11618931B2

公开(公告)日：2023-04-04

申请号：US15322947

申请日：2015-07-03

Applicant: ArcelorMittal

Inventor： Rashmi Ranjan Mohanty ,  Hyun Jo Jun ,  Dongwei Fan

IPC: C21D9/46 ,  C21D1/26 ,  C21D1/25 ,  C22C38/06 ,  C22C38/02 ,  C22C38/28 ,  C22C38/26 ,  C21D6/00 ,  C22C38/38 ,  C22C38/34 ,  C21D9/48 ,  C21D8/02 ,  C21D1/19 ,  C21D8/04

Abstract: A method for producing a high strength steel sheet having a yield strength YS of at least 850 MPa, a tensile strength TS of at least 1180 MPa, a total elongation of at least 14% and a hole expansion ratio HER of at least 30%. The chemical composition of the steel contains: 0.15%≤C≤0.25%, 1.2%≤Si≤1.8%, 2%≤Mn≤2.4%, 0.1%≤Cr≤0.25%, Nb≤0.05%, Ti≤0.05%, Al≤0.50%, the remainder being Fe and unavoidable impurities. The sheet is annealed at an annealing temperature TA higher than Ac3 but less than 1000° C. for more than 30 s, by cooling it to a quenching temperature QT between 275° C. and 325° C., at a cooling speed sufficient to have, just after quenching, a structure consisting of austenite and at least 50% of martensite, the austenite content en.) being such that the final structure can contain between 3% and 15% of residual austenite and between 85 and 97% of the sum of martensite and bainite, without ferrite, heated to a partitioning temperature PT between 420° C. and 470° C. and maintained at this temperature for time between 50 s and 150 s and cooled to the room temperature.

公开(公告)号：US10407751B2

公开(公告)日：2019-09-10

申请号：US15323258

申请日：2015-07-03

Applicant: ArcelorMittal

Inventor： Stavros Fountoulakis ,  Jean Philippe Masse ,  Dongwei Fan

IPC: C21D9/573 ,  B05C9/10 ,  B05C9/12 ,  B05C9/14 ,  C23C2/00 ,  C23C2/02 ,  C23C2/06 ,  C23C2/40 ,  C21D9/60 ,  C23C2/28 ,  B05C3/12

Abstract: A multipurpose continuous processing line able for heat treating and hot dip coating a steel strip containing: an annealing section (1) for heating the steel strip to a predetermined annealing temperature and for maintaining the steel strip at said annealing temperature, a first transfer section (2), an overaging section (3) able to maintain the temperature of the steel strip between 300° C. and 700° C., a second transfer section (4) able to adjust the temperature of the steel strip to allow the hot dip coating of the strip and, a hot dip coating section (5), wherein the first transfer section (2) includes, in sequence, a cooling section (21) and a heating section (22).

公开(公告)号：US20210095357A1

公开(公告)日：2021-04-01

申请号：US17247358

申请日：2020-12-08

Applicant: ARCELORMITTAL

Inventor： Dongwei Fan ,  Hyun Jo Jun ,  Rashmi Ranjan Mohanty

IPC: C21D9/46 ,  C21D8/04 ,  C21D8/02 ,  C21D1/19 ,  B32B15/01 ,  C21D6/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

Abstract: A coated steel sheet includes a chemical composition including in weight %: 0.13%≤C ≤0.22%; 1.2%≤Si≤1.8%; 1.8%≤Mn≤2.2%; 0.10%≤Mo≤0.20%; Nb≤0.05%; Al≤0.5%; Ti≤0.05%; and a remainder being Fe and unavoidable impurities. A structure of the steel sheet consists of, by volume fraction, 3% to 15% of residual austenite and 85% to 97% of martensite and bainite. The structure includes at least 65% of martensite and does not including ferrite. At least one face of the coated steel sheet includes a metallic coating. The steel sheet has a yield strength of at least 800 MPa, a tensile strength of at least 1180 MPa, a total elongation of at least 14% and a hole expansion ratio HER of at least 30%.

公开(公告)号：US20190256942A1

公开(公告)日：2019-08-22

申请号：US16398873

申请日：2019-04-30

Applicant: ArcelorMittal

Inventor： Dongwei Fan ,  Hyun Jo Jun ,  John A. Rotole

IPC: C21D9/46 ,  C23C2/28 ,  B32B15/01 ,  C22C38/24 ,  C21D8/02 ,  C23C2/40 ,  C23C2/12 ,  C22C38/22 ,  C22C38/08 ,  C22C38/04 ,  C22C38/00 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/02 ,  C23C2/06 ,  C23C2/02

Abstract: A method for producing a cold rolled and hot dip coated steel sheet is provided. The method includes casting a steel into a slab, reheating, hot rolling, cooling, coiling, descaling and cold rolling the slab. The cold rolled steel sheet is annealed so a layer of iron oxide forms on the surface with an internal oxidation underneath. The sheet is then heated so the surface is oxidized and the layer of iron oxide is fully reduced to obtain an internally oxidized depth between 200 nm and 100 μm which includes one or more of Si, Mn, Al, Ti containing oxides. The sheet is then hot dip coated and cooled.

公开(公告)号：US20170152581A1

公开(公告)日：2017-06-01

申请号：US15323258

申请日：2015-07-03

Applicant: ArcelorMittal

Inventor： Stavros Fountoulakis ,  Jean Philippe Masse ,  Dongwei Fan

IPC: C21D9/573 ,  C23C2/00 ,  C21D9/60 ,  C23C2/02 ,  C23C2/28 ,  C23C2/06 ,  C23C2/40

CPC classification number: C21D9/573 ,  B05C3/125 ,  B05C9/10 ,  B05C9/12 ,  B05C9/14 ,  C21D9/60 ,  C23C2/003 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/285 ,  C23C2/40 ,  Y02P10/253

Abstract: A multipurpose continuous processing line able for heat treating and hot dip coating a steel strip comprising: —an annealing section (1) for heating the steel strip to a predetermined annealing temperature and for maintaining the steel strip at said annealing temperature, —a first transfer section (2), —an overaging section (3) able to maintain the temperature of the steel strip between 300° C. and 700° C., —a second transfer section (4) able to adjust the temperature of the steel strip to allow the hot dip coating of the strip and, —a hot dip coating section (5), wherein the first transfer section (2) comprises, in sequence, cooling means (21) and heating means (22).

公开(公告)号：US11492676B2

公开(公告)日：2022-11-08

申请号：US16931001

申请日：2020-07-16

Applicant: ARCELORMITTAL

Inventor： Rashmi Ranjan Mohanty ,  Hyun Jo Jun ,  Dongwei Fan

IPC: C21D9/46 ,  B32B15/01 ,  C23C2/02 ,  C23C2/06 ,  C23C2/40 ,  C21D8/02 ,  C21D1/18 ,  C22C38/02 ,  C22C38/38 ,  C22C38/34 ,  C22C38/06 ,  C22C38/58

Abstract: A method is for producing a high strength coated steel sheet having a yield stress YS>800 MPa, a tensile strength TS>1180 MPa, and improved formability and ductility. The steel contains: 15%≤C≤0.25%, 1.2%≤Si≤1.8%, 2%≤Mn≤2.4%, 0.1%≤Cr≤0.25%, Al≤0.5%, the remainder being Fe and unavoidable impurities. The sheet is annealed at a temperature higher than Ac3 and lower than 1000° C. for a time of more than 30 s, then quenched by cooling it to a quenching temperature QT between 250° C. and 350° C., to obtain a structure consisting of at least 60% of martensite and a sufficient austenite content such that the final structure contains 3% to 15% of residual austenite and 85% to 97% of martensite and bainite without ferrite, then heated to a partitioning temperature PT between 430° C. and 480° C. and maintained at this temperature for a partitioning time Pt between 10 s and 90 s, then hot dip coated and cooled to the room temperature.

公开(公告)号：US20170152579A1

公开(公告)日：2017-06-01

申请号：US15322829

申请日：2015-07-03

Applicant: ArcelorMittal

Inventor： Rashmi Ranjan Mohanty ,  Hyun Jo Jun ,  Dongwei Fan

IPC: C21D9/46 ,  C21D1/18 ,  B32B15/01 ,  C22C38/06 ,  C23C2/06 ,  C23C2/40 ,  C22C38/58 ,  C22C38/02 ,  C21D8/02 ,  C23C2/02

CPC classification number: C21D9/46 ,  B32B15/013 ,  C21D1/18 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C21D2211/001 ,  C21D2211/008 ,  C22C38/02 ,  C22C38/06 ,  C22C38/34 ,  C22C38/38 ,  C22C38/58 ,  C23C2/02 ,  C23C2/06 ,  C23C2/40

Abstract: A method for producing a high strength coated steel sheet having a yield stress YS>800 MPa, a tensile strength TS>1180 MPa, and improved formability and ductility. The steel contains: 15%≦C≦0.25%, 1.2%≦Si≦1.8%, 2%≦Mn≦2.4%, 0.1% 23 Cr≦0.25%, Al≦0.5%, the remainder being Fe and unavoidable impurities. The sheet is annealed at a temperature higher than Ac3 and lower than 1000° C. for a time of more than 30 s, then quenched by cooling it to a quenching temperature QT between 250° C. and 350° C., to obtain a structure consisting of at least 60% of martensite and a sufficient austenite content such that the final structure contains 3% to 15% of residual austenite and 85% to 97% of martensite and bainite without ferrite, then heated to a partitioning temperature PT between 430° C. and 480° C. and maintained at this temperature for a partitioning time Pt between 10 s and 90 s, then hot dip coated and cooled to the room temperature.

公开(公告)号：US20170137906A1

公开(公告)日：2017-05-18

申请号：US15316600

申请日：2015-06-03

Applicant: ArcelorMittal

Inventor： Dongwei Fan ,  Hyun Jo Jun ,  John A. Rotole

IPC: C21D9/46 ,  C23C2/06 ,  C23C2/02 ,  C23C2/40 ,  C23C2/28 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/02 ,  C22C38/06 ,  C22C38/00 ,  C21D8/02

Abstract: The invention deals with a cold rolled and hot dip steel sheet, with a tensile strength of at least 980 MPa, with yield strength above or equal to 500 MPa, with total elongation above or equal to 8%, the composition consisting by weight percent: 0.05

公开(公告)号：US20170130292A1

公开(公告)日：2017-05-11

申请号：US15322947

申请日：2015-07-03

Applicant: ArcelorMittal

Inventor： Rashmi Ranjan Mohanty ,  Hyun Jo Jun ,  Dongwei Fan

IPC: C21D9/46 ,  C21D1/26 ,  C21D1/25 ,  C22C38/06 ,  C22C38/02 ,  C22C38/28 ,  C22C38/26 ,  C21D6/00 ,  C22C38/38

CPC classification number: C21D9/46 ,  C21D1/19 ,  C21D1/25 ,  C21D1/26 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0247 ,  C21D8/0447 ,  C21D9/48 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/008 ,  C22C38/02 ,  C22C38/06 ,  C22C38/26 ,  C22C38/28 ,  C22C38/34 ,  C22C38/38

Abstract: A method for producing a high strength steel sheet having a yield strength YS of at least 850 MPa, a tensile strength TS of at least 1180 MPa, a total elongation of at least 14% and a hole expansion ratio HER of at least 30%. The chemical composition of the steel contains: 0.15%≦C≦0.25%, 1.2%≦Si≦1.8%, 2%≦Mn≦2.4%, 0.1%≦Cr≦0.25%, Nb≦0.05%, Ti≦0.05%, Al≦0.50%, the remainder being Fe and unavoidable impurities. The sheet is annealed at an annealing temperature TA higher than Ac3 but less than 1000° C. for more than 30 s, by cooling it to a quenching temperature QT between 275° C. and 325° C., at a cooling speed sufficient to have, just after quenching, a structure consisting of austenite and at least 50% of martensite, the austenite content en.) being such that the final structure can contain between 3% and 15% of residual austenite and between 85 and 97% of the sum of martensite and bainite, without ferrite, heated to a partitioning temperature PT between 420° C. and 470° C. and maintained at this temperature for time between 50 s and 150 s and cooled to the room temperature.

公开(公告)号：US11047020B2

公开(公告)日：2021-06-29

申请号：US16398873

申请日：2019-04-30

Applicant: ArcelorMittal

Inventor： Dongwei Fan ,  Hyun Jo Jun ,  John A. Rotole

IPC: C21D9/46 ,  C21D8/02 ,  C23C2/02 ,  C23C2/06 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C22C38/22 ,  C23C2/40 ,  B32B15/01 ,  C22C38/04 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C23C2/12 ,  C22C38/24 ,  C23C2/28

Abstract: A method for producing a cold rolled and hot dip coated steel sheet is provided. The method includes casting a steel into a slab, reheating, hot rolling, cooling, coiling, descaling and cold rolling the slab. The cold rolled steel sheet is annealed so a layer of iron oxide forms on the surface with an internal oxidation underneath. The sheet is then heated so the surface is oxidized and the layer of iron oxide is fully reduced to obtain an internally oxidized depth between 200 nm and 100 μm which includes one or more of Si, Mn, Al, Ti containing oxides. The sheet is then hot dip coated and cooled.