公开(公告)号：US20220298598A1

公开(公告)日：2022-09-22

申请号：US17835347

申请日：2022-06-08

Applicant: ArcelorMittal

Inventor： Rashmi Ranjan MOHANTY ,  Hyun Jo JUN ,  Dongwei FAN ,  Pavan K. C. VENKATASURYA

IPC: C21D9/46 ,  C22C38/06 ,  C22C38/14 ,  C22C38/02 ,  C22C38/04 ,  C22C38/12 ,  C21D9/48 ,  C21D1/19 ,  C21D8/04 ,  C21D1/18 ,  C21D6/00

Abstract: A steel sheet made of a steel having a chemical composition containing 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%, Ti≤0.05%, Al≤0.5%, a remainder being Fe and unavoidable impurities. The steel sheet has a yield strength of at least 850 MPa, a tensile strength of at least 1180 MPa, a total elongation of at least 13% and a hole expansion ratio HER of at least 30%.

公开(公告)号：US20190010585A1

公开(公告)日：2019-01-10

申请号：US16130335

申请日：2018-09-13

Applicant: ARCELORMITTAL

Inventor： Hyun Jo JUN ,  Narayan S. POTTORE ,  Nina Michailovna FONSTEIN

IPC: C22C38/12 ,  C21D9/40 ,  C22C38/00 ,  C22C38/04 ,  C22C38/02 ,  C22C38/06

Abstract: A dual phase steel sheet is provided. The steel sheet has a microstructure containing ferrite and tempered martensite, a tensile strength of at least 980 MPa, a total elongation of at least 15%, and a hole expansion ratio of at least 15%. The dual phase steel sheet has a composition including 0.2 to 0.3 wt. % C, 1.6 to 2.5 wt. % Si and 1.75 to 2.5 wt. % Mn. A method for producing the dual phase steel sheet is also provided.

公开(公告)号：US20200224287A1

公开(公告)日：2020-07-16

申请号：US16827696

申请日：2020-03-23

Applicant: ArcelorMittal

Inventor： Dongwei FAN ,  Hyun Jo JUN ,  Rashmi MOHANTY ,  Pavan K. C. VENKATASURYA

IPC: C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C21D8/02 ,  C21D1/18 ,  C21D6/00 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

Abstract: A method is for producing a high strength coated steel sheet having an improved ductility and an improved formability, and a chemical composition containing: 0.13%≤C≤0.22%, 1.9%≤Si≤2.3%, 2.4%≤Mn≤3%, Al≤0.5%, Ti≤0.05%, Nb≤0.05%, the remainder being Fe and unavoidable impurities. The sheet is annealed at temperature TA higher than Ac3 but less than 1000° C. for a time of more than 30 s, quenched by cooling to a quenching temperature QT between 200° C. and 280° C. in order to obtain a structure consisting of austenite and at least 50% of martensite, the austenite content 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 up to a partitioning temperature PT between 430° C. and 490° C. and maintained at this temperature for a time Pt between 10 s and 100 s, hot dip coated and cooled to the room temperature.

公开(公告)号：US20180044750A1

公开(公告)日：2018-02-15

申请号：US15552485

申请日：2016-02-24

Applicant: Hyun Jo Jun ,  ArcelorMittal

Inventor： Hyun Jo JUN

IPC: C21D9/46 ,  C22C38/26 ,  C22C38/12 ,  C22C38/06 ,  C22C38/02 ,  B32B15/01 ,  C21D8/02 ,  C21D6/00 ,  C21D1/20 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  C22C38/38 ,  C22C38/00

CPC classification number: C21D9/46 ,  B32B15/013 ,  C21D1/20 ,  C21D1/25 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/06 ,  C22C38/12 ,  C22C38/26 ,  C22C38/38 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

Abstract: A cold rolled, coated and post annealed steel sheet. The cold rolled steel sheet may comprise (in wt. %): C—0.1-0.3 %; Mn—1-3%; Si—0.5-3.5%; Al—0.05-1.5%; Mo+Cr is between 0-1.0%; and Mo+Cr is between 0.2-0.5%. The steel sheet may be coated with a zinc or zinc alloy coating. The coated steel sheet may be formed by cold rolling, zinc coating the cold rolled sheet and annealing said steel sheet after application of said zinc coating. The annealing is performed at a temperature and for a time sufficient to significantly increase the yield strength and hole expansion of the annealed coated cold rolled steel sheet as compared with the as coated sheet.

公开(公告)号：US20230257846A1

公开(公告)日：2023-08-17

申请号：US18135962

申请日：2023-04-18

Applicant: ArcelorMittal

Inventor： Hyun Jo JUN

IPC: C21D9/46 ,  C21D8/02 ,  C23C2/06 ,  C23C2/28 ,  C21D1/20 ,  C21D1/25 ,  C23C2/02 ,  B32B15/01 ,  C21D6/00 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/12 ,  C22C38/26 ,  C22C38/38 ,  C23C2/40

CPC classification number: C21D9/46 ,  B32B15/013 ,  C21D1/20 ,  C21D1/25 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/06 ,  C22C38/12 ,  C22C38/26 ,  C22C38/38 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008

Abstract: A cold rolled, coated and post batch annealed steel sheet produced by a method is provided. The method includes cold rolling a steel sheet; coating the cold rolled steel sheet with a zinc or zinc alloy coating, the cold rolled, coated steel sheet having an initial hole expansion and an initial yield strength and post batch annealing the cold rolled, coated steel sheet at a tempering temperature in a range from 150 to 650° C., the post batch annealed steel sheet having a final hole expansion and a final yield strength. The steel sheet includes (in wt. %) C-0.1-0.3%, Mn-1-3%, Si-0.5-3.5%, Al-0.05-1.5% and Mo+Cr being between 0-1.0%. The final hole expansion is at least 80% greater than the initial hole expansion and the final yield strength is at least 30% greater than the initial yield strength.

公开(公告)号：US20210123114A1

公开(公告)日：2021-04-29

申请号：US17083451

申请日：2020-10-29

Applicant: ArcelorMittal

Inventor： Hyun Jo JUN

IPC: C21D9/46 ,  C21D8/02 ,  C23C2/06 ,  C23C2/28 ,  C21D1/20 ,  C21D1/25 ,  C23C2/02 ,  B32B15/01 ,  C21D6/00 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/12 ,  C22C38/26 ,  C22C38/38 ,  C23C2/40

Abstract: A method for forming a cold rolled, coated and post batch annealed steel sheet is provided. The method includes cold rolling a steel sheet; coating the cold rolled steel sheet with a zinc or zinc alloy coating, the cold rolled, coated steel sheet having an initial hole expansion and an initial yield strength and post batch annealing the cold rolled, coated steel sheet at a tempering temperature in a range from 150 to 650° C., the post batch annealed steel sheet having a final hole expansion and a final yield strength. The steel sheet includes (in wt. %) C—0.1-0.3%, Mn—1-3%, Si—0.5-3.5%, Al—0.05-1.5% and Mo+Cr being between 0-1.0%. The final hole expansion is at least 80% greater than the initial hole expansion and the final yield strength is at least 30% greater than the initial yield strength.

公开(公告)号：US20220259689A1

公开(公告)日：2022-08-18

申请号：US17616162

申请日：2020-05-12

Applicant: ArcelorMittal

Inventor： Hyun Jo JUN ,  Narayan POTTORE ,  Dongwei FAN ,  Xiang (Frank) CHEN ,  Oleg YAKUBOVSKY

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

Abstract: A cold rolled and coated steel sheet having a composition including of the following elements, expressed in percentage by weight: 0.140%≤Carbon≤0.2%, 1.5%≤Manganese≤2.15%, 0.5%≤Silicon≤0.8%, 0.4%≤Aluminum≤0.8%, 0%≤Phosphorus≤0.09%, 0%≤Sulfur≤0.09%, 0%≤Nitrogen≤0.09%, 0.01%≤Niobium≤0.1%, 0.01%≤Titanium≤0.1%, and can contain one or more of the following optional elements 0%≤Chromium≤0.1%, 0%≤Nickel≤0%, 0%≤Calcium≤0.005%, 0%≤Copper≤2%, 0%≤Molybdenum≤0.5%, 0%≤Vanadium≤0.1%, 0%≤Boron≤0.003%, 0%≤Cerium≤0.1%, 0%≤Magnesium≤0.010%, 0%≤Zirconium≤0.010% the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet including in area fraction, 40 to 60% Inter-critical Ferrite, 25 to 45% Transformed Ferrite, 8% to 20% and 5% to 20% Fresh Martensite, 0 to 10% Bainite, wherein the cumulated amount of Inter-critical and Transformed Ferrite is between 75% and 85%.

公开(公告)号：US20200080177A1

公开(公告)日：2020-03-12

申请号：US16685315

申请日：2019-11-15

Applicant: ArcelorMittal

Inventor： Hyun Jo JUN ,  Narayan S. POTTORE ,  Nina Michailovna FONSTEIN

IPC: C22C38/12 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C21D9/40

Abstract: A method for producing a dual phase steel sheet is provided. The method includes providing a dual phase hot rolled steel sheet having a microstructure including ferrite and martensite and a composition including 0.1 to 0.3 wt. % C, 1.5 to 2.5 wt. % Si and 1.75 to 2.5 wt. % Mn. The steel sheet is annealed at a temperature from 750 to 875° C., water quenched to a temperature from 400 to 420° C. and subject to overaging at the temperature from 400 to 420° C. to convert the martensite in the hot rolled steel sheet to tempered martensite. The overaging is sufficient to provide the hot rolled steel sheet with a hole expansion ratio of at least 15%.

公开(公告)号：US20190003007A1

公开(公告)日：2019-01-03

申请号：US16064545

申请日：2016-12-21

Applicant: ArcelorMittal

Inventor： Pavan VENKATASURYA ,  Hyun Jo JUN

IPC: C21D9/46 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C21D8/02 ,  C21D6/00 ,  B32B15/01 ,  C21D1/18

Abstract: A method for producing a steel sheet having a microstructure including 71% to 91% martensite and bainite, 9% to 13% retained austenite, and at most 20% ferrite is provided. The method includes providing a cold-rolled steel sheet including, in weight percent: 0.13%≤C≤0.22%, 1.2%≤Si≤2.3%, 0.02%≤Al≤1.0%, with 1.25%≤Si+Al≤2.35%, 2.4%≤Mn≤3%, Ti≤0.05%, Nb≤0.05% and a remainder of Fe and unavoidable impurities, annealing the steel sheet to obtain 80% to 100% austenite and 0% to 20% ferrite, quenching the steel sheet at a cooling rate between 20° C./s and 50° C./s to a quenching temperature between 240° C. and 310° C., heating the steel sheet to a partitioning temperature between 400° C. and 465° C. and maintaining the steel sheet at the partitioning temperature for 50 to 250 seconds, then immediately cooling the sheet to room temperature. Steel sheets are also provided.

公开(公告)号：US20190003005A1

公开(公告)日：2019-01-03

申请号：US16064513

申请日：2016-12-21

Applicant: ArcelorMittal

Inventor： Hyun Jo JUN ,  Pavan VENKATASURYA

IPC: C21D9/46 ,  C21D6/00 ,  C21D1/22 ,  C21D8/02 ,  C22C38/26 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  B32B15/01 ,  B32B15/18

Abstract: A method for producing a steel sheet is provided. The steel sheet has a microstructure including, in area fraction, 20% to 50% intercritical ferrite, 10% to 20% retained austenite, 25% to 45% tempered martensite, 10% to 20% fresh martensite, and bainite. The sum of tempered martensite and bainite is between 30% and 60%. The method includes providing a cold-rolled steel sheet including, in weight percent, 0.18%≤C≤0.25%, 0.9%≤Si≤1.8%, 0.02%≤Al≤1.0%, with 1.00%≤Si+Al≤2.35%, 1.5%≤Mn 2.5%, 0.010%≤Nb≤0.035%, 0.10%≤Cr≤0.40%, and a remainder including Fe and unavoidable impurities. The method further includes annealing the steel sheet to obtain 50% to 80% austenite and 20% to 50% of ferrite, quenching the sheet at a cooling rate between 20° C./s and 50° C./s to a quenching temperature between Ms-50° C. and Ms-5° C., heating the sheet to a partitioning temperature between 375° C. and 450° C. and maintaining the sheet at the partitioning temperature for at least 50 s, then immediately cooling the sheet to room temperature. A steel sheet is also provided.