公开(公告)号：WO2022018481A1

公开(公告)日：2022-01-27

申请号：PCT/IB2020/056787

申请日：2020-07-20

Applicant: ARCELORMITTAL

Inventor： LHOIST, Vincent ,  HEBERT, Véronique ,  SIEBENTRITT, Matthieu

IPC: C22C38/58 ,  C22C38/02 ,  C22C38/06 ,  C22C38/44 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/54 ,  C22C38/00 ,  C22C38/22 ,  C22C38/38 ,  C21D9/46 ,  C21D8/02 ,  C21D6/02 ,  C21D6/00

Abstract: A heat treated cold rolled steel sheet comprising of the following elements,0.1% ≦ C ≦ 0.2 %; 1.2 % ≦ Mn ≦ 2.2 %; 0.05% ≦ Si ≦ 0.6 %; 0.001% ≦ Al ≦ 0.1 %; 0.01% ≦ Cr ≦ 0.5 %;0% ≦ S ≦ 0.09%; 0% ≦ P ≦ 0.09%; 0% ≦ N ≦ 0.09%; 0% ≦ Mo ≦ 0.5%; 0% ≦ Ti ≦ 0.1%; 0% ≦ Nb ≦ 0.1%; 0% ≦ V≦ 0.1%; 0% ≦ Ni ≦ 1%; 0% ≦ Cu ≦ 1%; 0% ≦ Ca ≦ 0.005%; 0% ≦ B ≦ 0.05%; the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of said steel comprising, by area percentage, 60% to 85% of tempered martensite, a cumulated amount of ferrite and bainite of 15 % to 38%, an optional amount of residual austenite of 0% to 5% and an optional amount of fresh martensite of 0 to 5%.

公开(公告)号：WO2015087224A1

公开(公告)日：2015-06-18

申请号：PCT/IB2014/066647

申请日：2014-12-05

Applicant: ARCELORMITTAL INVESTIGACION Y DESARROLLO, S.L.

Inventor： DRILLET, Josée ,  HEBERT, Véronique

IPC: C21D8/02 ,  C21D8/04 ,  C21D9/46 ,  C21D9/48 ,  C23C2/00 ,  C22C38/00 ,  C22C38/28 ,  C22C38/32

CPC classification number: C21D9/46 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C21D8/0263 ,  C21D8/0273 ,  C21D8/0278 ,  C21D8/0436 ,  C21D8/0447 ,  C21D8/0473 ,  C21D9/48 ,  C21D2211/002 ,  C21D2211/004 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/06 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/36 ,  C23C2/40 ,  C23C14/16

Abstract: Acier à haute résistance et procédé de fabrication Tôle d'acier laminée à froid et recuite, dont la composition chimique comprend, les teneurs étant exprimées en poids : 0,10 ≤ C ≤ 0,13% 2,4 ≤ Mn ≤ 2,8% 0,30 ≤ Si ≤ 0,55% 0,30 ≤ Cr ≤ 0,56% 0,020 ≤ Ti ≤ 0,050% 0,0020 ≤ B ≤ 0,0040% 0,005 ≤ Al ≤ 0,050% Mo ≤ 0,010% Nb ≤ 0,040% 0,002 ≤ N ≤ 0,008% S ≤ 0,005% P ≤ 0,020%, le reste étant constitué de fer et d'impuretés inévitables provenant de l'élaboration, la tôle ayant une microstructure constituée, en proportion surfacique, de martensite et/ou de bainite inférieure, ladite martensite comprenant de la martensite fraîche et/ou de la martensite auto-revenue, la somme des proportions surfaciques de martensite et de bainite inférieure étant comprise entre 60 à 95%, de 4 à 35% de bainite à faible quantité de carbures, de 0 à 5% de ferrite, et de moins de 5% d'austénite résiduelle sous forme d'îlots. Figure

Abstract translation: 高强度钢及其制造方法。 一种冷轧和退火钢板，其化学组成包括：重量含量：0.10≤C≤0.13％2.4≤Mn≤2.8％0.30≤Si≤0.55％0.30≤Cr≤0.56％0.020≤Ti ≤0.050％0.0020≤B≤0.0040％0.005≤Al≤0.050％Mo≤0.010％Nb≤0.040％0.002≤N≤0.008％S≤0.005％P≤0.020％，余量由制备中的铁和不可避免的杂质组成， 具有由马氏体和/或下贝氏体组成的显微组织的片材，所述马氏体包含新鲜的马氏体和/或自回火马氏体，马氏体与下贝氏体的面积比之和为60〜95％ ，具有少量碳化物的4至35％的贝氏体，为铁素体的0％至5％，岛状形式的残余奥氏体为5％以下。

公开(公告)号：WO2023067406A1

公开(公告)日：2023-04-27

申请号：PCT/IB2022/058327

申请日：2022-09-05

Applicant: ARCELORMITTAL

Inventor： CHALEIX, Daniel ,  HEBERT, Véronique ,  LAFFINEUR, Fabrice ,  RUWET, Vincent

IPC: C23C14/02 ,  C23C14/16 ,  C23C14/24 ,  C23C14/56 ,  B32B15/01 ,  C21D1/26 ,  C21D1/76 ,  C21D3/04 ,  C21D8/00 ,  C21D9/46 ,  C21D9/52 ,  C22C18/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/38 ,  C22C38/44 ,  C22C38/58 ,  C21D8/02

Abstract: This patent relates to a method for depositing metallic coatings on a substrate comprising : - an annealing step, in an annealing furnace, forming on said substrate, a ferritic surface layer having a thickness from 10 µm to 50 µm and a microstructure comprising in surface fraction up to 10% of cumulated amount of martensite, bainite and the balance being made of ferrite, - a skin pass step, - a coating step, inside a vacuum chamber, wherein a metallic vapour is ejected towards at least a side of said substrate to form a surface layer of at least one metal.

公开(公告)号：WO2017109540A1

公开(公告)日：2017-06-29

申请号：PCT/IB2015/059839

申请日：2015-12-21

Applicant: ARCELORMITTAL

Inventor： GOSPODINOVA, Maya ,  HEBERT, Véronique ,  VENKATASURYA, Pavan

IPC: C21D9/46 ,  C22C38/00

CPC classification number: C21D9/46 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D2211/001 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/04

Abstract: A method for producing a steel sheet, the method comprising the following successive steps: providing a cold-rolled steel sheet, the chemical composition of the steel containing in weight %:0.15% ≤ C ≤ 0.23%, 1.4 % ≤ Mn ≤ 2.6%, 0.6% ≤ Si ≤ 1.5%, 0.02% ≤ Al ≤.0%, with 1.0% ≤ Si+Al ≤ 2.0%, 0 ≤ Nb ≤ 0.035%, 0 ≤ Mo ≤ 0.3%, 0 ≤ Cr ≤ 0.3%,the remainder being Fe and unavoidable impurities, annealing the steel sheet at an annealing temperature TA comprised between Ac and Ac3 so as to obtain a structure comprising at least 40% of austenite and at least 40% of intercritical ferrite, quenching the sheet from a temperature of at least 600°C at a cooling rate of at least 20°C/s down to a quenching temperature QT comprised between 180°C and 260°C, heating the sheet up to a partitioning temperature PT between 375°C and 470°C and maintaining the sheet at this partitioning temperature PT for a partitioning time Pt comprised between 25s and 440s, the partitioning time Pt being comprised between 100s and 440s if the partitioning temperature PT is comprised between 375°C and 400°C, and comprised between 25s and 150s if the partitioning temperature PT is comprised between 450°C and 470°C, - cooling the sheet down to the room temperature, the steel sheet having a final microstructure consisting, in area fraction, of: - at least 11% of tempered martensite, - between 10% and 20% of retained austenite, - between 40% and 60% of ferrite, - at most 6% of fresh martensite, - at most 18% of bainite.

Abstract translation: 一种用于生产钢板的方法，该方法包括以下连续步骤：提供冷轧钢板，钢的化学组成包含重量％：0.15％≤C≤0.23％ ，1.4％≤Mn≤2.6％，0.6％≤Si≤1.5％，0.02％≤Al≤0.0％，1.0％≤Si+Al≤2.0％，0≤Nb≤0.035％，0≤Mo≤0.3％ ，0≤Cr≤0.3％，余量为Fe和不可避免的杂质，在Ac和Ac3之间的退火温度TA下对钢板进行退火，以获得包含至少40％的奥氏体和至少40％的临界 从至少600℃的温度以至少20℃/秒的冷却速率将片材淬火至180℃和260℃之间的淬火温度QT，将片材加热至分配温度 PT在375℃和470℃之间的温度，并将片材保持在该分配温度PT，分配时间Pt在2 如果分配温度PT包括在375℃和400℃之间并且如果分配温度PT包括在450℃和470℃之间则包括在25s和150s之间，则分配时间Pt包括在100s和440s之间。 将片材冷却至室温，所述钢片具有最终的显微组织，其面积分数为： - 至少11％的回火马氏体， - 10％至20％的残余奥氏体， - 40 ％和60％的铁素体， - 最多6％的新鲜马氏体， - 最多18％的贝氏体。

公开(公告)号：WO2017108866A1

公开(公告)日：2017-06-29

申请号：PCT/EP2016/082037

申请日：2016-12-20

Applicant: ARCELORMITTAL

Inventor： GOSPODINOVA, Maya ,  HEBERT, Véronique ,  VENKATASURYA, Pavan

IPC: C21D9/46 ,  C22C38/00

CPC classification number: C21D9/46 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D2211/001 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/04

Abstract: A method for producing a steel sheet, the method comprising the following successive steps: - providing a cold-rolled steel sheet, the chemical composition of the steel containing in weight %:0.15% ≤ C ≤ 0.23%, 1.4 % ≤ Mn ≤ 2.6%, 0.6% ≤ Si ≤ 1.5%, 0.02% ≤ Al ≤.0%, with 1.0% ≤ Si+Al ≤ 2.0%, 0 ≤ Nb ≤ 0.035%, 0 ≤ Mo ≤ 0.3%, 0 ≤ Cr ≤ 0.3%,the remainder being Fe and unavoidable impurities, - annealing the steel sheet at an annealing temperature TA comprised between Ac1 and Ac3 so as to obtain a structure comprising at least 40% of austenite and at least 40% of intercritical ferrite, - quenching the sheet from a temperature of at least 600°C at a cooling rate of at least 20°C/s down to a quenching temperature QT comprised between 180°C and 260°C, - heating the sheet up to a partitioning temperature PT between 375°C and 470°C and maintaining the sheet at this partitioning temperature PT for a partitioning time Pt comprised between 25s and 440s, the partitioning time Pt being comprised between 100s and 440s if the partitioning temperature PT is comprised between 375°C and 400°C, and comprised between 25s and 150s if the partitioning temperature PT is comprised between 450°C and 470°C, - cooling the sheet down to the room temperature, the steel sheet having a final microstructure consisting, in area fraction, of: - at least 11% of tempered martensite, - between 10% and 20% of retained austenite, - between 40% and 60% of ferrite, - at most 6% of fresh martensite, - at most 18% of bainite.

Abstract translation: 一种生产钢板的方法，所述方法包括以下连续步骤： - 提供冷轧钢板，钢的化学组成包含重量％：0.15％≤C≤0.23 ％，1.4％≤Mn≤2.6％，0.6％≤Si≤1.5％，0.02％≤Al≤0.0％，1.0％≤Si+Al≤2.0％，0≤Nb≤0.035％，0≤Mo≤0.3 ％，0≤Cr≤0.3％，剩余部分为Fe和不可避免的杂质， - 在退火温度TA下，在Ac1和Ac3之间对钢板进行退火，以获得包含至少40％奥氏体和至少40％ 的间临界铁素体， - 以至少20℃/ s的冷却速率将片材从至少600℃的温度淬火至淬火温度QT在180℃和260℃之间， - 将片材加热 到375℃和470℃之间的分配温度PT，并将该片材保持在该分配温度PT下，分配时间Pt包括 如果分配温度PT包括在375℃和400℃之间并且如果分配温度PT包括在450℃和470℃之间并且包括在25s和150s之间，则分配时间Pt包括在100s和440s之间 ; C，将板冷却至室温，该钢板具有最终的显微组织，其面积分数为： - 至少11％的回火马氏体， - 10％至20％的残余奥氏体， - 40％和60％的铁素体， - 最多6％的新鲜马氏体， - 最多18％的贝氏体。

公开(公告)号：WO2021250450A1

公开(公告)日：2021-12-16

申请号：PCT/IB2020/055526

申请日：2020-06-12

Applicant: ARCELORMITTAL

Inventor： HOFFMANN, Etienne ,  HEBERT, Véronique

IPC: C21D1/76 ,  C21D8/02 ,  C21D9/56 ,  C22C38/02 ,  C22C38/04 ,  C22C38/12 ,  C22C38/22 ,  C21D1/22 ,  C21D1/25 ,  C21D2211/002 ,  C21D3/04 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0426 ,  C21D8/0436 ,  C21D8/0447 ,  C21D8/0457 ,  C21D9/48 ,  C22C38/38

Abstract: The invention relates to a cold rolled and heat-treated steel sheet, the steel comprising, in weight percentage, 0.17% ≤ carbon ≤ 0.25%, 2% ≤ manganese ≤ 3%, 0.9% ≤ silicon ≤ 2%, 0% ≤ aluminum ≤0.09%, 0.01%≤ molybdenum ≤ 0.2%, 0%≤ phosphorus ≤ 0.02%, 0%≤ sulfur ≤ 0.03%, 0% ≤ nitrogen ≤ 0.09%, and optionally one or more of the following elements 0%≤ chromium ≤ 0.3%, 0%≤ niobium ≤ 0.06%, 0%≤ titanium ≤ 0.06%, 0%≤ vanadium ≤0.1%, 0%≤ calcium ≤ 0.005%, 0%≤ boron ≤ 0.010%, 0%≤ Magnesium ≤ 0.05%, 0%≤ Zirconium ≤ 0.05%, 0%≤ Cerium ≤ 0.1%, and the balance including iron and unavoidable impurities, the steel sheet having a microstructure comprising 50% to 80% of Bainite, 10% to 30% of residual austenite, 15% to 50% of Partitioned martensite, 0% to 10% of ferrite and 0% to 5% fresh martensite in area fractions, and a ferrite-enriched layer extending up to 50 microns from both surfaces of said steel sheet, such ferrite-enriched layer having a mean ferrite content from 55% to 80% in area fraction.

公开(公告)号：WO2017109541A1

公开(公告)日：2017-06-29

申请号：PCT/IB2015/059840

申请日：2015-12-21

Applicant: ARCELORMITTAL

Inventor： GOSPODINOVA, Maya ,  HEBERT, Véronique

IPC: C21D6/00 ,  C23C2/02 ,  C23C2/06 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12

CPC classification number: C21D9/46 ,  C21D6/005 ,  C21D8/0236 ,  C21D8/0247 ,  C21D8/0263 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

Abstract: A method for producing a coated steel sheet having a tensile strength TS of at least 100 MPa, a total elongation TE according to ISO standard 6892-1 of at least 12%, the product TSx TE of the tensile strength by the total elongation being at least 14200 MPa%, and a hole expansion ratio HER according to ISO standard 16630:2009 of at least 25%, comprising the following successive steps: providing a cold-rolled steel sheet, the chemical composition of the steel containing in weight %:0.15% ≤ C ≤ 0.23%, 2.0 % ≤ Mn ≤ 2.7%, with C+Mn/10 ≥ 0.420%, 0 ≤ Cr ≤ 0.40%, with Mn + Cr ≥ 2.25%, 0.2% ≤ Si ≤ 1.6%, 0.02% ≤ Al ≤ 1.2%, with 1.0 % ≤ Si+Al ≤ 2.2%, 0 ≤ Nb ≤ 0.035 %, 0 ≤ Mo ≤ 0.1%, the remainder being Fe and unavoidable impurities, annealing the steel sheet at an annealing temperature T A so as to obtain a structure comprising at least 65% of austenite and at most 35% of intercritical ferrite, quenching the sheet from a temperature of at least 600°C at a cooling rate comprised between 20°C/s and 50°C/s down to a quenching temperature QT between 200°C and 270°C, heating the sheet up to a partitioning temperature PT comprised between 400°C and 480°C and maintaining the sheet at this partitioning temperature PT for a partitioning time Pt comprised between 50s and 250s, hot-dip coating the sheet at a temperature less than 515°C, cooling the coated sheet down to the room temperature, the steel sheet having a microstructure consisting of, in surface fraction : between 3 % and 15% of retained austenite, at least 30% of tempered martensite, at most 5% of fresh martensite, at most 35% of bainite, the sum of the surface fractions of tempered martensite, fresh martensite and bainite being comprised between 55% and 92%, and between 5% and 35% of ferrite.

Abstract translation: 生产具有至少100MPa的抗拉强度TS，根据ISO标准6892-1的总延伸率TE为至少12％的涂覆钢板的方法，所述产品的TS×TE 根据ISO标准16630：2009的总伸长率的拉伸强度为至少14200MPa％，并且根据ISO标准16630：2009的扩孔率HER为至少25％，所述方法包括以下连续步骤：提供冷轧钢板， 含有重量百分比为：0.15％≤C≤0.23％，2.0％≤Mn≤2.7％，C + Mn /10≥0.420％，0≤Cr≤0.40％，Mn +Cr≥2.25％，0.2％ ≤Si≤1.6％，0.02％≤Al≤1.2％，其中1.0％≤Si+Al≤2.2％，0≤Nb≤0.035％，0≤Mo≤0.1％，余量为Fe和不可避免的杂质，对钢进行退火 在退火温度T℃下进行热处理，以获得包含至少65％的奥氏体和至多35％的临界铁素体的组织，将片材从 在20℃/ s和50℃/ s之间的冷却速率下至少600℃，直至在200℃和270℃之间的淬火温度QT，将所述板加热至介于400℃和400℃之间的分配温度PT; 并在该分配温度PT下保持片材的分配时间Pt在50s和250s之间，在低于515℃的温度下热浸涂覆片材，将涂覆的片材冷却至室温， 所述钢板的表层分率为：残留奥氏体3％〜15％，回火马氏体30％以上，新鲜马氏体5％以下，贝氏体35％以下， 回火马氏体的表面部分，新鲜马氏体和贝氏体含量为55％至92％，铁素体含量为5％至35％。

公开(公告)号：WO2016198906A1

公开(公告)日：2016-12-15

申请号：PCT/IB2015/000891

申请日：2015-06-10

Applicant: ARCELORMITTAL

Inventor： DRILLET, Josée ,  HEBERT, Véronique

IPC: C23C2/02 ,  C21D8/02 ,  C21D8/04 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  C21D9/46 ,  C21D9/48 ,  C23C14/02 ,  C23C14/06 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/18 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38

CPC classification number: C23C2/02 ,  B32B15/013 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C21D8/0273 ,  C21D8/0426 ,  C21D8/0436 ,  C21D8/0447 ,  C21D8/0473 ,  C21D9/46 ,  C21D9/48 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/06 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  C23C14/02

Abstract: L'invention a pour objet une tôle d'acier laminée à froid et recuite, dont la composition chimique comprend, les teneurs étant exprimées en poids :0,09 ≤ C ≤ 0,11 %, 2,6 ≤ Mn ≤ 2,8%, 0,20 ≤ Si ≤ 0,55%, 0,25 ≤ Cr ≤ 0,5 %, 0,025 ≤ Ti ≤ 0,040 %, 0,0015 ≤ B≤ 0,0025 %, 0,005 ≤ Al ≤ 0,18 %, 0,08 ≤ Mo ≤ 0,15 %, 0,020 ≤ Nb ≤ 0,040%, 0,002 ≤ N ≤ 0,007 %, 0,0005 ≤ S ≤ 0,005%, 0,001≤ P ≤ 0,020%, Ca ≤ 0,003%, le reste étant constitué de fer et d'impuretés inévitables provenant de l'élaboration, la tôle ayant une microstructure constituée de martensite et/ou de bainite inférieure, ladite martensite comprenant de la martensite fraîche et/ou de la martensite auto-revenue, la somme des proportions surfaciques de martensite et de bainite inférieure étant comprise entre 40 à 70%, de 15 à 45% en proportion surfacique de bainite à faible quantité de carbures, de 5 à 20% en proportion surfacique de ferrite, la fraction de ferrite non recristallisée par rapport à la fraction de ferrite totale, étant inférieure à 15%, et de moins de 5% en proportion surfacique, d'austénite résiduelle sous forme d'îlots.

Abstract translation: 本发明涉及一种冷轧和退火钢板，其化学组成包括：含量以0.09≤C≤0.11％，2.6≤Mn<2.8％，0.20

公开(公告)号：WO2023067371A1

公开(公告)日：2023-04-27

申请号：PCT/IB2021/059600

申请日：2021-10-19

Applicant: ARCELORMITTAL

Inventor： CHALEIX, Daniel ,  HEBERT, Véronique ,  LAFFINEUR, Fabrice ,  RUWET, Vincent

IPC: C23C14/02 ,  C23C14/16 ,  C23C14/24 ,  C23C14/56 ,  B32B15/01 ,  C21D1/26 ,  C21D1/76 ,  C21D3/04 ,  C21D8/00 ,  C21D9/46 ,  C21D9/52 ,  C22C18/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/38 ,  C22C38/44 ,  C22C38/58 ,  C21D8/02

Abstract: This patent relates to a method for depositing metallic coatings on a substrate comprising : - an annealing step, in an annealing furnace, forming on said substrate, a ferritic surface layer having a thickness from 10 µm to 50 µm and a microstructure comprising in surface fraction up to 10% of cumulated amount of martensite, bainite and the balance being made of ferrite, - a skin pass step, - a coating step, inside a vacuum chamber, wherein a metallic vapour is ejected towards at least a side of said substrate to form a surface layer of at least one metal.

公开(公告)号：WO2017125809A1

公开(公告)日：2017-07-27

申请号：PCT/IB2017/000018

申请日：2017-01-17

Applicant: ARCELORMITTAL

Inventor： UTA, Helena ,  HEBERT, Véronique

IPC: B32B15/01 ,  C21D8/02 ,  C23C2/02 ,  C23C2/06 ,  C23C2/40 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/26 ,  C22C38/38

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

Abstract: A cold rolled and heat treated steel sheet having a composition comprising of 0.17 % ≦ carbon ≦ 0.24 %, 1.9 % ≦ manganese ≦ 2.2%, 0.5 % ≦ aluminum ≦ 1.2 %, 0.5 % ≦ silicon ≦ 1 %, 0.05 % ≦ Chromium≤ 0.2 %, 0.015% ≦ niobium ≦ 0.03%, Sulphur ≦ 0.003%, Phosphorus ≦ 0:03% and optionally contain 0.005% ≦ titanium ≦ 0.05%, 0.001 % ≦ Molybdenum ≦ 0.05%, the remainder composition being composed of iron and the unavoidable impurities caused by processing, wherein Si + Al ≥ 1.3%, the remainder consisting of iron and unavoidable impurities resulting from, the microstructure of the coated steel sheet comprising, in area fraction, 10 to 20% residual austenite, said austenite phase having a carbon content between 0.9 to 1.1 %, 40 to 55 % of polygonal ferrite, 15 to 40% granular bainite and at least 5% of tempered martensite, the sum of tempered martensite and residual austenite being comprised between 20 to 30%.

Abstract translation: 具有0.17％≤碳≤0.24％，1.9％≤锰≤2.2％，0.5％≤铝≤1.2％，0.5％≤硅的组成的冷轧和热处理钢板≤ 1％，0.05％≤铬≤0.2％，0.015％≤铌≤0.03％，硫≤0.003％，磷≤0.03％和任选地含有0.005％≤钛≤0.05％，0.001％≤钼≤0.05％， 其余部分由铁和由加工引起的不可避免的杂质组成，其中Si +Al≥1.3％，其余部分由铁和不可避免的杂质组成，所述涂层钢板的显微组织包含面积分数为10-20％ 所述奥氏体相的碳含量为0.9-1.1％，多边形铁素体为40-55％，粒状贝氏体为15-40％，回火马氏体为至少5％，回火马氏体和残余奥氏体之和包括在 20到30％。