公开(公告)号：US20160298207A1

公开(公告)日：2016-10-13

申请号：US15100436

申请日：2014-11-27

Applicant: JFE STEEL CORPORATION

Inventor： Kohei HASEGAWA ,  Koichiro FUJITA ,  Yusuke KIMATA ,  Kozo HARADA

IPC: C21D9/46 ,  C21D8/02 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/18 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C23C2/06 ,  C23F17/00 ,  C23C2/40 ,  C21D1/76

CPC classification number: C21D9/46 ,  B32B15/013 ,  B32B15/04 ,  B32B15/043 ,  B32B15/18 ,  C21D1/673 ,  C21D1/74 ,  C21D1/76 ,  C21D8/0236 ,  C21D8/0247 ,  C21D8/0263 ,  C21D2211/003 ,  C21D2211/005 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/54 ,  C23C2/06 ,  C23C2/40 ,  C23C30/00 ,  C23C30/005 ,  C23F17/00 ,  Y10T428/12799 ,  Y10T428/12951 ,  Y10T428/12972 ,  Y10T428/263 ,  Y10T428/264 ,  Y10T428/265 ,  Y10T428/273

Abstract: Provided is a bake-hardening galvanized steel sheet which can preferably be used for, for example, automotive outer panels, which has a bake hardenability and corrosion resistance, which has good press formability, and with which a blister defect does not occur when a galvanizing treatment is performed, despite being manufactured at low cost by using low-carbon steel which can be comparatively easily manufactured.The steel sheet is a bake-hardening galvanized steel sheet having a base steel sheet and a coating layer formed on the base steel sheet, the base steel sheet having a specified chemical composition and a metallographic structure including a ferrite phase and a cementite phase, in which an average ferrite grain diameter is controlled to be 10 μm or more and 30 μm or less, and in which the surface area of the interface between ferrite and cementite per unit volume is controlled to be 1.0/mm or more and 10.0/mm or less, a hydrogen concentration in steel of the base steel sheet is controlled to be less than 0.1 ppm, and a zinc coating weight per unit surface area of the steel sheet is controlled to be 40 g/m2 or more and 100 g/m2 or less.

Abstract translation: 钢板是具有基材钢板和形成在基材钢板上的涂层的热硬化镀锌钢板，所述基材钢板具有规定的化学成分和包含铁素体相和渗碳体相的金相组织， 将平均铁素体晶粒直径控制在10μm以上且30μm以下，将单位体积的铁素体与渗碳体的界面的面积控制在1.0 / mm以上10.0.0mm以下， 将钢板的钢中的氢浓度控制为小于0.1ppm，将钢板的单位面积的锌镀层重量控制为40g / m 2以上100g / m 2以上 减。

公开(公告)号：US20170022582A1

公开(公告)日：2017-01-26

申请号：US15301097

申请日：2015-03-17

Applicant: JFE STEEL CORPORATION

Inventor： Katsutoshi TAKASHIMA ,  Kohei HASEGAWA

IPC: C21D9/46 ,  C22C38/34 ,  C22C38/32 ,  C22C38/28 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  B22D11/00 ,  C22C38/38

CPC classification number: C21D9/46 ,  B22D11/001 ,  C21D1/25 ,  C21D8/021 ,  C21D8/0226 ,  C21D8/0263 ,  C21D8/0273 ,  C21D8/0473 ,  C21D2211/001 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/38 ,  C22C38/58

Abstract: A high-strength cold-rolled steel sheet having good ductility, hole expandability, and delayed fracture resistance and being excellent in material homogeneity. The steel sheet has a chemical composition containing, in mass %, C: 0.15 to 0.25%, Si: 1.2 to 2.2%, Mn: 1.7 to 2.5%, P: 0.05% or less, S: 0.005% or less, Al: 0.01 to 0.10%, N: 0.006% or less, Ti: 0.003 to 0.030%, B: 0.0002 to 0.0050%, and Fe and inevitable impurities. The steel sheet has a microstructure that includes ferrite having an average crystal grain diameter of 4 μm or less at a volume fraction of 5 to 20%, retained austenite at a volume fraction of 5% or less, including 0%, and tempered martensite at a volume fraction of 80 to 95%. Additionally, the mean free path of the ferrite is 3.0 to 7.5 μm.

Abstract translation: 具有良好的延展性，扩孔性和延迟抗断裂性，材料均匀性优异的高强度冷轧钢板。 该钢板具有以质量％计含有C：0.15〜0.25％，Si：1.2〜2.2％，Mn：1.7〜2.5％，P：0.05％以下，S：0.005％以下的化学成分，Al： 0.01〜0.10％，N：0.006％以下，Ti：0.003〜0.030％，B：0.0002〜0.0050％，Fe及不可避免的杂质。 该钢板具有包含体积分数为5〜20％的平均结晶粒径为4μm以下的铁素体的微观结构，体积分数为5％以下的残留奥氏体为0％，回火马氏体为 体积分数为80〜95％。 此外，铁素体的平均自由程为3.0〜7.5μm。

公开(公告)号：US20170321297A1

公开(公告)日：2017-11-09

申请号：US15535175

申请日：2015-10-27

Applicant: JFE STEEL CORPORATION

Inventor： Katsutoshi TAKASHIMA ,  Kohei HASEGAWA ,  Yoshimasa FUNAKAWA

IPC: C21D9/46 ,  C21D6/00 ,  C22C38/28 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C22C38/32 ,  C22C38/38

CPC classification number: C21D9/46 ,  C21D1/28 ,  C21D6/001 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C21D8/0263 ,  C21D8/0273 ,  C21D8/0278 ,  C21D8/0405 ,  C21D8/0426 ,  C21D8/0436 ,  C21D8/0447 ,  C21D8/0463 ,  C21D8/0473 ,  C21D8/0478 ,  C21D9/48 ,  C21D2211/002 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C22C38/58

Abstract: A high-strength cold-rolled steel sheet having a specified chemical composition and a microstructure including ferrite having an average crystal grain diameter of 2 μm or less in an amount of 10% to 25% in terms of volume fraction, retained austenite in an amount of 5% to 20% in terms of volume fraction, martensite having an average crystal grain diameter of 2 μm or less in an amount of 5% to 15% in terms of volume fraction, and the balance being a multi-phase structure including bainite and tempered martensite having an average crystal grain diameter of 5 μm or less, in which a relational expression, 0.35≦V2/V1≦0.75 (1), is satisfied, where V1 is a volume fraction of phases which are different from ferrite and V2 is a volume fraction of tempered martensite.