DH&DP钢显微组织、力学性能及形变机制差异研究  

Study on the differences in microstructure,mechanical properties,and deformation mechanism between DH and DP steels

作　　者：周莉[1] 薛仁杰 曹晓恩 文才君 Zhou Li;Xue Renjie;Cao Xiaoen;Wen Caijun(School of Mechanical Engineering and Automation,Chongqing Industry Polytechnic College,Chongqing 401120,China;Materials Technology Research Institute,HBIS Group,Shijiazhuang 050000,Hebei,China;Technology Center,Hansteel Company,HBIS Group,Handan 056015,Hebei,China;Material Science and Engineering School,Xi'an Jiaotong University,Xi'an 710049,Shaanxi,China)

机构地区：[1]重庆工业职业技术学院机械工程与自动化学院,重庆401120 [2]河钢集团材料技术研究院,河北石家庄050000 [3]河钢集团邯钢公司技术中心,河北邯郸056015 [4]西安交通大学材料科学与工程学院,陕西西安710049

出　　处：《钢铁钒钛》2023年第6期186-191,共6页Iron Steel Vanadium Titanium

基　　金：重庆市教委科学技术研究项目(KJQN202103211)。

摘　　要：采用高速拉伸试验、综合成形试验、场发射扫描电镜(SEM)、X射线衍射(XRD)、电子背散射衍射(EBSD)等表征方法研究了DH780与DP780冷轧双相钢组织性能差异。研究表明,DH780与DP780显微组织差异关键在于是否存在残余奥氏体,前者存在约5.1%残余奥氏体,呈块状、薄膜状、链状与细小粒状位于相界面与铁素体晶界处,在变形过程中具有显著TRIP效应,同时残余奥氏体具有更多滑移系可有效减缓位错塞积、延缓应力集中与裂纹源的形成,使得DH780较DP780具有更优良的强塑积及扩孔性能。高速拉伸试验表明,DH780较DP780具有更高的应变速率敏感性特征;随着应变速率的提升,DH780强塑积增加至38.83 GPa·%,吸能性能显著增强。High speed tensile test,comprehensive forming test,field emission scanning electron microscope(SEM),X-ray diffraction(XRD),electron backscatter diffraction(EBSD)and other characterization methods were used to study the differences of microstructure and properties between DH780 and DP780 cold-rolled dual phase steels.The research shows that the main differences between the microstructures of DH780 and DP780 steels depend on the occurrence of retained austenite.The former has about 5.1%retained austenite,which is located at the phase interfaces and ferrite grain boundary in the blocks,thin films,chains and fine particles appearances.It has a significant TRIP effect during deformation.At the same time,the retained austenite has more slip systems,which can effectively retard the dislocation accumulation,stress concentration and crack initiation.DH780 has better strength-ductility balance(TS×EL)and hole expanding performance than DP780.High speed tensile test shows that DH780has higher strain rate sensitivity than DP780;With the increase of strain rate,the strength-ductility balance(TS×EL)of DH780 increases to 38.83 GPa·%,and the energy absorption performance is significantly enhanced.

关 键 词：双相钢 残余奥氏体 TRIP效应 应变速率 强塑积 扩孔性能 

分 类 号：TF76[冶金工程—钢铁冶金] TG142.1[一般工业技术—材料科学与工程]