摘要
对第三代先进高强钢QP980和第一代先进高强钢DP980的成形性能进行分析研究。采用数字化图像相关方法(DIC)进行标准试样的单向拉伸试验,对变形区域全场轴向应变和横向应变进行分析,并比较了标距区域和变形区域最大点的应力—应变曲线;基于Marciniak方法采用DIC方法进行两种材料成形极限试验,并对材料在不同应变下的残余奥氏体含量进行了测试。结果表明:QP980的综合成形性明显高于DP980,表现为QP980材料的均匀延伸率高出DP980约9%,达到17.26%;加工硬化指数接近0.18,比DP980高80%;成形极限FLD0为0.18,比DP980高出50%;在均匀变形阶段,QP980中大部分残余奥氏体发生向马氏体的转化,提高其加工硬化能力,表现为比DP980材料更高的均匀延伸率;但进入局部变形阶段后,残余奥氏体含量很低,继续变形相变诱导强化能力明显减弱,表现为两种材料相当的局部变形能力。
The formability of the 3rd generation advanced high strength steels(AHSS)QP980 was studied and compared with that of the 1st generation AHSS DP980.The static uni-axial tensile test was conducted and the longitudinal strain of the whole deformation area were analyzed with the DIC(Digital Image Correlation)techniques.Forming limit tests of QP980 and DP980 were operated in the Marciniak way using VIC-3D.The‘RA’volume fraction of QP980 at different plastic strain was detected by XRD(X-ray Diffraction).The results show that the formability of QP980 is obviously better than DP980.The uniform elongation of QP980 is about 9%higher than that of DP980,reaching 17.26%;The work hardening index is close to 0.18,while that is 0.10 for DP980;The FLD0 of QP980 is 0.18,which is 0.09 larger than that of DP980.Most of the residual austenite in QP980 transforms into martensite during the homogeneous deformation stage,which improves the work hardening ability of QP980.However,the retained austenite volume is very low during the local deformation stage,and the transformation induced strengthening is greatly weakened,which shows that the two material have the same local deformation ability.
作者
牛超
陈新平
林建平
NIU Chao;CHEN Xinping;and LIN Jianping(Baoshan Iron&Steel Co.,Ltd.,Shanghai 201999,China;State Key Laboratory of Development and Application Technology of Automotive Steels(Baosteel),Shanghai 201999,China;Tongji University,Shanghai 201804,China)
出处
《宝钢技术》
CAS
2020年第4期8-13,共6页
Baosteel Technology
基金
国家重点研发计划项目(2017YFB0304403)。
关键词
先进高强钢
QP钢
成形性
均匀变形
成形极限
advanced high strength steel(AHSS)
QP steel
formability
uniform deformation
forming limit diagram(FLD)
