不同成分780 MPa级高强双相钢成形性能对比分析  

Comparative analysis of forming performance of 780 MPa grade high strength dual phase steel with different components

作　　者：张伟 刘华赛 桑贺 李春光 陈洪生 何朗 邱木生 ZHANG Wei;LIU Hua-sai;SANG He;LI Chun-guang;CHEN Hong-sheng;HE Lang;QIU Mu-sheng(Research Institute of Technology,Shougang Group Co.,Ltd.,Beijing 100043,China;QC Department,Shougang Jingtang United Iron and Steel Co.,Ltd.,Tangshan 063210,China)

机构地区：[1]首钢集团有限公司技术研究院,北京100043 [2]首钢京唐钢铁联合有限责任公司质检部,河北唐山063210

出　　处：《塑性工程学报》2024年第5期171-178,共8页Journal of Plasticity Engineering

基　　金：河北省重点研发计划项目(20311004D)。

摘　　要：针对不同成分高强双相钢HC420/780 DPD+Z开展了性能对比分析。首先,在常规C-Si-Mn化学成分体系的基础上,通过增加微合金元素或改变原有化学成分含量形成了3种同强度级别的材料,对3种材料的金相组织和力学性能进行了对比分析;基于液压成形试验机对3种材料的成形极限曲线进行了对比,并与3种理论预测模型进行了对比;对3种材料的扩孔性能和折弯性能进行了对比;基于AutoForm搭建了某车型纵梁零件成形过程仿真模型,分析了3种材料的应变分布;通过折弯性能验证材料是否满足纵梁的成形需求。结果表明,对于增加微合金元素的材料,其组织得到明显细化,马氏体呈现出弥散细小的状态,材料的拉延能力增强;对于高碳含量的材料,其C和Cr元素的含量提高,Si元素含量降低,有明显的带状马氏体组织,晶粒尺寸增大,材料的塑性应变比r值增大;根据成形极限曲线可知,微合金成分材料的平面主应变最大,约为0.175,扩孔率最高,达到26.2%,90°折弯极限圆角半径优于其他两种材料,应用纵梁零件的开裂风险最小;高碳含量材料的平面主应变最小,约为0.133;常规成分材料的扩孔率最低,仅为13.0%,折弯性能也最差;微合金元素材料具有良好的拉延和弯曲综合成形性能,而高碳含量可以明显提升材料的折弯和扩孔性能。The properties of different components of high strength dual phase steel HC420/780 DPD+Z were compared and analyzed.Firstly,on the basis of conventional C-Si-Mn chemical component system,the three kinds of materials with the same strength grade were formed by increasing microalloying elements or changing the original chemical component content.The metallographic structure and mechanical properties of the three kinds of materials were compared and analyzed.Based on the hydraulic forming experiment machine,the forming limit curves of the three kinds of materials were compared and compared with the three theoretical prediction models.The hole expansion performance and bending performance of the three kinds of materials were compared.Based on AutoForm,the simulation model of the forming process of a car longitudinal beam part was built,and the strain distribution of the three kinds of materials was analyzed.The bending performance verifies whether the material meets the forming requirements of the longitudinal beam.The results show that the microstructure of material with microalloy elements is obviously refined,the martensite presents dispersed and fine state,and the drawing ability of material is enhanced.For material with high carbon component,the contents of C and Cr elements increase,the content of Si element decreases,and there is obvious banded martensite structure,the grain size increases,and the plastic strain ratio r of material increases.According to the forming limit curves,it is obtained that the plane major strain of microalloy component material is the maximum,which is about 0.175,and the hole expansion rate is the highest,reaching 26.2%.The 90°bending limit fillet radius is better than the other two kinds of materials,and the cracking risk of longitudinal beam parts is the smallest.The plane major strain of materials with high carbon component is the minimum,which is about 0.133.Conventional component material has the lowest hole expansion rate,only 13.0% and the worst bending performance.Microalloy

关 键 词：化学成分 高强度双相钢 成形性能 成形极限曲线 扩孔率 

分 类 号：TG142.1[一般工业技术—材料科学与工程]