摘要
针对第三代先进高强高塑性中锰汽车钢在冷冲压成形中的应用瓶颈,以0.1C-5.5Mn(质量分数,%)中锰汽车钢为研究对象,系统探究奥氏体逆相变退火工艺对中锰钢微观组织与力学性能的影响,基于数值模拟分析该工艺在新能源汽车A柱内板冲压成形中的可行性。通过真空熔炼、热轧、冷轧及奥氏体逆相变退火工艺制备试验钢,结合扫描电镜(scanning electron microscopy,SEM)、透射电镜(transmission electron microscopy,TEM)、X射线衍射(X-ray diffraction,XRD)及拉伸试验,揭示了退火温度与保温时间对组织演变及性能的协同作用。结果表明,在650℃保温15 min的优化条件下,碳化物充分溶解,C、Mn元素均匀配分,铁素体等轴化显著改善变形协调性,试验钢抗拉强度达1148 MPa,屈服强度达907 MPa,伸长率达32.54%,强塑积峰值达到36.51 GPa·%,这归因于相变诱导塑性效应与晶界特征优化的协同强化。进一步通过数值模拟分析A柱内板冲压成形规律发现,压边力由200 kN增至300 kN时,材料流动阻力增强,最大厚度减薄率从29.18%降至28.79%,有效抑制法兰区的无序堆积;冲压速度由200 mm/s增至800 mm/s时,减薄率呈先升后降的非线性响应,成形极限图显示零件主体区域应变点均位于安全区,证实基础工艺参数是可行的,这为中锰钢在汽车零件中冲压成形的应用提供参考。
Aiming at the application bottleneck of the third generation of advanced high strength and high plasticity medium manganese automobile steel in cold stamping forming,0.1C-5.5Mn(mass fraction,%)medium manganese automobile steel was taken as the research object,systematically explored the effect of austenite reverse phase transformation annealing process on the microstructure and mechanical properties of medium manganese steel,and analyzed its feasibility in the stamping forming of A-pillar inner plate of new energy vehicle based on numerical simulation.The experimental steel was prepared by vacuum melting,hot rolling,cold rolling and austenite reverse phase transformation annealing process.Combined with scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD)and tensile test,the synergistic effect of annealing temperature and holding time on microstructure evolution and properties was revealed.The results show that under the optimized conditions of holding at 650℃for 15 min,the carbide is fully dissolved,the C and Mn elements are evenly distributed,and the ferrite is equiaxed,which significantly improves the deformation coordination.The tensile strength of the experimental steel reaches 1148 MPa,the yield strength is 907 MPa,the elongation is 32.54%,and the peak value of the product of strength and plasticity reaches 36.51 GPa·%,which is attributed to the synergistic strengthening of the phase transformation induced plasticity effect and the optimization of grain boundary characteristics.Further,the stamping forming law of A-pillar inner plate is analyzed by numerical simulation.It is found that when the blank holder force increases from 200 kN to 300 kN,the material flow resistance increases,and the maximum thickness reduction rate decreases from 29.18%to 28.79%,which effectively inhibits the disorderly accumulation in the flange area.When the stamping speed increases from 200 mm/s to 800 mm/s,the thinning rate shows a nonlinear response of increasing first and then decreasing.The forming limit diagram shows that the strain points in the main area of the part are located in the safe area,which confirms that the basic process parameters are feasible.It provides a reference for the application of medium manganese steel in stamping of automotive parts.
作者
万志远
董瑞峰
赵军徽
张明旺
WAN Zhiyuan;DONG Ruifeng;ZHAO Junhui;ZHANG Mingwang(School of Mechanical Engineering,Shandong Huayu University of Technology,Dezhou 253034,Shandong,China;School of Materials Science and Engineering,Inner Mongolia University of Technology,Hohhot 010051,Nei Mongol,China)
出处
《钢铁》
北大核心
2025年第9期175-183,共9页
Iron and Steel
基金
山东省高等学校特色实验室建设资助项目(PT2022TS02)
内蒙古自治区自然科学基金资助项目(2025ZD005)
数字钢铁全国重点实验室(东北大学)开放课题基金资助项目(2024DSLKFKT002)。
关键词
中锰钢
残余奥氏体
逆相变退火
A柱内板
相变诱导塑性效应
压边力
冲压速度
成形极限图
medium manganese steel
retained austenite
reverse phase transformation annealing
A-pillar inner plate
transformation induced plasticity
blank holder force
stamping speed
forming limit diagram
