Fe-12Mn-2Al-0.1C冷轧钢板冲压成形数值模拟与实验

Numerical simulation and experiment of stamping forming of Fe-12Mn-2Al-0.1C cold rolled steel sheet

以Fe^(-1)2Mn-2Al-0.1C冷轧钢板为研究对象,进行了扩孔成形实验,获得了不同冲压速度下的扩孔率,讨论了冲压速度对板料成形性能的影响机制。使用Dynaform 9.2有限元仿真软件对钢板扩孔成形过程进行了数值模拟,获得了该材料在不同虚拟凸模速度下的扩孔成形极限图、板料厚度以及扩孔率。通过数值模拟发现,扩孔率随着虚拟凸模速度的增加大体呈上升趋势,在虚拟凸模速度为15000 mm·s^(-1)时进行扩孔,既能保持冲压件板形,又可改善其扩孔性能。实验结果表明,扩孔率随着冲压速度的增大呈先上升后下降的趋势并在冲压速度为20 mm·min^(-1)时获得最大扩孔率50.90%;冲压成形过程中的冲压速度决定了相变诱导塑性(TRIP)效应中残余奥氏体的相变速率,从而决定了钢板的成形性能。

Taking Fe^(-1)2Mn-2Al-0.1C cold rolled steel sheet as research object,the hole expansion forming experiments were carried out and the hole expansion rates with different stamping speeds were obtained.The effect mechanism of stamping speed on the formability of sheet metal was discussed.Numerical simulation software Dynaform 9.2 was used to simulate the hole expansion forming process of steel sheet,and the forming limit diagram,sheet thickness and hole expansion rate with different stamping speeds were obtained.Through numeri-cal simulation,it is found that the hole expansion rate gererally increases with the increase of virtual punch speed.When the virtual punch speed is 15000 mm·s^(-1),the hole expansion can not only maintain the shape of stamping parts,but also improve the hole expansion perform-ance.The experiment results show that the hole expansion rate increases first and then decreases with the increase of stamping speed,and the maximum hole expansion rate is 50.90%when the stamping rate is 20 mm·min^(-1).The stamping speed during the stamping process determines the transformation rate of the retained austenite in transformation induced plasticity(TRIP)effect,which consequently determines the formability of steel sheet.