变压边力下TRIP600高强钢板的成形窗口

Formability window of TRIP600 high strength steel sheet at variable blank-holder force

为了提高TRIP高强钢板的冲压成形性能,在板料成形基本理论的基础上,通过单向拉伸试验和基于成形极限曲线的Naddrg模型,获得了TRIP600高强钢板的基本力学参数。在分析板料成形失效判据的基础上,提出变压边力成形窗口的建立方法,以圆筒件为例建立了TRIP600高强钢板的成形窗口,通过数值模拟和试验验证了该方法的准确性。结果表明:TRIP600高强钢板同时兼有高强度和高延伸性,但其弹性模量较低;1.2mm厚TRIP600高强钢板的平面应变点FLD0为0.397;成形窗口中的临界起皱变压边力曲线可通过实时调节压边力大小使零件始终处于临界起皱状态而获得;临界破裂变压边力曲线可通过两种极端加载模式获得;该成形窗口的建立能够有效指导TRIP高强钢板的实际冲压生产。

In order to improve the stamping formability of TRIP high strength steel effectively,based on the principal theory of sheet metal forming,the basic mechanical parameters of TRIP600 high strength steel sheet were got via uniaxial tensile test and the Naddrg model of forming limit curve（FLC）.And on the basis of the analysis of failure criterion of sheet metal forming,the established method of VBHF forming window was proposed.With the example of a cylindrical part,the VBHF forming window whose accuracy was proved by numerical simulation and experiment was established.The result of the experiment and numerical simulation shows that the TRIP high strength steel material is a new type high strength material with high elongation and low elastic modulus.The plane strain（FLD0） of TRIP600 high strength steel plate with the thickness of 1.2 mm is 0.397.The variable blank-holder force curve of critical wrinkless and critical fracture in formability window can be obtained by adjusting the variable blank-holder force（VBHF） to make parts in the critical wrinkling state and two extreme loading modes respectively.And the forming window can guide the practical stamping production of TRIP high strength steel.