QP1180超高强钢复杂构件冷冲压成形性能

Cold stamping performance for complex components of ultra-high strength steel QP1180

针对QP1180钢汽车B柱,通过有限元模拟、冲压试验、扫描电镜等方法研究了零件冷冲压成形性能。模拟结果表明:压边力为1400 kN、摩擦因数为0.17、冲压速率为500 mm·s^(-1)下,零件主要部位的最大减薄率为12.7%,成形性良好。试验结果表明:冷冲压成形零件无起皱和开裂缺陷,成形质量较好。成形后零件D处的抗拉强度达到1343 MPa,伸长率达到24.5%,强塑积达到32.9 GPa·%,表现出较高的应变诱导强化能力;E处的强塑积达到30.2 GPa·%;F处的抗拉强度达到1454 MPa,强塑积为22.1 GPa·%。3处显微硬度均达到410 HV。零件变形较大区F处明显比D处的残余奥氏体含量少,马氏体含量多。3处断口形貌均为韧性断裂。D处的韧窝尺寸大,深度较深,塑性好;E处的韧窝尺寸变小,韧窝深度变浅;F处则出现明显撕裂棱,材料塑性下降。

For QP1180 steel automobile B-pillar,its cold stamping performance was investigated by finite element simulation,stamping experiments,scanning electron microscopy and other methods.The simulation results indicate that the maximum thinning rate of main parts for the part is 12.7%under the blank holder force of 1400 kN,the friction coefficient of 0.17 and the stamping rate of 500 mm·s^(-1),with good formability.The experimental results show that the cold stamping parts have no wrinkling or cracking defects,and the surface forming quality is excellent.After forming,the tensile strength at position D of the part reaches 1343 MPa,with an elongation of 24.5%and a strong plastic product of 32.9 GPa·%,demonstrating a high capacity of strain-induced reinforcement.At position E,the strong plastic product reaches 30.2 GPa·%,while at position F,the tensile strength reaches 1454 MPa and the strong plastic product is 22.1 GPa·%.The micro-hardness at three positions reaches 410 HV.In the area with larger deformation of part,the residual austenite content at position F is significantly lower than that at position D,and the martensite content is higher.The fracture morphologies in three positions belong to the ductile fracture,with large and deep dimples at position D,indicating good plasticity.The size of dimple at position E decreases,and the depth of dimple becomes shallower.At position F,there are obvious tearing edges and a decrease in material plasticity.