摘要：基于单向拉伸试验获得的真实应力-应变数据，通过曲线拟合来确定硬化模型参数，是目前确定金属薄板应力-应变关系广泛应用的方法。然而，硬化模型的外推结果因所选模型和参数的不同而有所差异，为此，准确研究超高强复相钢CP1180大变形下硬化模型的适用性有重要的意义。采用单向拉伸试验得到材料的真实应力应变数据，基于Hollomon、Lian、Swift、Hockett-Sherby及Swift/Hockett-Sherby模型对曲线进行拟合，建立了材料室温下塑性变形硬化模型。采用液压胀形试验并结合DIC在线检测技术得到了材料胀形件顶点处大应变范围下的真实等效应力应变数据，验证了不同模型的准确性。对厚度为1.48 mm的超高强钢板CP1180分别进行弯曲试验和有限元模拟分析，结果表明，板料弯曲试验后拉伸方向的最大塑性应变为0.249 3，S/H-S(a=0.4)模型计算得到的应变为0.253 56，偏差仅有1.68%，预测精度最高。
Abstract：Based on uniaxial tensile tests, the real stress-strain data is obtained to determine the parameters of the hardening model through curve fitting. This method is widely used to establish the stress-strain relationship for metal thin plates. However, the extrapolation results of the hardening model may vary depending on the chosen model and parameters. Therefore, it is crucial to accurately assess the applicability of the hardening model under significant deformation for CP1180 ultra-high strength complex phase steel. The uniaxial tensile test is used to obtain the true stress-strain date of the material. The curve is fitted at room temperature based on Hollomon, Lian, Swift, Hockett-Sherby and Swift/Hockett-Sherby respectively, and then five hardening models are established. To verify the accuracy of the five models, the combination of the hydraulic bulging test and DIC online detection technology are used to obtain the true equivalent stress-strain date under large strain at vertex of bulging part. The bending test and finite element simulation analysis are conducted on the ultra-high-strength steel plate CP1180 with a thickness of 1.48 mm. The results show that：the maximum plastic strain in the tensile direction after the bending test of the plate is 0.249 3, while the strain calculated by the Swift/Hockett-Sherby (a=0.4) model is 0.253 56，with a deviation of only 1.68%, which had the highest prediction accuracy.
关键词：超高强复相钢CP1180, 硬化模型, 弯曲, 有限元模拟
Key words：ultra-high strength complex phase steel CP1180, hardening model, bending, finite element simulation