高强钢热冲压成形相变模型研究

Study on Phase Transformation Model for Hot Stamping Forming of High Strength Steel

对高强钢热冲压成形过程中的相变模型进行了研究,在K-V模型,A-O模型和Li模型的基础上对相变模型进行了修正。在此基础上用两种材料对修正模型进行了验证。结果表明,经过优化后的修正模型预测得到的CCT曲线与试验结果更加吻合。比较了四种不同模型在不同冷却速率下的马氏体转化量,发现修正模型预测的马氏体相转变量最多,铁素体/珠光体相转变量最少。数值模拟的硬度值与实验值进行了对比,发现根据修正模型模拟得到的硬度值基本能预测实际硬度值,说明修正模型是准确的。

The phase transformation model of high strength steel during hot stamping was studied. The phase transformation model was modified on the basis of the Li model. On this basis, the model was verified by using two kinds of the materials. The results show that the CCT curves predicted by the modified model are in good agreement with the experimental results. The martensite transformation rates volume content of four different models at different cooling rates were compared. It is found that the martensite phase transformation volume content predicted by the modified model is the most, and the ferrite/pearlite phase transformation is the least. The hardness values of the numerical simulation were compared with the experimental values. It is found that the hardness value obtained from the simulation of the modified model can basically predict the actual hardness value, which shows that the modified model is accurate.