DP590级双相钢奥氏体晶粒长大模型

Austenite grain growth model of DP590 dual-phase steel

通过改变保温温度和保温时间研究了DP590级双相钢奥氏体晶粒长大行为,并探讨了加热速率对各温度下初始晶粒尺寸的影响规律.初始晶粒尺寸随着加热速率增加而不断降低,并最终趋于定值;奥氏体晶粒尺寸随保温时间的延长不断增大并最终趋于不变.采用Sellars晶粒长大模型对实验数据进行拟合,为避免处理方法不同造成的处理结果偏差,提出了一种新的实验数据处理方法,并建立了双相钢初始晶粒尺寸模型和晶粒长大模型.所得模型参数更加合理可靠,计算结果与实验结果吻合很好.

Austenite grain growth behavior of DP590 dual-phase steel was studied and the influence rule of heating rate on the initial grain size was analyzed by changing the heating rate and heating time. The initial grain size decreases with the heating rate increasing and finally comes to a constant. When the soaking time is long enough, the austenite grain size increases and tends to remain unchanged. These experimental data were fitted by the Sellars model. In order to avoid the deviation caused by model parameters, a new data processing method was proposed. With this method, the models of initial austenite grain size and austenite grain growth were built. It is found that the model parameters are much more reasonable and reliable, and the calculated data is in good agreement with the experiment data.