热轧中厚板显微组织和平均流变应力的预测与优化

Prediction and Optimization of Microstructure and Mean Flow Stress During Hot Rolling of Steel Plates

在考虑动态、亚动态再结晶及静态再结晶的基础上，建立了Nb—V微合金钢物理冶金模型，并在线应用于中厚板热轧过程奥氏体再结晶、晶粒尺寸和流变应力的预测与控制．结果表明，对30mm板材，待温温度900～950℃，待温厚度为成品厚度的2～2．7倍时，待温后采用中间冷却，奥氏体平均晶粒尺寸可以细化到30μm左右，同时残余应变在0．08～0．4的范围内．在平均流变应力模型中引入了晶粒尺寸和残余应变的影响，提高了精轧阶段的预测精度．

A metallurgical model of Nb-V HSLA steels was developed considering the effects of dynamic, metadynamic and static recrystallization. The model was applied to the on-line prediction and control of austenite recrystallization, grain size and flow stress during plate hot rolling. The results showed that when the starting temperature of finish rolling is at 900-950 ℃ with intermediate water cooling and the intermediate slab is 2-2.7 times as thick as the finished product, the final austenite grain size of 30 mm plate can be refined to about 30μm with residual strain in a range from 0.08 to 0.4. The prediction accuracy of MFS （mean flow stress） in finish rolling will be greatly improved if introducing the effects of grain size and residual strain into MFS model.