利用数据处理与理论推导相结合的方法建立了钢在完全再结晶区变形后奥氏体晶粒平均直径的预报模型。在模型中引进了微合金化元素Nb、Ti的影响，并对该模型进行实验验证及理论分析。 Using the combination of data processing and theoretical derivation, the prediction model of average austenite grain diameter after the steel was completely recrystallized was established. The micro-alloying elements Nb and Ti were introduced into the model, and the model was verified by experiments and theoretical analysis.