碳钢高温流变应力模型研究

High Temperature Flow Stress Model of Carbon Steel

建立简洁、包含动态再结晶信息、具有普遍性的碳钢高温流变应力模型,分析应力-应变曲线的可能形态,提出了模型必须满足的基本条件.从基本条件入手,结合现有研究成果,通过数学推导,提出了包含动态再结晶信息的碳钢高温流变应力模型,实现了从数学和物理上对应力-应变曲线的描述.利用Gleeble-1500实验机对Q235B进行单道次压缩实验,通过实验数据的非线性拟合构建了Q235B对应的流变应力模型.应用结果表明:模型能很好地描述Q235B的高温力学行为,合理且准确,为高温流变应力模型的建立提供了新的思路.

Concise and universal high temperature flow stress model of carbon steel containing dynamic recrystallization is described. Conditions that the model should satisfy are proposed by analyzing the possible shapes of the stress-strain curves. Focusing on the conditions and combining with the existing research results, the high temperature flow stress models containing the dynamic recrystallization information are first established through rigorous mathematical derivation. Single pass compression experiments of Q235B are done by using the thermal simulation machine Gleeblel500. High temperature flow stress models of Q235B are established through nonlinear fitting of experimental data. Analytical results show that the models for Q235B are consistent with the experimental results, and the model proposed are reasonable and accurate. This work provides a new method for the establishment of high temperature flow stress model.