【作者】 陈荣创； 郑志镇； 李建军；

【Author】 Chen Rong-chuang;Zheng Zhen-zhi;Li Jian-jun;Huazhong University of Science and Technology;

【机构】 华中科技大学材料成形与模具技术国家重点实验室；

【摘要】 现有的基于位错密度演化的流动应力模型,在动态回复段和动态再结晶段的形式不统一,而且没有充分考虑到动态再结晶过程的影响,会使流动应力的计算结果不准确。为此,本文研究了动态再结晶对材料加工硬化和动态软化的影响,提出了一个统一的流动应力模型。通过在Gleeble 3500试验机上开展热压缩实验,得到了300M钢在不同温度(950-1150℃)、应变(0-0.8)、应变速率(0.01-10/s)下的流动应力,并通过Matlab计算和迭代,建立了300M钢流动应力模型。最后,将该模型用于变应变速率热压缩流动应力预测,取得了较高的计算精度。本文提出的耦合动态再结晶过程的流动应力模型很好的预测300M钢在高温下的流动行为。更多还原

【Abstract】 The forms of flow stress models are not unified at the dynamic recrystallization stage from that of dynamic recovery stage in existing dislocation density based models, and the consideration of dynamic recrystallization is insufficient. Therefore, a unified flow stress model is proposed considering the influences of dynamic recrystallization on hardening and softening. Hot compression tests of 300 M steel were performed on Gleeble 3500 machine at different temperatures(950-1150℃) and strain rates(0.01-10/s), and an iterative procedure was implemented on MATLAB software to get the parameters of the model. Finally, the model was applied in a flow stress prediction of a thermal compression which involves strain rate changes. The model in this paper provides an effective way to establish stress-strain relationships for complicated deformation conditions.更多还原