超高强DP980钢的动态再结晶模型

采用Gleeble-3500热模拟试验机对超高强DP980钢进行热压缩试验,研究其在变形温度为900~1 200℃、应变速率为0.05~30s~(-1)条件下的动态再结晶行为,分析了变形温度和应变速率对真应力-真应变曲线的影响。结果表明:超高强DP980钢在变形过程中,存在动态再结晶和动态回复两种软化机制,且随着温度的升高和应变速率的降低,临界应变越小,动态再结晶越容易发生;同时,得到了发生动态再结晶时的形变激活能,建立了峰值应变模型、动态再结晶临界应力模型和动态再结晶动力学模型。

Dynamic recrystallization model of ultra- high strength DP980 steel

The dynamic recrystallization behavior of DP980 ultra- high strength steel during hot compression deformation was investigated at 900～1 200 ℃ and strain rate of 0.05～30 s-1 on a Gleeble- 3500 thermo- simulation machine,and the effects of deformation temperature and strain rate on the true stress- true strain curves were analyzed.The results showed that dynamic recrystallization and dynamic recovery of these two kinds of softening mechanism were exited.When ultra high strength DP980 steel in the deformation process,as the deformation temperature increaseing and strain rate decreaseing，the critical strain and peak stress of dynamic recrystallization were decreased，and softening caused by dynamic recrystallization was more obvious.The dynamic recrystallization activation energy was obtained,peak strain model,dynamic recrystallization critical stress model and dynamic recrystallization kinetics model was set up.