变形温度对高强IF钢应力-应变曲线及组织的影响

Effect of Deformation Temperature on Strain-stress Curve and Microstructure for High Strength IF Steel

以高强IF钢为研究对象,在Gleeble 3800热模拟机上,测定了在变形量为50%,变形速率为10s-1时,变形温度分别为1000￣700℃的应力-应变曲线。实验结果表明,在实验条件下,应力-应变曲线仅为动态回复型,不随温度的变化而改变类型;在铁素体区进行变形时,动态软化行为明显大于在奥氏体区变形,且在高温区域铁素体区变形的流变应力显著降低,同时随变形温度的升高,晶粒变的细小。

The strain-stress curve of high-strength IF steel were carried out on Gleeble-3800 thermal mechanical simulator with 10 s^-1 strain rate,50% reduction and the deformation temperature at 700-1000℃. The single pass compression test showed that in the condition of the experiment, the mode of the stress-strain curve is dynamic recovery, which doesn＇t change with temperature. The effect of deformation on the dynamic soften behavior in ferrite region is greater than that in austenite region, and deformation resistance decrease greatly in high temperature zone of ferrite region. At the time, the grain is fine with the temperature increasing.