Cu-P-Cr-Ni-Mo耐候钢高温变形奥氏体的动态再结晶

用Gleeble-3500热模拟试验机研究了Cu-P-Cr-Ni-Mo耐候钢(%:0.10C、0.075P、0.65Cr、0.22Ni、0.43Mo、0.28Cu)在应变速率0.01～1 s-1、温度850～1150℃时的动态再结晶行为,得出该钢奥氏体区的真应力-真应变曲线和动态再结晶图,分析了变形参数对峰值应力的影响和不同热变形时耐候钢的动态再结晶体积分数与真应变的关系,建立了该钢的奥氏体热变形方程、动态再结晶临界条件回归方程和奥氏体动态再结晶体积分数数学模型。结果表明,随变形温度升高,峰值应力下降;随变形速率增大,峰值应力升高;随Z参数增大即变形温度降低,应变速率增加,发生再结晶的临界应变εc和发生完全再结晶的应变εs均呈线性增加。

Dynamic Recrystallization of Elevated Temperature Deforming Austenite of Cu-P-Cr-Ni-Mo Weathering Steel

The dynamic recrystallization behavior of Cu-P-Cr-Ni-Mo weathering steel (% ： 0. 10C, 0. 075P, 0. 65Cr, 0. 22Ni, 0.43Mo, 0. 28Cu) with strain rate 0. 01 ~ 1 s ~1 at 850 — 1 150 T： has been studied by Gleeble-3500 thermal simulation test machine to get true train-true stress curves in austenite area and dynamic recrystallization diagram of the steel, the effect of deformation parameters on peak stress and the relation between true strain and volume fraction of dynamic recrystallization of the weathering steel with various hot deformation are analyzed, and the thermal deformation formula of austenite of the steel, the regression formula of dynamic recrystallization at critical conditions and the math model of dynamic recrystallization volume fraction of austenite are established. Results show that with raising deformation temperature the peak stress decreases and with increasing strain rate the peak stress increases ； with increasing Z parameter i. e. decreasing deformation temperature and increasing strain rate the critical strain of occurred recrystallization and the strain εs of occurred complete recrystallization increase linearly.