稀土Ce改性超级双相不锈钢的热变形行为

Hot deformation behavior of rare earth Ce modified super duplex stainless steel

用Gleeble-3800热模拟试验机研究了两种Ce含量的改性超级双相不锈钢(SDSS)在温度为1000~1150℃、应变速率0.01~10 s^-1,真应变量为0.7的变形条件下的热变形行为。得到了两种超级双相不锈钢的真应力-应变曲线,建立了相应的双曲正弦本构方程,同时研究了热变形过程中微观组织的演变情况。结果表明:两种超级双相不锈钢的峰值应力均随着变形温度的升高和应变速率的降低而逐渐减小;稀土元素Ce的添加不仅能有效细化晶粒,同时可以促进热变形过程中动态再结晶的发生。

The hot deformation behavior of super duplex stainless steel( SDSS) modified by two different contents of Ce was investigated on Gleeble-3800 thermo-mechanical simulator with the temperature range of 1000-1150 ℃,strain rate range of 0. 01-10 s^-1 and true strain of 0. 7. The true stress-strain curves of the two SDSSs were obtained,and the corresponding hyperbolic sinusoidal constitutive equations were established. The evolution of microstructure during hot deformation was also studied. The results show that peak stress decreases with the increase of deformation temperature and the decrease of strain rate for both of the two SDSSs. The addition of rare earth element Ce can not only refine the grain size effectively,but also promote the occurrence of dynamic recrystallization during hot deformation.