粗晶硅钢热变形后静态再结晶及晶粒尺寸的演化模型研究

Study on Evolution Models of Static Recrystallization and Grain Size of Coarse-grained Silicon Steel after Hot Deformation

采用热模拟方法对硅钢不同工艺参数热变形后的静态再结晶及晶粒尺寸演化行为进行研究。单相铁素体硅钢及双相硅钢(含奥氏体)再结晶激活能分别为197、226kJ/mol。单相硅钢晶界的三角地带(晶棱)是优先的形核位置,双相硅钢以晶界和晶内再结晶为主,优先位置形核比例随初始晶粒尺寸的减小而增加。静态再结晶期间,随着再结晶体积分数的增加,单位体积可移动晶界面积出现峰值,双相硅钢的峰值较单相硅钢峰值更髙,且随着变形温度的增加,峰值降低。随着退火温度的降低和应变的增加,再结晶晶粒尺寸减小。

The static recrystallization and grain size evolution of Si steels after different hot deformation were studied bythermal simulation method. The results show that the recrystallization activated energy of single phase ferritic silicon steel andtwo-phase steel (including austenite) is 197 kJ/mol and 226 kJ/mol, respectively. The preferential nucleation position is at thetriple junction (grain edge) of single phase silicon steel, while the two-phase silicon steel is mainly grain boundaries and grainrecrystallization. The nucleation proportion of preferential position increases with the initial grain size decreases. In staticrecrystallization period, the maximum value of the migrating boundary area per unit volume appears with the increase of therecrystallization volume fraction. The maximum value of two-phase steel is higher than that of single phase ferritic siliconsteel, and the maximum value decreases with deformation temperature increasing. The recrystallized grain size decreases withthe annealing temperature decreasing and the strain increasing.