利用元胞自动机法模拟电渣重熔钢锭定向凝固组织

The cellular automata model of electroslag remelting ingot structure

本文应用元胞自动机法发展电渣重熔钢锭组织结构的计算模型,建立基于高斯分布的连续形核模型和生长模型;在节点上采用元胞自动机法(CA)对钢液凝固进行形核和生长计算.结果表明:电渣重熔钢锭凝固组织结构主要由柱状晶构成,在底部有一个垂直的柱状晶带,两边有一个延伸的倒V形柱状晶带.本文还考查了电极熔速、渣池温度等工艺参数对温度场的影响,以及平均形核过冷度和最大晶粒密度对微观组织的影响.模拟结果与低倍检测实验结果吻合较好.故可以据模拟结果调整制备工艺条件,获得具有理想凝固态组织的钢锭.

A two -dimensional axisymmetric geometry which was established in this paper was divided into macro - grid finite element in order to compute temperature field; then grid was divided into more detailed and uniform cells, and at the last the continuous nucleation model based on the Gaussian distribution and KGT growth model was established for nucleation and growth calculations using cellular automaton method （CA） on the solidification of molten steel. The results show that： a vertical columnar grain zone and a inverted V - shaped columnar crystal zone appeared in the ESR ingot. In addition, the temperature field with different electrode melting rate and slag pool temperature parameters and the microstructure with different average nucleation undercooling and maximum grain density were studied in this paper. The sinmlation results agree well with the experimental results, so it is proved that the model and calculation method is refiable. To produce ideal solidified ingot and achieve the purpose of optimizing the production process, the production process was adjusted according to the simulation results.