铸钢锭凝固过程数值模拟和缩孔缩松预测

Numerical Simulation of Solidification Process of Steel Ingot and Shrinkage Prediction

用有限元法对22t钢锭凝固过程进行了模拟,计算中采用了Galerkin方法和八节点等参数单元,同时考虑钢锭和锭模界面上初期紧密接触和后期气隙形成过程中界面热阻的变化。建立的模型具有通用性,能够处理各种不同类型的边界条件和变热物性参数,用等效凝固收缩量法预测钢锭冒口部位缩孔的位置和大小,用经适当修正后的G/(?)参数(G-温度梯度,R-冷却速度)预测钢锭内部缩松。计算温度与实测温度基本吻合。

Solidification process of 22t steel ingot is simulated using the finite element method. The thermal model used utilises the Galerkin Method and eight-noded quadratic isoparametric elements and takes into account the intimate contact of ingot and mold in the initial atage and the presence of the air gap thereafter. The model is general and can deal with different types of boundary conditions and with variations in material properties. The quantity and position of shrinkage cavity in riser of steel ingot is simulated using the equivalent solidification contraction quantity method and a properly modified parameter G/R^(1/2) (the temperature gradient divided by the square root of the cooling rate) is used for the prediction of porosity in steel ingot. The calculated temperatures are found to agree closely with the measured ones.