Multiphase Modeling of Macrosegregation Formation in Steel Ingot

Although modeling of macrosegregation during solidification has been progressed, more effective models and methods are still required to improve the simulation precise of the practical steel ingot. A multi-phase model has been utilized and realized which incorporates the descriptions of heat transfer, melt convection, and solid movement on the macroscopic scale with microscopic relations for grain nucleation and growth. The prediction of column to equiaxed transition (CET) has been included in the model. Firstly, the performance of final CET position prediction is validated by simulations for 1-dimensional and 2-dimensional castings of Al-Cu alloy. Then, macrosegregation of a 3.3-ton benchmark steel ingot is predicted, and the prediction results agree well with the measurements along the centerline. Finally, the model is applied to a 231-ton industrial steel ingot with plant measurements. The final macrosegregation pattern exhibits a negative segregation zone in the bottom and a positive segregation zone in the hot top. Comparisons are made between the prediction and measurements.