Investigation of Liquid/Solid Slag and Air Gap Behavior inside the Mold during Continuous Slab Casting

The mold flux fundamentally determines solidification and friction by controlling heat transfer and lubrication within the mold, and it results in dominating the formation of various primary cracks. It is critical to reveal the distribution and evolution of the slag layers and the air gap, especially for control and optimization of the initial slab surface defects. Based on the measured temperatures in combination with the inverse heat transfer numerical model, this paper establishes a numerical model which describes the distribution of the slag layers and the air gap in the mold, aiming to calculate the non-uniform distribution of liquid slag, solid slag air gap and their evolution during actual casting process. The effect of slag solidification temperature and casting temperatures on the slag layers and air gap is investigated, and the liquid lubrication length, air gap formation position and evolution of the slag layers are also analyzed quantitatively. The results provide reference for deepening the understanding of complicated distribution and evolution of mold flux, and may lay the theoretical foundation for online visualization of non-uniform heat transfer and lubrication behavior inside the continuous casting mold.