Evolution of CFD numerical models of the continuous casting mold aimed to the study of the origin of cracks in steel slabs

Abstract

Surface and internal cracks in slabs (transverse and longitudinal) originate primarily within the continuous casting mold as a result of the combination of thermal gradients, non-uniform growth of the solidified shell, friction with the casting powder, and mechanical stresses associated with mold oscillation. Predicting the areas and operating conditions with the highest risk of cracking requires, as a preliminary step, a precise understanding of the flow field, temperature distribution, and solidification profile within the mold. This paper presents the evolution of a series of numerical models developed in ANSYS Fluent for the continuous casting of SAE 1010 steel slabs, conceived as a progressive step toward a thermofluid dynamic-structural model capable of estimating cracking risk. The study began with a two-dimensional model validated with plant data and progressed to three-dimensional models incorporating the two-phase interaction between steel and casting powder, mold oscillation, heat extraction from the walls, and solidification with taper, each contributing relevant variables for crack analysis. Future lines of research, focusing on incorporating temperature-dependent physical properties and coupling them with a structural model for direct stress calculation are also described.