OPTIMIZATION OF MOLD DESIGN IN CONTINUOUS CASTING OF  STELL BILLETS

In the continuous casting of steel billets, the mold region is the most critical stage governing initial shell formation, heat transfer stability, and final product quality. However, conventional mold designs are generally based on fixed taper geometries and do not adequately account for the actual shrinkage behavior of the billet during solidification. This study investigates the influence of solidification shrinkage on the thermo-mechanical interaction between the billet and the mold and develops a scientifically grounded approach for mold geometry optimization. A coupled thermo-mechanical finite element model was employed to simulate transient heat transfer, latent heat release during solidification, temperature-dependent material properties, and elastic-plastic deformation of the solidifying shell. Shrinkage behavior was analyzed along both the billet face center and corner regions. The results reveal a non-uniform shrinkage distribution, characterized by staged contraction at the face center and a more uniform linear contraction in the corner region. Based on these shrinkage trajectories, an adaptive mold taper was designed, improving billet-mold contact, reducing air-gap formation, stabilizing heat flux distribution, and enhancing shell thickness uniformity. The proposed shrinkage-based optimization strategy provides an effective and scientifically justified approach for improving casting stability, reducing the risk of defect formation, and increasing the overall reliability of the continuous casting process.