• A three-dimensional thermal-mechanical finite element model was developed to analyze temperature and deformation fields during liquid core reduction (LCR) in thin slab continuous casting.
• High-temperature tensile tests established critical strain criteria for corner crack propagation and intermediate crack initiation, incorporating strain rate and temperature via the Zener-Hollomon parameter.
• The maximum theoretical reduction amount for SPA-H steel slabs (145 mm × 1600 mm) was determined as 41.8 mm, with a segment-wise reduction scheme (15.8, 7.3, 6.5, 6.4, 5.8 mm) to minimize crack risk.
• The proposed crack risk prediction model enables optimization of LCR parameters to enhance slab quality and production efficiency while avoiding deformation-induced defects.