Numerical simulation and industrial validation of heat transfer and solidification uniformity in continuous casting slab mold

Non-uniform heat transfer in slab continuous casting molds is a major cause of surface defects such as longitudinal cracks and off-corner depressions. To improve mold heat transfer uniformity, a three-dimensional multi-body multiphysics coupled model incorporating heat transfer across the strand–mold interface was developed. The model was used to investigate the effects of copper plate geometry and cooling conditions on mold heat transfer and strand solidification behavior. Model predictions were validated against industrial thermocouple measurements obtained from a commercial slab caster. The average deviation between the steady-state simulation results and the measured copper plate temperatures was less than 5%, demonstrating the reliability of the proposed model. At a casting speed of 1.9 m/min, the shell-thickness non-uniformity at the mold exit decreased from 5.4% for the original copper plate (Case 1) to 4.2% after the integrated modification of the cooling-channel geometry and plate thickness in Case 2. The mean wide-face shell thickness increased from 17.02 to 17.91 mm, while the standard deviation remained approximately 0.25 mm and the coefficient of variation decreased from 1.49% to 1.42%. Further increasing the average cooling-water velocity to 9.5 m/s in Case 3 produced no additional improvement, with a mean shell thickness of 17.86 mm, a standard deviation of 0.26 mm, and a coefficient of variation of 1.46%. Both redesigned plates outperformed the original design in shell growth and relative thickness uniformity, with Case 2 showing the most pronounced overall improvement.