A hybrid radial basis function-finite difference method for modelling two-dimensional thermo-elasto-plasticity, Part 3: Application to thermo-mechanical modelling of continuous casting of steel billets

This paper, Part 3 of a series, extends the previously developed strong-form hybrid radial basis function-finite difference (RBF-FD) method to model the thermomechanics of continuous casting (CC) of steel. Part 1 introduced the method for non-linear thermomechanics, and Part 2 applied it to the cooling of steel bars on a cooling bed. Here, a one-way coupled thermo-mechanical slice model is developed, where the temperature field provides thermal loading for the mechanical analysis. The previously introduced 2.5D formulation is adapted to include strand straightening. A visco-plastic material model, validated in our recent work, is used to describe material behaviour close to the mushy-zone temperatures. The analysis focuses on the solidified part of the strand, while the space discretisation remains constant and liquid-zone results are disregarded. Two hot-tearing criteria—temperature-based and stress-based are implemented and compared with experimental data, showing that the stress-based approach produces more realistic predictions. The influence of electromagnetic stirring, steel grade composition, and casting speed on hot-tearing susceptibility is explored. This study represents the first strong-form RBF-FD solution of CC thermomechanics, demonstrating that the hybrid RBF-FD can efficiently handle complex non-linear thermo-mechanical behaviour and allows for further process optimisation and defect mitigation in industrial CC.