Thermo-mechanical Modeling in Continuous Slab Casting Mould and Its Application

摘要

In order to understand the thermal and mechanical behavior during solidification of the strand in the slab casting mould, a two-dimensional coupled thermo-mechanical finite element model was built and the corresponding FEM program was developed. The model simulates a quarter of the transverse section of the strand as it moves down in the mould at the casting speed. The heat transfer in the mould and the strand is analyzed with the steady model and the transient model, respectively. A thermo-elastoplastic plane stress model is used for analyzing the strand deformation. The heat transfer and the deformation are coupled through the interfacial thermal resistance between the strand and the mould. The model was used to investigate the effects of mould corner configuration and mould taper on the crack formation tendency of strand. The results show that employing a chamfered mould with proper corner size could modify the 2D heat transfer conditions at slab corners, hence reducing the risk of transverse corner cracks. Likewise, employing an optimized parabolic mould taper could remarkably achieve better uniformity of the strand temperature and stress, and simultaneously reduce the peak value of the stress, thus resulting in less crack occurrence, which favorably coincides with the theoretical expectation. The successful application of the coupled thermo-mechanical model demonstrates its tremendous potentialities for further understanding of the internal crack formation and for the optimization of operation parameters and the mould configuration.