Microstructure simulation and Multi-physical field Analysis of 400mm thick Continuous Casting Slabs

Abstract

Based on the parameters were provided by a caster enterprise, Pro-cast was adopted to simulate temperature field and solidus rate of continuous casting steel about the 2400 mm×400 mm cross section. On the premise of validation of simulation method, the effects of different casting speeds, degree of superheat and secondary cooling to the microstructure have been studied by the numerical simulation. The results show that, Grain number, average grain size and maximum grain size are little changed along with the change of casting speed and secondary cooling, but average grain size decrease with the increase of superheat. The equiaxed grain ratio is unchanged with casting speed increase, is about 13.9%. The center of narrow face shell at the mold exit is thinnest and the thickness is about 10.4 mm, and increases along the wide face direction gradually. the wide face shell thickness near the corner is 18.9 mm, and the center thickness is 27.6 mm. The trend of stress change at the slab solidification front is almost consistent with temperature, demonstrating the initial solidified shell stress is mainly thermal stress. Therefore. the 20℃ superheat, 0.54m/min casting speed and low water flow rate are reasonable parameters for 400mm×2400mm extra-thick special slabs in the continuous casting. Theoretical basis is provided for the practical production in the future.