Combined Study on Mold Taper and Corner Radius in Bloom Continuous Casting by FEM Simulation and Trial Experiment

Abstract

A plane stress model was developed to study the coupled effect of mold taper and corner radius on the thermal–mechanical behavior of a 250 mm × 280 mm continuously cast bloom for a given special steel. Good agreement was obtained in both shell thickness and the off-corner cracking location from modeling and trial experiment. The results show that increasing mold taper results in the obvious decrease of surface temperature near the corner, while enlarging mold corner radius makes the shell surface temperature at the corner region more even with the mold taper between 0 and 1.5% m−1. It is also found that both the mold corner radius and taper are the key factors influencing the shell crack sensitivity but with different mechanism. For the internal crack, the mold taper takes more dominant effect for its corner radius between 0–10 mm, as the hoop strain at the solidification front decreases with increasing mold taper. For the surface crack, more sensitivity is noticed to the mold corner radius. Increasing mold corner radius leads to the increase of the surface hoop strain in the corner region, almost regardless of mold taper. The proper mold taper and corner radius for the present bloom casting should be 1.0–1.5% m−1 and 15–25 mm respectively.