Study of Cc Narrow-face Taper Design – Influence of the Casting Speed and Steel Composition

The objectives in this work were to develop, calibrate, and apply a model to predict ideal taper profiles down the narrow faces of the SIDERAR slab casting mold for several different casting speeds, steel grades, flux powder compositions, and widths. A significant amount of original research was undertaken for this challenging problem. A finite difference model of transient 1-D heat conduction and solidification in the slab casting mold and shell was developed: CON1D. The model has been enhanced to make shell shrinkage and ideal taper predictions in slab molds, including narrow-face distortion and wide-face expansion. The CON1D model was calibrated to match the heat extraction rates for the wide face of the SIDERAR slab-casting mold under several casting conditions. These results were validated through comparison with published results for the same caster. A 2-D elastic-viscoplastic thermal-stress finite-element model, CON2D, was applied to perform computations of shell shrinkage during slab casting, and compared with the 1-D model shrinkage predictions for the same thermal conditions. The calibrated models were used to predict ideal taper profiles down the narrow face for several casting conditions at SIDERAR, where mold temperature measurements were available. The effects of several different types of mold distortion were taken into account, in addition to variable flux layer thickness profiles. Parametric studies were performed to investigate the effects of steel grade, casting speed, and mold powder on ideal taper (over 20 cases in all).