BEHAVIOR OF LIQUID AND SOLID INCLUSIONS AT ADVANCING PLANAR AND CELLULAR FRONTS DURING THE SOLIDIFICATION OF STEELS

摘要

In the case particle pushing versus engulfment of inclusions by advancing steel solidification fronts, the comparison between CSLM observations and predictions resulted in the following: 1. In the case of irregular solid Al_2O_3 inclusions, all 4 models studied underestimated the critical velocity. 2. When comparing the 4 predictions according to the models given by Equations (9)-(12) the current results indicate that, for liquid spherical CaO-Al_2O_3-MgO inclusions, the models of Uhlmann et al. [5] and Chernov et al, [8] result in to low critical velocities. The models proposed by Stefanescu et al. [14] and Poetschke and Rogge perform excellently when some degree of interaction is considered between the solid steel and inclusion. For entrapment versus escape at the cellular grain boundaries it was found that inclusions slided along the front into the boundary at low solidification velocities and: 1. Liquid inclusions appear to be more readily engulfed. 2. No appreciable difference was observed for the large solid inclusion clusters. 3. The dihedral angle at the cellular boundaries was estimated to be 25 °.