Measurement and modeling of heat transfer across interfacial mold flux layers

Surface quality problems in continuous cast steel are greatly affected by h eat transfer across the interfacial layers in the gap between the solidifyi ng steel shell and the mold. An experimental apparatus has been constructed to measure temperatures in the steel, mold Aux layers, and copper under co nditions approximating those in continuous casting. The flux solidified in multiple layers similar to those observed from continuous casting molds and contained many pas bubbles. Flu?; conductivities average about 1.0 W/m . K and appear to evolve with time. Contact resistances at both interfaces are significant and average about 0.0015 m(2).K/W. Flux crystallization appear s to be the only significant effect of flux composition. The one glassy flu x tested had much greater thermal conductivities, presumably due to radiati on transport. Temperature and gap thickness had a negligible effect on the properties. These properties depend on the model used to extract them. They are being implemented into a mathematical model to simulate heat transfer in the mold, interface, and solidifying shell of a continuous slab-casting machine. (C) 2000 Canadian Institute of Mining and Metallurgy. Published by Elsevier Science Ltd. All rights reserved.