The Heat Transfer Mechanism Of Mold Flux In Continuous Casting

Mold flux plays important roles in the continuous casting through a variety of functions, such as, lubricating the strand, adsorbing inclusions, adjusting heat transfer between the mold and steel shell and insulating the molten steel from oxidation. Most of the research has indicated that the surface quality of strand is strongly dependent upon the heat transfer rate from the solidified strand to caster mold. Thus the main goal of this study is to investigate the effects of mold flux composition and crystallization and melting on heat transfer rates, especially on radiative heat transfer rates.In this study, an advanced infrared emitter techinue was used to investigate the heat transfer phenomena through mold flux disks. By using this technique, a radiative heat flux was applied to a copper mold covered with solid mold flux disk to simulate the heat transfer phenomena in continuous casting. The crystallization and melting behaviors of mold fluxes with different composition and their impact on the heat transfer were investigated specifically. The thermal-physical properties, such as:crystallization and melting temperatures were studied by the recently developed hot thermocouple techniques (DHTT) as well. It has been shown that the crystallization and melting behaviors of slag disks have important effects on heat transfer rate in this work, i.e., the crystallization of mold fluxes can block the radiative heat transfer while the melting is able to enhance the heat transfer capacity. By studying the heat transfer mechanism across mold flux, the results established in this paper can be used in real casting industry to help adjusting heat transfer rate by controlling the structure of mold fluxes, and to achieve a defects free final strand and direct the design of new mold flux.