Effect of Natural Deposited Films on Interfacial Heat Transfer During Sub-rapid Solidification of Non-oriented Electrical Steel

As an emerging process, the ultra-thin strip casting has significant advantages in the production of non-oriented electrical steel with a short process flow. However, there is a problem of poor surface quality of casting product, which is significantly influenced by the interfacial heat transfer. During the production of ultra-thin strip casting, natural deposition films are deposited while the steel solidifies on the water-cooled copper rolls. The deposited films between the molten steel and the rolls significantly affect the interfacial heat transfer. In this study, the copper substrate used for the experiments was modified to make them more accurate. The effect of naturally deposited films on the interfacial heat transfer during sub-rapid solidification of non-oriented electrical steel was investigated by means of the droplet solidification technique. On the basis of the temperature data collected by one pair of high-sensitivity thermocouples, the heat flux are calculated by the Inverse Heat Conduction Program (IHCP). It was found that the heat flux of the high-silicon steel showed a trend of decreasing, then increasing and finally decreasing as the number of depositions increased.