STUDY OF HEAT TRANSFER CHARACTERISTICS OF LAMINATED STEEL HEAT TREATMENT FURNACE

The heating process in a heat treatment furnace bears importance in laminated steel production. The two main heat transfer methods for a laminated steel heat treatment furnace were studied. Contact heat transfer between the strip and heating roller was experimentally studied, and the relationship between contact pressure and contact heat transfer coefficient was analyzed. The results show that within the pressure range, the contact heat transfer coefficient varied between 880 and 1560 W·m-2·K-1. The unforced convective heat transfer caused by movement of the strip and heating roller was analyzed by numerical simulation. Findings reveal the increased strip velocity and convective heat transfer coefficient. Within the strip velocity range of 60−120 m·min-1, the convective heat transfer coefficient varied between 6 and 20 W·m-2·K-1. Finally, the off-line thermal process model of the laminated steel heat treatment furnace was constructed on the basis of the above results, and heat transfer characteristics were analyzed. Contact heat transfer is the main heat transfer method in laminated steel heat treatment furnace. The relative error between the value calculated by the off-line-model and the actual process value was less than 0.5%.