Analytical and Experimental Study on Radial Equivalent Thermal Conductivity for Steel Coil Heat Transfer in HPH Furnace
In the recent work, the hot/cold rolled steel coils in HPH furnace have been considered as a periodically multi-layers material in radial direction. Its radial equivalent thermal conductivity is very important in analysis of coil's temperature behavior. In a heat transfer unit layer, constructed by two adjacent half-thickness steel layers and their interface, the total thermal resistance consists of the conductive thermal resistance of the steel layers and the contact thermal resistance at the interface. A new formula for determining the radial equivalent thermal conductivity has been proposed, which is based on the steel surface characteristic, the strip thickness and the compressive stress of rolled coils. Several experimental measurements of temperatures at the special points of rolled coils in HPH furnace have been executed. The calculated annealing curves using the radial equivalent thermal conductivity are in good agreement with experimental data.