Thermal Diffusivity Measurement of Oxide Scale Formed on Steel during Hot-rolling Process

Thermal diffusivity and conductivity of oxide scales formed on steel plates are essential to control the cooling rate of the steel in the hot-rolling process. A flash method was applied to measure the thermal diffusivity of oxide scales. Sample specimens were commercial hot-rolled plates on which about 25 μm-thick oxide scales were formed. The results of the flash measurement with the analysis for two-layered sample provided an average thermal diffusivity value of 7.3 × 10–7 m2s–1 for the oxide scale. This value produces a thermal conductivity value of 3.8 W m–1 K–1. The future application of this measurement and analysis technique was also discussed to derive the thermal diffusivity and conductivity of oxide scales formed in actual hot-rolling processes.