Effect of crystallinity on thermal diffusivities of mould fluxes for the continuous casting of steels

The thermal diffusivities of mould flux having the glassy and crystalline states were measured as a function of temperature by the laser flash method to obtain the relationship between the thermal diffusivity and the degree of crystallization. The thermal diffusivities of the liquid mould flux were also measured to compare the data with those of the solid samples. The thermal diffusivity increases roughly linearly with an increase in the degree of crystallization. The thermal diffusivities of glassy and liquid samples having the ratios of NBO/T 1.48, 1.65 and 2.11 exhibit roughly the same values of 4.6 x 10(-7) m(2)s(-1) and 4.0 x 10(-7) m(2)s(-1), respectively. It is considered that because the silicate network is largely broken down, there is not a significant change of the structure for these samples.