Some mathematical expressions available in the literature are described in order to determine, in a theoretical way, the main devitrification parameters of industrial glasses from their chemical composition. By means of a comparison with the measurements carried out by the SSV laboratory, it appears evident that the most reliable mathematical model is that proposed by R R Cuartas. On the basis of this model, it was possible to ascertain how 1,2% equiponderal substitutions of the component oxides to the detriment of silica may affect the above considered parameters. Furthermore, it was found that the relationship between these parameters and the viscosity allows the determination of the viscosity at the maximum crystallization rate and liquidus temperature.
