Development of viscosity calculation method for mould powders

Abstract

Various physiochemical properties of mould powders, such as viscosity and break point, are found to be related to chemical composition through molar ratios, such as number of non-bridging oxygen per tetrahedrally coordinated atom and oxygen to silicon. A number of relationships have been developed between physical properties and molar ratios, and a mathematical model has been developed using the relationships to develop a quick method for analysing the suitability of the mould powder for continuous casting. The method can predict viscosity within a range of temperatures, break temperature, and the effect of inclusion pick-up on the mould powder viscosity. A Microsoft Office Excel interface has been developed to display the results, including the viscosity versus temperature curve and the effect of alumina pick-up. The model output results have been validated using a high temperature viscometer.

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