CRYSTALLIZATION OF MOLD POWDERS USED IN THE CONTINUOUS-CASTING OF STEEL

Mould powders used in the continuous casting of steel play an important role in the heat transfer and lubrication between the liquid metal strand and mould. A range of industrial fluxes was investigated, each sample being decarburized and milled prior to DTA. On heating, the powders undergo silicate crystallization producing exotherms in the range 600-degrees-1000-degrees-C, before melting. The activation energy of crystallization (E(a)) was determined from the peak shifts of each flux heated at different rates, and ranged from 100-450 kJ/mol. E(a) values increased with flux viscosity and decreased with basicity, suggesting that DTA can be applied to mould powder evaluation for use in continuous steel casting.