With using hot wire method to get the mould fluxes continuous cooling transformation (CCT) and time-temperature transformation (TTT) curves and using polarizing microscope combined with X-ray diffraction analysis

the effect of fluorite content (8% ~ 16% ) on crystallization properties of thin slab casting mould fluxes with basicity 1. 0 has been studied. Results show that with increasing fluorite content by each 2%

the average critical cooling rate increases by 2. 5 ℃. ； at same cooling rate with increasing fluorite content in mould fluxes

the mould fluxes crystallization temperature raises and the crystallization rate increases

they are favourable to improve the interfacial thermal resistance

control the heat transfer of slag film and decrease the forming of surface crack of casting slab; as the fluorite content is more than 14%

large amount of crystalline mineral cuspidine forms in slag film

for the steel grades with higher casting lubricating requirement

it should be to control the fluorite content in fluxes no less than 14%.