Abstract: According to the issue of easily forming surface longitudinal crack on casting slab of hypo-peritectic steel, the effect of fluorite adding amount on melting temperature, viscosity and average heat flux of mould powder (/% ： 29 〜37 cement grog, 8 borax, 20 quartz sand, 15 wollastonite, 12 soda, 8 ~ 16 fluorite) , and mineralogical structure of flux film has been studied and analyzed. Results show that with increasing fluorite content the crystallization ratio of flux film and cuspidine content in film increase, the wollastonite content in film decreases, and the melting temperature, viscosity and average heat flux of mould powder decrease. It is obtained that adding fluorite content 12% in mould powder could satisfy the requirement on mineralogical structure of flux film for hypo-peritectic steel casting slab and improve the quality of casting slab.

摘要： 针对亚包晶钢连铸板坯易发生表面纵裂现象,研究和分析了萤石配加量对保护渣（/%:2937水泥熟料,8硼砂,20石英砂,15硅灰石,12纯碱,816萤石）熔化温度、黏度和平均热流密度以及渣膜矿相结构的影响。结果表明,随着萤石含量的增加,渣膜结晶率和枪晶石含量升高,硅灰石含量降低,同时保护渣熔化温度、黏度、平均热流密度降低;提出萤石配加量为12%时,能满足亚包晶连铸板坯对渣膜矿相结构的要求,并改善了铸坯质量。