连铸结晶器保护渣渣膜传热特性研究进展

传统保护渣主要以CaO和SiO₂为基料，辅以适量助熔剂如CaF2等构成；而无氟保护渣则是选用B₂O₃、TiO₂等合适的助熔剂来替代CaF₂达到绿色环保的目的。从保护渣的碱度、化学成分和结晶性能三方面，分别综述了传统含氟渣系CaO-SiO₂-CaF₂和新型无氟渣系CaO-SiO₂-B₂O₃、CaO-SiO_2-TiO₂渣膜传热的影响规律，总结了近十年来冶金工作者对含氟和无氟保护渣渣膜传热的研究成果，得出无氟保护渣结晶矿相中硅硼酸钙和钙钛矿与传统保护渣中枪晶石具有相似的结晶行为，B₂O₃和TiO₂的含量在4%~8%和3%~11%可有效控制传热，从而减少铸坯纵裂纹的发生。并提出了开发新型高效无氟保护渣的进一步研究方向，即无氟渣中氟化物替代物的迁移赋存规律对渣膜传热性能的影响机理。

Research Progress on Heat Transfer Characteristics of Mold Flux Film in Continuous Casting Mold

The traditional mold flux is mainly composed of CaO and  SiO₂ as the base material,supplemented by an appropriate amount of fluxing agent such as CaF₂;and the fluorine-free mold flux is to choose B₂O₃ 、TiO₂ and other suitable flux to replace CaF₂ to achieve the role of green metallurgy.In this paper,the influence laws of heat transfer of the traditional fluorine mold flux CaO-SiO₂-CaF₂ and new fluorine-free mold flux CaO-SiO₂-B₂O₃ and CaO-SiO₂-TiO₂ flux films are re- viewed from three aspects of basicity, chemical composition and crystallization properties of the mold flux. Summarizes the metallurgical workers in nearly a decade of fluoride and fluorine-free mold fluxs film heat transfer of research results,it is concluded that the fluorine-free mold flux silicon calcium borate and perovskite crystal mineral phases and traditional mold flux  cuspidine  have  similar  crystallization behavior,the  content  of B₂O₃  and  TiO₂  range  from  4%  to8%  and  3%  to 11%  can  effectively  control the heat transfer,thereby reducing the  occurrence  of slab longitudinal  cracks.