It is necessary to study crystallization from glass (devitrification) for non-reactive F-free CaO-Al 2 O 3 based mold fluxes; this is especially important for the development of mold fluxes for continuous casting of high aluminum steels. To the knowledge of the authors, there is no report in the literature regarding devitrification of F-free mold fluxes based on the CaO-Al 2 O 3 -B 2 O 3 -Na 2 O-Li 2 O system. Therefore, crystallization kinetics for particular compositions in this system, with different w(CaO)/w(Al 2 O 3 ) ratios, was investigated by Differential Scanning Calorimeter, Field-Emission Environmental Scanning Electron Microscopy / Energy Dispersive Spectroscopy, and X-ray Diffraction techniques. The first crystal, which precipitates during heating from glass, is Ca 12 Al 14 O 33 , followed by CaO. For the first crystal, which precipitates as plate-like (2-dimensional), it was found that, when using the Matusita–Sakka model, agreement between the calculated Avrami parameters and the micrographs obtained from electron microscope was reached. In the same way, agreement was found for the second event—CaO precipitation—which grows 2-dimensionally or 3-dimensionally, depending on the w(CaO)/w(Al 2 O 3 ) ratio. The most important event (in terms of energy liberated and amount of crystals) is Ca 12 Al 14 O 33 precipitation. For this event, the effective activation energy for crystallization, E G , decreases with the increase of w(CaO)/w(Al 2 O 3 ) ratio. The activation energy for crystallization reflects the energy barrier for crystallization. Thus, it can be concluded that mold fluxes crystallization during heating is enhanced when increasing the w(CaO)/w(Al 2 O 3 ) ratio, for constant contents of B 2 O 3 , Na 2 O, and Li 2 O.

中文翻译：

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用于高铝钢的非反应性无 F 助熔剂的开发：用于脱玻的非等温结晶动力学

有必要研究非反应性无氟 CaO-Al 2 O 3 基保护渣的玻璃结晶（失透）；这对于开发用于高铝钢连铸的保护渣尤为重要。据作者所知，文献中没有关于基于 CaO-Al 2 O 3 -B 2 O 3 -Na 2 O-Li 2 O 体系的无氟保护渣脱玻的报道。因此，该系统中具有不同 w(CaO)/w(Al 2 O 3 ) 比的特定组合物的结晶动力学通过差示扫描量热仪、场发射环境扫描电子显微镜/能量色散光谱和 X 射线进行了研究。衍射技术。在加热过程中从玻璃中析出的第一种晶体是 Ca 12 Al 14 O 33 ，其次是 CaO。对于第一个水晶，沉淀为板状（二维），发现当使用 Matusita-Sakka 模型时，计算出的 Avrami 参数与从电子显微镜获得的显微照片之间达到了一致。以同样的方式，发现第二个事件——CaO 沉淀——在二维或三维增长，这取决于 w(CaO)/w(Al 2 O 3 ) 比率。最重要的事件（就释放的能量和晶体数量而言）是 Ca 12 Al 14 O 33 沉淀。对于该事件，结晶的有效活化能EG随着w(CaO)/w(Al 2 O 3 )比的增加而降低。结晶的活化能反映了结晶的能垒。因此，