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在高铝钢的连铸过程中,CaO-SiO_2系保护渣在与钢中的[Al]反应过后转变为CaO-SiO_2-Al_2O_3系保护渣,同时液渣结晶能力增强,润滑效果变差。为了控制钢渣反应后形成的CaO-SiO_2-Al_2O_3系保护渣的结晶行为,利用差热分析研究了保护渣的非等温结晶动力学,基于Avrami方程及Friedman法分析了Li_2O及Na_2O的加入对保护渣的结晶速率、晶体生长方式,及有效结晶活化能的影响。结果表明,Li_2O的加入在降低保护渣结晶温度的同时使结晶速率变慢。此外,Li_2O的加入可以降低保护渣的有效结晶活化能,这表明Li_2O的加入可以使保护渣的结晶变得更容易。当渣中含有8%Na_2O时,Li_2O的加入促进了渣膜中12CaO·Al_2O_3的生成,导致固态渣膜的结晶比升高,这有可能对保护渣的润滑效果带来不利影响。
In the continuous casting of high-aluminum steels, the CaO-SiO 2 fluxes change to CaO-SiO_2-Al_2O_3-based fluxes after reacting with [Al] in steel, and the crystallizing ability of liquefied slag is enhanced and the lubrication effect deteriorates. In order to control the crystallization behavior of CaO-SiO_2-Al_2O_3-based fluxes formed after the reaction of slag, the non-isothermal crystallization kinetics of the fluxes was studied by differential thermal analysis. Based on the Avrami equation and Friedman’s method, the effects of Li_2O and Na_2O addition on the flux The crystallization rate, the crystal growth mode, and the effective crystallization activation energy. The results show that the addition of Li 2 O decreases the crystallization temperature of mold flux and slows the crystallization rate. In addition, the addition of Li 2 O can reduce the effective crystallization activation energy of the mold flux, which indicates that the addition of Li 2 O can make the crystallization of the mold flux easier. When 8% Na_2O is contained in the slag, the addition of Li_2O promotes the formation of 12CaO · Al_2O_3 in the slag film, resulting in an increase in the crystallization ratio of the solid slag film, which may adversely affect the lubricating effect of the flux.