Li_2O对高铝钢保护渣结晶行为及渣膜传热的影响

Effects of Li_2O on the crystallization and heat transfer of mould fluxes for high Al steel

设计了非反应性保护渣,利用热丝法和渣膜热流模拟仪研究了Li_2O含量对其结晶行为和渣膜传热特性的影响.结果表明:在小于2%的范围内增加Li_2O的质量分数可减弱非反应性保护渣的结晶性能;而在2%～5%范围内增加Li_2O的质量分数,则渣系晶体析出孕育时间缩短,结晶温度升高,临界冷却速度增大,结晶速率常数增大,即促进了非反应性渣系的结晶.同时发现,在2%～5%范围内增加Li_2O的质量分数,非反应性保护渣的最大热流密度、平均热流密度及特征时间均减小.

Non-reactive mould fluxes were designed, and the effects of Li_2O on the crystallization and heat transfer of the fluxes were investigated by using the single hot thermocouple technique （SHTT） and a heat-flux simulator. The results show that increasing the Li2O content which is less than 2% can weaken the crystallization property of the fluxes. Whereas, when the Li_2O content increases from 2% to 5%, the crystallization temperature, critical cooling rate and crystallization rate constant enhance, but the incubation time of the slag system decreases, indicating that Li_2O improves the crystallization of the fluxes in this range. It is also found that the maximum heat flux density, average heat flux density and characteristic time of the fluxes reduce with the increase of Li_2O content within the range of 2% to 5%.