碱度对保护渣渣膜导热系数和结晶矿相的影响

Effect of Basicity on Thermal Transfer Coefficient and Crystallized Phases of Flux Film

实验室内配制不同碱度的保护渣,模拟制作结晶器与铸坯之间的固态渣膜;测定了固态渣膜的高温传热传导系数,并研究了渣膜结晶矿相与其导热系数的关系。结果表明,固态渣膜在高、低温面平均温度为500~550℃时,其导热系数大致为2.5~2.8 W/m·℃;研究渣系碱度在0.8~1.1的范围内递增,促进了枪晶石的大量生成,迫使结晶矿物硅灰石和黄长石的相区缩小,从而增大了固态渣膜的热阻,导致其导热系数值下降。

The mold powders with different basicity was prepared for making simulative flux films between mold and billet in the laboratory;Then,the thermal conductivity coefficient of films was measured,and it was studied the relationship between mineralogical phase and thermal conductivity coefficient of films.The results show that,when the average temperature of films is about 500~550 ℃,the thermal conductivity coefficient is about 2.5~2.8W/m·℃.As the increasing of basicity of mold powders is from 0.8to 1.1,it makes the content of cuspidine enlarge and the area of wollastonite and akermanite shrink,so as to increase the thermal resistance and reduce the heat transfer coefficient of films.