硅微粉对铝镁浇注料的性能影响

Effects of Microsilica on Properties of Alumina Magnesia Castable

铝镁浇注料具有优良的高温强度、抗蠕变性、抗热震性和较高的使用温度,其抗碱性渣的能力较强,广泛应用于钢包包壁。硅微粉对铝镁浇注料性能影响较大,本文通过在铝镁浇注料中变化硅微粉含量,分析了硅微粉对铝镁浇注料性能的影响。研究结果表明：铝镁浇注料在1773 K及1373 K热处理条件下,随着硅微粉含量的增加,试样体积密度及耐压抗折强度呈现先增大后减小趋势,显气孔率呈现先减小后增大趋势;加入5%硅微粉的试样线膨胀系数比4%试样的大,1773 K热处理的线膨胀系数比1373 K热处理试样的大,在低于873 K情况下铝镁浇注料导热系数随硅微粉含量增加而增加。综合考虑铝镁浇注料在钢包使用过程中各方面的性能要求,在现有颗粒级配工艺下,硅微粉含量较为合适的配比值为3%-4%。

Alumina magnesia castable has excellent high temperature strength,creep resistance,thermal shock resistance and high end-use temperature. For high resistance to alkaline slag,alumina magnesia castable is widely used in ladle wall. Since microsilica has grerat influence on the properties of alumina magnesia castable,microsilica is added into alumina magnesia castable,and the influence mechanism of microsilica on the properties of alumina magnesia castable was investigated. The results show that the bulk density,bending and compressive strength of alumina magnesia castable increase at first and then decrease with the increase of microsilica addition at the heat-treating temperature of 1773 K and 1373 K,but apparent porosity changes in the opposite direction. The coefficient of linear thermal expansion of the alumina magnesia castable samples with 5% microsilica is larger than that with 4% microsilica.Coefficient of linear thermal expansion of the samples at the heat-treating temperature of 1773 K is larger than that of the samples at the heat-treating temperature of 1373 K. Thermal conductivity of alumina magnesia castable increase with microsilica addition at the lower firing temperature. After comprehensive consideration,the proper microsilica addition is 3%-4% according to the performance requirements of alumina magnesia castable applied in steel ladle.