具有多孔结构的刚玉—尖晶石浇注料的制备及其性能

发布时间：2018-06-15 03:54

  本文选题：刚玉-尖晶石浇注料 + 泡沫法　； 参考：《武汉科技大学》2015年硕士论文

【摘要】：刚玉-尖晶石耐火浇注料因其优异的高温服役性能作为钢包工作衬材料得到广泛的运用。随着钢包精炼技术的提升，钢水的出钢温度也相应提高，致密的刚玉-尖晶石浇注料具有较高的导热系数，会增加炼钢过程中的能耗。但是要降低材料的导热系数其显气孔率将显著提高，势必会影响材料对熔渣和钢水的侵蚀和渗透作用。为此，本论文拟利用泡沫法制备具有孔径分布均匀且多为封闭气孔、体积密度可控的多孔材料的特点，分别将泡沫引入到刚玉-尖晶石浇注料的基质与骨料中，设计并制备具有多孔结构的刚玉-尖晶石浇注料，旨在保持力学性能和抗渣性能的前提下，改善其隔热保温性能，为钢包内衬耐火浇注料的轻量化提供理论依据。具体研究内容及结果如下： （1）将泡沫直接引入到基质中制备出具有多孔结构的刚玉-尖晶石浇注料，系统研究了泡沫加入量对材料的微观结构、常温物理性能、高温服役性能以及导热性能的影响。结果表明，，当泡沫加入量为200mL/kg时所制备的试样综合性能最接近常规刚玉-尖晶石浇注料，但导热系数有明显下降。其体积密度在110℃×24h烘后为3.03g·cm-3，1550℃×3h热处理后为2.94g·cm-3；常温抗折强度和耐压强度在110℃×24h烘后分别为10.1MPa和67MPa，1550℃×3h热处理后分别为27.1MPa和144MPa；在水冷热震1次和水冷热震3次后的残余抗折强度保持率分别为29.0%和16.6%；与未加入泡沫试样相比，其抗渣性基本没变化；在1000℃时试样的导热系数为0.788W/m·K，相对于未加入泡沫试样下降了10%。 （2）采用湿法造粒法，向其中引入泡沫，设计制备了具有核壳结构的多孔刚玉球。结果表明，刚玉球经1800℃×3h热处理后的平均孔径为6.47μm；其未破碎的显气孔率和闭口气孔率分别为10.9%和13.6%，而破碎后的显气孔率和闭口气孔率分别为15.5%和6.6%；刚玉球的筒压强度为443.3MPa。 （3）将所制备的具有核壳结构的多孔刚玉球取代板状刚玉骨料，基质不变制备了刚玉-尖晶石浇注料。结果表明，试样永久线变化率均呈现出微膨胀现象；试样在110℃×24h烘后的体积密度为2.96g·cm-3，在1550℃热处理后为2.90g·cm-3；在110℃×24h烘后的常温抗折强度和耐压强度分别为10.3MPa和87MPa，1550℃×3h热处理分别后为28.7MPa和172MPa；虽然试样的侵蚀指数比使用板状刚玉骨料制备的刚玉-尖晶石浇注料高，但其渗透性能相对较优；在1000℃时试样的导热系数为0.753W/m·K，相对于板状刚玉骨料制备的刚玉-尖晶石浇注料的导热系数下降了13.9%。
[Abstract]:Corundum-spinel refractory castables are widely used as ladle lining materials for their excellent high temperature service performance. With the improvement of ladle refining technology, the tapping temperature of molten steel increases accordingly, and the dense corundum spinel castable has higher thermal conductivity, which will increase the energy consumption in the steelmaking process. However, to reduce the thermal conductivity of the material, its apparent porosity will be significantly increased, which will inevitably affect the erosion and permeability of the material to molten slag and molten steel. Therefore, the foam method was used to prepare porous materials with uniform pore size distribution and controlled volume density, and foam was introduced into the matrix and aggregate of corundum spinel castable, respectively. The corundum spinel castable with porous structure was designed and prepared to improve its thermal insulation and thermal insulation performance under the premise of maintaining mechanical properties and slag resistance and to provide a theoretical basis for lightening the refractory castable in ladle lining. The specific research contents and results are as follows: (1) foam was introduced directly into the matrix to prepare corundum spinel castable with porous structure. The effect of high temperature service performance and thermal conductivity. The results show that when the foam content is 200mL / kg, the comprehensive properties of the samples are the closest to the conventional corundum spinel castable, but the thermal conductivity decreases obviously. The bulk density was 3.03g / cm ~ (-3) after drying at 110 鈩

本文编号：2020514