添加Si粉-埋碳热处理对刚玉浇注料性能的影响

Effect of Si powder addition and carbon embedded heat treatment on properties of corundum castables

为了进一步提高刚玉浇注料的高温使用性能,在超低水泥刚玉浇注料中加入不同质量分数(分别为0、4%、6%、8%、10%)的Si粉,经振动浇注成型、养护、烘干后,在埋碳条件下于1400℃热处理6 h,测定试样的加热永久线变化率及烧后试样的显气孔率、体积密度、常温抗折强度、常温耐压强度以及1200和1400℃的热态抗折强度,并对部分热处理后试样进行了XRD和SEM分析。结果表明:1、在刚玉浇注料中引入Si粉,并在埋碳条件下热处理可显著提高浇注料的热态强度。2、埋碳热处理后,试样中不仅形成了非氧化物SiAlON和SiC,而且生成了莫来石,可有效提高浇注料在1400℃的热态强度。

In order to further improve the high-temperature performance of corundum castables,different amounts of Si powder(0,4%,6%,8%,10%,by mass,respectively)were added to the ultra-low cement corundum castables.After vibration casting,curing,drying and heat treatment at 1400℃for 6 h in carbon embedded condition,the specimens were tested in terms of the permanent linear change on heating,the bulk density,the apparent porosity,the cold modulus of rupture,the cold crushing strength and the hot modulus of rupture at 1200℃and 1400℃.XRD and SEM analyses were performed on some specimens after heat treatment.The results show that:(1)the introduction of Si powder and the heat treatment in the carbon embedded condition can significantly improve the hot strength of the corundum castables;(2)after the heat treatment in the carbon embedded condition,non-oxides SiAlON and SiC,and mullite are formed,which can effectively improve the hot strength of the castables at 1400℃.