不同添加剂对镁碳质水口材料性能的影响  

Effects of additives on properties of MgO-C nozzles

作　　者：闫广周[1] 钱凡[1] 杨文刚[1] 刘国齐[1] Yan Guangzhou;Qian Fan;Yang Wengang;Liu Guoqi(State Key Laboratory of Advanced Refractories,Sinosteel Luoyang lnstitute of Refactories Research Co.,L td.,Luoyang 471039,Henan,China)

机构地区：[1]中钢集团洛阳耐火材料研究院有限公司,先进耐火材料国家重点实验室,河南洛阳471039

出　　处：《耐火材料》2018年第2期136-139,共4页Refractories

基　　金：国家自然科学基金项目(51372231);国家重点研发计划专项资助项目(2017YFB0304000);河南省科技创新人才计划(杰出青年)项目(164100510023)。

摘　　要：为了进一步改善浸入式水口用镁碳质耐火材料的抗热震性能,向以电熔镁砂(加入质量分数78%)和鳞片石墨(加入质量分数22%)为主原料,以酚醛树脂为结合剂的镁碳材料中外加6%(w)的添加剂(分别为熔融石英、斜锆石、锆莫来石和Si粉),成型后试样经干燥和950℃保温3 h(氮气保护)热处理后,研究添加剂对浸入式水口用镁碳质材料显气孔率、体积密度、常温抗折强度、高温抗折强度(1 400℃,埋炭)、热膨胀系数(室温至1 400℃)、抗热震性(1 200℃,水冷)和重烧线变化率(1 550℃保温10 h,埋炭)的影响。结果表明:添加熔融石英和Si粉能够在一定程度上改善浸入式水口材料的高温使用性能,抗热震性明显提高,且高温体积稳定性较好;而添加锆质材料(斜锆石或锆莫来石)则不能提高镁碳材料的抗热震性,且高温体积稳定性明显变差。工业试验结果表明:引入熔融石英或Si粉的镁碳质水口能够满足现场工况条件下的钢液热冲击,无开裂穿孔现象。In order to further improve the thermal shock resistance of submerged entry nozzle,MgO-C materials were prepared using fused magnesia( 78 mass%),flake graphite( 22 mass%) as starting materials,phenolic resin as a binder,extra adding 6 mass% of additives( fused quartz,monoclinic zirconia,zirconium mullite,and silicon powder,respectively),shaping,drying,firing at 950 ℃ for 3 h( N2 protection). Effects of additives on apparent porosity,bulk density,cold modulus of rupture,hot modulus of rupture( 1 400 ℃,carbon embedded),coefficient of thermal expansion( room temperature to 1 400 ℃),thermal shock resistance( 1 200 ℃,water quenching),and reheating linear change rate( 1 550 ℃ 10 h,carbon embedded)were studied. The results show that the addition of fused quartz and silicon powder can improve the performance of MgO-C materials to a certain extent at high temperatures,the thermal shock resistance is obviously enhanced and the high temperature volume stability is good; however,the addition of monoclinic zirconia or zirconium mullite is not conducive to the thermal shock resistance,and the high temperature volume stability deteriorates obviously. The results of industrial test show that MgO-C nozzles with fused silica or silicon powder can endure the thermal shock of hot steel in working conditions without cracking and perforation.

关 键 词：镁碳材料 抗热震性 浸入式水口 添加剂 熔融石英 SI粉 

分 类 号：TQ175[化学工程—硅酸盐工业]