不同种类氮化硅粉在Al2O3-SiC-C铁沟料中的作用比较

Effects of different silicon nitride powders on performance of Al2O3-SiC-C castables for iron runner

为进一步提高出铁沟的高温使用性能,以棕刚玉颗粒、板状烧结刚玉细颗粒、白刚玉粉、碳化硅颗粒和细粉、活性氧化铝粉、硅微粉、铝酸钙水泥、抗氧化剂、单质硅粉、球沥青、氮化硅粉制备了Al2O3-SiC-C浇注料。比较了三种不同种类的氮化硅粉(氮化硅-氧氮化硅复合粉、氮化硅铁粉、高纯氮化硅粉)在铁沟料中的作用,结果发现:1.三种氮化硅粉的引入,降低了浇注料的流动值,对线变化率影响不大,但增强了致密度,改善了抗氧化性,提高了高温抗折强度。2.氮化硅-氧氮化硅复合粉对铁沟料高温抗折强度和抗渣性均有显著提高,且与高纯氮化硅粉综合作用相当;氮化硅铁粉的引入提高了铁沟料的致密度,并改善其在1100、1450℃时的抗氧化性,但也降低了材料的强度及抗渣性能。3)将氮化硅-氧氮化硅复合粉与氮化硅铁粉共同加入铁沟料中时,相对于仅加氮化硅-氧氮化硅复合粉有更好的流动性,又抑制了氮化硅铁粉对强度和抗渣性能的劣化,具有良好的综合性能,可望在铁沟料中得以应用与发展。

In order to further improve the high temperature performance of iron runner,Al 2O 3 - SiC - C castables were prepared using brown corundum particles,sintered tabular corundum fine particles,white corundum powder,silicon carbide particles and powder,active alumina powder,silica fume,calcium aluminate cement,antioxidant,Si powder,ball pitch and Si 3N 4 powders as the main raw materials.Effects of three different kinds of Si 3N 4 powders (Si 3N 4 - Si 2N 2O composite powder,Si 3N 4 - Fe powder and high purity Si 3N 4 powder) on performance of castables for iron runner were compared.The results show that:(1.the introduction of the three kinds of Si 3N 4 powder reduces the fluidity of castables,has little effect on the linear change rate,but enhances the density,and improves the oxidation resistance and the HMOR.(2.The Si 3N 4 - Si 2N 2O composite powder can improve the HMOR and slag resistance of the castables remarkably,which is comparable to the high purity Si 3N 4 powder;the Si 3N 4 - Fe powder can enhance the density of the castables and improve the oxidation resistance at 1 100 and 1 450 ℃,but it deteriorates the strength and slag resistance of the materials.(3)The joint adding of the Si 3N 4 - Si 2N 2O composite powder and the Si 3N 4 - Fe powder not only improves the fluidity compared with adding the Si 3N 4 - Si 2N 2O composite powder alone ,but also inhibits the deterioration of the strength and slag resistance caused by Si 3N 4 - Fe,meaning that the joint addition has a good comprehensive performance,and is expected to be applied and developed in castables for iron runner.