摘要
在Al_2O_3-MgO质钢包浇注料基质内引入不同配比的镁砂细粉、SiO_2微粉及预合成尖晶石细粉,固定MgO的总量约为5%(质量分数,下同),制成不同试样;研究各试样分别在400℃、800℃、1100℃、1400℃及1600℃处理3h后的物理性能以及随着温度升高而发生的物相变化。结果表明加入预合成尖晶石细粉的试样由于没有太多的膨胀反应及液相,其显气孔率、线变化率及热态抗折强度等物理性能相对较好;基质中反应生成的尖晶石、CA6以及CA6晶粒的长大会对浇注料的显气孔率及线变化率起到不利影响;基质中加入0.5%SiO_2微粉的试样,由于在高温下产生较多液相,使其在1400℃时的高温抗折强度发生明显下降,但对控制浇注料的高温膨胀还是有贡献的。
Magnesia powder, microsilica and pre-synthesized spinel in different proportions were added into matrix of the alumina-magnesia castable,in which the MgO content remained invariable 5% （mass ratio）. Various specimens were composed and studies were focused on their physical properties and phase changes after heat treatment at 400 ℃,800 ℃, 1100 ℃, 1400 ℃ and 1600℃ for 3 h respectively. The results show that the castable with pre-synthesized spinel has low AP and PLC and high HMOR contributed by limited expansion and only a little liquid phase in the matix. The generation of spinel and CA6, and the growth of CA6 crystal will increase the AP and PLC, leading to a negative effect. The HMOR decreases dramatically with addition of 0.5% silica fume in the matrix due to forming of a large amount of liquid phase at high temperature,contributing to control of castable expansion at high temperature.
出处
《耐火材料》
EI
CAS
北大核心
2006年第1期30-33,共4页
Refractories
基金
国家自然科学基金重点基金资助项目(50332010)。
