不同碱度渣对铝镁浇注料的侵蚀行为

摘要

Alumina-magnesia castable crucible specimens were prepared using tabular corundum (≤ 5 mm) ,fused magnesia powder (≤0.088 mm),fused spinel powder ( ≤0.044 mm) ,and α-AI2O3 micropow-der (d50≤0.7 μm) as main starting materials,batching,mixing,shaping,and drying. Slag resistance was determined by static crucible method at 1 600 ℃ for 3 h adopting two ladle slags with different basicities (3.40 and 1.03). The corrosion and penetration indexes and microstructure characteristics of the specimens after slag resistance test were analyzed to study the corrosion behaviors of the two slags to alumina -magnesia castables. The results show that the corrosion of the low-basicity slag to alumina-magnesia castables is much more serious than that of the high-basicity slag for that their reactions with castables form different products:for the low-basicity slag,the multi-phases coexistence of CA6 and compounds of CaO-AI2O3-SiO2 in the materials together with volume expansion caused by the formation of CA6 intensify the slag corrosion and penetration:for the high-basicity slag,the reaction between slag and castables generates a CA2 dense layer and a large amount of in-situ MA in the interface, reducing the slag corrosion to the materials effectively.%以板状刚玉颗粒(≤5 mm)、电熔镁砂粉(≤0.088 mm)、电熔尖晶石粉(≤0.044 mm)、α-Al2O3微粉(d50≤0.7 μm)为主要原料,经配料、混料、成型、烘干后制备了铝镁质坩埚试样,采用2种不同碱度的钢包渣(碱度分别为3.40和1.03),通过静态坩埚法对铝镁浇注料进行抗渣试验(1600℃3h),分析了抗渣试验后试样的渣蚀指数和显微结构,以研究不同碱度渣对铝镁浇注料试样的侵蚀行为.结果表明,低碱度渣对铝镁浇注料的侵蚀和渗透比高碱度渣严重,这主要是因为不同碱度渣与浇注料反应生成的产物不同.低碱度渣对铝镁浇注料侵蚀时,材料内部CA6和钙铝硅系化合物多相共存的组织以及CA6生成时的体积膨胀效应加剧了渣对材料的侵蚀和渗透；在高碱度渣条件下,渣与材料界面生成了CA2致密层和大量的原位MA,有效地降低了渣对材料的蚀损.