【摘要】 为研究中等碱度精炼渣中Al₂O₃含量对钢洁净度和夹杂物的影响，在1 873 K温度下用MgO坩埚开展了初始碱度为4、不同Al₂O₃含量的CaO-SiO₂-Al₂O₃-MgO顶渣与铝脱氧钢的平衡试验。结果表明，渣-钢反应后，夹杂物类型由反应前的MgO-Al₂O₃-MnS复合类转变为中心为MgO-Al₂O₃,边部为MgO-Al₂O₃-SiO₂-CaO（-MnO）系的包裹体复合类；形貌由边界多棱角的块状和簇群状转变为边界圆滑的类球状。随着渣中Al₂O₃含量的增加，夹杂物中Al₂O₃含量显著增加，MgO含量减少，其他组分含量变化不大；夹杂物尺寸呈现增大的趋势；夹杂物数量密度增大，钢的洁净度降低。该试验条件下，当w（Al₂O₃）≈20%时，夹杂物数量密度最小，钢液的洁净度最高。基于试验结果，对渣、钢的成分变化和夹杂物转变做了热力学讨论。更多还原

【Abstract】 In order to study the influence of Al₂O₃ content in medium-basicity refining slag on steel cleanness and inclusions, the equilibrium experiment between CaO-SiO₂-Al₂O₃-MgO top slag with initial basicity of 4 and different Al₂O₃ content and Al-killed steel was carried out by MgO crucible at 1 873 K. The results show that after slag-steel reaction, the inclusion type changes from MgO-Al₂O₃-MnS to complex centered with MgO-Al₂O₃and surrounded by MgO-Al₂O₃-SiO₂-CaO（-MnO） system. The shape changes from block and cluster shape with angular boundary to near-spherical shape with smooth boundary. With the increase of Al₂O₃ content in slag, Al₂O₃ content in inclusions increases significantly, MgO content decreases, and other components have little change. The inclusion size tends to increase. The number density of inclusions increases which indicates that the cleanliness of steel deteriorates. Under present experimental conditions, when the Al₂O₃ mass fracton is about 20 %, the number density of inclusions is the lowest, and the steel cleanliness is the best. Based on the experimental results, thermodynamic analysis was done to discuss the composition change of slag and steel as well as the transformation of inclusions.更多还原