镁处理低碳钢中MgAl2O4夹杂物的聚集行为

 为了研究MgAl₂O₄夹杂物的聚集行为,通过金相试样法和有机溶液电解分离法结合场发射扫描电子显微镜对镁处理铝脱氧低碳钢中单颗MgAl₂O₄夹杂物、多粒子MgAl₂O₄夹杂物进行观察。热力学计算结果表明,MgAl₂O₄夹杂物在液相中析出。FactSage计算得到钢中夹杂物相变规律,夹杂物预测种类与试验观察结果一致。对多粒子MgAl₂O₄夹杂物进行分析,发现腔桥力远远大于毛细管作用力、范德瓦尔斯力、黏滞力。因此,腔桥力是诱导MgAl₂O₄夹杂物发生聚集的主要作用力。钢液条件为温度升高、低a_O(氧活度)、低w([S])时,腔桥力数值较小,引起MgAl₂O₄夹杂物的聚集能力最弱。

Aggregation behavior of MgAl2O4 inclusions in magnesium-treated low carbon steel

In order to study the aggregation behavior of MgAl₂O₄ inclusions, single MgAl₂O₄ inclusions, and multi-particle MgAl₂O₄ inclusions in magnesium-treated aluminum deoxidized low carbon steel were observed by metallographic sample method and organic solution electrolytic separation method combined with field emission scanning electron microscope. Thermodynamic calculation results indicate that MgAl₂O₄ inclusions are precipitated in the liquid phase. The phase transformation law of inclusions in steel was calculated by FactSage, and the predicted types of inclusions were consistent with the experimental observations. The analysis of the multi-particle MgAl₂O₄ inclusions shows that the cavity bridge force is much greater than the capillary force, van der Waals force, and viscous force. Therefore, the cavity bridge force is the main force that causes the aggregation of MgAl₂O₄ inclusions. When the molten steel condition is that increasing temperature, low a_O(oxygen activity), and low w([S]), the cavity bridge force value is small, which causes the weakest aggregation ability of MgAl₂O₄ inclusions.