脱氧方式对高铝钢中非金属夹杂物的影响

摘要：为了研究不同脱氧方式对高铝钢中非金属夹杂物的影响，采用高温试验和热力学计算相结合的方法，对比分析了先SiMn后Al和先Al后SiMn两种脱氧方式下高铝钢中夹杂物形貌、类型、数量和尺寸特征。结果显示：先加入SiMn后，生成大量液态球形的Mn-Si-Al-O系复合夹杂物，再加入Al后夹杂物演变为Al2O3，且夹杂物数量明显减少；采用先Al后SiMn脱氧方式时，高铝钢中夹杂物始终以Al2O3为主，夹杂物最终数量相对较低。2种脱氧方式钢中夹杂物平均等效圆直径和尺寸分布相差不大。此外，采用先SiMn后Al进行脱氧时，发现尺寸较小的AlN颗粒附着在Al2O3夹杂物表面形成Al2O3-AlN复合夹杂物。而采用先Al后SiMn脱氧方式时，高铝钢中发现单一AlN夹杂物和Al2O3-AlN复合夹杂物，AlN夹杂物的形成与钢水中的氧势和合金原料有关。

Effect of deoxidation methods on non metallic inclusions in high-Al steel

Abstract： In order to study the influence of deoxidation method on non metallic inclusion (NMI) in high Al steel, high temperature experiment and thermodynamic calculation were adopted to compare and study the deoxidation methods of SiMn addition before Al addition (Heat SA) and Al addition before SiMn addition (Heat AS), then the morphology, type, number and size of NMIs were discussed. The results show that a large number of spherical Mn-Si-Al-O inclusion are observed after SiMn addition, and then the NMI is changed to Al2O3 with Al addition. For the case of Heat AS, the main NMI in high-Al steel is always the Al2O3, and the final number of NMI decreases. The difference in size and size distribution of NMI for the different deoxidation methods is not significant. Moreover, fine AlN inclusion precipitated on the surface of Al2O3 are detected by using the deoxidation method of Heat SA. However, the single AlN inclusion and Al2O3-AlN complex inclusion are found in high-Al steel for Heat AS. The formation of AlN is related to the oxygen potential and the alloy materials.