RH精炼过程钢中非金属夹杂物行为及演变规律

以RH精炼为研究对象，在不同时间节点取样，采用金相显微镜、SEM等手段研究了钢中夹杂物成分、数量、尺寸分布的变化规律，并对RH过程夹杂物的碰撞聚合、长大、去除行为进行了讨论.结果表明:RH精炼过程中夹杂物的去除明显，软吹结束后，几乎没有大于10μm的夹杂物.随精炼时间延长，夹杂物平均粒径变化不大，但单位面积夹杂物数量显著减少，而夹杂物面积比呈先增大后降低的趋势.弹簧钢中硅酸盐夹杂物具有一定的硫容量，可形成边缘为富硫相，内核为硅酸盐的双层夹杂物.由于RH内钢水的强烈混合，固态夹杂物极易被液态铝酸钙夹杂物捕获，形成镶嵌特征的复合夹杂物.

The Evolution and Behavior of the Non-metallic Inclusions During the RH Refining Process

Two sets of RH furnaces were taken as the main objects. The specimens were sampled at different refining times. The composition, content, and size distribution of the inclusions in steels were analyzed by means of metallographic microscope, SEM and EDS, and the collision, growth and removal of the inclusions during RH refining process were discussed. The results showed that the inclusion removal was very obvious during RH refining process, and almost no inclusion with the dimension more than 10 μm were observed after the soft blowing. With the increase of refining time, the average size of inclusions changed little, however the amount of inclusions significantly decreased. The area ratio of inclusions in two type steels increased at first and then reduced. In Si-Mn deoxidized steels, silicate inclusions had a certain capacity of the sulphur, the dual layer inclusions were therefore easier to form with the surface of sulphur-rich phase and the inner core of silicate phase. As the strong mixture of the liquid steel in RH vacuum chamber, solid inclusions were always captured by the liquid calcium aluminate and formed a typical inlaid feature.