中包扩容提升钢液纯净度生产实践

Production Practice of Expanding Tundish Capacity to Improve Liquid Steel Purity

影响钢洁净度因素之一为钢中非金属夹杂物的数量、尺寸、成分和形貌。夹杂物的形核、长大和去除与钢液的流动、夹杂物颗粒间的碰撞密切相关。研究发现,在整个中间包浇注过程中,夹杂物颗粒间碰撞长大和去除过程一直处于非稳态,达到平衡所需时间为2 440 s,目前中间包平均停留时间仅为514 s,随着碰撞过程的进行,小尺寸夹杂物颗粒逐渐碰撞生成大尺寸夹杂物,针对当前连铸中间包内钢液停留时间短(514 s),进行扩容优化设计。优化后连铸中间包内钢液的平均停留时间延长686 s,夹杂物去除率较优化前提高。

One of the factors affecting the cleanliness of steel is the number, size, composition and morphology of non-metallic inclusions in steel. The nucleation, growth and removal of inclusions are closely related to the flow of liquid steel and the collision between inclusion particles. It is found that during the whole tundish pouring process, the collision growth and removal process between inclusion particles has been in an unsteady state, and the time required to reach equilibrium is 2 440 s. at present, the average residence time of tundish is only 514 s. With the progress of the collision process, small-size inclusion particles gradually collide to form large-size inclusions. Aiming at the short residence time(514 s)of liquid steel in continuous casting tundish, the capacity expansion optimization design is carried out. After optimization, the average residence time of molten steel in continuous casting tundish is prolonged by 686 s, and the inclusion removal rate is higher than that before optimization.