中间包气幕挡墙技术的工业化应用

Industrial application of bubble curtain in tundish

为适应中间包纯净钢冶炼的需求,进一步提高铸坯质量,以板状刚玉和烧结莫来石为主要原料,氧化铝微粉、二氧化硅微粉为结合剂,经振动浇注成型和1 500℃3 h热处理后制得显气孔率>30%,透气度>25μm2,孔径微小且分布均匀的高强气幕挡墙砖;同时根据某厂连铸中间包的操作工艺参数,进行了气幕挡墙中间包仿真优化,并付诸工业实践。数值仿真表明,中间包采用气幕挡墙技术优化后,尤其是将气幕挡墙砖安装在距钢液入口中心2 400 mm的位置时,可最有效地改善钢液的流动状态,提高夹杂物去除率;实践证明,中间包使用优化气幕挡墙技术后,铸坯的总氧均值下降了37%,中间包的钢液洁净化功能得到了有效提高。

High strength bubble curtain bricks were prepared using tabular corundum and sintered mullite as main starting materials,alumina micropowder and silica fume as binders,vibration casting and heat treating at 1 500 ℃ for 3 h to satisfy the requirement of clean steel on tundish and improve the casting block quality. The obtained bubble curtain bricks have apparent porosity 〉 30%, air permeability 〉 25 μm^2, and small and uniform pores. According to the operating parameters of tundish at some steel plant,the bubble curtain in the tundish was mathematical simulated and optimized,and then industrial application was conducted. The results show that, after optimization, especially installing the bubble curtain bricks in the position 2 400 mm away from the steel liquid entry center,the current of the steel liquid is effectively improved,and the inclusions removal rate is increased. The application conforms that tundish with bubble curtain technique can effectively decrease total oxygen rate by 37% and effectively enhance the clean function of tundish to steel liquid.