连铸中间包钢水的清洁度

Cleanliness of Molten Steel in Continuous Casting Tundish

针对宝山钢铁（集团）公司６０ｔ中间包，通过系统取样，研究了钢水流动控制、覆盖剂、内衬材质及保护浇注对中间包钢水清洁度的影响。结果表明，在中间包适当位置使用挡墙、坝和过滤器有利于促进夹杂物的去除；使用高碱度、低ＳｉＯ２的覆盖剂及ＭｇＯ－ＣａＯ质内衬有利于改善钢水的清洁度；长水口保护浇注可使钢水中吸氮量降至（３～５）×１０－４％。同时，运用Ｋ—ε双方程模型计算了中间包三维流场，从数学模型上分析了中间包流动控制装置对去除夹杂物的影响，为进一步提高中间包钢水清洁度提供了依据。

By systematical sampling during operation, the effect of flow control, flux, refractory lining and protective casting on molten steel cleanliness in tundish of Baoshan Iron and Steel Group is discussed in this paper. With properly positioned weir, dam and filter in tundish, the inclusion removal is improved. The use of cover powder with high basicity, low SiO2 content and MgOCaO based lining refractory is favourable to steel cleanliness. Protective casting is another way to reduce nitrogen pickup to (3～5)×10-4 % in tundish. The 3dimension velocity field of the molten steel is calculated with Kε model and the effect of flow control device on inclusion removal is analysed, which provides further proofs for improving steel cleanliness in tundish.