不同工艺路线超低碳钢洁净度分析

Analysis of Different Technological Processes on the Clean Degree of Ultra-Low Carbon Steel

针对厚板坯和中薄板坯连铸两条工艺路线生产的超低碳钢,采用相关手段分析了钢水从钢包到中间包的二次氧化、稳态和非稳态铸坯全氧、总体夹杂物水平、铸坯大颗粒夹杂物比例等。结果表明,两种工艺路线生产的超低碳钢在稳态浇注时铸坯洁净度基本一致;非稳态浇注时中薄板生产线钢水洁净度低于厚板坯连铸;受中薄板连铸结晶器和水口形状的制约,其水口结瘤现象较厚板坯连铸严重得多。作为中薄板连铸向薄板坯连铸的过渡,若在薄板坯连铸生产线实现正常浇注超低碳钢,进一步提高钢水洁净度、设计合理的浸入水口结构、稳定的连铸操作是亟待解决的问题。

According to the UI.C steel adapting the thick slab and medial-thin slab production technology respectively, some methods were introduced to analyze secondary oxidation of molten steel from ladle to tundish, total oxygen of steady state and non-steady state, inclusions level and ratio of large size inclusions, etc. The results indicated that the clean degree of ULC slab adapting two production technology was approximately consistent at the steady state casting; during the non-steady state casting process, the clean degree of medial-thin slab was much lower than that of thick slab casting. Restricted by mould and shape of submerge nozzle, the thin-slab casting blocking was more serious than thick slab casting. As transition from medial-thin slab to thin slab continuous casting, as if in the thin slab continuous casting production lines achieve normal casting ultra-low carbon steel, it must urgently solve the problem that should further improve the clean degree of molten steel, design reasonable structure of SEN and steadily operate continuous casting.