IF钢夹杂物演变和头尾坯洁净度研究

分析IF钢头、尾坯离端部不同距离氧、氮含量、夹杂物评价，为头、尾坯合适的切头、切尾、如何修磨提供依据。钢水从RH出站至凝固过程中大颗粒复合夹杂物不断去除，热轧材夹杂物主要是氧化铝、氮化钛。头坯离头端2.5 m以后，尾坯离尾端1 m后，D类夹杂减少，头坯D类夹杂评级比尾坯波动大；头坯[wT[O]、][w[N]]高于中间坯18×10－6、8×10－6、尾坯[wT[O]]高于中间坯2×10－6。头坯离头端1 m后，夹杂物少于15 个/mm2，粒径4.4 μm，尾坯上离尾端1 m后，夹杂物少于10 个/mm2，粒径5.1 μm，尾坯洁净度好于头坯。

Research on the first and last slab cleanness and inclusions evolved of IF steel

In this paper， the analysis of oxygen， nitrogen content of IF steel’s the first and last slab at the different distance from the end， and inclusion evaluation， provided basis for the suitable cutting of the first and last slab and how to grind. Large particles of composite inclusions continue to be removed in molten steel from the RH to the solidification process. The inclusions of hot rolled plate are mainly alumina and titanium nitride. At the first slab after 2.5 m from the heat end and the last slab after 1m from the tail end， the D class inclusions reduce. The fluctuation of D class inclusions in the first slab is larger than the last slab. The[wT[O]、][w[N]]content of the first slab are 6×10－6 and 4×10－6 higher than the middle slab. The last[wT[O]]content is 1ppm higher than the middle slab. After 1m from the head of the first slab， the inclusions are less than 15/mm2， and particle size is 4.4 μm. After 1m from the end of last slab， the inclusions are less than 10/mm2， particle size is 5.1 μm. The last slab’s cleanliness is better than the first slab.