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对某厂冶炼冷镦钢从精炼到连铸过程钢的洁净度进行了研究,结果表明:开浇过程,由于严重的二次氧化,钢中w(T.O)和w(N)比正常浇铸过程要分别高出39×10~(-6)和21×10~(-6),夹杂物的w(CaO)/w(Al_2O_3)不断降低;正常浇铸过程中,钢中w(T.O)和w(N)分别稳定在30×10~(-6)和65×10~(-6)左右,钢中夹杂物的w(CaO)/w(Al_2O_3)呈波动变化,且基本落入CaO-Al_2O_3-MgO-CaS低熔点区。热力学计算表明,在当前的钢液条件下,增氮质量分数3.5×10~(-6)将产生固态夹杂物。通过对连铸头坯T.O含量和氮含量、钢成分、夹杂物等方面综合分析,在现有条件下,切除头坯前3 m有利于铸坯质量和洁净度的控制。
The results show that the w (TO) and w (N) in steel are more serious than the normal casting due to the severe secondary oxidation during the pouring process, (CaO) / w (Al_2O_3) of inclusions decreased continuously at 39 × 10 ~ (-6) and 21 × 10 ~ (-6) respectively. During the normal casting, the w (TO) and w (N) were stable at about 30 × 10 -6 and 65 × 10 -6, respectively. The content of w (CaO) / w (Al 2 O 3) in the inclusions in steel fluctuated and fell into CaO-Al 2 O 3 -MgO-CaS low melting point zone. Thermodynamic calculation shows that under the current molten steel conditions, increasing the mass fraction of nitrogen 3.5 × 10 -6 will produce solid inclusions. Through the comprehensive analysis of T.O content, nitrogen content, steel composition, inclusions and other aspects of the continuous casting billet, under the existing conditions, the removal of the first 3 m of the billet is conducive to the control of slab quality and cleanliness.