强底吹转炉终点超低碳氧积真实性研究

STUDY ON THE AUTHENTICITY OF ULTRA-LOW PRODUCT OF CARBON AND OXYGEN AT THE END OF BOF WITH STRONG BOTTOM BLOWING

某钢厂300 t转炉底吹系统改造后,在0.12 Nm^(3)·min^(-1)·t^(-1)底吹强度下发现转炉终点碳氧积大幅降低,尤其是在炉役前期1000炉炉龄内的转炉终点平均碳氧积为0.0013。为考察其真实性,冶炼超低碳钢时对转炉终点碳、氧含量的真实性进行了验证,并根据转炉烟气中CO体积含量计算CO分压,结合热力学原理,最终证实了转炉终点碳氧积的真实性。研究结果表明,提高底吹强度使得CO分压降至0.75以下,强化了熔池搅拌,促进了钢水表面更新速率,使转炉脱碳反应接近于对应CO分压条件下的C-O平衡,实现了转炉冶炼终点超低碳氧积。

After the transformation of 300 t converter bottom blowing system in a steel plant,it was found that the product of carbon and oxygen at the end of BOF was greatly reduced under the bottom blowing strength of 0.12(Nm^(3)·min^(-1)·t^(-1)),especially the average product of carbon and oxygen at the end of converter was 0.0013 in the first 1000 furnace.In order to investigate its authenticity,oxygen determination and sampling of molten steel at the end of BOF are carried out during the smelting of ultra-low carbon steel,and the product of carbon and oxygen is calculated by spectral analysis[C],and the volume content of CO in converter gas is collected to calculate the CO partial pressure.Combined with the thermodynamic analysis product of carbon and oxygen,the authenticity of the end point product of carbon and oxygen of converter is confirmed.The results show that the increase of bottom blowing strength reduces the CO partial pressure to below 0.75,strengthens the stirring of molten pool,promotes the renewal rate of molten steel surface,makes the decarburization reaction of BOF close to the C-O reaction equilibrium under the corresponding CO partial pressure,and realizes the ultra-low carbon oxygen deposition at the end of BOF smelting.