“全三脱”铁水转炉少渣冶炼低氮钢生产实践

Production practice of low nitrogen steel in less slag steelmaking

在首钢京唐钢铁联合有限责任公司“全三脱”铁水少渣冶炼工艺过程中，通过生产历史数据对影响钢水氮含量因素进行分析，结果表明：转炉顶枪漏氮对钢水增氮有很大影响；采用硅铁作为提温剂可以有效控制钢水训（N）在12×10^-6左右；脱碳转炉采用全程底吹氩钢水训（N）可以降低3．3×10^-6；转炉熔池内训（C）=0．3％～0．4％时，加入矿石可有效降低钢水氮含量；转炉后吹以及出钢时间越长，钢中氮含量越高；采取优化措施后，脱碳转炉出钢后，可稳定控制钢包内钢水训（N）≤15×10^-6，达到了冶炼低氮钢的控制要求。

The factors influencing nitrogen content in BOF were anatyzed in less slag steelmaking. The results showed that the good equipments of top oxygen blowing were very important. The nitrogen mass fraction of blowing end in steel could be within 12 ×10^-6 using FeSi for raising temperature. The argon stirring at the BOF bottom in the whole blowing process could decrease nitrogen mass fraction of 3.3 ×10^-6. The nitrogen content would decrease when some coolant were added to the BOF with the carbon mass fraction of 0.3% - 0. 4 %. Re-blowing and long tapping time would increase nitrogen content in steel. Through optimized measures the nitrogen mass fraction could be within 15 ×10^-6 at the ladle and meet the demand of low nitrogen steel.