超低氧弹簧钢脱磷回磷的热力学研究

A Study on Thermodynamics of Dephosphorization and Rephosphorization of Ultra-Low Oxygen Spring Steel

采用80 t LD-LF-VD-CC流程生产超低氧弹簧钢(0.60%C、1.8%Si、0.8%Mn、5×10^(-6)O),对精炼过程脱磷回磷进行了热力学分析和研究。结果表明,碱度≥4,FeO+MnO≤1%高碱度低氧化性炉渣精炼弹簧钢时,回磷现象不可避免,但还原脱磷有可能发生。通过转炉挡渣出钢,保持精炼渣高碱度,精炼时避免强搅拌,在高碱低氧化性炉渣下,可有效减少精炼过程钢水回磷,可控制[P]为0.010%。

The thermodynamics on dephosphorization and rephosphorizafion of an ultra-low oxygen spring steel （0. 60 C, 1.8Si, 0. 8Mn, 5 ×10^-6 O） during refining process with 80 t LD-LF-VD-CC flow sheet has been analyzed and studied. Results show that as spring steel refined by basieity ≥4, FeO ＋ MnO ≤ 1% high basieity low oxidation slag, the rephosphorization couldn＇t be avoided but the reduetive dephosphorization was likely to occur. With LD tapping by stopping slag, avoiding strongly stirring during refining, and using high basieity low oxidation slag, it is available to decrease liquid steel rephosphorization during refining and control 0. 010% [ P].