GCr15轴承钢LF精炼过程脱硫能力的热力学评价

通过现场取样分析和热力学计算,评价了工业化生产GCr15轴承钢LF精炼工序的脱硫能力.分析了精炼温度、钢中酸溶铝含量、精炼渣的光学碱度对LF精炼过程硫分配比的影响.由于实际精炼过程中脱硫反应未达到平衡,实际测得的硫分配比低于理论计算值.得到了精炼温度为1 830～1 855 K,钢中酸溶铝的质量分数为0.020％～o.050％,精炼渣光学碱度在0.760～0.795范围内,精炼温度、钢中酸溶铝、渣的光学碱度及渣中Al2O3、SiO2含量对硫分配比影响的回归方程,该方程可作为实际生产条件下LF精炼工序脱硫能力的评价依据.根据回归方程,设计了改变精炼渣组成的3因素4水平正交实验,分析了精炼渣二元碱度R2及Al2O3和SiO2含量对硫分配比的影响,得出渣-钢间最优硫分配比的精炼渣组成(质量分数)为:CaO 55.11％,Al2O3 30％,SiO26.89％,MgO 8％,光学碱度为0.777.

Thermodynamic evaluation of desulfurization ability of GCr15 bearing steels during LF refining process

Desulfurization ability was evaluated by analyzing samples sampled from industrialized production of GCr15 bearing steel during LF refining process.The influences of refining temperature,acid soluble aluminum content in the steel and optical basicity of refining slag on sulfur distribution ratio were analyzed in LF refining process.Because sulfur distribution between slag and steel didn't reach equilibrium during actual refining process,the measured sulfur distribution ratios were smaller than those of theoretically calculated.The relationship equation of sulfur distribution ratio with refining temperature,acid soluble aluminum in the steel,optical basicity of the refining slag and Al2O3,SiO2 content in the slag was regressed when the operation temperature was controlled in the range of 1830-1855 K,the content of acid soluble aluminum in the steel was controlled in the range of 0.020 ％-0.050 ％ and the optical basicity of the refining slag was controlled in the range of 0.760-0.795,which can be used as a method to evaluate desulfurization ability to LF refining slag during actual production.Three factors and four levels of refining slag composition orthogonal experiments were designed according to the above regression equation and the effects of binary basicity,content of Al2O3 and SiO2 in the refining slag on sulfur distribution ratio were analyzed.The optimal refining slag composition with high sulfur distribution ratio between the slag and steel was designed to be 55.11％ CaO,30％ Al2O3,6.89％ SiO2,8％ MgO(mass fraction),and the optical basicity was controlled to be 0.777.