RH真空吹氮过程钢水的吸氮行为

Behavior of Nitrogen Absorption of Molten Steel during Blowing Nitrogen Process in RH Vacuum

在 8 0tRH装置用 30m3 /h氮气循环进行钢水吸氮操作和氮 /氩切换方法控制氮含量 ,在平均为836 0Pa真空度下研究了真空吹氮过程中 [S]为 0 0 2 4 %～ 0 0 30 %、铝 硅镇静钢水的吸氮行为。结果表明 ,真空下吸氮反应表观速率常数k′随 [S]、[N]的增加而降低 ;活性元素在表面的富集阻碍了氮的进一步吸附。通过表面吸附位置的封闭修正模型 ,建立了吸氮过程表观一级反应速率常数的关系式k′ =(a/Vm)kΣ′ =k°(1-KN′[N]-KS′[S]) 2 ,计算值和实测值吻合良好。

The behavior of nitrogen absorption of molten steel contained 0.024%～0.030% sulphur and killed by aluminium-silicon during blowing nitrogen process in average 8 360 Pa vacuum has been studied by 80 t RH unit using 30 m3/h nitrogen circulation for molten steel absorbing nitrogen and using nitrogen/argon switch shift to control nitrogen amount. The test results showed that with sulphur and nitrogen content in molten steel increasing the apparent rate constant k′ of nitrogen absorbed reaction in vacuum decreased and the further absorption of nitroger was blocked due to active elements richened at surface. With modified absorption model for surface closed site a relationship to express apparent first order reaction rate constant k′ (a/Vm) k Σ′ k°(1-K N′-K S′)2 has been established, and the calculated values well agreed with the measured values.