| 摘要 |
PURPOSE:To preferentially cool only the slab and to accelerate dephosphorization by adding a slag forming agent which is specified in the contents of P2O5 and S and basicity and specific gravity onto slag and blowing an inert gas from the bottom upon ending of top blowing of oxygen. CONSTITUTION:The slag forming agent which has <=2.5% content of P2O5, <=0.085 content of S and >=2.7 basicity (CaO/SiO2) and has the specific gravity equal to or larger than the specific gravity of the slag in a converter is added atop the slag in the converter to cool the slag from the top surface side. The inert gas such as gaseous argon is blown into the converter from the bottom simultaneously with such addition to stir the molten steel in the converter and to accelerate the dephosphorization. The concn. of the phosphorus in the molten steel is quickly decreased by the above-mentioned method. There is no need for increasing the target temp. of blowing out as in the case of a rinse method and the cost is reduced. |
