| 摘要 |
<p>PURPOSE:To decrease the total amt. of the flux to be used and to attain the reduction of the entire treatment time, the suppression of decarburization, etc. by adjusting the conditions for blowing an injection gas in the period for accelerating desiliconization reaction and specifying the driving power value for stirring. CONSTITUTION:The surface of the molten iron which is substantially not subjected to a desiliconization treatment in a preliminary treatment furnace is coated with a dephosphorizing flux and is subjected to the top blowing of oxygen and injection of a desiliconizing flux. The conditions for blowing the injection gas are so adjusted that the driving power value epsilon for stirring (watt/1 ton of molten steel) determined by the equation attains 650-1,100 in the period for accelerating the desiliconization reaction in the above-mentioned treatment. The rate of blowing the injection gas is so adjusted that the driving power value epsilon for stirring attains >=300 - <650 in the decarburization reaction period. The adjustment is executed by changing the flow rate of the injection gas, the immersion depth of an injection lance, etc. according to the temp. of the molten iron, the amt. of the molten iron to be charged, etc.</p> |
