| 摘要 |
<p>PURPOSE:To establish a stable production method of a high cleanliness steel by making a dead soft steel the low oxygen content. CONSTITUTION:A dephosphorized pretreated molten iron having <=0.10% P with a top-bottom combined converter is used and slag quantity is restrained to 15kg/t and the blowing oxygen is stopped to make the molten steel having <=0.10% C and <=0.02 P, and this molten steel is tapped into a ladle and the slag is reformed with Al slag to make <=10% (T.Fe) and 1-2 CaO/Al2O3. A secondary refining is executed with the following oxygen top-blowing RH vacuum degassing treatment and the molten steel made to be <=100ppm C and <=30ppm [O] is continuously cast in the non-oxidizing atmosphere. By this method, the stable producing method for obtaining the low oxygen content of the dead soft steel having <=100ppm C and <=30ppm [O], is established and the defective rate in the product can be made almost zero.</p> |
