PURPOSE: To contrive to perform stable desulfurization while prolonging the life of a furnace, by charging the specified amounts of CaO and MgO in response to the amount of SiO2 in slag inside a refining furnace and the specified concentration of CaF2, respectively, to reductively refine stainless steel.
CONSTITUTION: In a single slag process for refining stainless steel in a refining furnace, CaO and MgO in the amounts of MgO/SiO2=1.5W2.0 and CaO/SiO2= 0.3W0.5 in response to the amount of SiO2 in the slag inside the refining furnace and CaF2 at the ratio to hold the concentration of CaF2 in the slag at 3W5wt% are added as auxiliary materials during reducing in succession to refining in the step of oxidation such as decarburization and desiliconization by the injection of oxidizing gas. Hence, the damage of a refractory material is suppressed to contrive to prolong the life of the furnace, and effective desulfurization is performed while stabilizing a slag-forming condition. Said method is advantageously applicable for a refining furnace, such as an AOD, or a bottom or top- blown rotary converter.
NOZAKI TSUTOMU
EMI TOSHIHIKO
KAWARADA AKIRA
OGURA SHIGERU
IMAI TAKUO
