PURPOSE: To eliminate problems such as decrease of decarburizing speed, the oxidation of a metal or the like, in a decarburizing process by blowing O2-gas and dilution gas into molten steel, by specifying the blow-in condition of the aforementioned both gases in three regions due to the C-content in the molten steel.
CONSTITUTION: In a decarburizing process by blowing protective gas and a gaseous mixture of O2-gas and dilution gas into molten steel from the outer and the inner pipes of a double pipe tuyere, the C-content in the molten steel divided into three regions, that is, a region of up to 0.7%, a region to 0.05W0.25% from 0.7% and a region to up to a final C-value from 0.25W0.05%. In this state only the O2-gas, a gaseous mixture continuously changed in the ratio of the O2-gas and the dilution gas corresponding to the C-content and only the dilution gas are successively and respectively blown into the molten steel in these regions from the inner pipe. By this method, the conservation of a required reducing agent, shortening of a reduction time, prevention of the molten loss of a refractory material and enhancing effect of refining efficiency are obtained.
ARIYOSHI HARUKI
TAKANO HIRONORI
| JPS5036209A | 1975-04-05 | |||
| JPS51107215A | 1976-09-22 |