APPARATUS FOR VACUUM OXYGEN DECARBURIZING CHROMIUM CONTAINED MOLTEN STEEL AND VACUUM OXYGEN DECARBURIZATION METHOD USING THE SAME

摘要

PURPOSE: An apparatus for vacuum oxygen decarburizing chromium contained molten steel is provided to effectively prevent peroxidation of the chromium contained molten steel in the decarburizing three steps by real-time predicting the decarburizing rate and carbon concentration in molten steel and judging the decarburizing transition point using information of flue gas, and a method for vacuum oxygen decarburizing the chromium contained molten steel using the apparatus is provided. CONSTITUTION: The apparatus comprises a hardware part (10) consisting of a ladle (12) carrying molten steel (11), a lance (13) ejecting a gas phase oxygen, an exhaust pipe exhausting flue gas, a flue gas analyzer (15) measuring a concentration of carbon oxide in the flue gas in a certain period, and a flue gas flow meter (16) measuring a flow rate of the flue gas in the same period as the flue gas analyzer (15); and a software part (20) consisting of a carbon concentration calculation part (21) calculating the carbon concentration from output signals outputted from the flue gas analyzer (15) and the flue gas flow meter (16), a decarburizing rate calculation part (22) calculating the decarburizing rate from output signals outputted from the flue gas analyzer (15), the flue gas flow meter (16) and the lance (13), a decarburizing transition point operation part (23) operating the decarburizing transition point, and an oxygen blowing flow rate control part (24) controlling the oxygen blowing flow rate by calculating an oxygen blowing flow rate and feedbacking the calculated oxygen blowing flow rate to the lance (13).