METHOD FOR REDUCING NITROGEN IN DEOXIDIZED MOLTEN STEEL

摘要

PURPOSE: A method for reducing nitrogen in deoxidized molten steel is provided to reduce cracks of slab, coil and plate by reducing the content of nitrogen that is a cause of cracks when continuously casting molten steel passing through the refining process. CONSTITUTION: In a method for refining a steel containing 0.04 to 1.00 wt.% of carbon (C), 0.005 to 0.050 wt.% of aluminum (Al), 0.010 wt.% of sulfur (S), 0.50 to 1.60 wt.% of manganese (Mn) and 0.10 to 0.40 wt.% of silicon (Si), the method comprises the steps of injecting flux for second refining into converter at a time point corresponding to 10% of tapping in the tapping process after completing blowing operation in converter process; injecting manganese based ferro alloy into the converter after adding the flux for second refining to the converter; and injecting aluminum and silicon based ferro alloy into the converter at a time point corresponding to 70 to 80% of tapping.