METHOD FOR MANUFACTURING HIGH CHROME FERRITE STAINLESS STEEL

摘要

PURPOSE: Provided is a method for manufacturing high chrome ferrite stainless steel, excluding deoxidation process, by performing rough decarburization and desulfurization at the same time, thereby preventing infiltration of nitrogen into liquid steel. CONSTITUTION: The manufacturing method of high chrome ferrite stainless steel includes: (i) charging of molten steel having a carbon content higher than 2wt.% into an argon oxygen decarburization(AOD) facility; (ii) after maintaining slag basicity within 4.0 and 5.0 in an initial stage of decarburization, pouring fluorite in an amount of 9.0 to 11.0kg/ton-molten steel; (iii) carrying out stirring for 2-3min followed by tapping; (iv) refining the liquid steel in vacuum oxygen decarbonization(VOD) facility. Slag basicity in an initial stage of decarburization is kept within a basicity range of 4.0 and 5.0 in such a manner that oxygen is injected into liquid steel in an amount of 35 to 40Nm¬3 until carbon content of the liquid steel reach 0.5-1.0% while pouring ferro silicon 3.5-7.5kg and lime 35-50kg per ton-liquid steel, respectively.