Method for manufacturing ferritic stainless steel slabs with equiaxed grain structures and the ferritic stainless steel manufactured by it

Abstract

Disclosed is a method for manufacturing ferritic stainless steel slabs with equiaxed grain structures and the ferritic stainless steel manufactured by it, which control concentration of alumina inclusions in molten steel to maximize an available TiN generation effect serving as a non-uniform nucleating site of ferrite when solidifying it, thereby improving equiaxed crystal ratio, the method comprising the steps of: performing oxygen decarburization reaction by blowing oxygen from the upper part of the molten steel in a vacuum oxygen decarburization ladle; injecting Al in the molten steel to which the oxygen decarburization reaction is made for Cr2O3 reduction; making composite deoxidation by injecting deoxidizer in the molten steel into which the Al is injected for the Cr2O3 reduction; making alloying process by injecting alloying metal in the molten steel; first judging for judging whether Al concentration is in the range of a setting value by analyzing the Al concentration in the molten steel; if the Al concentration satisfies the setting value, stirring it using inert gas and second judging for judging whether alumina inclusion concentration in the final molten steel corresponds to a target value; and if the alumina inclusion concentration satisfies the target value, continuously casting the molten steel.

Description

technical field [0001] The present invention relates to a method for manufacturing a ferritic stainless steel slab having an equiaxed grain structure and the ferritic stainless steel manufactured by the method, and more particularly, the present invention relates to such a method for manufacturing a slab having an equiaxed grain structure. A method for slabs of ferritic stainless steel with an axial grain structure, and ferritic stainless steel produced by the method, which controls the concentration of alumina inclusions in molten steel to maximize the generation of useful TiN, The equiaxed crystal ratio is thereby increased, wherein TiN serves as heterogeneous nucleation sites for ferrite when the molten steel is solidified. Background technique [0002] Generally, there are cases where 0.2% to 0.5% of Ti is added to ferritic stainless steel having a Cr concentration of 10% to 30% to improve the corrosion resistance of the ferritic stainless steel. In this case, TiN is fo...

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Problems solved by technology

[0018] However, it can be concluded that whenever stainless steel water is refined, it takes a relatively long time to measure the oxygen activity in molten steel using an oxygen sensor with slightly lower accuracy and without specifying the specific type of deoxidizer, thus Makes the deoxidizer somewhat ambiguous in its use in actual operation

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