Method for removing total oxygen in molten steel

Abstract

The invention relates to a method for removing total oxygen in low-carbon molten steel. The method of the invention solves the shortcomings that in the prior art, the content of dissolved oxygen of molten steel is increased, the inclusion is increased after deoxygenation, and the total oxygen content is higher and the like. The method has the following steps: tapping by a slag dam method; adding lime with 2.6-3.0kg of each ton of steel into steel ladle liquid level when tapping amount reaches 1 / 2-2 / 3; transmitting steel ladle to an RH work station after tapping, controlling the content of carbon in molten steel to be 0.03-0.04% in weight ratio, the content of dissolved oxygen to be 0.055-0.07% in weight ratio, and the slag thickness to be 50-70 mm; carrying out RH vacuum processing: firstly carrying out vacuum decarbonizing, deoxidizing and alloying; adding blending agent composed of lime and fluorite to the molten steel, wherein, the adding amount is 3-5 kg of each ton of steel; and driving molten steel circulation by argon during the time. In the invention, the equipment does not need to change, the operation is flexible, the total oxygen content in the molten steel and the sulphur content are obviously lowered after processing, and the performance and quality of post-procedure products are improved.

Description

technical field [0001] The invention relates to a method for removing impurities in steel, in particular to a method for removing total oxygen in molten steel with ultra-low carbon content. Background technique [0002] The total oxygen content (T.[O]) is an important index to measure the cleanliness of steel. The cleanliness of total oxygen is often related to the surface quality defects of cold-rolled sheets, and also reduces the magnetic properties of silicon steel sheets and the deep drawability of automotive sheets. The disadvantage of the existing smelting is that after the molten steel enters the ultra-low carbon area, the dissolved oxygen content corresponding to the ultra-low carbon content increases, and the inclusions increase after the steel is deoxidized, and some tiny inclusions are difficult to remove; the secondary refining process The reoxidation of molten steel by slag, furnace lining and other environments further reduces the ability of molten steel to rem...

AI Technical Summary

Problems solved by technology

The disadvantage of the existing smelting is that after the molten steel enters the ultra-low carbon area, the dissolved oxygen content corresponding to the ultra-low carbon content increases, and the inclusions increase after the steel is deoxidized, and some tiny inclusions are difficult to remove; the secondary refining process The reoxidation of molten steel by slag, furnace lining and other environments further reduces the ability of molten steel to remove oxide inclusions and process production efficiency

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