Refining device and method for controlling nitrogen content of molten steel

Abstract

The invention provides a refining device for controlling the nitrogen content of molten steel. The refining device comprises a lifting hydraulic cylinder, immersing pipes, a furnace cover, electrodes, a bin and a steel ladle. The front end of a connecting rod at the front end of a piston rod of the lifting hydraulic cylinder is welded to the furnace cover. The electrodes are arranged in the middle of the furnace cover. The bin is arranged above a feeding port in one side. The immersing pipes are fixed below the furnace cover. The furnace cover is lifted and hung above the steel ladle through the lifting hydraulic cylinder. Compared with a conventional method, the contact opportunity between the molten steel and air can be reduced, and the nitrogen increasing amount of the molten steel is not larger than 0.0003%; the temperature drop of the molten steel in the treatment process is reduced, and the temperature loss is reduced by 50%; and inclusions in the molten steel are effectively removed, the cleanliness of the molten steel is improved, the use amount of pre-melted slag is reduced by 40%, and cost is reduced. The refining device is simple in structure, easy to operate, low in investment and free of influences on normal operation of other equipment, and the immersing pipes can be repeatedly used.

Description

technical field

[0001] The invention belongs to the technical field of continuous steel, and in particular relates to a refining device and method capable of controlling the nitrogen content of molten steel. Background technique

[0002] The role of nitrogen in steel has two sides: on the one hand, nitrogen, as an interstitial solid solution element, can greatly increase the strength of steel. On the other hand, nitrogen will significantly reduce the ductility of steel, which is particularly prominent in ultra-low carbon steel; in terms of toughness, nitrogen will greatly increase the ductile-brittle transition temperature; nitrogen forms nitrides with aluminum, titanium and other elements, and in a certain In some cases, it will lead to hot embrittlement of steel; in addition, the delayed precipitation of nitrogen at room temperature is also related to some aging effects of steel. For most steel types, nitrogen is regarded as an impurity element in steel. When the nitrogen...

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