METHOD FOR PRODUCTION OF NITROGEN-DOPED STEEL IN BUCKET Russian patent published in 2021 - IPC C21C7/72 C22B9/05 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, in particular to the production of steel with purging of the melt with nitrogen gas in a bucket. The method includes arc heating of the metal melt, purging the melt on the furnace-ladle unit through bottom purge plugs with argon, then purging the melt with nitrogen to its content exceeding the lower limit of the marking composition of steel by 30÷50%, and subsequent purging with argon. Before vacuuming the steel, the slag is loaded to a residual slag thickness of no more than 50 mm, vacuuming is carried out when the steel is purged in a bucket with nitrogen under deep vacuum at a pressure of no more than 2 mbar for at least 20 minutes until the oxygen content in the steel is no more than 20 ppm. After vacuuming, the deoxidizer is recoated in the form of a wire, followed by soft purging of the steel with argon with argon consumption, which excludes the exposure of the metal mirror from under the slag.

EFFECT: invention makes it possible to increase the degree of saturation of steel with nitrogen, but no more than 500 ppm, reduce the content of non-metallic inclusions, oxygen and the maximum temperature of steel during processing, reduce the duration of out-of-furnace processing.

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