DOPING TECHNIQUE OF NONCORROSIVE STEEL BY NITROGEN Russian patent published in 2008 - IPC C21C7/00 

FIELD: metallurgy.

SUBSTANCE: invention concerns ferrous metallurgy field. Particularly, it concerns noncorrosive steel making. Method includes nitrogen feeding into metal through the facility, mounted in brickwork of ladle bottom. Before nitrogen feeding it is defined sulphur content in metal and saturation by nitrogen is implemented subject to its content. Maximal nitrogen consumption is defined subject to sulphur content in metal. Nitrogen consumption have to be in the range not less 0.5 of maximal value and no more maximal value of nitrogen consumption, defined by ratio. Metal temperature is kept up in the range of 1520°-1640°C. It is probable addition of nitride ferroalloys at a finishing stage.

EFFECT: increasing of metal recovery degree of gaseous nitrogen while reducing of its consumption.

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