METHOD OF DOUBLE DOPING AND NANOPHASE MODIFICATION OF STEEL BY ATOMIC NITROGEN Russian patent published in 2017 - IPC C21C7/00 B82Y30/00 

FIELD: metallurgical engineering.

SUBSTANCE: doping of a steel melt is performed to ensure the process of self-propagating synthesis of nitride nanophases of the doping elements, and the steel melt processing with atomic nitrogen is carried out by introducing a carbamide (NH₂)₂CO at a melt temperature of 1650 °C with a consumption of the carbamide of 0.4-1.8 kg/t of steel and a rate of its supply to the melt of 5.0-8.0 kg per minute, the carbamide is introduced into the melt in the form of a filler of a flux-cored wire with simultaneous feeding of an aluminium wire rod at a rate of 1.2 kg/t of steel. Reducing the metal intensity of building structures to 20-25% and guaranteed operation in climatic conditions to -65 °C, as well as saving up to 50-60% of expensive doping elements.

EFFECT: increased strength, ductility and cold resistance of steels for the construction industry.

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