METHOD FOR GAS LOW-TEMPERATURE NITRO-CEMENTATION OF TOOL MADE OF HIGH-SPEED STEELS (SATURATION LAYERS UP TO 0.05 mm) WITHOUT CARBONITRIDE HIGH-NITROGEN SURFACE LAYER IN VACUUM FURNACES Russian patent published in 2022 - IPC C23C8/32 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to chemical-thermal processing; it can be used in mechanical engineering, automobile production. A method for gas low-temperature nitro-cementation of a cutting tool made of high-speed steel in a vacuum furnace includes following operations: vacuuming of the furnace, filling of the furnace with gaseous nitrogen, preheating of the cutting tool to a saturation temperature of 520-550°C in oxygen-free atmosphere in a nitrogen medium, saturation in a medium of 70% nitrogen, 15% ammonium, and 15% exothermal gas for 10-60 min, subsequent cooling in a gaseous nitrogen medium to a temperature of less than or equal to 300°C.

EFFECT: increase in a resource of a cutting tool made of high-speed steels, increase in the quality of strengthening the cutting tool to obtain strengthened layers in a range of 20-50 mcm without a surface nitride ε-phase with hardness of HV0.3≥1050.

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