METHOD FOR HARDENING PARTS MADE OF TOOL AND STRUCTURAL STEELS IN BORATED MEDIUM Russian patent published in 2021 - IPC C23C8/70 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, in particular to chemical-thermal treatment of structural and tool steels, and can be used for surface hardening of machine parts and technological equipment in machine-building, metallurgical, chemical, tooling and other industries. The method for strengthening parts made of structural and tool steels by boriding includes preparing a paste for boriding containing components in the following ratio, wt%: boron carbide В₄С – 50-55, ferrochrome FX800А - 15-20, aluminum fluoride AlF₃ – 2-3, bentonite - 5-10, marshalite - 10-15, amorphous carbon DG-100 - the rest. As a pasting agent, a polyvinyl acetate emulsion is used, constituting 30-35% of the mass of powder components, consisting of PVA glue - 60-65, methanol or ethanol - 20-25 and water - the rest. The aforementioned paste is applied to the part, dried at a temperature of 70-75°С for 0.5-1.0 hours. Then the part is heated to a temperature of 920-1100°С for 3-6 hours. Then it is subjected to quenching and tempering at a temperature of 200-550°C for 2 hours.

EFFECT: wear resistance and corrosion resistance of parts, the strength of the coating are increased, and possibility of processing parts of any size and shape, in particular, local boriding, is provided, and the uniformity of heating of parts is increased.

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