METHOD OF BORONIZING STEEL PARTS Russian patent published in 2019 - IPC C23C8/70 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, and in particular to methods for applying boride coatings on steel during chemical-thermal treatment under conditions of induction heating, and can be used in mechanical engineering to increase the durability of machine parts operating in conditions of intensive abrasive wear, corrosion, impact loads. Conduct induction heating of parts with a hold-up in the boronizing medium. As the boronizing medium, a powder mixture of the following composition is used, wt. %: boron carbide - 80–85, flux for induction welding P-0.66 - 10–15, cryolite - the rest. Mentioned induction heating is carried out in a boronizing medium in two stages, while in the first stage - at a temperature of 1250–1350 °C for 90 seconds, and in the second stage - at a temperature of 920–960 °C for 15 seconds. Then the parts are cooled to the hardening temperature or immediately quenched in a medium that has a temperature not lower than the temperature of the onset of martensitic transformation in steel. After that, the parts are placed in a muffle furnace and kept there for at least 20 minutes at a temperature of 20–60 °C above the temperature of the end of the martensitic transformation in steel, then the parts are cooled.

EFFECT: reduction of process time, increase in wear resistance of parts, simplification of instrumentation design and reduction of labour intensity without increasing the duration of borization.

1 cl, 3 dwg, 1 tbl, 1 ex