METHOD OF PHOTOCHEMICAL PROCESSING OF STEELS IN POWDER MIXTURES Russian patent published in 2009 - IPC C23C8/76 C23C8/80 

FIELD: metallurgy.

SUBSTANCE: invention concerns metallurgy. Particularly it concerns methods of photochemical processing of steels and can be used in mechanical engineering for strengthening of steel fine-sized details and tools. Method includes two-stages nitrocarburising in activated arboreal-carbon composition. Composition contains wood charcoal, carbamide and Trilon-B. Process of nitrocarburising is implemented at pressure 50-300 Pa, at the first stage at temperature 600-800°C with isolation during 3-6 hours and at the second stage - at hardening temperature with isolation during 30-90 minutes. After what it is implemented cooling and tempering at temperature 240-450°C during 2-4 hours. At nitrocarburising of carbon steels isolation at the second stage is implemented at temperature 780-820°C, and cooling is implemented in water. For lean alloy steel isolation is implemented at temperature 840-870°C and cooling is implemented in oil. For hot-work alloyed steel isolation is implemented at temperature 940-980°C and cooling is implemented in liquid nitrogen at temperature 196°C. For high-chromium steel isolation is implemented at temperature 1000-1040°C and cooling is implemented on air.

EFFECT: reduction of diffusion layer shortness, hardening and endurance increasing of products.

5 cl, 5 dwg, 1 tbl, 3 ex