METHOD OF HARDENING TITANIUM ALLOYS IN GAS ENVIRONMENT Russian patent published in 2009 - IPC C23C8/24 C23C8/80 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to the methods of nitride hardening of metals and can be used for manufacturing the parts from titanium alloys working at cyclic loads. High-temperature nitride hardening is performed at 700-750°C for 30-10 min. This is followed by recovery annealing in argon at the temperature exceeding the nitride hardening temperature by 100-150°C, for as long as the time τ_annealing, selected from the condition: , where K_{nitride hardening}, K_p is empirical coefficients accordingly allowing the rate of formation and the rate of dissolving of the nitride gas-saturated layer, mcm²/sec; E_{nitride hardening} is the process activation energy controlling increase in the nitrogen concentration in the brittle nitride hardened layer J/mole; E_p - is the process activation energy controlling decrease in the nitrogen concentration in the brittle nitride hardened layer J/mole; R is gas constant, J/Kmole; T_{nitride hardening} is nitride hardening temperature, K; T _annealing is recovery annealing temperature, K; τ_{nitride hardening} is nitride hardening time, sec.

EFFECT: reduced power inputs and enhanced cyclic endurance and durability of the titanium alloy structures.

1 ex