  The corrosion-fatigue strength in 3% aqueous NaCl solution and the resistance
against hot salt corrosion (HSC) of the fine-grained near-a alloy Ti-5Al-2V
(Russian analog of Grade 9 titanium alloy with increased aluminum content) has
been studied. The properties of the Ti-5Al-2V alloy in the coarse-grained
state, in the fine-grained after cold Rotary Swaging (RS), in partly
recrystallized state, and in fully recrystallized one have been investigated.
The mechanical properties of the alloy were characterized using compression
tests and microhardness measurements. The effects of RS and of the annealing
temperature and time on the character of corrosion destruction of the surface
and on the composition of the products of the HSC were studied. RS was shown to
result in an increase in the depth of the intergranular corrosion defects while
the recrystallization annealing promotes the increasing of the corrosion
resistance of the Ti-5Al-2V titanium alloy. The parameters of the Basquin
equation for the corrosion-fatigue curves for the near-a Ti-5Al-2V alloy in the
coarse-grained state, in the severely strained one, and after recrystallization
annealing were determined for the first time. An effect of nonmonotonous
dependencies of the slopes of the corrosion-fatigue curves for the strained
near-a Ti-5Al-2V alloy on the recrystallization annealing temperature has been
observed.
