Influence of surface state of titanium alloy products after annealing in variuos environments on their service behaviour

The paper ir aimed at investigation of the effect of the furnace atmosphere during annealing on the survice properties of VT6 alloy (5.5% Al; 4.3% V; 0.06% Si; 0.2% Fe; 0.09% O; 0.02% N; 0.008% H). It is stated that in vacuum furnaces and also in the firnaces with argon and air atmosphere the surface layers are saturated with oxygen and carbon that increases their microhardness and as a consequence decreases the VT6 alloy durability and fatigue strength. Removal of gas-saturated surface layers by etching or sandblasting of VT6 alloy samples makes it possible to increase their durability at cyclic test by a factor of 10 and fatigue strength-by 30%