Analysis of the creep and long-term strength of VT6 titanium alloy with preliminarily injected hydrogen

We describe the results of experimental and theoretical investigation of the influence of the concentration of preliminarily injected hydrogen on the creep and long-term strength of VT6 titanium alloy under the action of tensile stresses equal to 47–217 MPa. The tests carried out at a temperature of 600°C show that hydrogen (up to 0.3 wt.%) strongly decreases the steady-state creep rate of this alloy, increases the time to fracture, and lowers (severalfold) its ultimate fracture strain. The obtained results are interpreted on the basis of the analysis of changes in the structural state of the alloy. The proposed version of the kinetic theory of creep gives good agreement between the experimental and theoretical values of the principal characteristics of creep and long-term strength.