Creep of V–4Cr–4Ti in a lithium environment

Biaxial creep specimens of V–4Cr–4Ti were exposed to liquid lithium at 665 and 765 °C to complement similar tests in a vacuum environment. Although the Li tests are at an early stage, results are consistent with those of the vacuum tests. At 765 °C, exposures of nearly 2000 h have been reached, and at 665 °C, 1100 h have been attained. There is only a brief period of steady-state creep, a power law stress dependence is observed, and temperature dependence is described by an activation energy slightly lower than that of self-diffusion, 2.8 eV. At this stage, even the vacuum tests had little increase in oxygen so that the similarity is not unexpected. No creep failures have been observed. This is expected based upon comparison with vacuum tests on similar specimens and with uniaxial tests with specimens of the same heat of V–4Cr–4Ti.