A study of the thermal creep properties of V-4Cr-4Ti was performed using pressurized tube specimens. Creep tubes nominally 4.57 mm OD by 0.25 mm wall thickness were pressurized with high-purity helium gas to mid-wall effective stresses below the uniaxial yield strength. Specimens were heated to 700 and 800?C in an ultra-high vacuum furnace and periodically removed to measure the change in OD with a high-precision laser profilometer. The secondary creep rate was found to be power-law dependent on the applied stress with a stress exponent of 3.7 at 700?C and 2.7 at 800?C. The average activation energy for creep of V-4Cr-4Ti was 299 kJ/mole, which is quite close to the activation energy for self-diffusion in pure vanadium in this temperature regime. The predominant mechanism of creep deformation for the conditions employed in this study is most likely climb assisted dislocation motion.
Revised: August 4, 2008 |
Published: November 27, 2000
Citation
Kurtz R.J., and M.L. Hamilton. 2000.Biaxial Thermal Creep of V-4Cr-4Ti at 700°C and 800°C.Journal of Nuclear Materials 283-287, no. 1:628-632.PNNL-SA-33661.doi:10.1016/S0022-3115(00)00274-9