Effects of microtexture and Ti3Al (α2) precipitates on stress-corrosion cracking properties of a Ti-8Al-1Mo-1V alloy

Effects of microtexture and Ti3Al (α2) precipitates on the Stress-Corrosion Cracking (SCC) properties of Ti-8Al-1Mo-1V (Ti-811) have been investigated using a constant displacement SCC test in 0.1 M aqueous sodium chloride (NaCl) solution. SEM, TEM, and EBSD were employed to characterize microstructure and microtexture. Results reveal that both microtexture and α2precipitates increase the SCC susceptibility of Ti-811. The SCC propagation direction aligns with microtextured regions, and most α grains were preferentially orientated for basal slip along the SCC crack. SCC susceptibility was eliminated by implementing hot isostatic pressing (HIPping) and post heat-treatment processes through eliminating both crystallographic microtexture and α2precipitates. Fractography showed that the formation mechanism of the propagation facets could be attributed to Hydrogen Enhanced Localized Plasticity (HELP).