The stress corrosion crack initiation and growth rate response was evaluated on titanium Grades 7 (UNS
R52400), 28 (UNS R55323) and 29 (UNS R56404) at 105 – 165 °C in several aerated, concentrated groundwater
environments. Time-to-failure experiments on actively-loaded tensile specimens at 105 °C were used to evaluate
the resistance to SCC, and included specimens of stainless steel and alloy 22. Long-term U-bend experiments at
165 °C were also performed. Long term crack growth rate data showed stable crack growth under constant-K (no
cycling) conditions in the titanium alloys. Creep tests in < 200 °C air confirmed the literature data that these
alloys are quite susceptible to creep failure, even below the yield stress. It is unclear whether cracking in the SCC
tests is strongly accelerated by the creep response, or whether creep alone fully accounts for the observed
cracking.