Stress Corrosion Evaluation of Inconel X-750 for the International Space Station Environmental Control and Life Support System

Inconel X-750 alloy was evaluated for stress corrosion in support of the International Space Station Environmental Control and Life Support System. Round tensile specimens that were obtained from 0.25 in thick material successfully completed 365 days of exposure to baseline pretreat, baseline brine, alternate pretreat, alternate brine, and 3.5% NaCl alternate immersion without any failures at stresses of up to 90% of the yield strength. Posttest evaluations consisting of metallography and tensile testing did not indicate stress corrosion susceptibility.