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Pressurized Gaseous Oxygen Pneumatic Impact for Nonmetals Test 14 from NASA-STD-6001 Purpose: To provide information on reaction sensitivity of nonmetals to adiabatic compression heating when pneumatically impacted in pressurized GOX Test Conditions Worst case pressure and thickness
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Pressurized Gaseous Oxygen Pneumatic Impact for NonmetalsTest 14 from NASA-STD-6001 • Purpose: • To provide information on reaction sensitivity of nonmetals to adiabatic compression heating when pneumatically impacted in pressurized GOX • Test Conditions • Worst case pressure and thickness • Rapid pressurization in GOX • Acceptance Criteria • Used to evaluate reaction sesativity • Normally a reaction threshold is determined with 60-120 samples at use pressure MAPTIS Presentation
Reactivity of Materials in Aerospace FluidsTest 15 from NASA-STD-6001 • Purpose: • To identify changes resulting from exposure of materials to aerospace fluids that render either the material or fluid unusable or cause a pressure rise • Test Conditions • Screening: 2 hours at ambient temp. • Immersion: 48 hours at max. temp. • Post-test analysis of material and fluid • Acceptance Criteria • No change to material or test fluid MAPTIS Presentation
Stress Corosion CrackingMSFC-SPEC-522/ASTM G44, G47, etc. • Definition: • The combined action of sustained tensile stress and corrosion to cause premature failure in a susceptible material • Purpose: • To characterize the resistance of metallic material to SCC • Test Conditions • .35% NaCl alternate immersion or 5% salt spray • 90 days exposure • 75 to 90% of yield strength • Acceptance Criteria • No occurrence of stress corrosion cracking failures at the appropriate percentage of yield strength for highly resistant, moderately resistant and low resistant materials MAPTIS Presentation
Other Metallic Materials Tests • Corrosion • MSFC-SPEC-250 • Criteria • Corrosion Rate in a Class II environment shall not exceed 1 mil per year • Class II: Moderately corrosive environment such as exposure to sea coast or industrial environments • Hydrogen Environment Effects • Embrittlement • Criteria • Metallic materials shall exhibit no more than a 20% reduction in ductility or strength at the tested gaseous hydrogen pressure when compared to the same test while exposed to helium MAPTIS Presentation