Pressurized Gaseous Oxygen Pneumatic Impact for Nonmetals Test 14 from NASA-STD-6001

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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

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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

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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

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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