Corrosion fatigue crack growth in aircraft structural materials. Final technical report, 1 Jun 1971--30 Jun 1973. [T0T5-T651 and T4T5-T651 aluminium, 6Al--4V (ELI) beta annealed and recrystallized annealed titanium, and 9Ni--4Co--0. 3C steel, T2, 175 and -65F and recrystallized annealed]

Technical Report · Sat Sep 01 04:00:00 EDT 1973

OSTI ID:7223269

Hall, L R; Finger, R W; Spurr, W F

This experimental program was undertaken to obtain information on stress corrosion cracking and corrosion fatigue crack growth in high-strength metal alloys suitable for airframe components. In addition, tests were conducted to evaluate the effects of overloads and metallurgical factors on corrosion fatigue crack growth. The test program involved five alloys and seven test media. The four principal alloys were 7075-T651 Aluminum, 6Al--4V(ELI) Beta annealed (Beta A) Titanium, 6Al--4V recrystallize Annealed (RA) titanium, and 9Ni--4Co--0.3C Steel (220-240 ksi); in addition the 7475-T651 alloy was subjected to a limited number of tests. All alloys were tested in the form of hot rolled plate. Test media included: desiccated air, water saturated JP-4 fuel, distilled water, 3.5% NaCl solution, sump tank water, alternating JP-4 fuel and distilled water, and dye penetrant (type ZL-2A). Most tests were conducted at 72F with a few tests being performed at +175F and -65F. Double cantilever beam specimens were used for all tests with the exception of a limited number of surface-flawed specimen tests. Corrosion fatigue tests were conducted using two cyclic frequencies (6 and 60 cpm) and three ratios of minimum to maximum stress (0.1, 0.5 and 0.8). Overload effects were investigated by testing 7075-T651 Aluminum, Ti--6Al--4V and Ti--6Al--4V RA tapered double cantilever beam specimens in both desiccated air and 3.5% NaCl solution. Finally, a series of tests was undertaken to evaluate the effects on SCC and corrosion fatigue cracking of variations in metallurgical characteristics imparted to Ti--6Al--4V RA alloy plate by various thermal cycles. (auth)

• Research Organization: Boeing Aerospace Co., Seattle, WA (USA)
• OSTI ID: 7223269
• Report Number(s): AD-916695
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
AIR
AIRCRAFT
ALKALI METAL COMPOUNDS
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
AQUEOUS SOLUTIONS
AVIATION FUELS
CARBON ADDITIONS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
COBALT ALLOYS
CORROSION
CORROSION FATIGUE
CRACKS
DISPERSIONS
DYES
FATIGUE
FLUIDS
FUELS
GASES
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
IRON ALLOYS
IRON BASE ALLOYS
LOW TEMPERATURE
MECHANICAL PROPERTIES
MEDIUM TEMPERATURE
METALLURGICAL EFFECTS
MIXTURES
NICKEL ALLOYS
OXYGEN COMPOUNDS
PLATES
QUATERNARY ALLOY SYSTEMS
SODIUM CHLORIDES
SODIUM COMPOUNDS
SOLUTIONS
STEELS
STRESS CORROSION
TEMPERATURE EFFECTS
TERNARY ALLOY SYSTEMS
TITANIUM ALLOYS
TITANIUM BASE ALLOYS
VANADIUM ALLOYS
WATER