Aluminum alloys protected against stress- corrosion cracking
Topcoat of epoxy-polyamide paint is effective protection for aluminum alloys against stress corrosion cracking. The paint can be used on unprimed surfaces.
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Topcoat of epoxy-polyamide paint is effective protection for aluminum alloys against stress corrosion cracking. The paint can be used on unprimed surfaces.
Aluminum concentration effects on stress corrosion cracking of titanium alloys at ambient temperatures in aqueous solutions of salt
The use of aluminum-lithium alloys for aerospace applications is currently being studied at NASA Langley Research Center's Metallic Materials Branch. The alloys in question will operate under stress in a corrosive environment. These conditions are ideal for the phenomena of Stress-Corrosion Cracking (SCC) to occur. The test procedure for SCC calls for alternate immersion and breaking load tests. These tests were optimized for the lab equipment and materials available in the Light Alloy lab. Al-Li alloy ML377 specimens were then subjected to alternate immersion and breaking load tests to determine residual strength and resistance to SCC. Corrosion morphology and microstructure were examined under magnification. Data shows that ML377 is highly resistant to stress-corrosion cracking.
Stress corrosion cracking of titanium alloys at ambient temperature in aqueous solutions
Stress corrosion cracking of titanium alloys at ambient temperature in aqueous solutions
Solution of hydrogen flouride, hydrogen peroxide, and water reveals hot salt stress corrosion cracks in various titanium alloys. After the surface is rinsed in water, dried, and swabbed with the solution, it can be observed by the naked eye or at low magnification.
The effects of alloy composition on the aqueous stress corrosion of titanium alloys were studied with emphasis on determining the interrelations among composition, phase structure, and deformation and fracture properties of the alpha phase in alpha-beta alloys. Accomplishments summarized include the effects of alloy composition on susceptibility, and metallurgical mechanisms of stress-corrosion cracking.
An investigation was conducted to determine the cause of the failure of a massive AISI Type 316 stainless steel valve which controlled combustion air to a jet engine test facility. Several through-the-wall cracks were present near welded joints in the valve skirt. The valve had been in outdoor service for 18 years. Samples were taken in the cracked regions for metallographic and chemical analyses. Insulating material and sources of water mist in the vicinity of the failed valve were analyzed for chlorides. A scanning electron microscope was used to determine whether foreign elements were present in a crack. On the basis of the information generated, the failure was characterized as external stress-corrosion cracking. The cracking resulted from a combination of residual tensile stress from welding and the presence of aqueous chlorides. Recommended countermeasures are included.
Stress corrosion cracking of titanium alloys at ambient temperature in aqueous solutions
Grain morphology and preferred orientation effects on direction and propagation of stress corrosion cracking of aluminum alloy plate
Electrochemical mass transport kinetic model used to study metallurgical and mechanical effects of titanium alloy stress corrosion cracking
Stress corrosion cracking tests of titanium alloys at ambient temperature in aqueous solutions
Stress corrosion cracking of titanium alloys
Hydrogen embrittlement of titanium as related to stress corrosion cracking
Hot salt stress corrosion cracking effects on tensile properties of titanium alloy sheets
Metal composition effects on stress corrosion cracking of titanium alloys in nitrogen tetroxide, water, and salt
Aluminum concentration effects on stress corrosion cracking of titanium alloys in aqueous solutions
Effects of dimethyl-dichlorovinyl phosphate and sodium chloride solution on stress corrosion cracking of aluminum and steel