Corrosion Cracking of Metallic Materials

Item

Title
Corrosion Cracking of Metallic Materials
Date
1970
Index Abstract
Not Available
Photo Quality
Complete
Report Number
AFML TR 70-2
Corporate Author
Ohio State Univ Columbus Dept Of Metallurgical Engineering
Laboratory
Air Force Materials Laboratory
Extent
210
Identifier
AD0867061
Access Rights
Export Controls
Distribution Classification
1
Contract
F33615-69-C-1258
DoD Project
7312
DoD Task
731202
DTIC Record Exists
No
Distribution Change Authority Correspondence
USAFML LTR
Distribution Conflict
No
Abstract
Stress corrosion behavior of titanium alloys and high strength steels was studied. In titanium alloys the initiation and propagation of cracks in aqueous and methanolic environments is being studied as a function of alloy composition, electrochemical control, and applied stress. Corrosion processes within crevices are being studied. Straining electrode studies are also reported. Crack initiation in Ti-6Al-4V specimens was observed at alpha-beta interfaces and in beta grains. Studies of crack velocity show it to depend on applied stress but not on potential. Crevice studies show corrosion to be accelerated when the IR drop is large. In high strength steels the processes of transient passivity, dissolution of carbides, crack propagation and hydrogen permeation are being studied. The kinetics of transient passivity on iron alloy surfaces shows good agreement with classic models for growth of thin films. Dissolution of iron carbides is shown to depend on pH, potential and anion. The action of cathodic poisons such as arsenic is shown to depend on co-deposition of the poison species.
Report Availability
Full text available
Date Issued
1970-01
Provenance
Lockheed Martin Missiles & Fire Control
Type
report
Format
1 online resource
Creator
Fontana, Mars G.
Media
AFMLTR70-002.pdf