Abstract
An experimental study of stress corrosion cracking (SCC) was conducted on 7075-T651 aluminum alloy in a chromate-inhibited, acidic 3.5 pct sodium chloride aqueous solution using compact tension specimens with a thickness of 3.8 mm under permanent immersion conditions. The effects of loading magnitude, overload, underload, and two-step high-low sequence loading on incubation time and crack growth behavior were investigated. The results show that the SCC process consists of three stages: incubation, transient crack growth, and stable crack growth. The incubation time is highly dependent on the load level. Tensile overload or compressive underload applied prior to SCC significantly altered the initiation time of corrosion cracking. Transition from a high to a low loading magnitude resulted in a second incubation but much shorter or disappearing transient stage. The stable crack growth rate is independent of stress intensity factor in the range of 10 to 22 MPa √m.
| Original language | English |
|---|---|
| Pages (from-to) | 448-460 |
| Number of pages | 13 |
| Journal | Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science |
| Volume | 42 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2011 |
Funding
The work was financially supported by the Office of Naval Research (N00014-08-1-0646). The authors gratefully acknowledge the inspiring suggestions made by Dr. Asuri K. Vasudevan in the course of the research.