Effect of Sensitization on Corrosion-Fatigue Cracking in Al 5083 Alloy
Memorandum rept. Oct 2011-Sep 2014
NAVAL RESEARCH LAB WASHINGTON DC MATERIALS SCIENCE AND TECHNOLOGY DIV
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An investigation was carried out to characterize the effect of sensitization or aging, environment including NaCl concentration, and load ratio on fatigue crack growth and stress-corrosion cracking SCC of Al 5083 alloy. Both low and high load ratios, corresponding to R 0.1 and R 0.85 were examined. The results indicate 1 fully sensitized Al 5083 has very low high stress-ratio at R 0.85 corrosion-fatigue CF threshold stress intensity Kth and SCC threshold K1SCC in saltwater 2 the as-received Al 5083-H131 has good CF and SCC resistance 3 at 175 C aging temperature, high stress ratio Kth and K1SCC in saltwater decrease with increasing aging time up to about 240 hours aging times longer than 240 hours produce little additional degradation 4 sensitization has no effect on fatigue crack growth at low stress ratio of R 0.1 in any environment, and no effect at any stress ratio in vacuum and in ambient air 5 both high stress ratio Kth and K1SCC are influenced by NaCl concentration, higher NaCl results in a lower high stress ratio Kth and K1SCC.
- Properties of Metals and Alloys