Abstract
Transition of corrosion pit to crack under fatigue condition was investigated in high-strength 7075-T6 aluminum alloy. The pit was formed at the edge of a hole in a specimen. Specimen was subjected to a constant stress during the pit formation. Two types of corrosion pit were considered: corner-pit and through-pit. Two sizes were tested for each pit type. Also, the baseline data of cycles to initiate a 250-µm-long crack were established when the corrosion pit was created without any applied stress on the specimen, i.e., S appl = 0. The cycles to initiate a 250-µm-long crack initially decreased with increasing S appl relative to the baseline value and then increased with increasing S appl such that this increase was significant with higher value of S appl. The transition between this increase and decrease occurred when the S appl was greater or less than a value which caused the onset of plastic deformation at the root of the pit, respectively. Microstructural analysis showed that this decrease in cycles to initiate the crack was due to microcracks at the pit front which developed at the lower level of S appl, and the increase was due to plastic deformation at the higher levels of S appl.
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References
P.P. Milella, Fatigue and Corrosion in Metals, Springer, New York, 2013
A.J. McEvily and R.P. Wey, Fracture Mechanics and Corrosion Fatigue, DTIC document, 1972
R.P. Gangloff, Environmental Cracking—Corrosion Fatigue, ASTM International, West Conshohocken, PA, 2005, p 302–321
P. Robert, D. Wei, and H. Gary, Corrosion and Fatigue of Aluminum Alloys: Chemistry Micromechanics And Reliability. AFRL-SR-BL-TR-01-0569.2001, 2001
R.P. Wei, Some Aspects of Environment-Enhanced Fatigue-Crack Growth, Eng. Fract. Mech., 1970, 1, p 633–651
Q. Wang, N. Kawagoishi, and Q. Chen, Effect of Pitting Corrosion on Very High Cycle Fatigue Behavior, Scr. Mater., 2003, 49(7), p 711–716
J.T. Burns, J.M. Larsen, and R.P. Gangloff, Driving Forces for Localized Corrosion-to-Fatigue Crack Transition in AlZnMgCu, Fatigue Fract. Eng. Mater. Struct., 2011, 34, p 745–773
S. Kim, J.T. Burns, and R.P. Gangloff, Fatigue Crack Formation and Growth from Localized Corrosion in Al-Zn-Mg-Cu, Eng. Fract. Mech., 2009, 76, p 651–667
G.S. Chen, K.C. Wan, M. Gao, R.P. Wei, and T.H. Flournoy, Transition from Pitting to Fatigue Crack Growth Modeling of Corrosion Fatigue Crack Nucleation in a 2014-T3 Aluminum Alloy, Mater. Sci. Eng., 2002, 219(1–2), p 126–132
Y. Lee and S.G. Dorman, Effect of Chromate Primer on Corrosion Fatigue in Aluminum Alloy 7075, Proc. Eng., 2011, 10, p 1220–1225
J.T. Burns, S. Kim, and R.P. Gangloff, Effect of Corrosion Severity on Fatigue Evolution in Al-Zn-Mg-Cu, Corros. Sci., 2010, 52, p 498–508
A. Turnbull, L.N. McCartney, and S. Zhou, A Model to Predict the Evolution of Pitting Corrosion and the Pit-to-Crack Transition Incorporating Statistically Distributed Input Parameters, Corros. Sci., 2006, 48, p 2084–2105
D.A. Horner, B.J. Connolly, S. Zhou, L. Crocker, and A. Turnbull, Novel Images of the Evolution of Stress Corrosion Cracks from Corrosion Pits, Corros. Sci., 2011, 53, p 3466–3485
X.D. Li, X.S. Wang, H.H. Ren, Y.L. Chen, and Z.T. Mu, Effect of Prior Corrosion State on the Fatigue Small Cracking Behavior of 6151-T6 Aluminum Alloy, Corros. Sci., 2012, 55, p 26–33
X.S. Wang, X.D. Li, H.H. Yang, N. Kawagoishi, and P. Pan, Environment-Induced Fatigue Cracking Behavior of Aluminum Alloys and Modification Methods, Corros. Rev., 2015, 33(3–4), p 119–137
H.H. Yang, Y.L. Wang, X.S. Wang, P. Pan, and D.W. Jia, Synergistic Effect of Corrosion Environment and Stress on the Fatigue Damage Behavior of Al Alloys, Fat. Fract. Eng. Mater. Struct., 2016, 39, p 1309–1316
V. Sabelkin, V.Y. Perel, H.E. Misak, E.M. Hunt, and S. Mall, Investigation into Crack Initiation from Corrosion Pit at 7075-T6 Under Ambient Laboratory and Saltwater Environments, Eng. Fract. Mech., 2015, 134, p 111–123
V. Sabelkin, H.E. Misak, V.Y. Perel, and S. Mall, Crack Initiation from Corrosion Pit in Three Aluminum Alloys Under Ambient and Saltwater Environments, J. Mater. Eng. Perform., 2016, 25(4), p 1631–1642
ABAQUS, Abaqus 6.14 User’s Manual, Dassault Systemes Simulia Corp., Providence, RI, 2014
MIL-STD-1530C (USAF), Department of Defense Standard Practice: Aircraft Structural Integrity Program (ASIP), 1 Nov 2005
H.E. Misak, V.Y. Perel, V. Sabelkin, and S. Mall, Corrosion Fatigue Crack Growth Behavior of 7075-T6 Under Biaxial Tension—Tension Cyclic Loading Condition, Eng. Fract. Mech., 2013, 106, p 38–48
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Sabelkin, V., Mall, S. & Misak, H. Investigation into Corrosion Pit-to-Fatigue Crack Transition in 7075-T6 Aluminum Alloy. J. of Materi Eng and Perform 26, 2535–2541 (2017). https://doi.org/10.1007/s11665-017-2697-4
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DOI: https://doi.org/10.1007/s11665-017-2697-4