Effect of Aging Treatments on the Tensile Strength and SCC Resistance of 7A04 Aluminum Alloy

Abstract:

Effect of different aging treatments(namely AT1, AT2, AT3 and AT4) on the tensile strength(TS) and stress corrosion cracking(SCC) resistance of 7A04 aluminum alloy in 3.5% NaCl+0.5% H₂O₂ solution was investigated using constant load tensile stress corrosion test. Electrochemical behavior of the alloy after different aging treatments was analyzed in 3.5% NaCl solution. The results show that AT1 (i.e. 135°C/16h) increases the TS but decreases the SCC resistance of 7A04. AT2 (i.e. 120°C/7h+165°C/10h) provides the highest SCC resistance and simultaneously retains the TS. AT3 (i.e. 115°C/5h+165°C/10h) decreases both the TS and SCC resistance. The electrochemical analysis indicates that the corrosion resistance of AT2 is the highest, which helps enhance the SCC resistance. The scanning electron micrographs reveal that intergranular corrosion occurs from the corrosion pits on the surface of the specimens when tested under stress, resulting in the ultimate fracture.

• Periodical: Applied Mechanics and Materials (Volumes 490-491)
• Pages: 73-77
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.490-491.73
• Online since: January 2014
• Authors: Chun Juan Fu, Mei Yu, Rong Bao Ma, Rui Yang Wang, Jian Hua Liu
• Keywords: 7A04, Aging Treatment, Electrochemical Method, SCC Resistance

References

[1] Z. Herong, L. Xiaogang, X. Kui and D. Chaofang: Rare Metal Mat Eng Vol. 38 (2009), p.293.

[2] T. Marlaud, B. Malki, C. Henon, and B. Baroux: Corros Sci Vol. 53 (2011), p.3139.

[3] J. Wloka, T. Hack and S. Virtanen: Corros Sci Vol. 49 (2007), p.1437.

[4] B. Sarkar, M. Marek and E. A. Starke: Jr, Met. Trans Vol. 12 (1981), p. (1939).

[5] D. Wang, Z. Y. Ma and Z. M. Gao: Mater Chem Phys Vol. 117 (2009), p.228.

[6] S. Chen, K. Chen, G. Peng, X. Liang and X. Chen: T Nonferr Metal Soc Vol. 22 (2012), p.47.

[7] B. M. Cina, U.S. Patent 3, 856, 584. (1974).

[8] D. K. Xu, N. Birbilis and P. A. Rometsch: Corros Sci Vol. 54 (2012), p.17.

[9] H. Zhou, X. Li, C. Dong, J. Ma, and J. Chin: Soc. Corros. Prot Vol. 28 (2008), p.345.

[10] D. Wang, Z. Y. Ma: Alloy Compd Vol. 494 (2009), p.360.