Effect of sampling direction on the stress corrosion cracking behavior of Al-Zn-Mg alloy

WU Jian-shan; DENG Yun-lai; ZHANG Zhen; ZHANG Yi-dan; SUN Lin

doi:10.13374/j.issn2095-9389.2019.03.008

Volume 41 Issue 3

Mar. 2019

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Article Navigation > Chinese Journal of Engineering > 2019 > 41(3): 350-358

WU Jian-shan, DENG Yun-lai, ZHANG Zhen, ZHANG Yi-dan, SUN Lin. Effect of sampling direction on the stress corrosion cracking behavior of Al-Zn-Mg alloy[J]. Chinese Journal of Engineering, 2019, 41(3): 350-358. doi: 10.13374/j.issn2095-9389.2019.03.008

Citation:

WU Jian-shan, DENG Yun-lai, ZHANG Zhen, ZHANG Yi-dan, SUN Lin. Effect of sampling direction on the stress corrosion cracking behavior of Al-Zn-Mg alloy[J]. Chinese Journal of Engineering, 2019, 41(3): 350-358. doi: 10.13374/j.issn2095-9389.2019.03.008

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Effect of sampling direction on the stress corrosion cracking behavior of Al-Zn-Mg alloy

doi: 10.13374/j.issn2095-9389.2019.03.008

WU Jian-shan^{1, 3},
DENG Yun-lai^{1, 2, 3},
ZHANG Zhen^{2, 3
,
,},
ZHANG Yi-dan^{1, 3},
SUN Lin⁴

1.
School of Materials Science and Engineering, Central South University, Changsha 410083, China
2.
Light Alloy Research Institute, Central South University, Changsha 410083, China
3.
Cooperative Innovation Center for Advanced Nonferrous Metal Structural Materials and Manufacturing, Central South University, Changsha 410083, China
4.
CRRC Qingdao Sifang Co., Ltd., Qingdao 266000, China

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Corresponding author: ZHANG Zhen, E-mail: helenyan_cheung@163.com
Received Date: 2018-08-19
Publish Date: 2019-03-20

Abstract

Abstract

Thick-section Al-Zn-Mg aluminum alloy extrusions are key materials for manufacturing rail transit vehicles, and stress corrosion cracking (SCC) is an important engineering application problem during the service life of these materials. The effect of sampling direction on the stress corrosion cracking behavior of Al-Zn-Mg alloys was investigated through constant load tensile stress corrosion and electrochemical tests. The microstructures of specimens were analyzed in different sampling directions both before and after stress corrosion via optical microscopy, scanning electron microscopy, and electron backscatter diffraction. Specimens with their tensile axes parallel or perpendicular to the extrusion direction of the extruded profiles were labeled as longitudinal specimens and transverse specimens, respectively. The specimens were completely immersed in a corrosive solution, a mixture of 35 g Na Cl and 1 L deionized water, with a constant unidirectional loading of 225 MPa for 360 h at 50 ± 2 ℃. The experimental results show that the transverse specimen is fractured at 315 h, whereas the longitudinal specimen does not break during the entire loading process. Thus, the transverse specimens have poor resistance to stress corrosion cracking. The corrosion current density of the longitudinal section (L-S) is0. 980 m A·cm-2, which is approximately 5 times that of the transverse section (T-S). Thus, corrosion tends to propagate along the longitudinal direction. The L-S is more susceptible to corrosion than the T-S owing to the larger misorientation difference and higher energy of the grain boundary. During the stress corrosion loading process, anodic dissolution occurs and forms corrosion pits. Then, the cooperation of the wedge force produced by the accumulation of corrosion products and constant load causes the crack to propagate along the grain boundary. Intergranular corrosion of the two types of samples is obvious under all immersion corrosion conditions. Different specimens exhibit the tendency to undergo stress corrosion cracking.
- Al-Zn-Mg alloy,
- sampling direction,
- stress corrosion cracking,
- anodic dissolution,
- intergranular corrosion

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References(25)

References

[1]	肖濤, 林化強, 葉凌英, 等. 腐蝕條件對Al-Zn-Mg鋁合金強韌性能的影響. 中國有色金屬學報, 2016, 26(7): 1391 https://www.cnki.com.cn/Article/CJFDTOTAL-ZYXZ201607004.htm Xiao T, Lin H Q, Ye L Y, et al. Effect of corrosion conditions on strength and toughness of Al-Zn-Mg aluminum alloys. Chin J Nonferrous Met, 2016, 26(7): 1391 https://www.cnki.com.cn/Article/CJFDTOTAL-ZYXZ201607004.htm
[2]	鄧運來, 王亞風, 林化強, 等. 擠壓溫度對Al-Zn-Mg合金力學性能的影響. 材料研究學報, 2016, 30(2): 87 https://www.cnki.com.cn/Article/CJFDTOTAL-CYJB201602002.htm Deng Y L, Wang Y F, Lin H Q, et al. Effect of extrusion temperature on strength and fracture toughness of an Al-Zn-Mg alloy. Chin J Mater Res, 2016, 30(2): 87 https://www.cnki.com.cn/Article/CJFDTOTAL-CYJB201602002.htm
[3]	李云, 于新. 鋁型材在軍用電子設備結構中的應用研究. 機械制造與自動化, 2015, 44(3): 68 doi: 10.3969/j.issn.1671-5276.2015.03.021 Li Y, Yu X. Research on application of aluminum-extruded-profiles in military electronic equipment. Machine Build Autom, 2015, 44(3): 68 doi: 10.3969/j.issn.1671-5276.2015.03.021
[4]	莊俊杰, 張曉燕, 孫斌, 等. 微弧氧化對7050鋁合金腐蝕行為的影響. 工程科學學報, 2017, 39(10): 1532 doi: 10.13374/j.issn2095-9389.2017.10.011 Zhuang J J, Zhang X Y, Sun B, et al. Microarc oxidation coatings and corrosion behavior of 7050 aluminum alloy. Chin J Eng, 2017, 39(10): 1532 doi: 10.13374/j.issn2095-9389.2017.10.011
[5]	陳愿情, 鄧運來, 萬里, 等. 蠕變時效對7050鋁合金板材組織與性能的影響. 材料工程, 2012(1): 71 doi: 10.3969/j.issn.1001-4381.2012.01.015 Chen Y Q, Deng Y L, Wan L, et al. Microstructures and properties of 7050 aluminum alloy sheet during creep aging. J Mater Eng, 2012(1): 71 doi: 10.3969/j.issn.1001-4381.2012.01.015
[6]	Braun R. Environmentally assisted cracking of aluminum alloys. Materialwiss Werkstofftech, 2007, 38(9): 674 doi: 10.1002/mawe.200700204
[7]	侯隴剛, 趙鳳, 莊林忠, 等. 基于厚向組織性能考量的7B50鋁合金中厚板回歸再時效熱處理. 工程科學學報, 2017, 39(3): 432 doi: 10.13374/j.issn2095-9389.2017.03.016 Hou L G, Zhao F, Zhuang L Z, et al. Retrogression and re-aging 7B50 Al alloy plates based on examining the through-thickness microstructures and mechanical properties. Chin J Eng, 2017, 39(3): 432 doi: 10.13374/j.issn2095-9389.2017.03.016
[8]	劉繼華, 李荻, 郭寶蘭. 7xxx系列Al合金應力腐蝕開裂的研究. 腐蝕科學與防護技術, 2001, 13(4): 218 doi: 10.3969/j.issn.1002-6495.2001.04.009 Liu J H, Li D, Guo B L. Investigation of stress corrosion cracking of 7xxx series aluminum alloys. Corros Sci Prot Technol, 2001, 13(4): 218 doi: 10.3969/j.issn.1002-6495.2001.04.009
[9]	Jha A K, Murty S V S N, Diwakar V, et al. Metallurgical analysis of cracking in weldment of propellant tank. Eng Fail Anal, 2003, 10(3): 265 doi: 10.1016/S1350-6307(02)00073-0
[10]	Rao A C U, Vasu V, Govindaraju M, et al. Stress corrosion cracking behaviour of 7xxx aluminum alloys: a literature review. Trans Nonferrous Met Soc China, 2016, 26(6): 1447 doi: 10.1016/S1003-6326(16)64220-6
[11]	O?oro J. The stress corrosion cracking behaviour of heat-treated Al-Zn-Mg-Cu alloy in modified salt spray fog testing. Mater Corros, 2010, 61(2): 125 doi: 10.1002/maco.200905255
[12]	Heinz A, Haszler A, Keidel C, et al. Recent development in aluminium alloys for aerospace applications. Mater Sci Eng A, 2000, 280(1): 102 doi: 10.1016/S0921-5093(99)00674-7
[13]	Chen K H, Huang L P. Strengthening toughening of 7xxx series high strength aluminum alloys by heat treatment. Trans Nonferrous Met Soc China, 2003, 13(3): 484 http://www.cqvip.com/qk/84127x/200302/8137849.html
[14]	于佰水, 邢書明, 敖曉輝, 等. 壓力對A380鋁合金的鑄造組織和力學性能的影響. 工程科學學報, 2017, 39(7): 1020 doi: 10.13374/j.issn2095-9389.2017.07.006 Yu B S, Xing S M, Ao X H, et al. Effect of pressures on macro-/microstructures and mechanical properties of A380 aluminum alloy. Chin J Eng, 2017, 39(7): 1020 doi: 10.13374/j.issn2095-9389.2017.07.006
[15]	Lee E U, Taylor R, Lei C, et al. Stress corrosion cracking of aluminum alloys. Metall Trans A, 1975, 6(4): 631 doi: 10.1007/BF02672284
[16]	Xiao Y P, Pan Q L, Li W B, et al. Influence of retrogression and re-aging treatment on corrosion behaviour of an Al-Zn-Mg-Cu alloy. Mater Des, 2011, 32(4): 2149 doi: 10.1016/j.matdes.2010.11.036
[17]	Wang D, Ma Z Y. Effect of pre-strain on microstructure and stress corrosion cracking of over-aged 7050 aluminum alloy. J Alloys Compd, 2009, 469(1-2): 445 doi: 10.1016/j.jallcom.2008.01.137
[18]	Rometsch P A, Zhang Y, Knight S. Heat treatment of 7xxx series aluminium alloys-Some recent developments. Trans Nonferrous Met Soc China, 2014, 24(7): 2003 doi: 10.1016/S1003-6326(14)63306-9
[19]	Speidel M O. Stress corrosion cracking of aluminum alloys. Metall Trans A, 1975, 6(4): 631 doi: 10.1007/BF02672284
[20]	Fang H C, Chao H, Chen K H. Effect of recrystallization on intergranular fracture and corrosion of Al-Zn-Mg-Cu-Zr alloy. J Alloys Compd, 2015, 622: 166 doi: 10.1016/j.jallcom.2014.10.044
[21]	黃俊, 彭國勝, 宋廣生, 等. 未溶相和再結晶對Al-Zn-Mg-Cu合金應力腐蝕抗力的影響. 齊魯工業大學學報, 2018, 32(2): 45 https://www.cnki.com.cn/Article/CJFDTOTAL-SQGX201802010.htm Huang J, Peng G S, Song G S, et al. The effect of undissolved particles and the recrystallization on the resistance of SCC of Al-Zn-Mg-Cu alloys. J Qilu Univ Technol, 2018, 32(2): 45 https://www.cnki.com.cn/Article/CJFDTOTAL-SQGX201802010.htm
[22]	Shi Y J, Pan Q L, Li M J, et al. Effect of Sc and Zr additions on corrosion behaviour of Al-Zn-Mg-Cu alloys. J Alloys Compd, 2014, 612: 42 doi: 10.1016/j.jallcom.2014.05.128
[23]	劉建華, 郝雪龍, 李松梅, 等. 新型含鈧Al-Mg-Cu合金的抗應力腐蝕開裂特性. 中國有色金屬學報, 2010, 20(3): 415 https://www.cnki.com.cn/Article/CJFDTOTAL-ZYXZ201003008.htm Liu J H, Hao X L, Li S M, et al. Resistance to stress corrosion cracking of new Ali-Mg-Cu alloy containing Sc. Chin J Nonferrous Met, 2010, 20(3): 415 https://www.cnki.com.cn/Article/CJFDTOTAL-ZYXZ201003008.htm
[24]	宋仁國, 曾梅光. 高強度鋁合金的氫脆. 材料科學與工程, 1995, 13(1): 63 https://www.cnki.com.cn/Article/CJFDTOTAL-CLKX501.012.htm Song R G, Zeng M G. Hydrogen embrittlement of high strength aluminum alloys. J Mater Sci Eng, 1995, 13(1): 63 https://www.cnki.com.cn/Article/CJFDTOTAL-CLKX501.012.htm
[25]	Viswanadham R K, Sun T S, Green J A S. Grain boundary segregation in Al-Zn-Mg alloys-Implications to stress corrosion cracking. Metall Mater Trans A, 1980, 11(1): 85 doi: 10.1007/BF02700441