Sensitization Failure Mechanism and Reversion Regulation of TIG Welded Joints in 5A06 Alloy
Received date: 2026-01-15
Revised date: 2026-04-10
Online published: 2026-06-17
Owing to their excellent corrosion resistance and weldability, 5xxx series Al-Mg alloys are widely used in marine and offshore structures. However, research on the sensitization behavior and reversion treatment of Al-Mg alloy welded joints remains underdeveloped with regard to base materials, despite welded joints being critical zones for failure. To address this limitation, the present study systematically investigated the microstructure and corrosion behavior of the base metal (BM), heat-affected zone (HAZ), and weld zone (WZ) of 5A06 alloy tungsten inert gas (TIG) welded joints under as-welded, sensitized (isothermal treatment at 175 °C for 100 h), and reversion-treated (isothermal treatment at 310 °C for 1 and 24 h) conditions. Various microstructural characterization techniques, along with the nitric acid mass loss test (NAMLT), were employed to clarify the sensitization-induced precipitation characteristics in different regions of the welded joints, as well as the effect of reversion treatment on corrosion performance. The results indicated that the as-welded BM consists of uniform, recrystallized grains formed by annealing. Due to welding thermal cycle, the grains in the HAZ were slightly coarsened, whereas the WZ exhibited equiaxed dendritic structures with notable Mg interdendritic segregation. After sensitization, continuous β' phase precipitates formed along the grain boundaries in the BM and HAZ, leading to severe intergranular corrosion during the NAMLT. In the WZ, additional acicular β' phase formed within the interdendritic regions, further inducing interdendritic corrosion and resulting in higher corrosion susceptibility. Reversion treatment at 310 °C for 1 h successfully dissolved the grain boundary β' phase; however, complete dissolution of the interdendritic acicular β' phase required a longer duration. Thus, to ensure the overall intergranular corrosion resistance of the joint, the reversion treatment parameters should be established based on the complete dissolution of the interdendritic acicular β' phase in the WZ.
LI Wei , FENG Jietao , FANG Canfeng , FENG Xiao , GAO Wu , LIU Min , WANG Yingmin . Sensitization Failure Mechanism and Reversion Regulation of TIG Welded Joints in 5A06 Alloy[J]. Acta Metall Sin, 2026 , 62(6) : 1105 -1116 . DOI: 10.11900/0412.1961.2026.00014
| [1] | Liu Z, Wang J R, Qin Z B, et al. A mechanistic study on stress corrosion cracking of sensitized AA5083 in a simulated water level fluctuation zone: Combined impedance analysis and tensile tests[J]. Corros. Sci., 2025, 245: 112701 |
| [2] | Sun F L, Li X G, Lu L, et al. Corrosion behavior of 5052 and 6061 aluminum alloys in deep ocean environment of South China Sea[J]. Acta Metall. Sin., 2013, 49: 1219 |
| 孙飞龙, 李晓刚, 卢 琳 等. 5052和6061铝合金在中国南海深海环境下的腐蚀行为研究[J]. 金属学报, 2013, 49: 1219 | |
| [3] | Shen Y Y, Dong Y H, Dong L H, et al. Corrosion inhibition effect of microorganism on 5754 Al alloy in seawater[J]. Acta Metall. Sin., 2020, 56: 1681 |
| 申媛媛, 董耀华, 董丽华 等. 微生物抑制5754铝合金的海水腐蚀行为[J]. 金属学报, 2020, 56: 1681 | |
| [4] | Meng Y, Deng S X, Liu Z Z, et al. Analyzing through-thickness corrosion homogeneity of stabilized AA5083 alloy after artificial sensitization[J]. Corros. Commun., 2024, 16: 24 |
| [5] | Ding Y S, Wu X L, Gao K Y, et al. The influence of stabilization treatment on long-term corrosion resistance and microstructure in Er and Zr containing 5083 aluminum alloy[J]. Mater. Charact., 2020, 161: 110143 |
| [6] | Gao W B, Gu Y, Chen L Y, et al. Effects of sensitization on environmentally assisted cracking of AA5083-H128 Al-Mg alloy[J]. J. Mater. Res. Technol., 2023, 25: 681 |
| [7] | Ji Y Y, Pan C C, Wang M Y, et al. Unraveling the role of tensile stress in corrosion and the formation of oxide films on sensitized Al-Mg alloys[J]. Corros. Sci., 2025, 257: 113306 |
| [8] | Seifi M, Holroyd N J H, Lewandowski J J. Deformation rate and sensitization effects on environmentally assisted cracking of Al-Mg naval alloys[J]. Corrosion, 2016, 72: 264 |
| [9] | Deng C M, Liu Z, Xia D H, et al. On the localized corrosion of AA5083 in a simulated dynamic seawater/air interface-Part 3: Effects of sensitization[J]. Corros. Sci., 2024, 228: 111821 |
| [10] | Zhang H T, Zhang Q D, Wang F Y, et al. Influence of Mo on microstructure, mechanical properties and intergranular corrosion properties of Al-Mg-Mn alloys[J]. J. Alloys Compd., 2024, 1007: 176284 |
| [11] | Meng C Y, Zhang D, Cui H, et al. Mechanical properties, intergranular corrosion behavior and microstructure of Zn modified Al-Mg alloys[J]. J. Alloys Compd., 2014, 617: 925 |
| [12] | Goswami R, Qadri S B. Suppression of Samson phase formation in Al-Mg alloys by boron addition[J]. Mater. Lett., 2017, 200: 21 |
| [13] | Li M J, Liu S, Wang X D, et al. Improved intergranular corrosion resistance of Al-Mg-Mn alloys with Sc and Zr additions[J]. Micron, 2022, 154: 103202 |
| [14] | Xu W, Xin Y C, Zhang B, et al. Stress corrosion cracking resistant nanostructured Al-Mg alloy with low angle grain boundaries[J]. Acta Mater., 2022, 225: 117607 |
| [15] | Yang Z J, Chen T T, Li Y Y, et al. Effect of laser surface desensitization on re-sensitization of AA5083 alloy[J]. J. Alloys Compd., 2025, 1020: 179336 |
| [16] | Gao W B, Guo Z Y, Zhao H Y, et al. Improving intergranular cracking and stress corrosion cracking resistance of highly sensitized AA5083 Al-Mg alloy via reversion heat treatment[J]. J. Alloys Compd., 2024, 1002: 175538 |
| [17] | Zhang R, Zhang Y, Yan Y, et al. The effect of reversion heat treatment on the degree of sensitisation for aluminium alloy AA5083[J]. Corros. Sci., 2017, 126: 324 |
| [18] | Kumar N, Chaudhari G P. Sensitization and stress corrosion cracking characteristics of 5059 alloy vis-à-vis 5083 alloy after reversion treatments[J]. Eng. Fai. Anal., 2024, 156: 107782 |
| [19] | Ning J A, Gao W B, Gu X Y, et al. Precipitation behavior and corrosion properties of friction stir welded AA5083 Al-Mg alloy after sensitization[J]. Mater. Charact., 2023, 199: 112782 |
| [20] | Yuan T, Zhao X H, Jiang X Q, et al. Mechanism of grain refinement of pulse current assisted plasma arc welded Al-Mg alloy[J]. Acta Metall. Sin., 2024, 60: 323 |
| 袁 涛, 赵晓虎, 蒋晓青 等. 脉冲电流辅助等离子弧焊Al-Mg合金晶粒细化机理[J]. 金属学报, 2024, 60: 323 | |
| [21] | Su S, Chen S J, Xiao J, et al. Study on vaporizing foil actuator welding process of 5A06/0Cr18Ni10Ti with interlayer[J]. Acta Metall. Sin., 2019, 55: 1041 |
| 苏 珊, 陈树君, 肖 珺 等. 基于中间过渡层的5A06/0Cr18Ni10Ti气化冲击焊接工艺研究[J]. 金属学报, 2019, 55: 1041 | |
| [22] | Sun J X, Yang K, Wang Q Y, et al. Microstructure and mechanical properties of 5356 aluminum alloy fabricated by TIG arc additive manufacturing[J]. Acta Metall. Sin., 2021, 57: 665 |
| 孙佳孝, 杨 可, 王秋雨 等. 5356铝合金TIG电弧增材制造组织与力学性能[J]. 金属学报, 2021, 57: 665 | |
| [23] | Woelke P B, Hiriyur B K, Nahshon K, et al. A practical approach to modeling aluminum weld fracture for structural applications[J]. Eng. Fract. Mech., 2017, 175: 72 |
| [24] | Liu Y, Wang W J, Xie J J, et al. Microstructure and mechanical properties of aluminum 5083 weldments by gas tungsten arc and gas metal arc welding[J]. Mater. Sci. Eng., 2012, A549: 7 |
| [25] | You J, Wang C, Qiu D, et al. Response of partitioning to cooling rate for different solutes in aluminum alloys[J]. J. Mater. Sci. Technol., 2024, 185: 155 |
| [26] | Zhang X X, Liu B, Zhou X R, et al. Laser welding introduced segregation and its influence on the corrosion behaviour of Al-Cu-Li alloy[J]. Corros. Sci., 2018, 135: 177 |
| [27] | Lei X W, Nuam V L, Bai Y, et al. Investigation on laser beam remelted Al-Cu-Li alloy part I: Segregation and aging behavior at grain and dendrite boundaries[J]. J. Alloys Compd., 2021, 855: 157519 |
| [28] | Vargel C. Corrosion of Aluminium[M]. 2nd Ed., Amsterdam: Elsevier, 2020: 189 |
| [29] | Pelton A D. Phase Transformations in Materials. Chapter 1[M]. Weinheim: Wiley-VCH, 2001: 10 |
| [30] | Ding Y S, Gao K Y, Huang H, et al. Nucleation and evolution of β phase and corresponding intergranular corrosion transition at 100-230 oC? in 5083 alloy containing Er and Zr[J]. Mater. Des., 2019, 174: 107778 |
| [31] | Du Y, Chang Y A, Huang B Y, et al. Diffusion coefficients of some solutes in fcc and liquid Al: Critical evaluation and correlation[J]. Mater. Sci. Eng., 2003, A363: 140 |
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