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Electrochemical Dissolution Behavior of N5 Nickel-based Single Crystal Superalloy in Aqua Regia Electrolyte |
Zengyi SONG, Li LIU, Li DENG, Yuan SUN, Yizhou ZHOU( ) |
Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China |
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Abstract The wet recovery efficiency of superalloy directly depends on its dissolution rate, therefore,the electrochemical dissolution behavior of a Ni-based superalloy N5 in aqua regia was studied by means of potentiondynamic polarization measurement and electrochemical impedance spectroscopy (EIS), as well as galvanostatic- and potentiostaic-electrolysis. While the surface morphology and dissolution products of the treated alloy were characterized by means of SEM, EDS, EPMA and XRD. It was found that during electrolysis a two layered corrosion product formed on the alloy surface, which consisted of an outer layer with loose deposition of oxides and carbides of Ta and W and an inner porous layer consisted of residual matrix and Cr-rich oxides. A qualitative model has been assumed to illustrate the electrochemical dissolution behavior. It follows that the diffusion barrier effect induced by corrosion products on the anode is the main cause responsible for the increase of the electrolytic resistance, hence, stripping off the corrosion products in time can increase the dissolution rate of the superalloy by ca 100%.
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Received: 06 May 2017
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Fund: Supported by National Natural Science Foundation of China (51271186) |
[1] | Sun X F, Jin T, Zhou Y Z, et al.Research progress of nickel-base single crystal superalloys[J]. Mater. China, 2012, 31(12): 1(孙晓峰, 金涛, 周亦胄等. 镍基单晶高温合金研究进展[J]. 中国材料进展, 2012, 31(12): 1) | [2] | Chang L H.Effects of the main alloy elements on microstructure and properties of nickel base alloys[J]. Turb. Technol., 2001, 43: 319(常连华. 主要合金元素对镍基合金组织和性能的影响[J]. 汽轮机技术, 2001, 43: 319) | [3] | Huang Y, Wang L, Liu Y, et al.Effects of alloying elements on oxidation behavior of a Ni-base superalloy at 1223 K[J]. Trans. Mater. Heat Treat., 2011, 32(12): 1(黄炎, 王磊, 刘杨等. 合金元素对Ni基高温合金1223K氧化行为的影响[J]. 材料热处理学报, 2011, 32(12): 1) | [4] | Xing W D, Fan X X, Dong H G, et al.Regeneration technology and progress of waste superalloy[J]. Chin. J. Rare Met., 2013, 37: 494(行卫东, 范兴祥, 董海刚等. 废旧高温合金再生技术及进展[J]. 稀有金属, 2013, 37: 494) | [5] | Srivastava R R, Kim M S, Lee J C, et al.Resource recycling of superalloys and hydrometallurgical challenges[J]. J. Mater. Sci., 2014, 49: 4671 | [6] | Meng H Q, Ma G, Wu X, et al.Hydrometallurgical recovery of waste Ni-Co super-allous[J]. Guangzhou Chem. Ind., 2012, 40(17): 29(孟晗琪, 马光, 吴贤等. 镍钴高温合金废料湿法冶金回收[J]. 广州化工, 2012, 40(17): 29) | [7] | Ma R J.New development of hydrometallurgy[J]. Hydrometall. China, 2007, 26: 1(马荣骏. 湿法冶金新发展[J]. 湿法冶金, 2007, 26: 1) | [8] | Palant A A, Levin A M, Levchuk O M, et al.Electrochemical processing of the metallic wastes of ZhS32 nickel superalloys[J]. Russ. Metall., 2013, 2013: 497 | [9] | Palant A A, Levchuk O M, Bryukvin V A, et al.Complex electrochemical processing of the metallic wastes from a rhenium-containing nickel superalloy in sulfuric acid electrolytes[J]. Russ. Metall., 2011, 2011: 589 | [10] | Palant A A, Gracheva O M, Bryukvin V A.Symmetric alternating current-assisted electrochemical processing of metallic rhenium wastes in ammonia electrolytes[J]. Russ. Metall., 2007, 2007: 643 | [11] | Stoller V, Olbrich A, Meese-Marktscheffel J, et al.Process for electrochemical decomposition of superalloys [P]. US Pat., 2003013 6685A1, 2003 | [12] | Stoller V, Olbrich A, Meese-Marktscheffel J, et al.Electrochemical dissolution process for disintegrating superalloy scraps [P]. European Patent. 1312686B1, 2008 | [13] | Haisch T, Mittemeijer E, Schultze J W.Electrochemical machining of the steel 100Cr6 in aqueous NaCl and NaNO3 solutions: Microstructure of surface films formed by carbides[J]. Electrochim. Acta, 2001, 47: 235 | [14] | Wang D Y, Zhu Z W, Wang N F, et al.Investigation of the electrochemical dissolution behavior of Inconel 718 and 304 stainless steel at low current density in NaNO3 solution[J]. Electrochim. Acta, 2015, 156: 301 | [15] | Meleka A H, Glew D A.Electrochemical machining[J]. Int. Mater. Rev., 1977, 22: 229 | [16] | Fernandes S Z, Mehendale S G, Venkatachalam S.Influence of frequency of alternating current on the electrochemical dissolution of mild steel and nickel[J]. J. Appl. Electrochem., 1980, 10: 649 | [17] | Olsson C O A, Landolt D. Passive films on stainless steels—chemistry, structure and growth[J]. Electrochim. Acta, 2003, 48: 1093 | [18] | Singh V B, Arvind U.Active, passive and transpassive dissolution of a nickel base super alloy in concentrated acid mixture solution[J]. Mater. Corros., 1995, 46: 590 | [19] | Abdallah M.Corrosion behaviour of 304 stainless steel in sulphuric acid solutions and its inhibition by some substituted pyrazolones[J]. Mater. Chem. Phys., 2003, 82: 786 | [20] | Kolotyrkin Y M.The electrochemistry of alloys[J]. Electrochim. Acta, 1980, 25: 89 | [21] | Mischler S, Vogel A, Mathieu H J, et al.Chemical composition of the passive film on Fe-24Cr and Fe-24Cr-11Mo studied by AES, XPS and SIMS[J]. ChemInform, 1991, 32: 925 |
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