Journal of Materials Engineering and Performance

, Volume 27, Issue 8, pp 4235–4243 | Cite as

Severe Hot Corrosion of the Superalloy IN718 in Mixed Salts of Na2SO4 and V2O5 at 700 °C

  • Dhananjay PradhanEmail author
  • Girija Shankar Mahobia
  • Kausik Chattopadhyay
  • Vakil Singh


This study presents hot corrosion behavior of the superalloy IN718 in 100 wt.% NaCl (salt S) and in salt mixtures of 60 wt.% Na2SO4 + 40 wt.% V2O5 (SM1) and 75 wt.% Na2SO4 + 15 wt.% NaCl + 10 wt.% V2O5 (SM2), deposited separately by spray gun technique, at elevated temperature of 700 °C. The weight gain per unit area at 700 °C was increased by 49% for salt S, 153% for the dual salt mixture SM1, and only 8% for the triple salt mixture SM2, in comparison with that observed earlier at 600 °C. The marked increase in the severity of corrosion at 700 °C is attributed to formation of the highly damaging compound NaVO3 that significantly enhances the oxygen activity, in the SM1 coated samples. The effect of surface roughness and dislocation density on corrosion behavior at 700 °C, however, is found to be similar to that at 600 °C. Ultrasonic shot peening, a novel technique of surface modification, is found to enhance the hot corrosion resistance in the salt mixture SM1 at 700 °C appreciably due to extensive grain refinement to nanoscale and formation of highly protective Cr2O3 layer in the surface region.


corrosion kinetics hot corrosion salt and salt mixtures ultrasonic shot peening 



The authors are thankful to Prof. N V C Rao and Dr. Dinesh Pandit, Department of Geology, Institute of Science, B.H.U., Varanasi for providing EPMA facility.


  1. 1.
    M. Sundararaman, P. Mukhopadhyay, and S. Banerjee, Precipitation of the δ-Ni3Nb Phase in Two Nickel Base Superalloys, Met. Trans A, 1988, 19(3), p 453–465CrossRefGoogle Scholar
  2. 2.
    J.P. Collier, S.H. Wong, J.K. Tien, and J.C. Phillips, The Effect of Varying AI, Ti, and Nb Content on the Phase Stability of Inconel 718, Met. Mater. Trans. A, 1988, 19(7), p 1657–1666CrossRefGoogle Scholar
  3. 3.
    G.Y. Lai, High-Temperature Corrosion and Materials Applications, 1st ed., U.S.A, ASM International, 2007Google Scholar
  4. 4.
    N. Eliaz, G. Shemshand, and R.M. Latanision, Hot Corrosion in Gas Turbine Components, Eng. Fail. Anal., 2002, 9, p 31–43CrossRefGoogle Scholar
  5. 5.
    G.S. Mahobia, N. Paulose, S.L. Mannan, R.G. Sudhakar, K. Chattopadhyay, N.C.S. Srinivas, and V. Singh, Effect of Hot Corrosion on Low Cycle Fatigue Behavior of Superalloy IN718, Int. J. Fatigue, 2014, 59, p 272–281CrossRefGoogle Scholar
  6. 6.
    V. Mannava, A.S. Rao, N. Paulose, M. Kamaraj, and R.S. Kottada, Hot Corrosion Studies on Ni-Base Superalloy at 650 °C Under Marine-Like Environment Conditions Using Three Salt Mixture (Na2SO4 + NaCl + NaVO3), Corr. Sci., 2016, 105, p 109–119CrossRefGoogle Scholar
  7. 7.
    F. Mansfeld, N.E. Paton, and W.M. Robertson, The High Temperature Behavior of Superalloys Exposed to Sodium Chloride: II, Corrosion, Met. Mater. Trans. B, 1973, 4(1), p 321–327Google Scholar
  8. 8.
    F. Saegusa and D.A. Shores, Corrosion Resistance of Superalloys in the range 800-1300 F (430-700 °C), J. Mater. Energy Syst., 1982, 4(1), p 16–27CrossRefGoogle Scholar
  9. 9.
    K.A. Ellison, P. Lowden, J. Liburdi, and D.H. Boone, Repair joints in nickel-based superalloys with improved hot corrosion resistance, International Gas Turbine and Aeroengine Congress and Exposition, Cincinnati, 1993, p 24–27Google Scholar
  10. 10.
    L. Jian, C.Y. Yuh, and M. Farooque, Oxidation Behavior of Superalloys in Oxidizing and Reducing Environments, Corr. Sci., 2000, 42(9), p 1573–1585CrossRefGoogle Scholar
  11. 11.
    S. Prakash, D. Puri, and H. Singh, Hot Corrosion Behaviour of Plasma Sprayed Coatings on a Ni-Based Superalloy in Na2SO4-60% V2O5 Environment, ISIJ Int., 2005, 45(6), p 886–895CrossRefGoogle Scholar
  12. 12.
    T.S. Sidhu, S. Prakash, and R.D. Agrawal, Characterisations of HVOF Sprayed NiCrBSi Coatings on Ni-and Fe-Based Superalloys and Evaluation of Cyclic Oxidation Behaviour of Some Ni-Based Superalloys in Molten Salt Environment, Thin Solid Films, 2006, 515(1), p 95–105CrossRefGoogle Scholar
  13. 13.
    T.S. Sidhu, S. Prakash, and R.D. Agrawal, Study of Molten Salt Corrosion of High Velocity Oxy-Fuel Sprayed Cermet and Nickel-Based Coatings at 900 °C, Met. Mater. Trans. A, 2007, 38(1), p 77–85CrossRefGoogle Scholar
  14. 14.
    S.H. Cho, I.J. Cho, G.S. You, J.S. Yoon, and S.W. Park, Corrosion Behavior of Ni-Base Alloys in a Hot Lithium Molten Salt Under an Oxidizing Atmosphere, MMI, 2007, 13(4), p 303–309Google Scholar
  15. 15.
    S. Kamal, R. Jayaganthan, S. Prakash, and S. Kumar, Hot Corrosion Behavior of Detonation Gun Sprayed Cr3C2-NiCr Coatings on Ni and Fe-Based Superalloys in Na2SO4-60% V2O5 Environment at 900 °C, J. Alloys Compd., 2008, 463(1), p 358–372CrossRefGoogle Scholar
  16. 16.
    L. Xueming, S. Wenru, G. Shouren, and H. Zhuangqi, Hot Corrosion Behavior of IN718 Alloy and Its Effect on Mechanical Properties, Rare Met. Mater. Eng., 2008, 2, p 016Google Scholar
  17. 17.
    G. Sreedhar, M.D.M. Alam, and V.S. Raja, Hot Corrosion Behaviour of Plasma Sprayed YSZ/Al2O3 Dispersed NiCrAlY Coatings on Inconel-718 Superalloy, Surf. Coat. Tech., 2009, 204(3), p 291–299CrossRefGoogle Scholar
  18. 18.
    G. Sreedhar and V.S. Raja, Hot Corrosion of YSZ/Al2O3 Dispersed NiCrAlY Plasma-Sprayed Coatings in Na2SO4–10 wt.% NaCl Melt, Corr. Sci., 2010, 52(8), p 2592–2602CrossRefGoogle Scholar
  19. 19.
    S. Kamal, R. Jayaganthan, and S. Prakash, High Temperature Cyclic Oxidation and Hot Corrosion Behaviours of Superalloys at 900 °C, Bull. Mater. Sci., 2010, 33(3), p 299–306CrossRefGoogle Scholar
  20. 20.
    J.L. Trinstancho-Reyes, M. Sanchez-Carrillo, R. Sandoval-Jabalera, V.M. Orozco-Carmona, F. Almeraya-Calderon, J.G. Chacon-Nava, J.G. Gonzalez-Rodriguez, and A. Martinez-Villafane, Electrochemical Impedance Spectroscopy Investigation of Alloy Inconel-718 in Molten Salts at High Temperature, Int. J. Electrochem. Sci., 2011, 6, p 419–431Google Scholar
  21. 21.
    A. Rahman, V. Chawla, R. Jayaganthan, R. Chandra, and R. Ambardar, Study of Cyclic Hot Corrosion of Nanostructured Cr/Co-Al Coatings on Superalloy, Mater. Chem. Phys., 2011, 126(1), p 253–261CrossRefGoogle Scholar
  22. 22.
    W. Garkas, S. Weiß, and Q.M. Wang (Cr1−xAlx)N as a Candidate for Corrosion Protection in High Temperature Segments of CCS Plants, Environ. Earth Sci., 2013, 70(8), p 3761–3770CrossRefGoogle Scholar
  23. 23.
    S. Saladi, J. Menghani, and S. Prakash, Hot Corrosion Behaviour of Detonation-Gun Sprayed Cr3C2-NiCr Coating on Inconel-718 in Molten Salt Environment at 900 °C, Trans. IIM, 2014, 67(5), p 623–627Google Scholar
  24. 24.
    A. Ajay, V.S. Raja, G. Sivakumar, and S.V. Joshi, Hot Corrosion Behavior of Solution Precursor and Atmospheric Plasma Sprayed Thermal Barrier Coatings, Corr. Sci., 2015, 98, p 271–279CrossRefGoogle Scholar
  25. 25.
    C.J. Wang and Y.C. Chang, NaCl-Induced Hot Corrosion of Fe-Mn-Al-C Alloys, Mater. Chem. Phys., 2002, 76(2), p 151–161CrossRefGoogle Scholar
  26. 26.
    T.S. Sidhu, A. Malik, S. Prakash, and R.D. Agrawal, Cyclic Oxidation Behavior of Ni-and Fe-Based Superalloys in Air and Na2SO4-25% NaCl Molten Salt Environment at 800 °C, Int. J. Phys. Sci., 2006, 1(1), p 027–033Google Scholar
  27. 27.
    H. Singh, D. Puri, and S. Prakash, An Overview of Na2SO4 and/or V2O5 Induced Hot Corrosion of Fe-and Ni-Based Superalloys, Rev. Adv. Mater. Sci., 2007, 16(1), p 27–50Google Scholar
  28. 28.
    R.A. Rapp, Hot Corrosion of Materials: A Fluxing Mechanism, Corr. Sci., 2002, 44(2), p 209–221CrossRefGoogle Scholar
  29. 29.
    J.R. Nicholls, Designing Oxidation-Resistant Coatings, JOM, 2000, 52(1), p 28–35CrossRefGoogle Scholar
  30. 30.
    M.Y. Nazmy, The Effect of Environment on the High Temperature Low Cycle Fatigue Behaviour of Cast Nickel-Base IN-738 Alloy, Mater. Sci. Eng., 1982, 55(2), p 231–237CrossRefGoogle Scholar
  31. 31.
    M.Y. Nazmy, Effect of Room Temperature Prestrain and Subsequent Heat Treatment on the Creep Life of a Ni-Base Superalloy, Scripta Met., 1982, 16(12), p 1329–1332CrossRefGoogle Scholar
  32. 32.
    M. Yoshiba, Effect of Hot Corrosion on the Mechanical Performances of Superalloys and Coating Systems, Corr. Sci., 1993, 35(5), p 1115–1124CrossRefGoogle Scholar
  33. 33.
    R. Walter and M.B. Kannan, Influence of Surface Roughness on the Corrosion Behaviour of Magnesium Alloy, Mater. Des., 2011, 32(4), p 2350–2354CrossRefGoogle Scholar
  34. 34.
    D. Pradhan, G.S. Mahobia, K. Chattopadhyay, and V. Singh, Effect of Surface Roughness on Corrosion Behavior of the Superalloy IN718 in Simulated Marine Environment, J Alloys Compd., 2018, 740, p 272–281CrossRefGoogle Scholar
  35. 35.
    S. Kumar, G.S. Rao, K. Chattopadhyay, G.S. Mahobia, N.S. Srinivas, and V. Singh, Effect of Surface Nanostructure on Tensile Behavior of Superalloy IN718, Mater. Des., 2014, 62, p 76–82CrossRefGoogle Scholar
  36. 36.
    A. Sanda, V. García Navas, and O. Gonzalo, Surface State of Inconel 718 Ultrasonic Shot Peened: Effect of Processing Time, Material and Quantity of Shot Balls and Distance from Radiating Surface to Sample’, Mater. Des., 2011, 32(4), p 2213–2220CrossRefGoogle Scholar
  37. 37.
    L. Tan, X. Ren, K. Sridharan, and T.R. Allen, Effect of Shot-Peening on the Oxidation of Alloy 800H Exposed to Supercritical Water and Cyclic Oxidation, Corr. Sci., 2008, 50, p 2040–2046CrossRefGoogle Scholar
  38. 38.
    X.Y. Zhang, M.H. Shi, C. Li, N.F. Liu, and Y.M. Wei, The Influence of Grain Size on the Corrosion Resistance of Nanocrystalline Zirconium Metal, Mater. Sci. Eng., A, 2007, 448, p 259–263CrossRefGoogle Scholar
  39. 39.
    S. Kumar, K. Chattopadhyay, G.S. Mahobia, and V. Singh, Hot Corrosion Behaviour of Ti-6Al-4V Modified by Ultrasonic Shot Peening, Mater. Des., 2016, 110, p 196–206CrossRefGoogle Scholar
  40. 40.
    G. Dini, R. Ueji, and A. Najafizadeh, Flow Stress Analysis of TWIP Steel Via the XRD Measurement of Dislocation Density, Mater. Sci., 2010, 527, p 2759–2763Google Scholar
  41. 41.
    J.I. Langford and A.J.C. Wilson, Scherrer After Sixty Years: A Survey and Some New Results in the Determination of Crystallite Size, J. App. Cryst., 1978, 11(2), p 102–113CrossRefGoogle Scholar
  42. 42.
    G. Williamson and W. Hall, X-ray Line Broadening from Filed Aluminium and Wolfram, Acta Metall., 1953, 1, p 22–31CrossRefGoogle Scholar
  43. 43.
    N.B. Pilling and R.E. Bedworth, The Oxidation of Metals at High Temperatures, J. Inst. Met., 1923, 29, p 529–591Google Scholar
  44. 44.
    A.S. Khanna, Introduction to High Temperature Oxidation and Corrosion, ASM International, Russell Township, 2002Google Scholar
  45. 45.
    W. Ozgowicz, A. Kurc-Lisiecka, and A. Grajcar, Corrosion Behaviour of Cold-Deformed Austenitic Alloys, Environmental and Industrial Corrosion-Practical and Theoretical Aspects, InTech, London, 2012Google Scholar
  46. 46.
    S.J. Balsone, The Effect of Stress and Hot Corrosion on Nickel-Base Superalloys, Air Force Institute of Technology, Wright-Patterson Air Force Base, 1985Google Scholar
  47. 47.
    P.S. Sidky and M.G. Hocking, The Hot Corrosion of Ni-Based Ternary Alloys and Superalloys for Application in Gas Turbines Employing Residual Fuels, Corr. Sci., 1987, 27(5), p 499–530CrossRefGoogle Scholar
  48. 48.
    E. Otero, M.C. Merino, A. Pardo, M.V. Biezma, and G. Buitrago, Study on Corrosion Products of IN657 Alloy in Molten Salts, Key Eng. Mater., 1987, 20(4), p 3583–3591Google Scholar
  49. 49.
    C. Cuevas-Arteaga, Corrosion Study of HK-40 m Alloy Exposed to Molten Sulfate/Vanadate Mixtures Using the Electrochemical Noise Technique, Corr. Sci., 2008, 50, p 650–663CrossRefGoogle Scholar
  50. 50.
    J. Porcayo-Calderon, V.M. Salinas Bravo, R.A. Rodriguez-Diaz, and L. Martinez-Gomez, Effect of the NaVO3-V2O5 Ratio on the High Temperature Corrosion of Chromium, Int. J. Electrochem. Sci., 2015, 10, p 4928–4945Google Scholar
  51. 51.
    M.S. Doolabi, B. Ghasemi, S.K. Sadrnezhaad, A. Habibollahzadeh, and K. Jafarzadeh, Hot Corrosion Behavior and Near-Surface Microstructure of a Low-Temperature High-Activity Cr-Aluminide Coating on Inconel 738LC Exposed to Na2SO4, Na2SO4 + V2O5 and Na2SO4 + V2O5 + NaCl at 900 °C, Corr. Sci., 2017, 128, p 42–53CrossRefGoogle Scholar
  52. 52.
    H. Matsuo, Y. Nishiyama, and Y. Yamadera, Steam oxidation properties of fine grain steels, in: Proceedings from the Fourth International Conference on Advances in Materials Technology of Fossil Power Plants, Hilton Head Island, South Carolina, 25–28 October 2004.Google Scholar
  53. 53.
    Z.B. Wang, N.R. Tao, W.P. Tong, J. Lu, and K. Lu, Diffusion of Chromium in Nanocrystalline Iron Produced by Means of Surface Mechanical Attrition Treatment, Acta Mater., 2003, 51, p 4319–4329CrossRefGoogle Scholar

Copyright information

© ASM International 2018

Authors and Affiliations

  • Dhananjay Pradhan
    • 1
    Email author
  • Girija Shankar Mahobia
    • 1
  • Kausik Chattopadhyay
    • 1
  • Vakil Singh
    • 1
  1. 1.Department of Metallurgical EngineeringIndian Institute of Technology (Banaras Hindu University)VaranasiIndia

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