Effect of the As-Forged and Heat-Treated Microstructure on the Room Temperature Anisotropic Ductile Fracture of Inconel 718

  • Javad Teimouri
  • Seyed Rahman Hosseini
  • Khosro Farmanesh
Article
  • 17 Downloads

Abstract

The purpose of the present work was to investigate the effect of primary carbides and the δ-phase on the anisotropic ductile fracture of Inconel 718 in the forging process. Inconel 718 alloys were prepared by VIM + VAR processes with various carbon contents (0.009 and 0.027 wt.%). Then, the alloys were forged and annealed at temperatures of 980 and 1030 °C. The room temperature mechanical anisotropy of the alloys was evaluated at the longitudinal direction (LD) and transverse direction (TD). Tensile and impact tests were used to characterize the mechanical properties of the specimens. The microstructural characterization and the fractography of the alloys were carried out by FE-SEM. The obtained results showed that the fracture strain and the impact energy in the TD were 30-50% lower than the LD. The fracture was accelerated by the δ-phase, leading to the reduction of impact energy in the longitudinal and the lateral directions up to 50%. The low-carbon alloy indicated similar characteristics in both the LD and the TD. Aligned carbides changed the fracture path from a zigzag path in the LD to a fibrous path in the TD, while the δ-phase created a flat fracture path. The shear lip area ratio in the tensile fracture cross section was decreased by reducing ductility.

Keywords

aligned carbide fracture anisotropy Inconel 718 low carbon δ-phase 

Notes

Conflict of interest

The authors declare that they have no conflict of interest.

References

  1. 1.
    S.K. Mannan, Alloy 718 for Oilfield Applications, JOM, 2012, 64(2), p 265–270CrossRefGoogle Scholar
  2. 2.
    A. Chamanfar, L. Sarrat, M. Jahazi, M. Asadi, A. Weck, and A.K. Koul, Microstructural Characteristics of Forged and Heat Treated Inconel-718 Disks, Mater. Des., 2013, 52, p 791–800CrossRefGoogle Scholar
  3. 3.
    M. Chaturvedi and Y. Han, Strengthening Mechanisms in Inconel 718 Superalloy, Metal Sci., 1983, 17(3), p 145–149CrossRefGoogle Scholar
  4. 4.
    C. Dandre, S. Roberts, R. Evans, and R. Reed, Microstructural Evolution of Inconel 718 During Ingot Breakdown: Process Modelling and Validation, Mater. Sci. Technol., 2000, 16(1), p 14–25CrossRefGoogle Scholar
  5. 5.
    Y. Huang and T.G. Langdon, The Evolution of Delta-Phase in a Superplastic Inconel 718 Alloy, J. Mater. Sci., 2007, 42(2), p 421–427CrossRefGoogle Scholar
  6. 6.
    Y. Ono, T. Yuri, H. Sumiyoshi, E. Takeuchi, S. Matsuoka, and T. Ogata, High-Cycle Fatigue Properties at Cryogenic Temperatures in INCONEL 718 Nickel-Based Superalloy, Mater. Trans., 2004, 45(2), p 342–345CrossRefGoogle Scholar
  7. 7.
    Y.C. Lin, J. Deng, Y.Q. Jiang, D.X. Wen, and G. Liu, Hot Tensile Deformation Behaviors and Fracture Characteristics of a Typical Ni-Based Superalloy, Mater. Des., 2014, 55, p 949–957CrossRefGoogle Scholar
  8. 8.
    S. Ghorbani, R. Ghasemi, R. Ebrahimi-Kahrizsangi and A. Hojjati-Najafabadi, Effect of Post Weld Heat Treatment (PWHT) on the Microstructure, Mechanical Properties, and Corrosion Resistance of Dissimilar Stainless Steels, Mater. Sci. Eng. A, 2017, 688, p 470–479CrossRefGoogle Scholar
  9. 9.
    S. Khaja, K.K. Mehta, R.V. Babu, R.S.R. Devi, and A.K. Singh, Mechanical Properties Anisotropy of Isothermally Forged and Precipitation Hardened Inconel 718 Disk, Metall. Mater. Trans. A, 2015, 46(3), p 1140–1153CrossRefGoogle Scholar
  10. 10.
    K. Mo, G. Lovicu, X. Chen, H.M. Tung, J.B. Hansen, and J.F. Stubbins, Mechanism of Plastic Deformation of a Ni-Based Superalloy for VHTR Applications, J. Nucl. Mater., 2013, 441(1), p 695–703CrossRefGoogle Scholar
  11. 11.
    M.S. Joo, D.W. Suh, J.H. Bae, N.S. Mourino, R. Petrov, L.A.I. Kestens, and H.K.D.H. Bhadeshia, Experiments to Separate the Effect of Texture on Anisotropy of Pipeline Steel, Mater. Sci. Eng. A, 2012, 556, p 601–606CrossRefGoogle Scholar
  12. 12.
    Y. Mo, D. Wang, B. Jiang, Y. Li, H. Liu, C. Wang, and J. Wang, Effect of Vanadium on the Solidification and Homogenization Behaviors in Inconel 718 Alloy, Adv. Eng. Mater., 2016, 18(8), p 1453–1459CrossRefGoogle Scholar
  13. 13.
    C.J. Boehlert, D.S. Dickmann, and N.N. Eisinger, The Effect of Sheet Processing on the Microstructure, Tensile, and Creep Behavior of INCONEL Alloy 718, Metall. Mater. Trans. A, 2006, 37(1), p 27–40CrossRefGoogle Scholar
  14. 14.
    S.P. Coryell, K.O. Findley, M.C. Mataya, and E. Brown, Evolution of Microstructure and Texture During Hot Compression of a Ni-Fe-Cr Superalloy, Metall. Mater. Trans. A, 2012, 43(2), p 633–649CrossRefGoogle Scholar
  15. 15.
    X.C. Chen, C.B. Shi, H.J. Guo, F. Wang, H. Ren, and D. Feng, Investigation of Oxide Inclusions and Primary Carbonitrides in Inconel 718 Superalloy Refined Through Electroslag Remelting Process, Metall. Mater. Trans. B, 2012, 43(6), p 1596–1607CrossRefGoogle Scholar
  16. 16.
    W.J. Zheng, X.P. Wei, Z.G. Song, Q.L. Yong, F.E.N.G. Han, and Q.C. Xie, Effects of Carbon Content on Mechanical Properties of Inconel 718 Alloy, J. Iron Steel Res. Int., 2015, 22(1), p 78–83CrossRefGoogle Scholar
  17. 17.
    S. Azadian, L.Y. Wei, and R. Warren, Delta Phase Precipitation in Inconel 718, Mater. Charact., 2004, 53(1), p 7–16CrossRefGoogle Scholar
  18. 18.
    W.C. Liu, M. Yao, Z.L. Chen, and S.G. Wang, Niobium Segregation in Inconel 718, J. Mater. Sci., 1999, 34(11), p 2583–2586CrossRefGoogle Scholar
  19. 19.
    C. Slama and M. Abdellaoui, Structural Characterization of the Aged Inconel 718, J. Alloys Compd., 2000, 306(1), p 277–284CrossRefGoogle Scholar
  20. 20.
    C. Dayong, L. Wenchang, L. Rongbin, Z. Weihong, and Y. Mei, On the Accuracy of the X-ray Diffraction Quantitative Phases Analysis Method in Inconel 718, J. Mater. Sci., 2004, 39(2), p 719–721CrossRefGoogle Scholar
  21. 21.
    Y. Zhang, Z. Li, P. Nie, and Y. Wu, Carbide and Nitride Precipitation During Laser Cladding of Inconel 718 Alloy Coatings, Opt. Laser Technol., 2013, 52, p 30–36CrossRefGoogle Scholar
  22. 22.
    C. Slama, C. Servant, and G. Cizeron, Aging of the Inconel 718 Alloy Between 500 and 750 °C, J. Mater. Res., 1997, 12(09), p 2298–2316CrossRefGoogle Scholar
  23. 23.
    A. Mitchell, Primary Carbides in Alloy 718, in 7th International Symposium on Superalloy 718 and Derivatives, (2010), pp. 161–167.Google Scholar
  24. 24.
    S. Hirano, E. Yamamoto, H. Okamoto, Y. Oka, and M. Igarashi, Extra Low Carbon Age-Hardenable Alloys for Tubular Application in Oil and Gas Industry, in Superalloys 718, 625, 706 and Various Derivatives, (1994), pp. 775–786Google Scholar
  25. 25.
    W.D. Becker and R.J. Shipley, ASM Handbook, Failure Analysis and Prevention, Vol 11, 10th ed., ASM International, Almere, 2002Google Scholar
  26. 26.
    A.A. Benzerga, J. Besson, and A. Pineau, Anisotropic Ductile Fracture: Part I: Experiments, Acta Mater., 2004, 52(15), p 4623–4638CrossRefGoogle Scholar
  27. 27.
    W.J. Mills and L.D. Blackburn, Fracture Toughness Variations in Alloy 718, J. Eng. Mater. Technol. (Trans. ASME), 1988, 110(3), p 286–293CrossRefGoogle Scholar
  28. 28.
    N.Y. Ye, M. Cheng, S.H. Zhang, H.W. Song, H.W. Zhou, and P.B. Wang, Effect of δ Phase on Mechanical Properties of GH4169 Alloy at Room Temperature, J. Iron Steel Res. Int., 2015, 22(8), p 752–756CrossRefGoogle Scholar
  29. 29.
    N. An, Y. An, Q. Fan, Z. Fu, Z. Li, and Y. Zhang, Effect of Carbon on the Microstructural Evolution and Thermal Fatigue Behavior of a Ni-Base Superalloy, Mater. Sci. Forum, 2016, 849, p 497–502CrossRefGoogle Scholar

Copyright information

© ASM International 2018

Authors and Affiliations

  • Javad Teimouri
    • 1
  • Seyed Rahman Hosseini
    • 1
  • Khosro Farmanesh
    • 1
  1. 1.Department of Materials EngineeringMaleke-ashtar University of TechnologyIsfahanIran

Personalised recommendations