Effect of Heat Input on Evolution of Microstructure and Tensile Properties of Gas Tungsten Constricted Arc (GTCA) Welded Inconel 718 Alloy Sheets

Abstract

The significant effect of heat input on the microstructural characteristics and tensile properties of 2-mm-thick Inconel 718 alloy sheets joined by gas tungsten constricted arc welding process was investigated systematically. It involves the application of magnetic arc constriction technique to solve the heat input-related metallurgical problems in gas tungsten arc welding of Inconel 718 alloy such as segregation of Nb and laves phase evolution in weld metal region which drastically reduces the weld mechanical properties. Heat input range was used from 495 to 585 J/mm by varying Main Current from 60 to 80 A at distinct levels of 5 A. The average secondary dendrite arm spacing was increased from 6.31 to 8.92 μm, revealing the corresponding cooling rate between 2087 and 720 °C/s. Superior tensile properties were obtained at an optimum heat input of 518 J/mm. It exhibited 98.16 and 78% of base metal strength and ductility. It is attributed to the grain refinement in fusion zone microstructure and the evolution of lower amount of laves phase with finer and discrete morphology. The average size and volume fraction of laves phase for the current sample were 3.12 μm and 7.68%. The benefits of magnetic arc constriction and Delta Current pulsing were not achieved at higher heat input.

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References

  1. 1.

    R. Damodaram, S.G.S. Raman, D.V.V. Satyanarayana, G.M. Reddy, K.P. Rao, Hot tensile and stress rupture behavior of friction welded alloy 718 in different pre-and post-weld heat treatment conditions. Mater. Sci. Eng. A 612, 414–422 (2014)

    CAS  Google Scholar 

  2. 2.

    M. Agilan, S.C. Krishna, S.K. Manwatkar, E.G. Vinayan, D. Sivakumar, B. Pant, Effect of welding processes (GTAW and EBW) and solutionizing temperature on microfissuring tendency in Inconel 718 welds. Mater. Sci. Forum 710, 603–607 (2012)

    CAS  Google Scholar 

  3. 3.

    L. Xiao, D.L. Chen, M.C. Chaturvedi, Effect of boron on fatigue crack growth behavior in superalloy IN 718 at RT and 650 °C. Mater. Sci. Eng. A 428(1–2), 1–11 (2006)

    Google Scholar 

  4. 4.

    S.H. Fu, J.X. Dong, M.C. Zhang, X.S. Xie, Alloy design and development of INCONEL718 type alloy. Mater. Sci. Eng. A 499(1–2), 215–220 (2009)

    Google Scholar 

  5. 5.

    G.D.J. Ram, A.V. Reddy, K.P. Rao, G.M. Reddy, Microstructure and mechanical properties of Inconel 718 electron beam welds. Mater. Sci. Technol. 21(10), 1132–1138 (2005)

    CAS  Google Scholar 

  6. 6.

    C.A. Huang, T.H. Wang, C.H. Lee, W.C. Han, A study of the heat-affected zone (HAZ) of an Inconel 718 sheet welded with electron-beam welding (EBW). Mater. Sci. Eng. A 398(1–2), 275–281 (2005)

    Google Scholar 

  7. 7.

    R.G. Thompson, S. Genculu, Microstructural evolution in the HAZ of Inconel 718 and correlation with the hot ductility test. Weld. J. 62(12), 337–345 (1983)

    Google Scholar 

  8. 8.

    C.H. Radhakrishna, K.P. Rao, The formation and control of Laves phase in superalloy 718 welds. J. Mater. Sci. 32, 1977–1984 (1997)

    CAS  Google Scholar 

  9. 9.

    G.D.J. Ram, A.V. Reddy, K.P. Rao, G.M. Reddy, Control of laves phase in Inconel 718 GTA welds with current pulsing. Sci. Technol. Weld. Join. 9, 390–398 (2004)

    CAS  Google Scholar 

  10. 10.

    K. Sivaprasad, S.G.S. Raman, P. Mastanaiah, G.M. Reddy, Influence of magnetic arc oscillation and current pulsing on microstructure and high temperature tensile strength of alloy 718 TIG weldments. Mater. Sci. Eng. A 428, 327–331 (2006)

    Google Scholar 

  11. 11.

    S.G.K. Manikandan, D. Sivakumar, K.P. Rao, M. Kamaraj, Microstructural characterization of liquid nitrogen cooled alloy 718 fusion zone. J. Mater. Process. Technol. 214(12), 3141–3149 (2014)

    CAS  Google Scholar 

  12. 12.

    R.K. Leary, E. Merson, R. Brydson, Microtextures and grain boundary misorientation distributions in controlled heat input titanium alloy fusion welds. J. Phy. Conf. Ser. 241, 012103 (2010)

    Google Scholar 

  13. 13.

    Heat Management, InterPulse and Plasma Systems. http://vbcie.com. Accessed 15 Aug 2017

  14. 14.

    R.K. Leary, E. Merson, K. Birmingham, D. Harvey, R. Brydson, Microstructural and microtextural analysis of InterPulse GTCAW welds in Cp-Ti and Ti–6Al–4V. Mater. Sci. Eng. A 527, 7694–7705 (2010)

    Google Scholar 

  15. 15.

    V. Vaithiyanathan, V. Balasubramanian, S. Malarvizhi, V. Petley, S. Verma, Establishing relationship between fusion zone hardness and grain size of gas tungsten constricted arc welded thin sheets of titanium alloy. SN Appl. Sci. 2, 1–12 (2020)

    Google Scholar 

  16. 16.

    V. Vaithiyanathan, V. Balasubramanian, S. Malarvizhi, V. Petley, S. Verma, Combined effect of gas tungsten arc welding process variants and post-weld heat treatment on tensile properties and microstructural characteristics of Ti–6Al–4V alloy joints. Metallogr. Microstruct. Anal. 9, 194–211 (2020)

    CAS  Google Scholar 

  17. 17.

    C.V.S. Murthy, A.G. Krishna, G.M. Reddy, Microstructure and mechanical properties of similar and dissimilar metal gas tungsten constricted arc welds: maraging steel to 13-8 Mo stainless steel. Def. Technol. 15(1), 111–121 (2018)

    Google Scholar 

  18. 18.

    C.V.S. Murthy, A.G. Krishna, G.M. Reddy, Dissimilar welding of maraging steel (250) and 13-8 Mo stainless steel by GTCAW, LBW and EBW processes. Trans. Indian Inst. Met. 72, 2433–2441 (2019)

    CAS  Google Scholar 

  19. 19.

    T. Sonar, V. Balasubramanian, S. Malarvizhi, T. Venkateswaran, D. Sivakumar, Effect of delta current and delta current frequency on tensile properties and microstructure of gas tungsten constricted arc (GTCA) welded Inconel 718 sheets. J. Mech. Behav. Mater. 28, 186–200 (2019)

    Google Scholar 

  20. 20.

    R. Cortés, E.R. Barragán, V.H. López, R.R. Ambriz, D. Jaramillo, Mechanical properties of Inconel 718 welds performed by gas tungsten arc welding. Int. J. Adv. Manuf. Technol. 94, 3949–3961 (2017)

    Google Scholar 

  21. 21.

    Rodríguez, N.K., Barragán, E.R., Lijanova, I. V., Cortés, R., Ambriz, R. R., Méndez, C., and Jaramillo D., Heat input effect on the mechanical properties of Inconel 718 gas tungsten arc welds, in Proceedings 17th International Conference New Trends Fatigue Fracture (2017), pp. 255–262

  22. 22.

    S.G. Rao, K. Saravanan, G. Harikrishnan, V.M.J. Sharma, P. Ramesh Narayan, K. Sreekumar, P. Sinha, Local deformation behaviour of Inconel 718 TIG weldments at room temperature and 550 °C. Mater. Sci. Forum 710, 439–444 (2012)

    Google Scholar 

  23. 23.

    G.M. Reddy, C.V.S. Murthy, N. Viswanathan, K.P. Rao, Effects of electron beam oscillation techniques on solidification behaviour and stress rupture properties of Inconel 718 welds. Sci. Technol. Weld. Join. 12(2), 106–114 (2007)

    CAS  Google Scholar 

  24. 24.

    A.K. Jawwad, M. Strangwood, C.L. Davis, Microstructural modification in full penetration and partial penetration electron beam welds in INCONEL-718 (IN-718) and its effect on fatigue crack initiation. Metall. Mater. Trans. A 36(5), 1237–1247 (2005)

    Google Scholar 

  25. 25.

    Y. Mei, Y. Liu, C. Liu, C. Li, L. Yu, Q. Guo, H. Li, Effect of base metal and welding speed on fusion zone microstructure and HAZ hot-cracking of electron-beam welded Inconel 718. Mater. Des. 89, 964–977 (2016)

    CAS  Google Scholar 

  26. 26.

    X. Cao, B. Rivaux, M. Jahazi, J. Cuddy, A. Birur, Effect of pre- and post-weld heat treatment on metallurgical and tensile properties of Inconel 718 alloy butt joints welded using 4 kW Nd: YAG laser. J. Mater. Sci. 44(17), 4557–4571 (2009)

    CAS  Google Scholar 

  27. 27.

    A. Odabasi, N. Unlu, G. Goller, M.N. Eruslu, A study on laser beam welding (LBW) technique: effect of heat input on the microstructural evolution of superalloy Inconel 718. Metall. Mater. Trans. A 41, 2357–2365 (2010)

    Google Scholar 

  28. 28.

    Y.N. Zhang, X. Cao, P. Wanjara, Microstructure and hardness of fiber laser deposited Inconel 718 using filler wire. Int. J. Adv. Manuf. Technol. 69(9–12), 2569–2581 (2013)

    Google Scholar 

  29. 29.

    K.R. Vishwakarma, N.L. Richards, M.C. Chaturvedi, Microstructural analysis of fusion and heat affected zones in electron beam welded ALLVAC® 718PLUS™ superalloy. Mater. Sci. Eng. A 480(1–2), 517–528 (2008)

    Google Scholar 

  30. 30.

    R. Mehrabian, B.H. Kear, M. Cohen, Rapid Solidification Processing: Principles and Technologies. Part I (Claitor’s Publication Division, Baton Rouge, 1978), p. 398

    Google Scholar 

  31. 31.

    G.D.J. Ram, A. Venugopal Reddy, K. Prasad Rao, G.M. Reddy, J.K. Sarin Sundar, Microstructure and tensile properties of Inconel 718 pulsed Nd-YAG laser welds. J. Mater. Process. Technol. 167(1), 73–82 (2005)

    CAS  Google Scholar 

  32. 32.

    G.M. Reddy, C.V.S. Murthy, K.S. Rao, K.P. Rao, Improvement of mechanical properties of Inconel 718 electron beam welds—influence of welding techniques and post weld heat treatment. Int. J. Adv. Manuf. Technol. 43(7–8), 671–680 (2008)

    Google Scholar 

  33. 33.

    G.D.J. Ram, A.V. Reddy, K.P. Rao, G.M. Reddy, Improvement in stress rupture properties of Inconel 718 gas tungsten arc welds using current pulsing. J. Mater. Sci. 40(6), 1497–1500 (2005)

    CAS  Google Scholar 

  34. 34.

    S.G.K. Manikandan, D. Sivakumar, D. Karthikesan, K.P. Rao, M. Kamaraj, Frequency modulation effect on the solidification of alloy 718 fusion zone. Proc. Mater. Sci. Technol. 1, 1361–1375 (2013)

    Google Scholar 

  35. 35.

    S.G.K. Manikandan, D. Sivakumar, K. Prasad Rao, M. Kamaraj, Laves phase control in Inconel 718 weldments. Mater. Sci. Forum 710, 614–619 (2012)

    CAS  Google Scholar 

  36. 36.

    D. Cai, W. Zhang, P. Nie, W. Liu, M. Yao, Dissolution kinetics of δ phase and its influence on the notch sensitivity of Inconel 718. Mater. Character. 58, 220–225 (2007)

    CAS  Google Scholar 

  37. 37.

    P. Gao, K. Zhang, B. Zhang, S. Jiang, B. Zhang, Microstructures and high temperature mechanical properties of electron beam welded Inconel 718 superalloy thick plate. Trans. Nonferr. Met. Soc. China 21, 315–322 (2011)

    Google Scholar 

  38. 38.

    K. Sivaprasad, S.G.S. Raman, Influence of weld cooling rate on microstructure and mechanical properties of alloy 718 weldments. Metall. Mater. Trans. A 39, 2115–2127 (2008)

    Google Scholar 

  39. 39.

    G.A. Knorovsky, M.J. Cieslak, T.J. Headley, A.D. Romig, W.F. Hammetter, Inconel 718: a solidification diagram. Metall. Trans. A 20(10), 2149–2158 (1989)

    Google Scholar 

  40. 40.

    M.J. Cieslak, T.J. Headley, A.D. Romig, T. Kollie, A melting and solidification study of alloy 625. Metall. Trans. A 19(9), 2319–2331 (1988)

    Google Scholar 

  41. 41.

    S. Rokhlins, A. Guu, A study of arc force, pool depression and weld penetration during gas tungsten arc welding. Weld. Res. 72, 381–390 (1993)

    Google Scholar 

  42. 42.

    A. Bansal, A.K. Sharma, S. Das, P. Kumar, Characterization of microstructure and strength of microwave welded Inconel 718 joints at 2.45 GHz frequency. Kov. Mater. 54, 27–35 (2016)

    CAS  Google Scholar 

Download references

Acknowledgements

The authors express their sincere gratitude to the Director, Vikram Sarabhai Space Centre (VSSC), ISRO, Thiruvananthapuram, Kerala, for providing the financial support and base material to carry out this investigation through ISRO RESPOND scheme (Project No. ISRO/RES/3/728/16-17).

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Sonar, T., Balasubramanian, V., Malarvizhi, S. et al. Effect of Heat Input on Evolution of Microstructure and Tensile Properties of Gas Tungsten Constricted Arc (GTCA) Welded Inconel 718 Alloy Sheets. Metallogr. Microstruct. Anal. 9, 369–392 (2020). https://doi.org/10.1007/s13632-020-00654-1

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Keywords

  • Gas tungsten constricted arc (GTCA) welding
  • Inconel 718 alloy
  • Heat input
  • Tensile properties
  • Microstructure
  • Laves phase
  • Segregation