Abstract
Superinvar Fe-31Ni-5Co alloy (SI) and Co-20Cr-15W-10Ni superalloy (SA) are used in space applications. Similar metal (SI-SI and SA-SA) joints as well as dissimilar metal (SA-SI) joints of these alloys have been made using electron beam welding (EBW) technique. Extensive characterization of these weldments has been carried out using optical and electron microscopy, microhardness measurements and tensile testing at ambient and cryogenic temperatures. It has been observed that weld efficiency is 100% for similar metal joints, whereas it is governed by base metal properties of the alloy having lower strength for dissimilar metal joint. Weld efficiency of SA-SI/EBW joint is comparable with base metal of lower strength indicating no detrimental formation of intermetallic/brittle phase. Microhardness of the SA-SI/EBW joint is found to be representative of the respective base metal properties with no sudden variation across the SA/SI interface in the weldment indicating good dilution in the weld. This has been confirmed through energy-dispersive spectrum using x-rays (EDX) showing the presence of Fe near the superalloy weldment interface and the presence of Cr and W near the superinvar weldment interface. Increase in strength and decrease in ductility of base metals are observed for all types of joints when tested at cryogenic temperature (77 K) vis-à-vis at ambient temperature. Fracture features of the failed surface of SA-SI/EBW joint are found to be similar to that of the SI-SI/EBW joint. Microhardness, mechanical properties and fracture analysis confirm that failure of dissimilar metal joint takes place toward lower strength base metal, i.e., superinvar.
Similar content being viewed by others
References
J.R. Davis, Alloying: Understanding the Basics, ASM Handbooks, ASM International, Materials Park, 2001, p 540
F. Duffaut and R. Cozar, Property Adjustments in Controlled Expansion and Elasticity Alloys, The Iron-Nickel Alloys, G. Beranger, F. Duffaut, J. Morlet, and J.F. Tiers, Ed., Lavoisier Publishing Intercept Ltd., Paris, 1996, p 109
V. Anil Kumar, R.K. Gupta, S.V.S. Narayana Murty, and A.D. Prasad, Hot Workability and Control of Microstructure in Cobalt Based Superalloy Co20Cr15W10Ni, J. Alloys Compd., 2016, 676, p 527
R.K. Gupta, P. Varma, V. Anil Kumar, P. Sarkar, J. Desai, and P. Ramkumar, Processing and Characterization of Superinvar for Space Application, Mater. Sci. Forum, 2015, 830–831, p 30
M.J. Donachi, Jr., Superalloy Source Book, ASM, Metals Park, 1984, p 37
T. Soysal, S. Kou, D. Tat, and T. Pasang, Macrosegregation in Dissimilar Metal Fusion Welding, Acta Mater., 2016, 110, p 149
S.W. Banovic, J.N. DuPont, and A.R. Marder, Dilution and Microsegregation in Dissimilar Metal Welds Between Super Austenitic Stainless Steel and Nickel Base Alloys, Sci. Technol. Weld. Join., 2002, 7(6), p 374
B.R. Ghosh, R.K. Gupta, S. Biju, and P.P. Sinha, Modified Welding Technique of a Hypo-eutectic Al-Cu Alloy for Higher Mechanical Properties, J. Solid Mech. Mater. Eng., 2007, 1(4), p 459
R.K. Gupta, B.R. Ghosh, S. Biju, and P.P. Sinha, Improvement in Weld Strength of Al Alloy AA2219 by Design of GTA Welding Process, Aust. Weld. J., 2009, 54, p 37
V. Anil Kumar, R.K. Gupta, S.K. Manwatkar, P. Ramkumar, and P.V. Venkitakrishnan, Effect of Prior and Post-weld Heat Treatment on Electron Beam Weldments of (α + β) Titanium Alloy Ti-5Al-3Mo-1.5V, J. Mater. Eng. Perform., 2016, 25(6), p 2147
M.G. Pillai, R.K. Gupta, B. Pant, and P.S. Sreejith, Role of Material Thickness on Tensile Properties of Ti6Al4V Welds, Trans. IIM, 2015, 68(3), p 423
Z. Sun and R. Karppi, The Application of Electron Beam Welding for the Joining of Dissimilar Metals: An Overview, J. Mater. Proc. Technol., 1996, 59, p 257
N. Arivazhagan, S. Singh, S. Prakash, and G.M. Reddy, Investigation on AISI, 304 Austenitic Stainless Steel to AISI, 4140 Low Alloy Steel Dissimilar Joints by Gas Tungsten Arc, Electron Beam and Friction Welding, Mater. Des., 2011, 32, p 3036
F. Findik, Recent Developments in Explosive Welding, Mater. Des., 2011, 32(3), p 1081
N. Ozdemira, F. Sarsılmaza, and A. Hascalıkb, Effect of Rotational Speed on the Interface Properties of Friction-Welded AISI, 304L to 4340 Steel, Mater. Des., 2007, 28(1), p 301
A.S. Lima, A.M. Nascimento, H.F.G. Abreu, and P. De Lima, Sensitization Evaluation of the Austenitic Stainless Steel AISI304L, 316L, 321 and 347, J. Mater. Sci., 2005, 40, p 143
V. Muthupandi, P. Bala Srinivasan, S.K. Seshadri, and S. Sundaresan, Effect of Weld Metal Chemistry and Heat Input on the Structure and Properties of Duplex Stainless Steel Welds, Mater. Sci. Eng., A, 2003, 358(9), p 16
G.M. Reddy and P.V. Ramana, Role of Ni as an Interlayer in Dissimilar Metal Friction Welding of Maraging Steel to Low Alloy Steel, J. Mater. Proc. Technol., 2012, 212, p 66
T.W. Nelson, J.C. Lippold, and M.J. Mills, Investigation of Boundaries and Structures in Dissimilar Metal Welds, Sci. Technol. Weld. Join., 1998, 3(5), p 249
M. Sireesha, V. Shankar, Shaju K. Albert, and S. Sundaresan, Microstructural Features of Dissimilar Welds Between 316LN Austenitic Stainless Steel and Alloy 800, Mater. Sci. Eng., A, 2000, 292, p 74
G. Phanikumar, S. Manjini, P. Dutta, J. Mazumder, and K. Chattopadhyay, Characterization of Continuous CO2 Laser Welded Fe-Cu Dissimilar Couple, Metall. Mater. Trans. A, 2005, 36A, p 2137
M. Sobih, Z. Elseddig, K. Almazy, and M. Sallam, Experimental Evaluation and Characterization of Electron Beam Welding of 2219 Al-Alloy, Indian J. Mater. Sci., 2016, doi:10.1155/2016/5671532
Acknowledgments
Authors thank DGM, MPA/ GM, MMA/ DD, MME, VSSC for providing guidance during this work and Director, VSSC for granting permission to publish this work.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Gupta, R.K., Anil Kumar, V. Studies on Similar and Dissimilar Metal EBW Joints of Fe-31Ni-5Co and Co-20Cr-15W-10Ni Alloys. J. of Materi Eng and Perform 26, 2963–2973 (2017). https://doi.org/10.1007/s11665-017-2718-3
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11665-017-2718-3