The Paton Welding Journal, 2012, №10



2012 №10 (09)

2012 №10 (02)

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The Paton Welding Journal, 2012, #10, 2-9 pages  

EXPERIMENTAL STUDY AND MODELLING OF THERMAL-DEFORMATION PROCESSES OCCURRING IN WELDED JOINTS ON NICKEL SUPERALLOYS

K.A. Yushchenko¹, V.A. Romanova², R.R. Balokhonov², V.S. Savchenko¹, N.O. Chervyakov¹ and A.V. Zvyagintseva¹

¹E.O. Paton Electric Welding Institute, NASU, Kiev, Ukraine
²Institute of Strength Physics and Materials Science, SB RAS, Tomsk, Russia
 
 
Abstract
Results of experimental and numerical investigations of the processes of deformation and fracture of welded joints on nickel superalloys under conditions of mechanical and thermal loading are presented. Structural transformations were investigated, and thermal-deformation processes in the heat-affected zone (HAZ) during the welding cycle process were evaluated. The mechanisms of initiation and propagation of hot cracks in the HAZ metal near the fusion line were determined, and local plastic strains under the thermal cycle condition were assessed. Evolution of the stress-strain state in the HAZ metal was analysed in terms of physical mesomechanics, and conclusions on the role of grain boundaries in the processes of initiation and propagation of cracks were made.
 
Keywords: arc welding, nickel superalloys, welded joints, thermal loading, inter-grain boundaries, hot cracks, numerical modelling
 
 
Received:                06.07.12
Published:               28.10.12
 
 
References
 
1. Yushchenko, K.A., Savchenko, V.S., Zvyagintseva, A.V. (2004) Effect of heat treatment and degree of alloying on structural changes in nickel alloys. The Paton Welding J., 7, 12-14.
2. Zvyagintseva, A.V., Yushchenko, K.A., Savchenko, V.S. (2001) Effect of structural changes in high-temperature heating on ductile characteristics of nickel alloys. Ibid., 4, 13-17.
3. Ibekwe, S.R., Gabb, T. (2005) Impulse excitation study of elasticity of different precipitated microstructures in IN738LC at high temperatures. J. Materials Eng. and Performance, 14, 188-193.
4. Balikci, E., Mirshams, R.A., Raman, A. (2000) Tensile strengthening in the nickel-base superalloy IN738LC. Ibid., 9(3), 324-329.
5. Yushchenko, K.A., Savchenko, V.S., Chervyakov, N.O. et al. (2004) Character of formation of hot cracks in welding cast heat-resistant nickel alloys. The Paton Welding J., 8, 34-38.
6. Makhnenko, V.I. (1976) Computational methods of study of kinetics of welding stresses and strains. Kiev: Naukova Dumka.
7. Romanova, V.A., Balokhonov, R.R. (2009) Numerical study of deformation processes on the surface and in the bulk of three-dimensional polycrystalline grains. Fiz. Mezomekhanika, 12(2), 5-16.
8. Wilkins, M. (1999) Computer simulation of dynamic phenomena. Berlin: Springer.
9. Panin, V.E., Egorushkin, V.E. (2009) Physical mesomechanics and non-equilibrium thermodynamics as a methodological basis of nanomaterials science. Fiz. Mezomekhanika, 12(4), 7-26.
10. Panin, V.E., Egorushkin, V.E., Panin, A.V. (2010) Effect of plastic shear channeling and non-linear waves of localised plastic deformation and fracture. Ibid., 13(5), 7-26.

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