Variation in Residual Stresses due to Thermal Cycling Induced on the Hardfaced Grid Plate in PFBR

Abstract:

In sodium cooled fast breeder reactors, the high operating temperature necessitates hard facing of grid plate to avoid galling and to reduce the wear loss of the base material . Nickel-base cobalt-free alloy called Colmonoy-5 has been chosen as the hard facing material for the Prototype Fast Breeder Reactor (PFBR) grid plate. The grid plate (GP) which is a critical component made of 316 LN SS that holds the core subassemblies are hard faced, to prevent galling and also to minimize wear caused by subassembly insertion/removal and erosion due to high sodium velocity at 670 K. Thermal cycling of hard faced circular grid plate made by Plasma Transferred Arc Welding (PTAW) generates residual stresses due to differential shrinkage of the molten deposit and difference in coefficients of thermal expansion between the deposit and substrate material. In this project the effect of thermal cycling of a nickel-base hardfacing alloy deposited on an austenitic stainless steel grid plate was studied. Finite element analysis of hard faced circular grid plate is performed for obtaining residual stress which includes elasto-plastic analysis. Coupled thermo-mechanical analysis is done for thermal cycling of hardfaced circular gridplate to quantitatively estimate the residual stress.

• Periodical: Applied Mechanics and Materials (Volume 591)
• Pages: 98-102
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.591.98
• Online since: July 2014
• Authors: S. Balaguru*, K. Saranraj, Murali Vela Murali Vela, P. Chellapandi
• Keywords: 316 LN SS, Colmonoy, Material Property, Plasma Transferred Arc Welding, Residual Stress, Thermal Cycling

References

[1] Punitharani K. et al, Finite element analysis of residual stress and distortion in hard faced gate valve, Vol. 69, pp: 129-134, (2010).

[2] Shankar. V,. Rao. B.P. S et al Residual stress distribution in hardfaced austenitic stainless steel sleeves, Trans. Indian Inst. Met. Vol. 57, No. 3, June 2004, pp: 271-276(2004).

[3] Nadimi S. and Rohani B., Investigation and Analysis of weld induced Residual Stresses in two dissimilar pipes by Finite Element modelling, Journal of applied Sciences, Vol. 8, pp: 1014-1020, (2008).

DOI: 10.3923/jas.2008.1014.1020

[4] Mao. W. G, Zhou .Y. C et al Modeling of residual stresses variation with thermal cycling in thermal barrier coatings, Journal of Mechanics of Materials, Vol. 38, pp: 1118–1127(2006).

DOI: 10.1016/j.mechmat.2006.01.002

[5] Shih-Ying Chiang, Tsung-Lin Chou et al Life prediction of HCPV under thermal cycling test condition,. Microelectronic Engineering, Vol. 88, pp: 785–790(2011).

DOI: 10.1016/j.mee.2010.07.033

[6] Bhaduri . A. K, Indira R et al, Selection of hardfacing material for components of the Indian Prototype Fast Breeder Reactor, , Journal of Nuclear Materials, Vol 334, pp: 109–114(2004).

DOI: 10.1016/j.jnucmat.2004.05.005

[7] Chellapandi . P, et al The design of the Prototype Fast Breeder Reactor, Nuclear Engineering and Design, pp: 852–860 (2006).

DOI: 10.1016/j.nucengdes.2005.09.025

[8] ABAQUS User's Manual, Version 6. 10, Karlsson & Sorensen, Inc., Hibbitt, (2010).