Fast Reactors and Accelerator Driven Systems Knowledge Base

Conference Article: Application of Chaboche viscoplastic theory for predicting the cyclic behaviour of modified 9Cr-1Mo (T91)

Chellapandi, P.; Ramesh, R.; Chetal, S.C.; Bhoje, S.B. (Indira Gandhi Centre for Atomic Research, Kalpakkam (India))

Abstract

Modified 9Cr 1Mo (grade 91) is the structural material for the SG of 500 MWe Prototype Fast Breeder Reactor. This material is codified in RCC-MR (1993). SG top tubesheet and its connecting shell see the hot sodium temperature of about 800 K. The steam temperature is about 770 K at 17 MPa. It is envisaged that this component can meet the creep fatigue damage rules of RCC-MR with 'elastic route' itself. One of the important material data needed to use the simplified rules given in RCC-MR (1993) is 'symmetrization coefficient' (Ks) which is not yet included in RCC-MR. Ks values are established from numerous stress strain cyclic data generated theoretically by using Chaboche viscoplastic model and recommended for the inclusion in the RCC-MR. The Chaboche model for grade 91 material has 20 material parameters which are identified based on the uniaxial monotonic and cyclic data available in RCC-MR (1993) as well as the published data and many uniaxial monotonic, cyclic, creep data are compared well with the predictions.

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key words: Fast Neutron Spectrum Systems, Nuclear Technology
Reference:
Creep-fatigue damage rules for advanced fast reactor design. Technical committee meeting, Manchester (United Kingdom). 11-13 Jun 1996
International Atomic Energy Agency, Vienna (Austria)
IAEA-TECDOC--933, pp:179-190