Residual Stress and Shrinkage Predictions on 14" Narrow Gap Dissimilar Metal Welds

For nuclear reactor applications, AREVA NP has to perform junctions between ferritic low alloy steel heavy section components and austenitic stainless steel piping systems. In these cases, welding remains the key process and AREVA NP has developed, for this kind of Dissimilar Metal Welds (DMW), narrow gap techniques requiring special manufacturing procedures to ensure a good resistance of the junctions. In parallel, numerical welding simulation has already proved its relevance to predict residual stress fields in welded components and becomes more and more a real support for industrial design engineers. This paper presents computations performed by AREVA NP on several 14" narrow gap DMW configurations. The simulations focused on the predictions of residual stress fields, for integrity issues, and shrinkages for manufacturing ones. Considering 2D axisymmetric hypotheses, the analyses simulate each elementary step of the mock-up manufacturing procedures. Multipass welding simulations reproduce the deposit of each bead by thermo-metallurgical and mechanical calculations. Note that non linear kinematic hardening models, strain annealing and phase transformation techniques, and self-clamping boundary conditions are used. The numerical results are in a good agreement with experimental data provided by neutron diffraction measurements and welding recording data. Thus, this work enables to give another evidence of the relevance of the numerical welding simulation and highlights the capability for AREVA NP to perform, with success, such a kind of analyses.

COURTIN Stephan;  ROBIN V.;  GILLES Philippe;  OHMS Carsten; 

2011-07-15

Verlag der Technischen Universität Graz

JRC53981

https://publications.jrc.ec.europa.eu/repository/handle/JRC53981,