Session: MF-03-01 Weld Residual Stress and Distortion

Paper Number: 123470

123470 - Residual Stress Modelling in Pwr Reactor Pressure Vessel Welded Joints 

Residual stress and strain measurements were performed on a narrow gap weld mock-up consisting of a 130 mm thick low-alloy ferritic steel plate of type SA508 Grade 3 Class 1. The welding process is a submerged arc welding (SAW) process with two beads per layer [1]. The thermal response during welding was recorded to provide information for numerical modelling of heat transfer. Detailed through-thickness measurements of residual stresses were made in the as-welded state using both incremental deep hole drilling and the contour method, and after post-weld heat treatment using deep hole drilling [2].

In this paper the FE modelling method is described as well as some recent modelling improvements achieved thanks to internal EDF R&D activities and within the framework of NeT Task Group 8 [3]. Comparison between measurements and simulation are in a very good agreement. The detailed results presented in this paper are very valuable for validation of numerical modelling, which can be used to predict the residual stress state including the description of the material behavior which depends on phase fraction evolution and tempering effects. Post-weld heat treatment significantly relieves the welding residual stresses and a focus on its modelling is presented in this paper as it is seen as a key step of the manufacturing operation determining the level of residual stresses in reactor pressure vessel welded joints.

 

[1]    D.W. Rathod, J.A. Francis, A.N. Vasileiou, M.J. Roy, P.D. English, J. Balakrishnan, M.C. Smith, N.M. Irvine : Residual stresses in arc and electron-beam welds in 130mm thick SA508 steel: Part 1 – Manufacture, International Journal of Pressure Vessels and Piping 172 (2019) 313–328.

[2]    A.N. Vasileiou, M.C. Smith, J.A. Francis, D.W. Rathod, J. Balakrishnan, N.M. Irvine : Residual stresses in arc and electron-beam welds in 130mm thick SA508 steel: Part 2 –measurements, International Journal of Pressure Vessels and Piping 172 (2019) 379–390.

[3]     V. Robin, J. Draup, M.C. Smith, A. Vasileiou, V. Akrivos, R.C. Wimpory, L. Depradeux, A. Brosse, D. Gallitelli, F. Hosseinzadeh, C.E. Truman, S. Pascal, S. Hendili, J. Delmas and C. Ohms : NeT Project Task Group 8, an international benchmark on residual stress assessment for welding repair with dissimilar materials, first phase results, PVP2023 107179, Proceedings of the ASME 2023 Pressure Vessels and Piping Conference.

Presenting Author: Vincent Robin EDF DT, Design and Technology Branch

Presenting Author Biography: Numerical modelling, Fracture mechanics, Welding

Authors:

Vincent Robin EDF DT, Design and Technology Branch
Lucas Breder Teixeira EDF DT, Design and Technology Branch
David Albrecht EDF DT Design and Technology Branch
Sofiane Hendili EDF R&D
Sami Hilal EDF R&D
Pablo Pereira Alvarez EDF R&D
Josselin Delmas EDF R&D
Lionel Depradeux EC2 Modelisation
Mike Smith University of Manchester
Anastasia Vasileiou University of Manchester