Plastic strain and residual stress distributions in an AISI 304 stainless steel BWR pipe weld

  • Tapio Saukkonen
  • Miikka Aalto
  • Iikka Virkkunen
  • Ulla Ehrnstén
  • Hannu Hänninen
Conference paper

Abstract

In AISI 304 stainless steel pipe welds weld shrinkage causes large variations in residual plastic strain in different parts of the weld metal and heat-affected zone (HAZ). The amount of strain was analyzed by EBSD quantitatively by comparing the intra-grain misorientations to the calibration curve. Highest degrees of plastic strain (10...20%) were detected in the HAZ close to the root area of a prototypical BWR plant weld. Strain in the weld metal varies in the different directions of solidification, being high in the weld bead boundaries and near the fusion lines. Preliminary studies of the effects of mechanical and elastic anisotropy of the weld metal microstructure on the grain size level were performed by EBSD and nanoindentation. The residual stress distribution in the same weld cross-section was determined by a contour method. The residual strain and stress distributions are superimposed and EAC susceptibility of various areas of the pipe weld is evaluated and discussed.

Keywords

Electron backsacatter diffraction Stainless steel piping Welding Boiling water reactor Stress corrosion cracking Residual stress and strain Mechanical anisotropy 
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Copyright information

© TMS (The Minerals, Metals & Materials Society) 2011

Authors and Affiliations

  • Tapio Saukkonen
    • 1
  • Miikka Aalto
    • 1
  • Iikka Virkkunen
    • 1
  • Ulla Ehrnstén
    • 2
  • Hannu Hänninen
    • 1
  1. 1.Aalto University School of Science and EngineeringFinland
  2. 2.VTT Technical Research Centre of FinlandFinland

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