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Microstructures of Oxide Films Formed in Alloy 182 BWR Core Shroud Support Leg Cracks

  • Jiaxin ChenEmail author
  • Daniel Jädernäs
  • Fredrik Lindberg
  • Henrik Pettersson
  • Martin Bjurman
  • Kwadwo Kese
  • Anders Jenssen
  • Massimo Cocco
  • Hanna Johansson
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)

Abstract

This paper contributes to a TEM examination on the oxide films formed at three locations along a crack path in Alloy 182 weld from a BWR core shroud support leg, namely, the crack mouth, the midway between the mouth and the crack tip, and the crack tip. In the crack mouth the oxide film was approximately 1.6 μm in thickness and consisted of relatively pure NiO. The midway oxide film was mainly a nickel chromium oxide with a film thickness of 0.3 μm. At the crack tip the oxide film was a nickel chromium iron oxide with a film thickness of 30 nm. In all studied locations the main oxides had the similar rocksalt structure and the cracks were much wider than the thicknesses of the oxide films. It probably suggests that the corroded metal was largely dissolved into the coolant. The different dissolution rates of nickel, chromium and iron cations in the oxide films are clearly displayed with the compositions of the residual oxides. The oxide stability under different redox potentials along the crack path is briefly discussed.

Keywords

Crack Oxide microstructure BWR Core shroud Support leg TEM FIB SEM 

Notes

Acknowledgements

The authors wish to express their sincere gratitude to Mr. Roger Lundström and Mr. Michael Jakobsson at Studsvik Nuclear AB who performed light optical microscopy work, and to Dr. J. Öijerholm at Studsvik Nuclear AB for his technical and administrative support.

References

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Copyright information

© The Minerals, Metals & Materials Society 2019

Authors and Affiliations

  • Jiaxin Chen
    • 1
    Email author
  • Daniel Jädernäs
    • 1
  • Fredrik Lindberg
    • 2
  • Henrik Pettersson
    • 3
  • Martin Bjurman
    • 1
  • Kwadwo Kese
    • 1
  • Anders Jenssen
    • 1
  • Massimo Cocco
    • 4
  • Hanna Johansson
    • 4
  1. 1.Studsvik Nuclear ABNyköpingSweden
  2. 2.Swerea KIMABKistaSweden
  3. 3.Department of PhysicsChalmers University of TechnologyGothenburgSweden
  4. 4.Forsmark Kraftgrupp ABForsmarkSweden

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