New insight into crack formation during corrosion of zirconium-based metal-oxide systems

Natasha Vermaak, Guillaume Parry, Rafael Estevez, Yves Bréchet

Research output: Contribution to journalArticleResearchpeer-review

32 Citations (Scopus)

Abstract

Zirconium alloys are typically used in nuclear pressurized water reactors (PWR) as fuel cladding tubes due to their chemical stability and their mechanical strength at operating temperatures (≈300 C). However, the corrosion of Zr-based cladding tubes is one of the factors limiting the burn-off rate in PWRs. It is commonly accepted that the corrosion kinetics involves a periodic succession of growth where the oxide thickness varies parabolically with time. As the oxide thickens, a cracking structure forms. The oxide appears striated with periodic layers of cracks running parallel to the metal/oxide interface. This cracking structure has been experimentally related to the periodicity of the oxide growth. In the present work, a finite-element study is used to investigate the development of stresses in the oxide under the combined influence of molar volume expansion during oxide formation, metal/oxide interface geometry and metallic substrate creep. The generation of tensile stresses capable of initiating the cracks that are observed experimentally is explored.

Original languageEnglish
Pages (from-to)4374-4383
Number of pages10
JournalActa Materialia
Volume61
Issue number12
DOIs
Publication statusPublished - 1 Jul 2013
Externally publishedYes

Keywords

  • Creep
  • Failure Zircaloy-4
  • Metal/oxide interface undulations
  • Oxide cracks

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