University of Illinois Urbana-Champaign

Steam oxidation of FeCrAl coated Zircaloy-2

Mouche, Peter A.

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https://hdl.handle.net/2142/90650

Description

Title
Steam oxidation of FeCrAl coated Zircaloy-2
Author(s)
Mouche, Peter A.
Issue Date
2016-04-29
Director of Research (if dissertation) or Advisor (if thesis)
Heuser, Brent J.
Department of Study
Nuclear, Plasma, & Rad Engr
Discipline
Nuclear, Plasma, Radiolgc Engr
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Keyword(s)
  • Oxidation
  • Cladding
  • Nuclear
  • Accident
  • Coating
  • FeCrAl
  • Steam
Abstract
A NEITZCH Jupiter 441 simultaneous thermal analysis with a water vapor furnace was installed and calibrated for temperature and di fferential scanning calorimetry (DSC). Bare and FeCrAl coated Zircaloy-2 nuclear fuel cladding and FeCrAl coated single crystal Yttria stabilized Zirconia (YSZ) samples were oxidized in an argon/steam environment at 700 C and 1100 C. FeCrAl coated Zircaloy-2 was also heated to 1200 C in an inert environment. Real-time thermo gravimetric analysis (TGA) and DSC data was taken during the steam oxidation. Glancing angle and 2 theta-omega X-ray di raction (XRD) scans were taken of the samples pre- and post- exposure. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Auger electron spectroscopy (AES) depth profiling was performed. The TGA showed that the coated Zircaloy-2 samples experienced significantly less weight gain as compared to the bare Zircaloy-2 samples, indicating a slower rate of oxidation. AES and XRD showed that at 700 C this decrease was due to the formation of a protective alpha -alumina layer. Chromium segregated below the alumina layer to form a secondary layer. Finally it was observed that iron di fused into the base Zircaloy-2. At 1100 C a eutectic interaction between the zirconium and iron on the Zr exists and is postulated to have caused the evaporation of the coating and loss of protection. The FeCrAl on YSZ samples did not exhibit this phenomenon, however a spinel oxide was formed at 1100 C as opposed to alpha-alumina.
Graduation Semester
2016-05
Type of Resource
text
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http://hdl.handle.net/2142/90650
Copyright and License Information
Copyright 2016 Peter Mouche

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