High-temperature oxidation of Zircaloy-4 in steam and steam-hydrogen environments

Technical Report · Sat Feb 01 00:00:00 EST 1986

OSTI ID:5955892

Prater, J T; Courtright, E L

The oxidation kinetics of Zircaloy-4 in steam have been extened to 2400/sup 0/C. The Zr/sub 2/ and ..cap alpha..-Zr layers display parabolic growth behavior over the entire temperature range studied. A discontinuity in the oxidation kinetics at 1510/sup 0/C causes rates to increase above those previously established by the Baker-Just relationship. This increase coincides with the tetragonal-to-cubic phase transformation in ZrO/sub 2-x/. No additional discontinuity in the oxide growth rate was observed when the metal phase melted. The effects of temperature gradients were taken into account, and corrected values representatives of near-isothermal conditions were computed. Oxide growth was also measured in various steam-hydrogen mixtures at 1565/sup 0/C and 1815/sup 0/C. Hydrogen concentrations up to 90 mol% had no effect on oxidation kinetics. The rate-controlling factor appears to be diffusion through the oxide layer. 17 refs., 10 figs.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 5955892
• Report Number(s): NUREG/CR-4476; PNL-5558; ON: TI86007270
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
REACTOR MATERIALS
OXIDATION
ZIRCALOY 4
HYDROGEN
MATERIALS TESTING
METALLOGRAPHY
STEAM
TEMPERATURE GRADIENTS
VERY HIGH TEMPERATURE
ALLOYS
CHEMICAL REACTIONS
ELEMENTS
MATERIALS
NONMETALS
TESTING
TIN ALLOYS
ZIRCALOY
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS
360105* - Metals & Alloys- Corrosion & Erosion