On the initial corrosion mechanism of zirconium alloy: Interaction of oxygen and water with Zircaloy at room temperature and 450 C evaluated by x-ray absorption spectroscopy and photoelectron spectroscopy

Book · Sat Dec 31 04:00:00 EST 1994

OSTI ID:55676

Doebler, U ^[1]; Knop, A ^[1]; Ruhmann, H; Beie, H J ^[2]

---

1. Sietec GmbH, Berlin (Germany)
2. Siemens AG, Erlangen (Germany)

The initial stages of zirconium oxide formation on Zircaloy after water (H{sub 2}O) and oxygen (O{sub 2}) exposures have been investigated in situ using photoelectron spectroscopy and X-ray-absorption spectroscopy. The reactivity of the zirconium alloy with O{sub 2} at room temperature is about 1,000 times higher than for H{sub 2}O. Up to 100 L (1 L = 1 Langmuir unit = 1 {center_dot} 10{sup {minus}6} mbar {center_dot} s) H{sub 2}O exposure, the reactivity of the zirconium alloy at 450 C is comparable to the room temperature reaction. At higher H{sub 2}O exposure, a sharp increase in the reaction rate for the high-temperature oxidation is observed. From the energy position of the Zr 3d photo emission line and their oxygen-induced chemical shifts, one can really follow the formation of the oxide films. Two different substoichiometric oxides were found during reaction with water. Suboxide (1) is located at the zirconium/zirconium-oxide interface. Subsequently, a Suboxide (2) is concluded from the chemical shift of the zirconium photoelectrons. After an oxide thickness of 2 nm, the stoichiometric ZrO{sub 2} phase is not yet developed.

• OSTI ID: 55676
• Report Number(s): CONF-930611--; ISBN 0-8031-2011-7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CORROSION PRODUCTS
EXPERIMENTAL DATA
OXIDATION
REACTOR MATERIALS
SCALING
ZIRCALOY
ZIRCONIUM OXIDES