Effects of Film Formation Conditions on the Chemical Composition and the Semiconducting Properties of the Passive Film on Alloy 690
Creators
- 1. Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)
Description
The chemical Composition and the semiconducting properties of the passive films formed on Alloy 690 in various film formation conditions were investigated by XPS, photocurrent measurement, and Mott-Schottky analysis. The XPS and photocurrent spectra showed that the passive films formed on Alloy 690 in pH 8.5 buffer solution at ambient temperature, in air at 400 .deg. C, and in PWR condition comprise Cr2O3, Cr(OH)3, γ-Fe2O3, NiO, and Ni(OH)2. The thermally grown oxide in air and the passive film formed at high potential (0.3 VSCF) in pH 8.5 buffer solution were highly Cr-enriched, whereas the films formed in PWR condition and that formed at low potential (-0.3 VSCF) in pH 8.5 buffer solution showed relatively high Ni content and low Cr content. The Mott-Schottky plots exhibited n-type semiconductivity, inferring that the semiconducting properties of the passive films formed on Alloy 690 in various film formation conditions are dominated by Cr-substituted γ-Fe2O3. The donor density, i.e., Concentration of oxygen vacancy, was measured to be 1.2 x 1021 ∼ 4.6 x 1021 cm-3 and lowered with increase in the Cr content in the passive film
Additional details
Publishing Information
- Journal Title
- Corrosion Science and Technology
- Journal Volume
- 5
- Journal Issue
- 4
- Series
- 24 refs, 8 figs, 3 tabs
- Journal Page Range
- p. 141-148
- ISSN
- 1598-6462
INIS
- Country of Publication
- Korea, Republic of
- Country of Input or Organization
- Korea, Republic of
- INIS RN
- 43053774
- Subject category
- S36: MATERIALS SCIENCE;
- Descriptors DEI
- BUFFERS; CHEMICAL COMPOSITION; INCONEL 690; PWR TYPE REACTORS
- Descriptors DEC
- ALLOY-NI59CR30FE9; ALLOYS; CHROMIUM ALLOYS; CORROSION RESISTANT ALLOYS; ENRICHED URANIUM REACTORS; HEAT RESISTANT MATERIALS; HEAT RESISTING ALLOYS; INCONEL ALLOYS; IRON ALLOYS; MATERIALS; NICKEL ALLOYS; NICKEL BASE ALLOYS; POWER REACTORS; REACTORS; THERMAL REACTORS; TITANIUM ADDITIONS; TITANIUM ALLOYS; TRANSITION ELEMENT ALLOYS; WATER COOLED REACTORS; WATER MODERATED REACTORS