Microstructural characterization of external and internal oxide products on V-4Cr-4Ti
- Oak Ridge National Lab., TN (United States)
Air oxidation of V-4Cr-4Ti at 500 C at 1 atm resulted in the formation of a thin (100--150 nm) external vanadium nitride layer which was identified beneath a thicker (1.5 {micro}m) vanadium oxide scale. This nitride layer would only be detected by high-resolution, analytical electron microscopy techniques. Subsequent tests comparing room temperature tensile properties for exposure in laboratory air, dry air and dry oxygen at 1 atm showed more embrittlement in air than in O{sub 2}. Internal oxidation of coarse-grained V-4Cr-4Ti at low oxygen pressures at 500 C was followed by TEM examination. In a sample with a 1400 ppmw O addition, which is sufficient to reduce the ductility to near zero, there appeared to be an oxygen denuded zone (150--250 nm) near the grain boundaries with precipitates at the grain boundaries and uniform ultra-fine (<5 nm) oxygen particles in the matrix. In a similar O-loaded specimen that was subsequently annealed for 4h at 950 C to restore ductility, large oxide particles were observed in the matrix and at the grain boundaries.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- OSTI ID:
- 330615
- Report Number(s):
- DOE/ER-0313/24; ON: DE98007433; TRN: 99:005070
- Resource Relation:
- Other Information: PBD: Sep 1998; Related Information: Is Part Of Fusion materials semiannual progress report for the period ending June 30, 1998; Burn, G. [ed.] [comp.]; PB: 314 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Subtask 12D1: Impact properties of production heat of V-4Cr-4Ti
Subtask 12G2: Effects of dynamically charged helium on tensile properties of V-4Cr-4Ti