Abstract
Samples of RR1000 with differing grain size and surface finish have been exposed to air at different pressures. Specimens were exposed for 4000 hours at 650°C with some exposed to atmospheric pressure air and some exposed to air at 40 bar pressure. Samples exposed to elevated pressure formed a surface layer of NiCr2O4 whereas that formed on samples tested at 1 bar pressure was chromia. The surface layer formed at 40 bar pressure was thinner than that a 1 bar pressure. At 1 bar pressure, some samples exhibited regions of convoluted buckled oxides but no spallation. In adjacent regions of planar oxides, spallation did occur. For the latter case, an estimate of 6 Jm-2 for the interfacial fracture energy has been made. None of the specimens tested at 40 bar pressure exhibited oxide spallation.
Original language | English |
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Pages (from-to) | 130-140 |
Journal | Materials at High Temperatures |
Volume | 35 |
Issue number | 1-3 |
Early online date | 17 Oct 2017 |
DOIs | |
Publication status | Published - 1 Mar 2018 |
Keywords
- Oxidation
- Pressure
- Chromia former
- Superalloy
- Spinel
- XRD