Abstract
The effect of microstructure on KCl corrosion attack was studied using a specifically chosen modified AISI 310 austenitic steel in a 15% (v/v) H2O (g)+ 5%(v/v) O2 (g) + N2 (g) (balance) atmosphere at 600°C for 168 h. The material was a targeted choice as it allows investigation of different microstructures i.e. as-received (without sigma phase) and heat-treated (29% σ-phase per area) microstructures. The corrosion attack was studied with light optical, scanning electron and transmission electron microscopy as well as X-ray diffraction. The heat-treated sample showed a corrosion attack that was 5 times higher than the as-received sample. In the heat-treated sample, the σ-phase was selectively attacked. At the corrosion front, chlorine (but not potassium) was detected in the selectively attacked σ- phase but not in the unattacked adjacent matrix. Therefore, the corrosion attack was propagated by preferential σ-phase attack by chlorine species.
Original language | English |
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Journal | Materials at High Temperatures |
Volume | 35 |
Issue number | 1-3 |
Pages (from-to) | 243-254 |
ISSN | 0960-3409 |
DOIs | |
Publication status | Published - 2018 |
Keywords
- Internal corrosion
- Effect of microstructure
- KCl corrosion
- Modified 310 steel
- High temperature corrosion
- Sigma-phase