Abstract
The high temperature corrosion of an austenitic stainless steel (TP 347H FG), widely utilised as a superheater tube material in Danish power stations, was investigated to verify the corrosion mechanisms related to biomass firing. KCl coated samples were exposed isothermally to 560 degrees C, for one week, under conditions simulating straw-firing. Thorough characterisation of the exposed samples was conducted by the analysis of sample cross-sections applying microscopy and spectroscopy based techniques. Cross-section analysis revealed the microstructure, as well as chemical and morphological changes within the near surface region (covering both the deposit and the steel surface). Such cross-section analysis was further complemented by plan view investigations (additionally involving X-ray diffraction) combined with removal of the corrosion products. Improved insights into the nature of the corrosion products as a function of distance from the deposit surface were revealed through this comprehensive characterisation. Corrosion attack during simulated straw-firing conditions was observed to occur through both active oxidation and sulphidation mechanisms.
| Original language | English |
|---|---|
| Journal | Materials at High Temperatures |
| Volume | 32 |
| Issue number | 1-2 |
| Pages (from-to) | 92-101 |
| ISSN | 0960-3409 |
| DOIs | |
| Publication status | Published - 2015 |
Keywords
- Materials
- Metallurgy
- Straw-fired boilers
- Oxidizing-Chloridizing Atmospheres
- Combustion conditions
- Superheater materials
- Commercial alloys
- Stainless steel
- Part II
- KCL
- Fireside corrosion
- Active oxidation
- Sulphidation
- KCl deposit