Abstract
To improve the efficiency of fossil fuel power plants
the operating temperatures and pressures have a need to
be increased. However, at high temperatures the steam
side oxidation resistance becomes a critical issue for
the steels used especially at the final stages of
superheaters and reheaters. Apart from the chemical
composition of the material, surface condition is a major
factor affecting the oxidation resistance in steam and
supercritical water. In this paper, stainless boiler
steels (UNS S34710, S31035, S31042, S30942) are
investigated in elevated steam oxidation conditions.
Tests were conducted in a supercritical water autoclave
environment (250 bar, with 125 ppb dissolved oxygen and a
pH of 7) at 625°C, 650°C and 675°C for up to 1000h.
Materials were tested with different surface finishes
shot peened, milled and spark eroded. The results show an
influence of surface finish on the early stages of
oxidation. Oxides formed on more rough surfaces were more
adherent, and thinner than on a ground surface. Tested
materials with a chromium over 20 wt-% showed similar
oxidation behavior at the lowest temperature, though
oxides formed were dependent on the small alloying agents
(Cu, Mn). More variation could be seen with increasing
temperature.
| Original language | English |
|---|---|
| Title of host publication | Advances in Materials Technology for Fossil Power Plants |
| Subtitle of host publication | Proceedings from the Seventh International Conference (EPRI 2013) |
| Editors | D. Gandy, J. Shingledecker |
| Publisher | ASM International |
| Pages | 791-802 |
| ISBN (Print) | 978-1-62708-060-6 |
| Publication status | Published - 2014 |
| MoE publication type | A4 Article in a conference publication |
| Event | 7th International Conference on Advances in Materials Technology for Fossil Power Plants - Waikoloa, United States Duration: 22 Oct 2013 → 25 Oct 2013 Conference number: 7 |
Conference
| Conference | 7th International Conference on Advances in Materials Technology for Fossil Power Plants |
|---|---|
| Country/Territory | United States |
| City | Waikoloa |
| Period | 22/10/13 → 25/10/13 |
Keywords
- steam oxidation
- boiler tube materials
- surface finish