Steam oxidation has become an important issue for steam power plants as operating temperatures increase from current to 650°C and even higher. 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, UNS S31035) 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 up to 1000 h. 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. To that extent that the oxide formed on the milled, most cold worked, surface of UNS S34710 (Cr 18 wt-%) was thinner than on the spark eroded and ground surface of S31035 (Cr 22 wt-%). More variation on oxidation rate could be seen with increasing temperature.
|Number of pages||11|
|Publication status||Published - 2014|
|MoE publication type||Not Eligible|
|Event||10th Liege Conference on Materials for Advanced Power Engineering - Liege, Belgium|
Duration: 14 Sep 2014 → 17 Sep 2014
Conference number: 10
|Conference||10th Liege Conference on Materials for Advanced Power Engineering|
|Period||14/09/14 → 17/09/14|
- steam oxidation
- surface treatment
Tuurna, S., Yli-Olli, S., Auerkari, P., Coda Zabetta, E., & Vänskä, K. (2014). Influence of temperature and surface treatment on steamside oxidation. Paper presented at 10th Liege Conference on Materials for Advanced Power Engineering, Liege, Belgium.