Water Vapor Effects on the Oxidation Behavior of Fe–Cr and Ni–Cr Alloys in Atmospheres Relevant to Oxy-fuel Combustion

Comparative Study on High Temperature Oxidation of T92 Steel in Dry and Wet Oxyfuel Environments

“…The oxide scale structure obtained for the T92 steel in the present investigation is similar to that reported in previous studies carried out in the oxyfuel environment [1,2,13,25,28]. The oxide scale consists of an outer layer of hematite on top of magnetite, while the inner layer contains a mixture of (Fe, Cr)-spinel and magnetite, with small amounts of sulphides and wustite.…”

“…A number of modified 9-12 % Cr ferritic/martensitic steels with higher creep strength have been developed and are currently being used for critical components in coal-fired power plants such as heat exchangers, headers, steam lines and exhaust gas systems [5][6][7]. Although these steels have excellent oxidation resistance during exposure in oxygen or air [7], their oxidation rates are significantly enhanced in environments containing water vapour as those prevailing in power plant service conditions [6][7][8][9][10][11][12][13]. Therefore, superheater tubes of modified 9-12 % Cr steels are limited for use up to a maximum working temperature of 620°C in the air-fired power plants due to their limitations to oxidation and creep [11,12].…”

Effect of water vapour partial pressure on the chromia (Cr2O3)-based scale stability

“…[13][14][15][16] Thermodynamic calculations of volatile Cr species partial pressures have shown that the most dominant phase that is responsible for oxide scale breakaway at temperatures below ~ 900 °C is Cr oxy-hydroxide:…”

Oxidation After Breakdown of the Chromium-Rich Scale on Stainless Steels at High Temperature: Internal Oxidation

“…Breakaway oxidation of stainless steels in various environments and at different temperatures have been reported to result in a similar microstructure consisting of an outward growing Fe-rich oxide and an inward growing Fe, Cr, (Ni) spinel oxide, see e.g. [4][5][6][7][8][9][10][11][12][13][14][15]. The microstructure of the inward growing spinel scale has been shown to be complex, including both fully oxidized regions and regions of internal oxidation as reported for Fe-Cr model alloys at 600 to 900°C [4,5,11,[15][16][17].…”