The present study investigates the fireside corrosion behavior of selected superheater materials, namely: T24, P92,
VM12-SHC, A800HT, and 7RE10 under oxy-coal combustion atmospheres. Data on mass change, scale thickness,
metal loss, surface morphology and micro-structural characteristics of corrosion products were obtained. The alloy
specimens were analyzed by SEM-EDX, light microscopy and X-Ray diffraction techniques. The results after
2000 hours of exposure at a metal surface temperature of 600 °C indicate that metal wastage increased with
decreasing Cr-content under oxy-coal conditions.
As power generation from variable renewable energy sources such as wind and solar power continues to increase in the future, fewer baseload power plants will be needed. As a result, high operational flexibility is becoming a vital requirement for conventional power plants to allow for the smooth integration of the variable renewable energy sources (v-RES) into the grid. To understand the impact of high operational flexibility (increased cycling) for coal-fired power plant materials, five commercial coal boiler superheater and reheater materials were investigated under isothermal and cyclic conditions for 1000 h each. The candidate alloys investigated were: T91, VM12-SHC, TP347-HFG, DMV304 HCu and DMV310 N. The results (weight change kinetics and metallographic analysis) after exposure at a metal surface temperature of 650 °C clearly showed the impact of increased flexibility on the corrosion and oxidation of the materials. Oxide growth (weight gain), metal loss, oxide spallation, and grain boundary attack were found to be more severe under cyclic conditions than under isothermal conditions.