Surface features on a low alloy steel exposed in a simulated fluidized bed combustor environment

Abstract A laboratory-scale test rig which simulates some aspects of a fluidized bed combustor environment was used to examine the wastage behaviour of a low alloy steel. Studies were made of the surface microstructure of specimens exposed at temperatures between 100 and 800 °C. At low temperatures embedment of abrasive bed material occurred over much of the specimen surface. Wear scars with thin surface oxide films, coloured by optical interference effects, developed on the samples exposed in the temperature range 300–500 °C. Severe wastage occurred within these wear scars. At higher temperatures a thicker oxide scale formed which was protective against mechanical wear. Comparisons are made with the wastage behaviour of other steels tested by the same method.