Failure analysis of anchoring system of a Circulating Fluidized Bed Boiler

The combustion of fuels plays an important role in the field of industry and power engineering. Circulating fluidized bed combustion (CFBC) is a clean technology and also it is a convenient method of energy production from a wide range of fuels. The present paper reports the results of the authors' investigation focused on the analysis of heat resistant steel samples from one of the Polish circulating fluidized bed boilers. The anchors were degraded during boiler operation and lost their mechanical durability. To determine the reasons for anchors degradation the materials were subjected to microstructural analysis using a light microscope, scanning microscopy Joel JSM 5400 equipped with EDS. In the case of the investigated anchor samples, the formation of a large number of hard and chromium-rich intrusions was determined. The reason for material problems as incorrect positioning of the anchors in the refractory material was determined.