Stress–Strain Behavior and Fatigue of High-Temperature Component Made of P92 Steel in a Coal-Fired Power Boiler

In the technical literature examining P92 steel grade, a common material used for elements of power equipment with enhanced operating parameters, there are numerous studies on creep tests. However, there is a lack of information on the fatigue processes of such materials, especially thermo-mechanical fatigue. The presented article investigates certain aspects of this phenomenon, focusing on the behavioral aspect of P92 steel under time-varying mechanical and thermal load conditions. The analysis of the behavior of the high-pressure elements of power equipment focused on the operating parameters. These parameters lead to various stress and strain fields in the elements, allowing the determination of their fatigue life. The issue of selecting fatigue life criteria for materials and forecasting the durability of elements operating under mechanical loads and time-varying elevated temperatures was also examined. In this case, the material characteristics determined under laboratory conditions and the applicable standard used by designers of power equipment were utilized.