Study on Creep Behavior and Fracture Life Prediction Method of P92 Steel Based on Finite Element Analysis

In aerospace, petrochemical, thermal power and other industrial fields, in addition to bearing certain loads, parts working in high-temperature environments are also affected by external factors such as mechanical start stop and load fluctuations. In this case, these components will be subject to the dual effects of high temperature creep and high temperature fatigue. Creep fatigue failure is the most common failure mode of high-temperature workpieces, and it is very necessary to study it in depth. For this reason, this project intends to take P92 steel-steel for thermal power plants as an example, and use finite element analysis and test methods to systematically study the creep-fatigue crack growth law at high temperature and high temperature. In this paper, taking continuum damage mechanics as the research object, taking the creep toughness dissipation rate as the theoretical basis and continuum damage thermodynamics as the basic principle, a creep-fatigue damage model that can reflect the creep-fatigue coupling effect is established. On this basis, combined with the stress-strain constitutive relation of materials, a finite element calculation model of creep-fatigue crack growth is established.