Modeling the Effect of Hydrogen Charging at Elevated Temperatures on the Strength of NPP Steam Generator Pipes Steel

The operating conditions for modeling and evaluating the invariant strength characteristics of steam generator 22K steel at elevated temperature and the effect of gaseous hydrogen are analyzed. The importance of using the energy criterion, which takes into account the change in true stresses and strains under the action of internal pressure at high temperatures of the hydrogen environment, is demonstrated. Diagrams of 22K steel limit state under the combined effect of mechanical load and elevated temperatures are plotted. An approach to determining the degree of pipeline damage under operating conditions based on the ratio of elastic-plastic deformation energy and specific fracture energy of 22K steel is proposed.