Prediction method of creep incubation period considering restraint effect under plastic transient creep conditions

Abstract

The invention discloses a prediction method for a creep incubation period taking constraint effect into consideration under a plasticity transient creep condition. On the basis of Davies work, a prediction model for the creep incubation period taking the constraint effect into consideration under the plasticity transient creep condition is provided. Through unitization of a toughness dissipation damage model, a constraint parameter Q is imported for calculation of the creep incubation period taking the constraint effect into consideration. Main load is applied through utilization of a compacttension specimen (CT), thereby carrying out a creep simulation experiment. The method has the beneficial effects that the corrected prediction model for the creep incubation period under the plasticity transient creep condition is provided, so the simplified prediction method for the creep incubation period under the plasticity transient creep condition is provided, and the creep incubation period can be concisely and effectively predicted under the plasticity condition in a structure.

Description

technical field [0001] The present invention relates to the engineering critical evaluation of the creep incubation period of a high-temperature structure considering the restraint effect under the condition of plastic transient creep. Creep crack initiation life of structures. Background technique [0002] The coal-based energy structure is one of the main causes of smog in my country, and coal-fired power generation is currently the most important power generation method in my country, and this trend will exist for a long time. Therefore, in addition to changing the energy structure, developing efficient and clean ultra-supercritical (USC) units is one of the important ways to save energy and reduce emissions. However, the increase of parameters such as steam temperature and pressure has led to a very harsh service environment for the key high-temperature pipelines of the unit, especially cracks, incomplete penetration, welding pores and slag inclusions in the pipelines, ...

AI Technical Summary

Problems solved by technology

The creep incubation period is the longest stage in the creep process, and the accurate prediction of the incubation period is of great significance for the prediction of the creep life of high-temperature structures; the incubation period prediction model proposed by Davies et al. based on the ductile dissipation model considers The integrity of the stress change in the creep process, but the influence of the restraint effect of the structure on the incubation period has not been studied; in recent years, researchers have conducted a lot of research on the influence of the restraint effect on the growth of creep cracks

Images