A creep incubation period prediction method coupling residual stress and a restraint effect under an elastic transient creep condition

Abstract

The invention discloses a method for predicting a creep incubation period of a high-temperature structure by coupling residual stress and a restraint effect under an elastic transient creep condition,and provides a creep incubation period prediction model coupling the residual stress and the restraint effect on the basis of Davis work. A reference stress method is utilized, and an elastic following factor Z is introduced to calculate the creep incubation period considering the residual stress. A compact tensile specimen (CT) is used to generate residual stress through pre-compression, and a main load is applied to carry out a creep experiment. According to the method, the creep incubation period under the elastic transient creep condition can be simply and effectively predicted in the structure.

Description

technical field [0001] The invention relates to the engineering critical evaluation of the creep incubation period of a high-temperature structure coupled with residual stress and restraint effect under the condition of elastic transient creep, that is to say, when there is a surface crack in the structure and it is under the condition of transient creep, the evaluation of this Creep crack initiation life of high temperature 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 servi...

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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 during the creep process, but the influence of the residual stress of the structure and the restraint effect on the incubation period has not been studied; the residual stress and the restraint effect widely exist in the high-temperature components processed and manufactured, and have a great impact on the service life of the components. had a major impact

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