Prediction method of creep incubation period with residual stress under elastic transient creep condition

Abstract

The invention discloses a predicating method for a creep incubation period containing residual stress under an elastic transient creep condition. On the basis of Davies work, a predicating model for the creep incubation period taking residual stress into consideration is disclosed; a reference stress method is utilized, and an elastic following factor Z is introduced to calculate a creep incubation period taking residual stress into consideration. A compact tensile specimen (CT) is pre-compacted to generate residual stress, and main load is applied to perform a creep test. The predicating method for the creep incubation period has the beneficial effects that the original predicating model can be expanded into a model containing the residual stress, so that a simplified predicating method for the creep incubation period under the transient creep condition is disclosed, and the creep incubation period can be simply and effectively predicated under the elastic transient creep condition inthe structure.

Description

technical field [0001] The invention relates to the engineering critical evaluation of the creep incubation period of high-temperature structures containing residual stress under elastic transient creep conditions, that is, to determine when there are surface cracks in the structure and under transient creep conditions, the evaluation of the high-temperature structure Creep crack initiation life. 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-temperatu...

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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 on the incubation period has not been studied; the residual stress widely exists in the high-temperature components processed and manufactured, and has a significant impact on the service life of the components

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