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

Abstract

The invention discloses a method for predicting a creeping incubation period containing residual stress under a plastic transient creeping condition. A prediction model for the creeping incubation period considering the residual stress is proposed; by utilizing a referential stress method, an elastic following factor Z is introduced so as to calculate the creeping incubation model considering theresidual stress; a compact tension specimen (CT) is pre-compressed to produce the residual stress, and main load is applied to carry out a creeping experiment. The method disclosed by the invention has the beneficial effects that a creeping incubation period prediction model under a modified elastic transient creeping condition is proposed, so that the simplified method for predicting the creepingincubation period under the transient creeping condition is provided; therefore, the creeping incubation period under the elastic transient creeping condition can be simply and effectively predictedin the structure.

Description

technical field [0001] The present invention relates to the engineering critical evaluation of the creep incubation period of high-temperature structures containing residual stress under plastic transient creep conditions, which is to determine the evaluation of the high-temperature structure when there are surface cracks in the structure and it is under plastic transient creep conditions. 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 ...

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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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