Creep-fatigue interaction damage evolution and life assessment of 12Cr1MoVG steel high temperature header in power plants

Abstract

Aiming at the problem of life loss of high-temperature headers of subcritical generator sets under the coupling of high-temperature creep and cyclic fatigue, this paper takes the high-temperature superheater outlet header of a power plant made of 12Cr1MoVG as the research object. Through finite element analysis, creep calculation, and fatigue calculation, the damage evolution law under creep-fatigue interaction is systematically analyzed. The study found that the creep loss of the high-temperature superheater outlet header reached 72.9% under the conditions of 545°C and 17.45MPa, and the remaining life was 67791 hours. The research results provide a cross-scale technical framework for the full life cycle management of high-temperature pressure vessels, and have engineering guidance significance for improving the reliability of high-temperature components of subcritical generator sets.