Research on Remaining Life Evaluation Method of T92 Steel for Superheater Tube Based on Oxide Layer Growth

Abstract

T92 steel is widely used in high-temperature superheater of supercritical power station boiler, and the researches on its remaining life have always been the hot spot of scholars around the world. In this paper, based on the analysis of high-temperature creep rupture strength data, the optimum C value of Larson–Miller parameter formula for T92 steel is obtained by using isothermal extrapolation method. On this basis, combining the relationship between the thickness of the oxide layer and the operating time, the relationship between the thickness of the oxide layer and the temperature of the tube wall and the relationship between the thickness of the oxide layer and the stress of the tube wall, a new remaining life evaluation formula is deduced. Finally, based on the cumulative creep damage life evaluation method, the service life of superheater tube is divided into three stages, which provides a new reference for the service life evaluation of superheater tube of ultra-supercritical boiler.