Study On Creep Performance Of TP347H In High Temperature Steam Environment

Nowadays,fossil energy is becoming increasingly precious,and it is particularly important to focus on energy conservation and environmental protection.For thermal power generation,it is very important to improve unit operating parameters and continuously develop supercritical and ultra-supercritical units in the contemporary era.Higher parameters will also bring greater challenges to the high-temperature components of the power station.In recent years,the researches of power station materials mainly focus on the material performance on a single aspect,such as high temperature oxidation or high temperature creep.Therefore,it is necessary to carry out material performance research under the combination of multiple factors,which can provide more reliable scientific guidance for preventing the failures of power station materials.This paper studies the creep properties of TP347H in high temperature steam environment and explores the creep effects of TP347H under the combined effect of environmental factors and mechanical factors.In this paper,creep tests on austenitic steel TP347H are carried out under high temperature steam environment at 650 ?,and the air environment is used as the test comparison group.After the test,by comparing the high temperature air environment test,the creep curve and creep mechanical properties of TP347H under high temperature steam environment were analyzed.The fracture morphology and oxide layer morphology of the sample under high temperature steam environment and high temperature air environment were compared through SEM and EDS.The results of analysis revealed the effect mechanism of high temperature steam environment on the creep properties of TP347H.The study found that the creep strength of sheet specimens is lower than that of rod specimens in the steam environment;Compared with the high temperature air environment,the creep ductility of TP347H is reduced in the high temperature steam environment,and the dimples in the fracture of the sample are unevenly distributed;Steam oxidation has a stronger ability to repair cracks on the outer surface of austenitic steel TP347H than air oxidation,and it can repair the crack damage caused by the creep of the specimen to a certain extent and slow down the creep rate of the specimen.Compared with the air environment,the influence of steam environment on the creep life of TP347H is lower,which makes its creep life higher than the air environment under the same conditions.