Numerical Analysis and Experimental Validation of Temperature Induced Creep and Fatigue life of Inconel 740H and Haynes 282

Abstract

The Nickel based super-alloys have gained lot of importance in the last decade or so owing to their applications in areas like power generation, military aircrafts, marine propulsion and nuclear reactors. Utilities worldwide are facing increased demand for additional electricity, reduced plant emissions and greater plant efficiency. To meet this challenge, it requires materials with very high temperature creep and fatigue strength and better coal ash corrosion resistance. For the realization of advanced ultra-supercritical (A-USC) thermal plant operating at service temperature and pressure about 700oC to 760oC and 24 MPa respectively, the use of Nickel based super alloys are indispensable. The two A-USC qualified alloys include Inconel 740H and Haynes 282. This study focus on improving the creep and fatigue life of the A-USC qualified alloys by predicting the optimum operating parameters through finite element modeling for temperature induced creep and fatigue analysis of the said A-USC alloys. The influence of various operating parameters like temperature, machining induced residual stress, surface finish, creep duration and fatigue loadings on output parameters like creep strain, elongation, creep and fatigue life were studied. Abaqus/Standard was used for the numerical simulation. Using ANOVA, the most influencing operating parameters were identified. It was observed that the machining induced residual stress and surface finish have greater influence on creep and fatigue life of alloys. Alloy with lower value of machining induced residual stress and better surface finish will have better creep and fatigue life. The proper validation of model was performed by comparing the results with relevant literature.