A Comparative Creep and Creep Fatigue Analysis of an Austenitic Steam Superheater

A steam superheater is a component which operates at elevated temperature in the creep regime. The component is normally not working in cycling conditions. Due to operation failures, the component has been subjected to several unplanned start-ups and shutdown. The SSH has reported a very high level of damage of the tubesheet to shell junction in field (high deformation and weld cracks). Several investigations have been performed to analyze the effect of temperature, pressure and external loads on the equipment with finite element techniques and different creep and creep-fatigue evaluation approaches: ASME III subsection NH, simplified inelastic analysis and a full creep model have been used. A comparison of the results is reported in this paper. Paper published with permission.