EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Tungsten inert gas welding (TIGW) and shielded metal arc welding (SMAW) have been used for welding SA213-T91 superheater tubes used in power plants. The optimal performance of power plant components during service entirely depends on the post-weld microstructural conditions. It is known that welding not only results in inhomogeneous microstructures and mechanical properties but as well may result in generating residual stresses across the weldment. The present investigation is focused on estimating the residual stress and microstructure development on T91 welded tubes. Both the welded and post-weld heat-treated (at 760 ℃ for 2 hours) tubes have been examined. The residual stresses have been measured using x-ray diffraction, nano-indentation, and EBSD LAM (local area misorientation) map methods. The results obtained from these techniques were then subsequently compared with the predicted values from the SYSWELD package. A good agreement between predicted and measured values have been obtained. Further, the residual stresses are corroborated well with the mechanical properties.