TEServices assisted and end user with the evaluation of the hot section components in order to determine the limitations and explore the possibility of extended operation cycles. For this project TEServices reviewed the most recent borescope inspections which was followed by an onsite visual inspection of the components as they were removed from the turbine. Hot section components (blades, vanes and heat shields) were then selected and evaluated by TEServices in their lab which involved Non Destructive Testing (visual, penetrant and x-ray), visual microscopy including internal / external surfaces, structure carbides, porosity and abnormalities followed by SEM evaluation including gamma prime analysis. Chemistry of the coating and base materials was confirmed and mechanical testing including hardness and stress rupture was performed. TEServices also developed a bid repair specification for the GT11NM gas turbine which was provided to the end user. This together with the hot section evaluation gave insight into various material lifetime properties and failure mechanisms not openly shared by the OEM as well as insight to improve the manufacturing/repair process to receive higher quality components as well as justify their current C-inspection interval.
This project was presented at the AOG Users Conference together with the end user in January of 2020.