Conventional Design to Design for Additive Manufacturing for Frame 5/1 Stage 1 Nozzle

Baker Hughes has been providing industrial gas turbines globally since the 1950s. Baker Hughes’s Frame 5/1 machine is well-known for its long-running performance in the field. After service life of parts are over, these parts are replaced with new parts. New technologies like Additive Manufacturing (AM) can reduce lead time and provide freedom to design engineers to explore designs that were not possible with conventional manufacturing in the past. This paper discusses the journey from conventional design to design for additive manufacturing for stage 1 nozzle (S1N) of the Frame 5/1 Machine. Direct Metal Laser Melting (DMLM), an AM technology, is considered for manufacturing of this nozzle. Furthermore, the extensive experience accumulated over the years from numerous 5/1 machines operating in the field is leveraged to enhance the optimization of nozzle design. Considering an in-house developed equivalent material in DMLM, the nozzle is redesigned to be compatible with the operating conditions of the current machine and its supporting structure without affecting performance. The structural integrity of the newly developed AM design of the S1N is validated by part life assessment, using the thermo-mechanical finite element Analysis (FEA), and compared against the product requirements. Based on the results of the part life assessment, further improvements were made through multiple design changes and iterations, resulting in the final design. The redesign leads to a significant improvement in the temperature gradient and lowers the metal temperature in S1N in comparison with conventional design. The analysis results demonstrate a significant improvement in overall stresses, plastic strains, creep strains and crack initiation life when compared to the conventional nozzle. Moreover, the predicted amount of oxidation for the new design is much lower than that for the conventional design.