Numerical simulation and of gas turbine nozzle baffle manufacturing by hydroforming method

In recent years, the hydroforming process for manufacturing complex parts such as combustion chamber and gas turbine nozzle baffle, in which the forming process of materials, especially super alloy sheets, has a key role, has attracted the attention of power plant industries. Also, this process is used as a supplementary and sizing process at the end of the manufacturing process to increase the dimensional accuracy of the assembled component. In this research, the hydroforming process of AISI304 stainless steel tube for manufacturing of gas turbine nozzle baffle has been investigated. Before conducting the experimental tests and for a more accurate evaluation, the hydroforming process of the pipe was simulated in three stages: pre-forming the pipe, heat treatment of the pre-formed pipe and finally performing the hydroforming process in the final form, and in this regard, a numerical model was created. Finite element simulation was developed in Abaqus commercial code environment. In the following, the simulation results were compared with the laboratory results and a good agreement was observed between them. Also, the best form change mode to achieve the final form of the baffle is hydroforming the annealed preform tube at 100 bar oil pressure.