The thin-walled eccentric nozzle usually adopts a welded structure for the straight sections at both ends

which seriously affects the assembly accuracy and in-service performance of aircraft. This study proposes a new method of integral hydroforming with a conical tube blank

which significantly reduces the wall thickness reduction compared to the hydroforming process with straight tube blanks. The stress characteristics

feeding behavior

springback characteristics

and wall thickness distribution of the GH3044 eccentric nozzle were studied under different end constraint conditions through  numerical simulation and experiments. The results show that the end constraint conditions have a significant impact on the stress state and yield sequence of the conical shell. Compared with the constraint method of both ends fixed

the tube blanks with only the small end fixed can obtain a self-feeding amount of 6 mm under the action of internal pressure

and the average axial wall thickness reduction rate of the nozzle is reduced from 6.2% to 4.2%

and the thickness reduction is more pronounced on the eccentric sidewalls of the tubular components. Furthermore

the overall springback of tubular components with the small end fixed is relatively small

and increasing the calibration pressure can reduce springback. Finally

the GH3044 eccentric nozzles with the inner diameter deviations of the straight sections at both ends meeting the design requirements were successfully formed under two conditions: Small end fixed and both ends fixed. This provides a theoretical basis and technical support for the precision integral net-shape forming of superalloy nozzles at room temperature.