How to form high-quality variable-section thin-walled conical parts through power spinning is a key issue for superalloy spinning manufacturing. A study into the hot power spinning deformation law of variable-section thin-walled conical parts and the effects of process parameters on surface straightness of forming quality are delineated in this paper. Through the establishment of finite element (FE) models using the single-factor and orthogonal design of experiments, the effects of four key process parameters on the surface straightness have been investigated and the optimal combination of process parameters have been yielded. These key factors include spinning temperature, roller nose radius, mandrel rotation rate and roller feed ratio. The results of FE simulation have been validated through the comparison of the surface straightness of modeled parts with those measured during a spinning experiment. The results reveal that, among the studied process parameters, the spinning temperature has the greatest influence on the surface straightness, followed by the roller nose radius and mandrel rotation rate, and the roller feed ratio has the least influence on the straightness. Larger mandrel rotation rate, smaller feed ratio and suitable spinning temperature can enhance the surface straightness.

In order to effectively control the deformation of tapered spinning parts with gradually changing wall thickness, the precise forming of such sheet metal casing parts can be realized. This paper uses experiments to establish the true stress-strain curve equations of GH3030 superalloy at normal temperature. Based on the equations, it establishes the finite element model of the strong spinning forming of a GH3030 superalloy tapered rotary part with wall thickness gradient. The equivalent stress field for the strong spinning forming is used to combine the finite element simulation with experiments. The strong spinning forming is simulated, and the distribution characteristics of the equivalent stress field and the equivalent strain field for the strong spinning forming are analyzed in some detail, and their distribution law is obtained. The strong spinning forming mechanisms for the GH3030 superalloy tapered rotary part with wall thickness gradient is clarified. The experimental and simulation results are verified with the conical flange plane degree.

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The conical rotary part with variable wall thickness is a typical aircraft engine sheet metal casing, which requires high forming quality. In this paper, the hot power spinning process of conical rotary part with continuously variable wall thickness of superalloy GH4169 was simulated by DEFORM-3D FE (finite element) software. The equivalent stress, equivalent strain and temperature distribution characteristics were analysed to explore the forming mechanism. The single factor variable method was used to explore the influence of three process parameters, namely, the mandrel speed, the roller feed ratio and the spinning temperature, on the forming quality. The wall thickness deviation and the roundness error of the cone outer surface were taken as the evaluation indexes. Excessive thinning rate will produce large equivalent strain, which may lead to work piece fracture. Therefore, appropriate roller feed ratio should be selected to reduce the generation of defects. The results provide a theoretical basis for improving the service life of aero-engine sheet metal casing.

The superalloy products formed by multi-pass conventional spinning are widely used in rotary forming parts with complex shapes. As the connection of each forming pass, the attaching-mandrel process has an important influence on forming quality and production efficiency. The hot spinning process is usually adopted in superalloy forming because its poor plasticity in normal temperature, meanwhile, it brings the poor surface quality of the parts and huge energy consumption. For this reason, the cold spinning and the attaching-mandrel process of nickel-base superalloy GH3030 are studied. The combination method of experiment and simulation is used to study the attaching-mandrel process based on one-forward-pass spinning process. The effects of pass pitch and the attaching-mandrel velocity on the tool forces, parts stress field, strain field and wall thickness distribution are analyzed. The microstructure of the part is divided into three layers: outer, middle and inner layer. The grain size of each layer is compared. Then the effect of different pass pitch on the grain structure is clarified. The results show that the reasonable pass pitch and the attaching-mandrel velocity can improve the forming quality and production efficiency. The multi-pass cold spinning process on superalloy GH3030 is feasible. The excessive pass pitch can cause seriously grain elongation, the grain boundaries are blurred, and even cracking.