Effects of flow forming parameters on plasticity investigated by means of residual stress and texture analysis

Flow forming is a near net shape manufacturing process for tubular components with variable wall thickness. In order to optimise processing parameters it is important to understand microstructure and residual stress evolution. The present work focuses on understanding the role of four variables, namely the preform hardness, feed rate, thickness reduction, and roller geometry, by means of two characterisation techniques; XRD residual stress measurements employing Mohr's circle analysis, and XRD pole figure measurements for texture analysis. The former technique provides information on plasticity via the calculation of the principal stress, its direction, and the shear stress, while the latter technique aids in understanding the microstructural variations imposed by the chosen parameters and constitutes a complementary characterisation method. The texture results are supported by predictions from a crystal plasticity finite element model.