The production of components by flow forming has a remarkable importance in transportation and aerospace industries, due to the manufacturing flexibility, resource optimization and the possibility to produce components with specific mechanical properties. The use of metastable austenitic stainless steel in combination with advanced manufacturing techniques makes the production of high-performance products possible. During forming of austenitic stainless steel, plastic deformation not only changes geometrical characteristics, but also the microstructure, modifying the mechanical properties. The implementation of an online closed-loop control within the process enables an application-oriented and efficient production. This requires the development of novel micromagnetic sensors to measure and monitor the evolution of properties online during plastic deformation. By means of offline techniques like microscopy and microanalysis techniques, the micromagnetic online measurements and microstructural phenomena involved during production of flow formed components can be properly interpreted and correlated. With this information a material model of the phase transformation can be formulated, which plays a crucial role in the development of the closed-loop control system.