Modeling Tube-Forming of an Austenitic Stainless Steel with Exploitation of Martensite Evolution

Within the last years the industrial manufacturing of tubes has developed to an increasingly complex process. In particular, during the forming procedure of sheets made of austenitic stainless steel, the increase and the content of strain-induced martensite needs to be controlled in order to achieve the optimal structural properties of the manufactured tube with respect to very-high-cycle fatigue (VHCF). On the basis of experimental investigations this contribution deals with the numerical simulation of the forming process with special consideration of the martensite ratio as a function of temperature and deformation field. A convenient approach of modeling the martensite evolution as well as the extension of this model to polyaxial states of stress and a comparison with experimental results is presented