MODELING AND MEASUREMENT OF FLARING OF OUTER FLANGES ON PIPE BLANKS IN THE ROLL STAMPING PROCESS USING THE FINITE ELEMENT METHOD

Roll stamping (RS) is an efficient process for shaping steels and alloys in a cold state, enabling the production of complex-profile parts. To improve RS processes, it is crucial to study the factors influencing material deformation and the stress-strain state of the blank. Research on flaring of outer flanges on pipe blanks is labor-intensive due to the complexity of accounting for real conditions of localized deformation and the contact interactions between the tool and the blank. An alternative to experimental methods is the use of simulation modeling with the finite element method (FEM). In this study, FEM was applied to model flange flaring on pipe blanks, based on a model consisting of a pipe blank, a conical roller, a die, and a mandrel. Calculations were performed using 8-node finite elements, with the tool modeled as a perfectly rigid body. Contact between the roller and the blank was defined using an automatic "surface-to-surface" contact algorithm. The results of the calculations revealed the deformation intensity in the flange cross-section after 55 seconds of compression, as well as the material microstructure and the distribution of deformation intensity and stresses. Comparison of the simulation results with experimental data showed that discrepancies in flange shape and deformation intensity distribution were within an error margin not exceeding 10–12%. Additionally, changes in the friction coefficient did not significantly affect the stress state on the free surface of the flange. The study confirmed good agreement between the stress-strain parameters obtained through simulation and experimental data, although some differences were observed for internal points in the flange cross-section. These results demonstrate the high efficiency of using FEM to model the flange flaring process in RS, allowing for more accurate prediction of deformation characteristics and the stress-strain state of the blank material.