U-drawing of Fortiform 1050 third generation steels. Numerical and experimental results

Abstract

Elasto–plastic behavior of the third generation Fortiform 1050 steel has been analysed using cyclic tension–compression tests. At the same time, the pseudo elastic modulus evolution with plastic strain was analysed using cyclic loading and unloading tests. From the experiments, it was found that the cyclic behavior of the steel is strongly kinematic and elastic modulus decrease with plastic strain is relevant for numerical modelling. In order to numerically analyse a U-Drawing process, strip drawing tests have been carried out at different contact pressures and Filzek model has been used to fit the experimental data and implement a pressure dependent friction law in Autoform software. Finally, numerical predictions of springback have been compared with the experimentally ones obtained using a sensorized UDrawing tooling. Different material and contact models have been examined and most influencing parameters have been identified to model the forming of these new steels.