Experimental Studies and Simulation of TRIP-TWIP Roll Bonding

To increase the safety of steels in high performance cases like crash energy absorption, even better properties of the materials are necessary. To advance this research, a TWIP and a TRIP steel were combined in a laminated composite via roll bonding at 450 °C with the goal of using accumulative roll bonding (ARB) in later research to further enhance the properties reaching an ultra-fine-grained material. Two different TWIP layer thicknesses (2 mm and 3 mm) were experimentally roll bonded with a 3 mm thick TRIP layer each using a 4-high rolling mill. A modular Python-based simulation incorporating coupled solving of ordinary differential equations of the temperatures and the horizontal stress changes of the layers were implemented to predict deformation and bonding behavior. Simulated results matched well with experimental data in terms of final geometry and temperature, while roll force deviations indicated the need for the refining of the used model. Furthermore, experimentally asymmetric layer relationships at the beginning and the addition of a thin (10 µm) Ni interlayer were found to enhance bond strength in high-strength steel laminates.