During the last 90 years, a lot of works have been published about rolling theories for the two-roll rolling process (2RP). In the last decades, the three-roll process (3RP) has become a significant technique in the production of wire rod and bars, as it allows to cover a wide range of finished dimensions with one pass design, or to realize very close tolerances, depending on the pass design method used (free size rolling or high precision rolling). Horihata and Motomura [2] made use of the upper bound theorem to construct a method for spread calculation, but up to now, a straightforward mathematical method for calculation of stress distribution, roll forces, torques and forward slip is still missing. The present paper aims at a transfer of the slab method, which is well-known and established for the 2RP, to the 3RP. After the rolling theory for flat passes is introduced, Lendl’s equivalent pass method is transferred to the 3RP, which allows the calculation of section passes. Computational results show, that roll forces, torques and forward slips can be calculated under inclusion of elastic stand feedback and interstand tensions. Therefore the model can be used for roll speed set-up to minimize interstand tensions, which is of great importance for the rolling industry.

The present work aims at the modelling and simulation of the hot rolling process for wire rod and bars. After the fundamentals of plasticity, which are essential for the understanding of the process characteristics have been described, typical section deviations that can be expected in wire rod and bar mills are calculated with help of a numerical simulation model. The model allows the calculation of section shapes under the influence of elastic rolling stand deformations and interstand tensions. From this computational assessment of section faults, the necessity of inline measurement and process control for wire rod and bar mills is shown. This work is part of the PIREF project which incorporates the development of sensors, control systems and process models in order to control the dimensional accuracy of hot rolled wire rod and bars. The metal forming process model, as described here is used internally as a model for the static and kinematic interactions in the rolling process inside of the control model.

In this study, we developed hot working process maps for incompressible TRIP steel composites with 0%, 5%, 10%, and 20% zirconia particles using crystal plasticity-based numerical simulations. Experimentally recorded material flow curves were used to calibrate material model parameters for TRIP steel and zirconia. The fitted material models were used for running the composite simulations. Representative volume elements (RVEs) for composites were generated using the open-source DREAM.3D program. After post-processing, the simulation results were used to calculate global and local stress–strain values at temperatures ranging from 700 to 1200 °C and strain rates ranging from 0.001 to 100 s−1. Local stress–strain maps allow researchers to investigate the effect of zirconia particles on composites, which is difficult to measure experimentally at these high temperatures. On the dynamic material model (DMM), the global results were then used to construct process maps. Because the ability of the simulation model to depict dynamic softening was constrained, the processing maps derived from the simulation data did not depict regions of instability. By running crystal plasticity-based numerical simulations, we reported important findings that might help in building hot working process maps for dual-phase materials.

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For the quality of rolled products, a perfect surface quality and tight, close tolerances apart from defined mechanical properties are essential. One key condition is a perfect pass design in the rolling mill. The paper deals with the models for a pass design calculation as well as a calculation of roll force and power demands for the rolling mill. On modern bar and rod mill, different types of mill stands are used, with 2-roll, 3-roll, and 4-roll stands. For each of these stand types, a special model system is used for the calculation. Heat balance and temperature control by water cooling are the basis for thermomechanical rolling to achieve the desired mechanical properties of the material. Free size rolling and the compensation of the numerous influencing parameters on the product dimensions must be incorporated in a pass design.