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mally arranged to meet the special requirements of the dies in the customer’s press. It is essential to know exactly which zones of the dies require more or less cooling, and in which areas the heat load is greatest. FE simulation models are able to map the temperatures present in the dies and in the forgings. The 3D display of a die on the monitor indicates – as in an image taken by an IR camera - which areas will be particularly heavily affected by high temper- atures during forging. In those areas cooling has to be more intensive. Based on the thus gained values, the most appropriate spray head can be designed by a dedicated software program and produced by 3D printing.
Koos van Putten: “Digitized FE models allow us to observe how materials behave during the forming process, without having to go through time-consum- ing field testing. Our specialty is that we are able to test varying parameters and analyze their individual effects separately in simulations.“
What looks on the computer monitor like a brief animated film of the forging process, requires a multitude of computations and state-of-the-art sim- ulation techniques. Koos van Putten: “We concen- trate on issues like flow behavior and changes in the geometry as well as thermal processes taking place within the material. Massive forming processes involve major changes of the shape and geometry of the workpiece. Consequently, the simulation has to take into account the complex interrelation between material behavior and the way the material interacts with the dies. All this requires the use of power- ful hardware, advanced software and comprehensive material property databases.“
Numerous benefits
The simulation results can be used for numerous pur- poses. They can be used to optimize processes or the process chain and to enhance the product prop- erties. Also measures that will save on raw mate- rial and energy can be derived from the simulation results. Last but not least, when plant operators turn to us for support in solving specific problems they face in their production processes, an FE analysis can provide answers and remedies.
A small selection from the wide range of simula- tion tasks
Forming processes are numerous and multi-facetted. So are the tasks to be performed by the SMS group simulation team. In drop forging, FEM simulations
Visualization makes highly complex processes easy to grasp
help to optimize the process design, for example, by analyzing the material flow in order to investigate whether there are underfills or overlaps in the dies. Based on the analysis results, it is possible to opti- mize the blank geometry and reduce flash formation.
As part of a tender for a new forging plant for iso- thermal forging of parts for aircraft nose wheels, the R&D department of SMS group carried out feasibil- ity studies by FE simulations. The simulation results could demonstrate that the real plant would be able to run the process within the very tight temperature limits required to achieve the desired microstructure of the forgings. The customers could convince them- selves of this by the “virtually produced” forging.
Simulating the ring rolling process entails a holistic approach that involves the mapping of the complete kinematics of the radial-axial ring rolling machine, even integrating the real machine control data. The latter would be accomplished by including the data from the sensors in the model. As well as predicting the development of the ring geometry and the forces and drive torques acting during rolling, it is possible to compute (statically or dynamically) the develop- ment of the microstructure, i.e. the grain size and rate of recrystallization. “Combining the microstruc- ture model and the simulation of the forming process
Technical Papers
ITAtube Journal No1/February 2019
29