Research and development New forging process reduces burr percentage from 54 to 7%
Germany – A new forging process developed by the Institut für Integrierte Produktion Hannover (IPH) brings considerable savings in material and energy. In the EU project Reforch, researchers were able to lower burr percentage in crankshafts forging from 54 to 7%.
The new forging process not only reduces burr percentage, it also brings energy savings of up to 20% in an industrial environment. The process has already been successfully tested, so it is only a small step to commercial application.
Funded by the European Union and in close collaboration with companies from Spain, Romania and Turkey, the IPH invested two years of research into the project. The result: Researchers were able to significantly reduce the burr percentage in the forging of a two-cylinder crankshaft.
Pressure from above and from the sides
In the conventional forging process, 10.8 kg of steel are required to forge a 7 kg crankshaft, which equals a burr percentage of 54%. The new multi-directional forging procedure lowers the burr percentage to only 7%, which means that the same crankshaft can be produced with just 7.5 kg of steel. The new process also consumes about 20% less energy because less steel must be heated.
These savings are achieved through so-called multi-directional forging. In conventional forging processes, metal is formed only through pressure from above and surplus material leaks to the sides, causing the so-called burr, which must be removed afterwards. In multi-directional forging, the heated steel is formed not only by pressure from above, but also by simultaneous pressure from the sides. Thus, it can be pressed in form in a more controlled manner and there is less waste.
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Two-cylinder crankshaft prototypes
The IPH has already been working on multi-directional forging for over ten years and has advanced the process in the course of several research projects. Within the EU project Reforch (Resource efficient forging process chain for complicated high duty parts), the procedure has now been successfully tested for the first time in an industrial environment.
The EU has invested approximately €1.1m in the research project, which was carried out by six companies and research institutes from Germany, Spain, Romania and Turkey. The Institut für Elektroprozesstechnik (ETP) of the Leibniz University Hanover designed the induction heating processes and studied the energy balance of the forging procedure. Spanish company Aurrenak produced the forming tool, which can be inserted into a regular eccentric press and diverts the applied pressure, so that the steel is simultaneously formed from above and from the sides.
The new process was successfully tested in Turkey: Turkish forging company Omtaş Otomotiv Transmisyon Aksami has already produced prototypes of two-cylinder crankshafts for quads and snowmobiles with the multi-directional tool and now wants to apply the process to the production of other crankshaft types as well. Now it is only a small step to commercial application.