P 805 – Inductive heating of sheet metal blanks and determination of corresponding process windows for press hardening
Normally, sheet metal blanks in a press hardening process are heated by roller hearth furnaces. Main disadvantages of this heating method are the high invest costs and the large required space. This will grow further in the future because of reduced cycle-times and long required heating times. In this research project the inductive heating was investigated as an innovative alternative to the roller hearth. The aims of the research project were the design of an inductive heating device for a homogenous heating of a rectangle blank, the determination of process windows and an economical benchmark of the new heating method.
The homogenous heating was reached by a meander inductor and an oscillating translational movement of the sheet metal blank. The temperature differences could be reduced to 40 K, so that no differences in the mechanical properties were determined after press hardening.
Furthermore, the process windows of the fast heating method were identified. It was shown, that a heating of the used material 22MnB5 up to 900° C within 20 s without additional soaking-time leads to mechanical properties, which are comparable with conventionally heated sheet metal blanks.
A concluding economic analysis has shown that the inductive heating method is able to reduce the manufacturing costs. It has to be considered, that the share of the heating costs is relatively small compared to the whole component costs.
The research project (IGF-Nr. 16319 N) was carried out at Lehrstuhl für Leichtbau im Automobilbau der Universität Paderborn. FOSTA has accompanied theresearch project work and has organized the project funding from the Federal Ministry of Economics and Technology through the AiF as part of the programme for promoting industrial cooperation research (IGF) in accordance with a resolution of the lower house of the German parliament.
Only available in german language.
T. Tröster, J. Niewel, R. Salomon