Research into thermomechanical interactions in the shear zone during fineblanking of high-strength heated sheet materials (HotFib)

 

Fine blanking is a manufacturing process of forming sheet metal separation that is used when large series of parts with high quality requirements are to be produced. Typical requirements are a high proportion of smooth cuts, low edge penetration and low burr formation.
Currently, fineblanking is reaching a technological limit in the processing of high-strength sheet materials. However, since these are gaining in importance in the course of any lightweight construction efforts, it is desirable to shift this limit.

Analogous to solid forming, where the formability of materials can be guaranteed by the additional supply of heat, the present research project investigates the fineblanking of sheets that have been heated by induction before the fineblanking process. The increased temperature contributes to a reduction of the yield stress and leads on the one hand to reduced process forces and on the other hand to the possibility of making high-strength sheet materials finely cutable.

In the course of this project, tests will be carried out on induction heating and fineblanking of induction-heated sheets in individual strokes. These consist of the materials 16MnCr5, 42CrMo4, X5CrNi18-10 as well as S700MC and are investigated in sheet thicknesses of 4 mm and 6 mm. Temperatures between 200 °C and 500 °C are considered, since a process temperature below the recrystallization temperature of the investigated materials is targeted. The evaluation parameters on the product side are cut surface quality, edge penetration and burr formation as well as the process forces on the process side. The thermomechanical interactions in the shear zone are investigated with the aid of validated finite element simulations, mainly in the Abaqus software, in order to enable a knowledge-based design of the fineblanking of inductively heated sheets.