Improvement of Sheet Metal Properties by Inducing Residual Stresses into Sheet Metal Components by Embossing and Reforming

Authors

  • Stefan Walzer Institute for Metal Forming Technology (IFU), University of Stuttgart, Stuttgart, Germany
  • Mathias Liewald Institute for Metal Forming Technology (IFU), University of Stuttgart, Stuttgart, Germany
  • Nicola Simon Institute for Applied Materials (IAM–WK), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
  • Jens Gibmeier Institute for Applied Materials (IAM–WK), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
  • Hannes Erdle Institute of Engineering Mechanics, (ITM), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
  • Thomas Böhlke Institute of Engineering Mechanics, (ITM), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

DOI:

https://doi.org/10.14416/j.asep.2021.09.006

Keywords:

Residual stresses, Sheet metal material, Embossing, Reforming

Abstract

In sheet metal forming, combination of embossing and reforming allows the mechanical properties of sheet metal materials to be specifically improved. Here, local property modification is achieved by the residual stresses induced as a result of the one-sided embossing process followed by a reforming step. The residual stresses induced in this specific way can lead to a significantly increase in the fatigue strength of processed sheet metal components. However, in order to ensure this kind of component optimization in continuous operation, the induced stresses have to be homogeneous. In this respect, the main objective of the study reported about in this paper was to identify a forming strategy, consisting of the process steps embossing and reforming, that generates preferably homogeneous residual stress distributions into sheet metal blanks. For this, numerical and experimental investigations were carried out with samples of the stainless steel (X6Cr17) having a thickness of 1.5 mm. It was found that embossing and reforming, integrated into a conventional forming process, is a novel approach to specifically induce very localized homogeneous compressive residual stresses in sheet metal materials. This eliminates the need for costly post-processing by means of surface treatment.

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References

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Published

2021-10-20

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Research Articles