FORVIA Faurecia

Investigation of the Fracture Toughness of a component made of a Dual Phase steel with edge-cracking

FORVIA is a newly formed entity resulting from the merger of the French group Faurecia and the German group Hella. This collaboration has established Forvia as the 7th largest automotive supplier worldwide, poised to become a global leader and drive innovations in the industry.

The company, applying to ToughSteel Open Call, comprises six major business units, including Seating, Interiors Systems, Clean Mobility, Electronics, Lighting, and Lifecycle solutions. With a workforce of 150,000 employees across 42 countries, including 35,000 engineers from 150 nationalities, Forvia holds a prominent position in research and development, boasting 14,000 patents and 800 programs in 2021.

Automotive component with edge cracks after cold forming. Material DP600

Case study definition

Investigation of a component made of a Dual Phase steel (HCT600X) with problems of edge-cracking. The raw material supplier had always been the same, but different batches presented different behaviour. Although the material is compliant regarding the expected specifications, Forvia experienced an impact in their production efficiency scraps.

The objective was to obtain a parameter that can predict the fracture behaviour of a material batch during forming. It was also intended to obtain a parameter that could be implemented in FEM modelling for edge-cracking prediction.

We were facing unexplained cracking from one of our supplier plants, and we were not able to find the root cause, even after material lab testing. The assessment of fracture toughness via the Essential Work of Fracture methodology allowed us to correlate the crack with energy measures and sort the batches accordingly, thus increasing our productivity

Valerie Woimbee, Scientific Expert, R&D Seating Product, FORVIA Faurecia

Case study results

The study assessed the fracture toughness of three Dual Phase steels via the EWF methodology, concluding that the OK batch shows the highest crack initiation and propagation resistance, as well as a greater thickness fracture strain.

The analysis allowed explaining the different fracture behaviour of the material batches during forming. These results were very useful to FORVIA Faurecia in order to establish a new testing protocol for material qualification and predicting the cracking sensitivity of cold-formed metal products.

The next step is to investigate how to implement these new parameters on FEM software, aimed at defining different fracture criteria to improve the accuracy of edge fracture prediction in forming simulations. The proposed fracture toughness-based approach provides key information about the overall fracture behaviour of sheet metal products during forming or in a crash event, which is critical for safety-related components.

EWF results for Faurecia Case study