SiGuphit-B³ - Determining the Performance of High-Silicon Ductile Cast Iron for Safe Component Design Based on Aspects of Fatigue Strength and Fracture Mechanics 

In all branches of industry, and especially in the wind energy sector, ductile cast iron (SGI) is an extremely important material group due to its good strength properties combined with good machinability and comparatively high fracture elongation. In addition to the conventional material grades with ferritic, ferritic-pearlitic, pearlitic and ausferritic matrix, ferritic solid solution strengthened grades have been increasingly used for some years. In this case, increased strength is not achieved through more pearlite in the material matrix, but through a higher silicon content for the purpose of solid state phase formation. In this way, the ferritic matrix is retained and comparatively good fracture elongation is achieved with high tensile strengths. However, in recent years, more and more questions have also arisen about the cyclic and fracture-mechanical material behavior of the new high-silicon (high-Si) cast materials EN-GJS-450-18, EN-GJS-500-14 and EN-GJS-600-10  for use in both thick and thin-walled components, such as for wind energy, general mechanical engineering and applications in the commercial vehicle sector. 

The overall goal of the research project "SiGuphit-B³" is therefore to work out the influencing variables on cyclic loading capacity and crack propagation, to derive a design concept for a reliable loading analysis and service life assessment for thick and thin-walled components made of high-silicon SGI. 

A sub-goal of the project deals with the further development of the solidification simulation for cast components made of high-Si SGI in order to make the application of these materials accessible at an early stage in the numerical process simulation. This makes it possible to link  the mechanically investigated material structures with the solidification simulation in order to systematically adapt calculation models to the new materials.

Finally, the findings from the experimental and numerical investigations will then be summarized in a design concept and advice will be given on how to handle the high-Si materials.

Project Key Data:

Project duration: 11/01/2019 – 10/31/2022 

Funding body: BMWi (PtJ)

Project partners: Fraunhofer Institute for Structural Durability and System Reliability LBF (coordinator), MAGMA Gießereitechnologie GmbH, Institute for Materials Applications in Mechanical Engineering IWM - RWTH Aachen, Meuselwitz Guss - Eisengiesserei GmbH, Heger Guss, Silbitz Group ZGG - Zeitzer Guss GmbH, WRD GmbH, MAN Truck & Bus, Walter Hundhausen GmbH, ZF Wind Power Technology, Aerodyn Energiesysteme GmbH, Fritz Winter Eisengießerei GmbH & Co. KG, Buchholz & Cie. Giesserei GmbH, Dossmann GmbH, Flender GmbH, WT Solutions AG

Project executing organization: PTJ, Jülich

Image source: Fraunhofer LBF

The project is funded by the German ZIM program for small and medium enterprises.