Untersuchung der maßgebenden Einflüsse auf das Biegewechselverhalten moderner mischkristallverfestigter Sphärogusswerkstoffe

Translated title of the contribution: Investigation on significant influences of reverse bending fatique of modern solution strengthening ductile cast irons

Reza Danesh Marnani

Research output: ThesisMaster's Thesis


Objective of the present study was to determine the influence of the surface and surface layer properties on the fatigue behavior of high silicon spherical graphite cast iron alloy. The goal of this master-thesis was to determine effects of mechanical surface treatments and the improvement of fatigue behaviour of high silicon spherical graphite cast iron EN-GJS-500-14 alloy. For this purpose, shot peening (SP) was applied. In order to gain a deeper understanding of the effect of the microstructure on the mechanical surface treatment, the different microstructures (ferritic matrix and ferrtic-perlitic Matrix) have been compared, using the EN-GJS-500-14 and EN-GJS-500-7 grades. In order to evaluate the hardening potential as a result of shot peening treatment the near-surface properties of different surface conditions were analyzed. Thereby such characteristics as surface roughness, residual stress depth profiles from peened and as-cast samples were determined. The results of this work show that shot peening creates a residual compressive stress on the material surface region and as a result leads to a significant improvement of fatigue behaviour in comparison to the as cast state. The crack initiation points were moved from the surface to inner regions of the shot peened sample. Results showed that the fatigue life and finite life was improved by shot peening of both grades GJS 500-7 and GJS -500-14. The shot peening treatment led to a higher increase in the fatigue limit with the ductile cast iron ferritic to perlitic grade EN-GJS-500-7 than a modern solid solution strengthening of the ferrite matrix grade EN-GJS-500-14. The reason for this is a different microstructure. A comparison of the different grades showed after shot penning a similar fatigue limit of around 260 MPa.
Translated title of the contributionInvestigation on significant influences of reverse bending fatique of modern solution strengthening ductile cast irons
Original languageGerman
  • Gassner, Gert, Co-Supervisor (internal)
  • Schumacher, Peter, Supervisor (internal)
Award date16 Dec 2016
Publication statusPublished - 2016

Bibliographical note

embargoed until null


  • Shot Peeening
  • Fatigue behavior of GJS
  • High Silicon spherical graphite cast iron

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