Very high cycle fatigue assessment at elevated temperature of 100 µm thin structures made of high-strength steel X5CrNiCuNb16-4

Florian Himmelbauer, Gerhard Winter, Benjamin Seisenbacher, Florian Grün, Constantin Kiesling

Research output: Contribution to journalArticleResearchpeer-review


Many components and structures are exposed to very high number of cycles and challenging environmental conditions during operation. This study contributes to a better understanding of the very high cycle fatigue (VHCF) properties of high-strength steel X5CrNiCuNb16-4 at room temperature (RT) and 350 °C. For this purpose, conventional specimens and thin-walled structures are extensively examined with novel high-frequency fatigue testing techniques at elevated temperature. Tests with unnotched specimens at 350 °C show a 21.7% reduction in fatigue strength for 107 cycles and a different failure mechanism compared to RT. In contrast, no temperature influence is observed for mildly notched specimens and even a higher local fatigue strength is found for sharply notched specimens at 350 °C. The decrease in fatigue strength for 109 cycles is more pronounced at 350 °C (−10%) than at RT (−5%), and it is proven that notched specimens adequately represent the VHCF behaviour of structures. The transferability of specimen results to components and structures is given great attention. A new proposal for the VHCF strength assessment of structures with high stress gradients is presented, which is based on specimen results, an extended material-mechanical support factor and a VHCF reduction factor. The prediction model gives conservative fatigue strength estimates for 109 cycles with a maximum deviation of 5.8%. This demonstrates that even complex shaped structures can be successfully evaluated with suitable specimens and methods.
Original languageEnglish
Pages (from-to)1811-1829
Number of pages19
JournalJournal of Materials Research and Technology
Issue numberNovember-December
Publication statusPublished - 12 Oct 2022

Bibliographical note

Publisher Copyright:
© 2022 The Author(s).


  • 17-4 PH
  • Component testing
  • Fatigue strength assessment
  • High temperature fatigue
  • Thin-walled structures
  • Very high cycle fatigue

Cite this