PSI - Issue 76

Afshin Khatammanesh et al. / Procedia Structural Integrity 76 (2026) 115–122

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For a more detailed investigation into the effect of residual stresses on the investigated martensitic stainless steel (material A), the reader is referred to the subsequent article by Mamagkinidou et al . (2025) published in the current proceedings. 4. Summary and conclusions Ultrasonic fatigue tests up to 10 10 cycles were performed with three precipitation-hardened martensitic stainless steels. TiN inclusions located at the surface and in the interior of test specimens were observed at the origin of fracture when failure occurred in the high and very high cycle fatigue regime, respectively. No fatigue limit associated with interior failure could be determined. A fracture-mechanics evaluation, employing the well-established √ area -parameter model, showed that interior failure in the VHCF regime originated from inclusions with unexpectedly low stress intensity factors. In contrast, relatively high values of Δ K were necessary to cause failure from surface inclusions. The obtained results suggest that residual stresses have a significant contribution to the observed fatigue strength. This is supported by fractographic investigation, which suggests that the sites of crack initiation are localised in areas with high tensile residual stresses. Acknowledgements The financial support by the Austrian Federal Ministry of Labour and Economy, the National Foundation for Research, Technology and Development and the Christian Doppler Research Association is gratefully acknowledged. We would like to thank our industry partner Berndorf Band GmbH for their continuous support in the Christian Doppler Laboratory for Defect Tolerance of Steels in the High and Very High Cycle Fatigue Regime. References Furuya Y., Abe T., Matsuoka S., 2003. 10 10 -cycle fatigue properties of 1800 MPa-class JISSUP7 spring steel, Fatigue Fract Eng M 26, 641-645. Ishii H., Taguchi, Y., Ishii K., Akagi H., 2003. Ultrasonic bending fatigue testing method for thin sheet materials, In: Proceedings of ATEM; International Conference on Advanced Technology in Experimental Mechanics, Volume 2003.2, OS11W0239. Mamagkinidou C., Khatammanesh A., Marsoner S., Gänser H.P., Rester M., Prunbauer M., Proschek M., Schönbauer B.M., 2025. Influence of residual stress profile on the very high cycle fatigue properties of a martensitic stainless steel sheet, In: Proceeding of the 5 th International Symposium on Fatigue Design and Materials Defects FDMD 2025, Procedia Structural Integrity (submitted). Mayer H., Schuller, R., Fitzka M., Tran D., Pennings B., 2014. Very high cycle fatigue of nitride 18Ni maraging steel sheet. Int J Fatigue 64, 104– 146. Mayer H., 2016. Recent developments in ultrasonic fatigue. Fatigue Fract Eng M 39, 3–29. More S.S., Vaara J., Kärkkäinen K., Väntänen M., Frondelius T., Mayer H., Schönbauer B.M., 2025. Defect sensitivity of high-strength steel 42CrMo4: The role of crack initiation and non-propagation defining the fatigue limit. Int J Fatigue 201, 109147. Müller-Bollenhagen C., Zimmermann M., Christ H.-J., 2010. Very high cycle fatigue behaviour of austenitic stainless steel and the effect of strain induced martensite. Int J Fatigue 32, 936-942. Murakami Y., Endo M., 1986. Effect of hardness and crack geometries on Δ K th of small cracks emanating from small defects. In: Miller K.J, de Los Rios E.R. (Eds.), The behaviour of short fatigue cracks, Mechanical Engineering Publications, pp. 275–293. Murakami Y., Nomoto T., Ueda T., 1999. Factors influencing the mechanism of superlong fatigue failure in steels. Fatigue Fract Eng M 22, 581– 90. Murakami Y., 2019. Metal fatigue: Effects of small defects and nonmetallic inclusions. 2 nd Edition. Academic Press. Schönbauer B.M., Mayer. H., 2019. Effect of small defects on the fatigue strength of martensitic stainless steels. Int J Fatigue 127, 362–375. Schönbauer B.M., Fitzka M., Jaskari M., Järvenpää A., Mayer. H., 2023. Very high cycle fatigue data acquisition using high-accuracy ultrasonic fatigue testing equipment. Materials Performance and Characterization 12(2), 172–185. Schönbauer B.M., More S.S., Morales-Espejel G.E., Mayer. H., 2023. Influence of elevated temperature on the very high cycle fatigue properties of bearing steels. Int J Fatigue 176, 107847. Sistaninia M., Maierhofer J., Spalek A., Gänser H.-P., Bucher C., Pippan R., Mayer H., Schönbauer B.M., 2024. Influence of surface condition, cycling frequency and ferritic zones on the high and very high cycle fatigue properties of a pearlitic steel. Mat Sci Eng A-Struct 900, 146483. Spriestersbach D., Grad P., Kerscher E., 2017. Threshold values for very high cycle fatigue failure of high-strength steels. Fatigue Fract Eng M 40, 1708–17. Stanzl-Tschegg S.E., Papakyriacou M., Mayer H.R., Schijve J., Tschegg E.K., 1993. High cycle fatigue crack growth properties of aramid reinforced aluminum laminates. In: Stinchcomb W.W., Ashbaugh N.E. (Eds.), Composite Materials: Fatigue and Fracture, Vol. IV, ASTM, Philadelphia, pp. 637-652.