PSI - Issue 75

Hannes Schwarz et al. / Procedia Structural Integrity 75 (2025) 625–632 Schwarz, Fliegener, Rennert / Structural Integrity Procedia (2025)

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the component SN curves from the FKM guideline. The evaluation of the component stress amplitude can be done either based on strain measurement, analytical methods or finite-element simulations. In this case, linear elastic finite element simulations were used to determine nodal stresses in the critical component areas, resulting from the corresponding load scenario. The hydrogen influence can be considered by HEIs as a function from hydrogen pressure as shown in the box at the bottom and center of the figure, following the approach presented by Michler et al. , 2021. In our validation case, the pressure dependence is neglected since for the demonstrator component level, only one hydrogen state via gaseous pre-charging was investigated. A design SN curve considering hydrogen conditions was derived using HEI values.

Fig. 2. Fatigue strength ratios  H2 /  ref of austenitic stainless steels from the literature review (top) and experimental data of pre-charged 304L specimens from our work (bottom). Literature sources see references, “Bosch 2021” refers to Bauer -Troßmann 2021.