This study investigates the fatigue behavior of AlSi9Cu3 aluminum die‐cast alloy after exposure to accelerated corrosive conditions. It underscores the significant impact of minor localized corrosion imperfections on fatigue strength and presents a numerically efficient method for fatigue assessment based on fracture mechanics principles. Fatigue tests under rotary bending load showed a 34% reduction in long‐life fatigue strength for precorroded surfaces compared to polished ones. Numerical simulations, which treated the precorrosion as a single crack‐like surface imperfections, provided good estimates of fatigue life, when using the mean corrosion depth as initial flaw depth. Variations in the assessed fatigue strengths for different flaw geometries and sizes ranged from 13.7% above to 22.2% below the experimental values. The findings underscore the importance of incorporating short crack propagation, particularly for small corrosive defects, in fatigue assessments to enhance accuracy and ensure component reliability and safety when corrosion‐induced imperfections are present.

This study investigates the influence of pre-corrosion damage on the fatigue behavior of AlSi10MgMn high-pressure die-cast specimens, using the statistical distribution of corrosion depths. The analysis is conducted on two different surface conditions: an unmachined rough surface ($R_a=5.05$$\mathsf{\mu }\mathrm{m}$) and a machined, polished surface ($R_a=0.25$$\mathsf{\mu }\mathrm{m}$). For the unmachined specimens, the corrosive damage manifests as homogeneously spread localized corrosion, whereas the polished specimens exhibit less uniform but deeper corrosion. The average corrosion depth of the polished specimens is found to be slightly higher (313 $\mathsf{\mu }\mathrm{m}$ compared to 267 $\mathsf{\mu }\mathrm{m}$) with a broader depth distribution. Specimens are tested under a constant bending load amplitude in laboratory conditions at a stress ratio of $R=0$ until fracture. A fracture mechanics-based methodology is developed to assess the remaining fatigue life of corroded specimens, utilizing short and long crack fracture mechanical parameters derived from SENB specimens. This model incorporates a thickness reduction of the critical specimen cross-section based on the corrosion depth distribution and combines it with a small initial crack of the intrinsic defect size ($a_{eff}=14$$\mathsf{\mu }\mathrm{m}$). Regardless of the surface condition, using the most frequent corrosion depth for thickness reduction provides a good estimate of the long-life fatigue strength, while using the 90th percentile depth allows for a conservative assessment.

Alternative fuels such as hydrogen, ammonia, and methanol are becoming increasingly important to meet global climate goals. However, their impact on mechanical and tribological properties is not yet fully understood. This creates a pressing need for the development of novel experimental methods to establish reliable design criteria for components exposed to these fuels. To date, hydrogen embrittlement has been the most extensively studied in this context.

This study investigates the fatigue behavior of AlSi9Cu3 aluminum die-cast alloy after pre-exposure to accelerated environmental conditions (pre-corrosion). The research highlights the significant impact of corrosion, particularly localized corrosion within the microstructure, on the fatigue strength of this alloy. It introduces a numerically efficient fatigue assessment method for pre-corroded specimens, employing fracture mechanics principles. The investigations reveal the significance of considering short crack propagation in fatigue assessment especially for small corrosive defects. Polished specimens were exposed to an acidic aqueous salt solution to simulate accelerated real-world corrosive conditions. Experimental fatigue tests revealed a 34 % reduction in long-life fatigue strength for pre-corroded surface condition compared to polished condition. Numerical simulations, which treated corrosion as a crack-like surface imperfection, were used to estimate fatigue life and fatigue limit. These simulations provide conservative estimates for the examined initial flaws equal to the maximum corrosion depth. The variation in long-life fatigue strength for all examined flaw geometries ranged from 13.7 % above to 22.2 % below the experimentally determined fatigue strength of the pre-corroded surface. These findings highlight the necessity of incorporating short crack propagation in fatigue assessments, particularly for small corrosive defects, to ensure the reliability and safety of components in corrosive environments.