Six-Stress-Ratio Fatigue Dataset for Mean-Stress Extrapolation in Laser Powder Bed-Fused 18Ni300 Steel

This dataset accompanies the article: Karolczuk A. Role of mean-stress transformations in Gaussian process-based fatigue-life extrapolation of laser powder bed-fused 18Ni300 steel. International Journal of Fatigue 2026;213:109874. https://doi.org/10.1016/j.ijfatigue.2026.109874. The Excel file contains fatigue-test data for unmachined laser powder bed-fused 18Ni300 maraging steel tested under six stress ratios: R = −2, −1, −0.5, −0.25, 0, and 0.5. The released dataset contains 216 test records and is therefore broader than the 195-test subset emphasized in the article. The data include force amplitude, mean force, loading frequency, specimen geometry, calculated stress amplitude and mean stress, stress ratio, experimental fatigue life, failure/run-out information, measured defect-size parameters, defect depth, damage mechanism, and crack-initiation classification. The dataset can be used to validate classical mean-stress fatigue models, machine-learning fatigue-life models, and extrapolative validation strategies in which entire stress-ratio regimes are excluded from model calibration.