1. Heterogeneous effect of aging temperature on the fatigue life of additively manufactured thin-walled 18Ni300 maraging steel tubular specimen
- Author
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Aleksander Karolczuk, Andrzej Kurek, Michał Böhm, Szymon Derda, Mariusz Prażmowski, Krzysztof Kluger, Krzysztof Żak, Łukasz Pejkowski, and Jan Seyda
- Subjects
18Ni300 maraging steel ,Aging temperature ,Additive manufacturing ,Gaussian process for regression ,Fatigue life ,Fatigue strength ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Optimizing the geometry for material savings, or heat transfer, can yield thin-walled additively manufactured parts. A wall thickness of only a few hatching spaces can be fabricated using laser powder bed fusion (LPBF). However, the unmachined surface quality and subsurface defects in the low-thickness wall put the load-bearing capacity of the manufactured part under scrutiny. This study aimed to determine the fatigue and quasi-static strengths of nominally 0.5-mm thick tubular specimens of LPBF 18Ni300 maraging steel with respect to the aging temperature (AT). The experimental tests were conducted on six batches of unmachined specimens: non-aged and age-hardened for 6 h at different temperatures, i.e., 450, 470, 490, 530, and 585 °C. The void distribution and specimen surface were characterized using X-ray micro-computed tomography. The heterogeneous effect of AT on fatigue life was recognized by a novel application of the Gaussian process for regression. The mechanical properties of a 0.5-mm thick tubular specimen were equal to or higher than those of a full cross-section specimen. Furthermore, the optimal AT to obtain the highest fatigue strength was 520 °C for low-cycle fatigue, decreasing to 480 °C for high-cycle fatigue.
- Published
- 2024
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