Effects of aging time on the microstructure and mechanical properties of 18Ni200 maraging steel
This study investigates the effect of aging treatment on the precipitates and reverse transformed austenite (RTA) in 18Ni200 maraging steel by transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), and X-ray diffraction (XRD). With the prolongation of aging time at 500 °C,...
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| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-07-01
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| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785425014383 |
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| Summary: | This study investigates the effect of aging treatment on the precipitates and reverse transformed austenite (RTA) in 18Ni200 maraging steel by transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), and X-ray diffraction (XRD). With the prolongation of aging time at 500 °C, the tensile strength first increases and then decreases, while the impact toughness displays inverse variation, which can be attributed to the synergistic actions of the precipitation of strengthening particles Ni3(Ti, Mo), Fe2Mo and the formation of RTA. At aging of 0.5 h, dispersed needle-like Ni3(Ti, Mo) precipitate within the lath interior, providing significant precipitation strengthening effect by preventing dislocation movements, and resulting in the enhanced strength and deteriorated toughness. With the prolongation of aging time to 8 h and 24 h, Ni3(Ti, Mo) particles gradually transform into globular Fe2Mo particles, and Ni atoms are excluded, which can promote the formation of RTA. The existence of RTA is unfavourable for the strength due to the lower hardness, while it can enhance the toughness by the transformation-induced plasticity (TRIP). The results obtained in this work provide a novel pathway for tailoring the formation of RTA by controlling the transformation process of precipitates, and simultaneously enhance the strength and toughness of maraging steels. |
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| ISSN: | 2238-7854 |