| Autor: |
König, C., Valente, E. H., Nadimpalli, V. K., Tokman, Y. G., Christiansen, T. L., Somers, M. A. J. |
| Zdroj: |
Journal of Heat Treatment and Materials: HTM; December 2024, Vol. 79 Issue: 6 p269-287, 19p |
| Abstrakt: |
Using laser powder bed fusion (L-PBF), nickel-free austenitic stainless steel was manufactured from mixing AISI 420S martensitic stainless-steel powder with austenite-stabilizing components. Chromium nitride (Cr2N), chromium carbide (Cr3C2), chromium (Cr) and graphite (C) powder were admixed in different quantities. The resulting microstructures were investigated using light- and electron microscopy, X-ray diffraction, and hardness indentations. Nitrogen, carbon, and chromium from the admixed powders were dissolved in solid solution; no remnants of nitrides/carbides were identified. The as-built specimens had a lower nitrogen content than the mixed powders. Insufficient additions of austenite-stabilizing elements resulted in a dual-phase microstructure of austenite and martensite, which experienced in-situ tempering of martensite during fusion of consecutive layer(s) in the L-PBF process. Relatively high contents of austenite-stabilizing elements resulted in a fully austenitic microstructure with a hardness of 380–500 HV5, depending on Cr and interstitial content. The tendency for forming hot cracks was found to correlate with the solidification interval as calculated using a modified version of the Scheil-Gulliver model. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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