

Niobium is recently considered one of the potential alloying elements for tool steels due to the formation of hard and stable carbides of MC type. Its use is limited by the fact that these carbides tend to coarsen during conventional melting metallurgy processing. This work explores the potential of additive manufacturing for processing Nb-alloyed tool steel with a high content of carbon. Directed energy deposition was used as the processing method. It was found that this method allowed us to obtain a microstructure very similar to that obtained after the use of consolidation via spark plasma sintering when subsequent heat treatment by soft annealing, austenitizing, oil quenching and triple tempering for secondary hardness was applied. Moreover, the soft annealing process could be skipped without affecting the structure and properties when machining would not be required. The hardness of the steel was even higher after additive manufacturing was used (approx. 800–830 HV 30) than after spark plasma sintering (approx. 720–750 HV 30). The wear resistance of the materials processed by both routes was almost comparable, reaching 5–7 × 10−6 mm3N−1m−1 depending on the heat treatment. © 2023 by the authors.
| Engineering controlled terms: | 3D printingAdditivesAlloying elementsCarbidesHardnessHeat resistanceNiobium alloysPowder metallurgySpark plasma sinteringWear resistance |
|---|---|
| Engineering uncontrolled terms | AustenitizingDirected energyEnergy depositionsHigh carbon tool steelHigh-contentOil quenchingProcessing methodSoft annealingSpark-plasma-sinteringTriple tempering |
| Engineering main heading: | Tool steel |
| Funding sponsor | Funding number | Acronym |
|---|---|---|
| European Regional Development Fund | A2_FCHT_2023_015,CZ02.1.01/0.0/0.0/16_019/0000836 | ERDF |
The study was supported by ERDF Research of advanced steels with unique properties, grant no. CZ02.1.01/0.0/0.0/16_019/0000836. This work was also supported by a grant for Specific university research, grant no. A2_FCHT_2023_015.
Borkovcová, K.; Department of Metals and Corrosion Engineering, University of Chemistry and Technology, Prague, Technická 5, Prague, Czech Republic;
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