Mechanism of Layer Formation during Gas Nitriding of Remelted Ledeburitic Surface Layers on Unalloyed Cast Irons
Unalloyed cast iron materials exhibit low tribological and corrosive resistance. In this respect, nitriding has a wide range of applications for steels. In the case of cast iron, the advantageous properties of nitrided layers are impaired by the presence of graphite. Electron beam remelting of cast...
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MDPI AG
2023-01-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/13/1/156 |
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| author | Anja Holst Stefan Kante Andreas Leineweber Anja Buchwalder |
| author_facet | Anja Holst Stefan Kante Andreas Leineweber Anja Buchwalder |
| author_sort | Anja Holst |
| collection | DOAJ |
| description | Unalloyed cast iron materials exhibit low tribological and corrosive resistance. In this respect, nitriding has a wide range of applications for steels. In the case of cast iron, the advantageous properties of nitrided layers are impaired by the presence of graphite. Electron beam remelting of cast iron surfaces prior to nitriding removes graphite. The homogeneous ledeburitic microstructure within the approx. 1 mm-thick remelted layer enables the formation of a dense compound layer during subsequent nitriding. The main objective of this study is to investigate the nitriding mechanism of unalloyed ledeburitic microstructures. Due to the complex relationships, investigations were carried out on both conventional ferritic and pearlitic cast irons and Fe-based model alloys containing one to four additional alloying elements, i.e., C, Si, Mn and Cu. The iron (carbo-)nitride composition (γ’, ε) of this compound layer depends on the gas nitriding conditions, the chemical composition of the substrates and the microstructural constituents. As a result, a schematic model of the nitriding mechanism is developed that includes the effects of the nitriding parameters and alloy composition on the phase composition of the nitriding layer. These findings enable targeted parameter selection and a further optimization of both the process and the properties. |
| first_indexed | 2024-03-09T11:41:35Z |
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| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-09T11:41:35Z |
| publishDate | 2023-01-01 |
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| spelling | doaj.art-83677f9ef7ac4cf6a9feb2c82e30f4992023-11-30T23:31:30ZengMDPI AGMetals2075-47012023-01-0113115610.3390/met13010156Mechanism of Layer Formation during Gas Nitriding of Remelted Ledeburitic Surface Layers on Unalloyed Cast IronsAnja Holst0Stefan Kante1Andreas Leineweber2Anja Buchwalder3Institute of Materials Engineering, Technische Universität Bergakademie Freiberg, 09599 Freiberg, GermanyInstitute of Materials Science, Technische Universität Bergakademie Freiberg, 09599 Freiberg, GermanyInstitute of Materials Science, Technische Universität Bergakademie Freiberg, 09599 Freiberg, GermanyInstitute of Materials Engineering, Technische Universität Bergakademie Freiberg, 09599 Freiberg, GermanyUnalloyed cast iron materials exhibit low tribological and corrosive resistance. In this respect, nitriding has a wide range of applications for steels. In the case of cast iron, the advantageous properties of nitrided layers are impaired by the presence of graphite. Electron beam remelting of cast iron surfaces prior to nitriding removes graphite. The homogeneous ledeburitic microstructure within the approx. 1 mm-thick remelted layer enables the formation of a dense compound layer during subsequent nitriding. The main objective of this study is to investigate the nitriding mechanism of unalloyed ledeburitic microstructures. Due to the complex relationships, investigations were carried out on both conventional ferritic and pearlitic cast irons and Fe-based model alloys containing one to four additional alloying elements, i.e., C, Si, Mn and Cu. The iron (carbo-)nitride composition (γ’, ε) of this compound layer depends on the gas nitriding conditions, the chemical composition of the substrates and the microstructural constituents. As a result, a schematic model of the nitriding mechanism is developed that includes the effects of the nitriding parameters and alloy composition on the phase composition of the nitriding layer. These findings enable targeted parameter selection and a further optimization of both the process and the properties.https://www.mdpi.com/2075-4701/13/1/156cast ironelectron beam remeltinggas nitridingledeburitecementiteFe carbonitrides |
| spellingShingle | Anja Holst Stefan Kante Andreas Leineweber Anja Buchwalder Mechanism of Layer Formation during Gas Nitriding of Remelted Ledeburitic Surface Layers on Unalloyed Cast Irons Metals cast iron electron beam remelting gas nitriding ledeburite cementite Fe carbonitrides |
| title | Mechanism of Layer Formation during Gas Nitriding of Remelted Ledeburitic Surface Layers on Unalloyed Cast Irons |
| title_full | Mechanism of Layer Formation during Gas Nitriding of Remelted Ledeburitic Surface Layers on Unalloyed Cast Irons |
| title_fullStr | Mechanism of Layer Formation during Gas Nitriding of Remelted Ledeburitic Surface Layers on Unalloyed Cast Irons |
| title_full_unstemmed | Mechanism of Layer Formation during Gas Nitriding of Remelted Ledeburitic Surface Layers on Unalloyed Cast Irons |
| title_short | Mechanism of Layer Formation during Gas Nitriding of Remelted Ledeburitic Surface Layers on Unalloyed Cast Irons |
| title_sort | mechanism of layer formation during gas nitriding of remelted ledeburitic surface layers on unalloyed cast irons |
| topic | cast iron electron beam remelting gas nitriding ledeburite cementite Fe carbonitrides |
| url | https://www.mdpi.com/2075-4701/13/1/156 |
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