Experimental Study of the Evolution of Creep-Resistant Steel’s High-Temperature Oxidation Behavior
This study shows that in an atmosphere containing water vapor, the oxide layer on the surface of the 9CrNB steel MarBN (Martensitic 9Cr steel strengthened by Boron and MX Nitrides) was formed by an outer layer of hematite Fe<sub>2</sub>O<sub>3</sub> and Cr<sub>2</sub...
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MDPI AG
2023-06-01
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| Online Access: | https://www.mdpi.com/2073-4352/13/6/982 |
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| author | Gabriela Baranová Mária Hagarová Miloš Matvija Dávid Csík Vladimír Girman Jozef Bednarčík Pavel Bekeč |
| author_facet | Gabriela Baranová Mária Hagarová Miloš Matvija Dávid Csík Vladimír Girman Jozef Bednarčík Pavel Bekeč |
| author_sort | Gabriela Baranová |
| collection | DOAJ |
| description | This study shows that in an atmosphere containing water vapor, the oxide layer on the surface of the 9CrNB steel MarBN (Martensitic 9Cr steel strengthened by Boron and MX Nitrides) was formed by an outer layer of hematite Fe<sub>2</sub>O<sub>3</sub> and Cr<sub>2</sub>O<sub>3</sub> and an inner two-phase layer of Fe<sub>3</sub>O<sub>4</sub> and Fe<sub>3</sub>O<sub>4</sub> + (Fe, Cr)<sub>2</sub>O<sub>4</sub>, which was confirmed by XRD analysis. Part of the layer consisted of nodules and pores that were formed during the increase in oxides when the present H<sub>2</sub>O(g) acted on the steel surface. The diffusion mechanism at temperatures of 600 and 650 °C and at longer oxidation times supported the “healing process” with a growing layer of Fe oxides and the presence of Cr and minor alloying elements. The effects of alloying elements were quantified using a concentration profile of the oxide layer based on quantitative SEM analysis, as well as an explanation of the mechanism influencing the structure and chemical composition of the oxide layer and the steel-matrix–oxide interface. In addition to Cr, for which the content reached the requirement of exceeding 7.0 wt. % in the inner oxide layer, W, Co, Mn, and Si were also found in increased concentrations, whether in the form of the present Fe-Cr spinel oxide or as part of a continuously distributed layer of Mn<sub>2</sub>O<sub>3</sub> and SiO<sub>2</sub> oxides at the steel-matrix–oxide interface. After long-term high-temperature oxidation, coarser carbides of the M<sub>23</sub>C<sub>6</sub> type (M = Fe,W) significantly depleted in Cr were formed at the oxide-layer/matrix interface. In the zone under the oxide layer, very fine particles of MC (M = V, Nb, and to a lesser extent also Cr in the particle lattice of the given phase) were observed, with a higher number of particles per unit area compared to the state before oxidation. This fact was a consequence of Cr diffusion to the steel surface through the subsurface zone. |
| first_indexed | 2024-03-11T02:36:14Z |
| format | Article |
| id | doaj.art-dfb037ff3d9149fba7d384bcf09b2303 |
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| language | English |
| last_indexed | 2024-03-11T02:36:14Z |
| publishDate | 2023-06-01 |
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| spelling | doaj.art-dfb037ff3d9149fba7d384bcf09b23032023-11-18T09:57:28ZengMDPI AGCrystals2073-43522023-06-0113698210.3390/cryst13060982Experimental Study of the Evolution of Creep-Resistant Steel’s High-Temperature Oxidation BehaviorGabriela Baranová0Mária Hagarová1Miloš Matvija2Dávid Csík3Vladimír Girman4Jozef Bednarčík5Pavel Bekeč6Institute of Materials and Quality Engineering, Faculty of Materials, Metallurgy and Recycling, Technical University of Košice, Letná 9, 042 00 Košice, SlovakiaInstitute of Materials and Quality Engineering, Faculty of Materials, Metallurgy and Recycling, Technical University of Košice, Letná 9, 042 00 Košice, SlovakiaInstitute of Materials and Quality Engineering, Faculty of Materials, Metallurgy and Recycling, Technical University of Košice, Letná 9, 042 00 Košice, SlovakiaInstitute of Materials and Quality Engineering, Faculty of Materials, Metallurgy and Recycling, Technical University of Košice, Letná 9, 042 00 Košice, SlovakiaInstitute of Physics, Faculty of Science, P. J. Šafárik University in Košice, Park Angelinum 9, 041 54 Košice, SlovakiaInstitute of Physics, Faculty of Science, P. J. Šafárik University in Košice, Park Angelinum 9, 041 54 Košice, SlovakiaŽeleziarne Podbrezová Research and Development Centre, Ltd., Kolkáreň 35, 976 81 Podbrezová, SlovakiaThis study shows that in an atmosphere containing water vapor, the oxide layer on the surface of the 9CrNB steel MarBN (Martensitic 9Cr steel strengthened by Boron and MX Nitrides) was formed by an outer layer of hematite Fe<sub>2</sub>O<sub>3</sub> and Cr<sub>2</sub>O<sub>3</sub> and an inner two-phase layer of Fe<sub>3</sub>O<sub>4</sub> and Fe<sub>3</sub>O<sub>4</sub> + (Fe, Cr)<sub>2</sub>O<sub>4</sub>, which was confirmed by XRD analysis. Part of the layer consisted of nodules and pores that were formed during the increase in oxides when the present H<sub>2</sub>O(g) acted on the steel surface. The diffusion mechanism at temperatures of 600 and 650 °C and at longer oxidation times supported the “healing process” with a growing layer of Fe oxides and the presence of Cr and minor alloying elements. The effects of alloying elements were quantified using a concentration profile of the oxide layer based on quantitative SEM analysis, as well as an explanation of the mechanism influencing the structure and chemical composition of the oxide layer and the steel-matrix–oxide interface. In addition to Cr, for which the content reached the requirement of exceeding 7.0 wt. % in the inner oxide layer, W, Co, Mn, and Si were also found in increased concentrations, whether in the form of the present Fe-Cr spinel oxide or as part of a continuously distributed layer of Mn<sub>2</sub>O<sub>3</sub> and SiO<sub>2</sub> oxides at the steel-matrix–oxide interface. After long-term high-temperature oxidation, coarser carbides of the M<sub>23</sub>C<sub>6</sub> type (M = Fe,W) significantly depleted in Cr were formed at the oxide-layer/matrix interface. In the zone under the oxide layer, very fine particles of MC (M = V, Nb, and to a lesser extent also Cr in the particle lattice of the given phase) were observed, with a higher number of particles per unit area compared to the state before oxidation. This fact was a consequence of Cr diffusion to the steel surface through the subsurface zone.https://www.mdpi.com/2073-4352/13/6/982creep-resistant steelhigh-temperature oxidationoxide layeroxidation kineticsalloying elements |
| spellingShingle | Gabriela Baranová Mária Hagarová Miloš Matvija Dávid Csík Vladimír Girman Jozef Bednarčík Pavel Bekeč Experimental Study of the Evolution of Creep-Resistant Steel’s High-Temperature Oxidation Behavior Crystals creep-resistant steel high-temperature oxidation oxide layer oxidation kinetics alloying elements |
| title | Experimental Study of the Evolution of Creep-Resistant Steel’s High-Temperature Oxidation Behavior |
| title_full | Experimental Study of the Evolution of Creep-Resistant Steel’s High-Temperature Oxidation Behavior |
| title_fullStr | Experimental Study of the Evolution of Creep-Resistant Steel’s High-Temperature Oxidation Behavior |
| title_full_unstemmed | Experimental Study of the Evolution of Creep-Resistant Steel’s High-Temperature Oxidation Behavior |
| title_short | Experimental Study of the Evolution of Creep-Resistant Steel’s High-Temperature Oxidation Behavior |
| title_sort | experimental study of the evolution of creep resistant steel s high temperature oxidation behavior |
| topic | creep-resistant steel high-temperature oxidation oxide layer oxidation kinetics alloying elements |
| url | https://www.mdpi.com/2073-4352/13/6/982 |
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