| 1. |
- Chyrkin, Anton, 1984, et al.
(författare)
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High-temperature oxidation behavior of additively manufactured IN625: Effect of microstructure and grain size
- 2022
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X. ; 205
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Tidskriftsartikel (refereegranskat)abstract
- High-temperature oxidation of additively manufactured (AM) Ni-base alloy IN625 has been studied in air and Ar-5%H2-3%H2O at 900–1000 °C. AM material is found to oxidize faster than the conventionally manufactured (CM) IN625 due to severe intergranular oxidation observed in the former. The AM IN625 was heat treated at 1100–1250 °C and hot rolled at 980 °C in order to modify the AM microstructure, primarily grain size, and analyze its role in alloy oxidation behavior. Grain size is shown to affect overall oxidation kinetics but not the intergranular oxidation morphology.
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| 2. |
- Chyrkin, Anton, 1984, et al.
(författare)
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Intergranular oxidation of additively manufactured Ni-base alloy 625: The role of Si
- 2023
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Ingår i: Corrosion Science. - 0010-938X. ; 219
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Tidskriftsartikel (refereegranskat)abstract
- Additively manufactured (AM) Ni-base alloy 625 exposed in air and H2/H2O at 900 °C has been shown to suffer from intergranular oxidation attack unlike its conventionally manufactured (CM) variant. Modification of the AM microstructure via hot-rolling and heat-treatment did not alter the oxidation pattern. Detailed analysis of minor differences in chemical composition of AM and CM exposed the critical role of Si in oxidation protection of alloy 625. Experiments with model alloys as well as diffusion modeling confirmed the crucial role of a minimum Si concentration to form a SiO2 subscale preventing thereby intergranular oxidation attack.
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| 3. |
- Gündüz, Kerem, 1985, et al.
(författare)
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The effect of additive manufacturing on the initial High temperature oxidation properties of RE-containing FeCrAl alloys
- 2021
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X. ; 188
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Tidskriftsartikel (refereegranskat)abstract
- The effect of additive manufacturing on the high temperature oxidation properties of FeCrAl materials was investigated. For this purpose, additively manufactured Kanthal AM100 cut parallel and perpendicular to the building direction and hot-rolled Kanthal AF as a reference were exposed to air at 900 and 1100 °C for 168 h. AM100 performed slightly better than AF in terms of mass gain. Nevertheless, an oxide scale with local differences in thickness formed on AM100 due to the bimodal grain structure of the underlying metal, which was composed of coarse-grained cuboidal repeating units (100 μm wide), separated by fine-grained rims.
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| 4. |
- Sangarimotlagh, Z., et al.
(författare)
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Precipitation and Flow Behavior of AISI 630 Stainless Steel Deformed at Elevated Temperatures
- 2023
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Ingår i: Journal of Materials Engineering and Performance. - : Springer Science and Business Media LLC. - 1059-9495 .- 1544-1024. ; 32:8, s. 3690-3702
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Tidskriftsartikel (refereegranskat)abstract
- Hot compression tests were performed on the samples of AISI 630 stainless steel in the temperature range of 900-1050 degrees C and at strain rates of 10(-3)- 1 s(-1). Single peak stress flow behavior was observed at all deformation conditions. An irregular relationship was found between the peak point of flow curves and processing condition, i.e., temperature and strain rate. The stress relaxation tests at the temperature range of 900-1050 degrees C revealed that dynamic precipitation (DP) of carbides in the matrix and grain boundaries causes the considered irregularities in the peak stress. The FE-SEM studies also showed that DP of carbides could be responsible for the retardation of dynamic recrystallization (DRX). The phase extraction by residual testing ascertained that fine niobium carbides are the major sources for the effect of DP on the microstructural mechanisms. EBSD and optical microscopy confirmed the occurrence of continuous dynamic recrystallization by the progressive evolution of substructure toward the formation of new small grains. The enhancing rotated (cube) or slight weakening of copper and brass/ Goss texture components were mainly associated with the DRX. The hyperbolic sine equation is used in calculating the activation energy at strain of 0.4 as 485.6 kJ/mol.
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| 5. |
- Visibile, Alberto, 1989, et al.
(författare)
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High temperature oxidation of inconel 939 produced by additive manufacturing
- 2024
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Ingår i: Corrosion Science. - 0010-938X. ; 233
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Tidskriftsartikel (refereegranskat)abstract
- High temperature oxidation of additively manufactured (Laser-powder bed fusion) IN939 (AM IN939) was studied at 900°C in dry air for 168 hours. AM IN939 cut parallel/perpendicular to the building direction, including conventionally manufactured (CM) IN939 were exposed to assess the influence of AM microstructure and its inherent anisotropy on oxidation properties. Microstructural anisotropy had no significant impact on oxidation properties. AM and CM IN939 exhibited nearly identical mass gains, yet local spallation was observed in the former. Further investigation involved oxidation of heat-treated AM IN939, revealing improved adhesion, possibly due to transformation of fine dendritic/cellular structure into coarse equiaxed grains.
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