Evolution of precipitates during creep deformation for alloy 718
This study investigated the microstructural evolution of the γ′′, γ′, and δ phases during creep for alloy 718. Creep tests on two-step aged samples were conducted under different stresses and temperatures ranging from 600 to 700 °C. Analysis of precipitates was performed on two-step aged and crept s...
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Elsevier
2025-01-01
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| Series: | Journal of Materials Research and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785424030412 |
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| author | Chanhee Park Joonho Lee Woo-Sang Jung |
| author_facet | Chanhee Park Joonho Lee Woo-Sang Jung |
| author_sort | Chanhee Park |
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| description | This study investigated the microstructural evolution of the γ′′, γ′, and δ phases during creep for alloy 718. Creep tests on two-step aged samples were conducted under different stresses and temperatures ranging from 600 to 700 °C. Analysis of precipitates was performed on two-step aged and crept samples using scanning electron microscopy and transmission electron microscopy. The creep rupture lives were decreased with increasing stresses and temperatures and showed a linear correlation between experimental data and Larson-Miller parameter curve predictions. The γ′′ phase was formed as a disc shape in the grain interior and had an orientation relationship of (001)γ′′//{001}γ and [100]γ′′//<100>γ with γ matrix. The length of the γ′′ phases increased with increasing temperatures and creep exposure time. The activation energy for γ′′ lengthening was 323 kJ/mol, similar to that for lattice diffusion of Nb in Ni. It was found that the formation mechanisms of δ phase were different from temperatures. The δ phase was formed in grain interiors and grain boundaries and had a blocky shape during a sub-δ solvus annealing process. On the other hand, the δ phase was formed as a plate shape and had an orientation relationship of (010)δ//(111¯)γ and [102]δ//[011]γ with γ matrix at creep temperatures. The growth rates of plate δ phase were faster than blocky δ phase at all creep temperatures. |
| format | Article |
| id | doaj-art-00e812e7e723482ca888ba8638284715 |
| institution | Kabale University |
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| language | English |
| publishDate | 2025-01-01 |
| publisher | Elsevier |
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| series | Journal of Materials Research and Technology |
| spelling | doaj-art-00e812e7e723482ca888ba86382847152025-01-19T06:25:55ZengElsevierJournal of Materials Research and Technology2238-78542025-01-013424532462Evolution of precipitates during creep deformation for alloy 718Chanhee Park0Joonho Lee1Woo-Sang Jung2Center for Hydrogen Energy Materials, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of KoreaDepartment of Materials Science and Engineering, Korea University, Seoul 02841, Republic of KoreaCenter for Hydrogen Energy Materials, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Corresponding author.This study investigated the microstructural evolution of the γ′′, γ′, and δ phases during creep for alloy 718. Creep tests on two-step aged samples were conducted under different stresses and temperatures ranging from 600 to 700 °C. Analysis of precipitates was performed on two-step aged and crept samples using scanning electron microscopy and transmission electron microscopy. The creep rupture lives were decreased with increasing stresses and temperatures and showed a linear correlation between experimental data and Larson-Miller parameter curve predictions. The γ′′ phase was formed as a disc shape in the grain interior and had an orientation relationship of (001)γ′′//{001}γ and [100]γ′′//<100>γ with γ matrix. The length of the γ′′ phases increased with increasing temperatures and creep exposure time. The activation energy for γ′′ lengthening was 323 kJ/mol, similar to that for lattice diffusion of Nb in Ni. It was found that the formation mechanisms of δ phase were different from temperatures. The δ phase was formed in grain interiors and grain boundaries and had a blocky shape during a sub-δ solvus annealing process. On the other hand, the δ phase was formed as a plate shape and had an orientation relationship of (010)δ//(111¯)γ and [102]δ//[011]γ with γ matrix at creep temperatures. The growth rates of plate δ phase were faster than blocky δ phase at all creep temperatures.http://www.sciencedirect.com/science/article/pii/S2238785424030412Alloy 718Gamma double primeGamma primeDeltaCreep |
| spellingShingle | Chanhee Park Joonho Lee Woo-Sang Jung Evolution of precipitates during creep deformation for alloy 718 Journal of Materials Research and Technology Alloy 718 Gamma double prime Gamma prime Delta Creep |
| title | Evolution of precipitates during creep deformation for alloy 718 |
| title_full | Evolution of precipitates during creep deformation for alloy 718 |
| title_fullStr | Evolution of precipitates during creep deformation for alloy 718 |
| title_full_unstemmed | Evolution of precipitates during creep deformation for alloy 718 |
| title_short | Evolution of precipitates during creep deformation for alloy 718 |
| title_sort | evolution of precipitates during creep deformation for alloy 718 |
| topic | Alloy 718 Gamma double prime Gamma prime Delta Creep |
| url | http://www.sciencedirect.com/science/article/pii/S2238785424030412 |
| work_keys_str_mv | AT chanheepark evolutionofprecipitatesduringcreepdeformationforalloy718 AT joonholee evolutionofprecipitatesduringcreepdeformationforalloy718 AT woosangjung evolutionofprecipitatesduringcreepdeformationforalloy718 |