Effect of thermal aging on microstructure and hardness of industrial heats of Alloy 690

Caitlin Huotilainen; Ulla Ehrnstén; Matias Ahonen; Hannu Hänninen

Effect of thermal aging on microstructure and hardness of industrial heats of Alloy 690

Caitlin Huotilainen, Ulla Ehrnstén, Matias Ahonen, Hannu Hänninen

Aalto University

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Abstract

Alloy 690 is a high-chromium nickel-base alloy used in various primary coolant system components and for steam generator tubes in many nuclear power plants. A thermal treatment is typically applied for Alloy 690 components, giving the material a better resistance to stress corrosion cracking, compared to mill-annealed condition, due to fine grain boundary carbides of type M23C6. The effect of thermal aging at 400 ^◦C was investigated in four different heats of Alloy 690. After 5000 h and 10 000 h of aging, one of the materials showed a significant increase in hardness, whereas the three other heats did not show a measurable effect of aging. Microstructural and hardness characterizations were performed, on both initial and aged material, by applying optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, microhardness and nanoindentation measurements, in order to study the microstructural features causing the observed increase in hardness.

Original language	English
Title of host publication	19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors
Publisher	American Nuclear Society (ANS)
Pages	156-164
Number of pages	9
ISBN (Electronic)	978-0-89448-765-1
Publication status	Published - 2019
MoE publication type	A4 Article in a conference publication
Event	19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, EnvDeg 2019 - Boston, United States Duration: 18 Aug 2019 → 22 Aug 2019

Conference

Conference	19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, EnvDeg 2019
Abbreviated title	ENVDEG 2019
Country/Territory	United States
City	Boston
Period	18/08/19 → 22/08/19

Cite this

@inproceedings{561045f976694b38b8293147fe8fc71c,

title = "Effect of thermal aging on microstructure and hardness of industrial heats of Alloy 690",

abstract = "Alloy 690 is a high-chromium nickel-base alloy used in various primary coolant system components and for steam generator tubes in many nuclear power plants. A thermal treatment is typically applied for Alloy 690 components, giving the material a better resistance to stress corrosion cracking, compared to mill-annealed condition, due to fine grain boundary carbides of type M23C6. The effect of thermal aging at 400 ◦C was investigated in four different heats of Alloy 690. After 5000 h and 10 000 h of aging, one of the materials showed a significant increase in hardness, whereas the three other heats did not show a measurable effect of aging. Microstructural and hardness characterizations were performed, on both initial and aged material, by applying optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, microhardness and nanoindentation measurements, in order to study the microstructural features causing the observed increase in hardness. ",

author = "Caitlin Huotilainen and Ulla Ehrnst{\'e}n and Matias Ahonen and Hannu H{\"a}nninen",

note = "Funding Information: The authors would like to thank EPRI for providing the Alloy 690 materials investigated in this study. This work was performed within the framework of the Thermal ageing and EAC research for plant life management (THELMA) project funded by the Finnish Research Programme on Nuclear Power Plant Safety 2015 - 2018 (SAFIR2018) and the Thermal aging of Alloy 690 and high-nickel alloys (TAAN) project funded by the Finnish Research Programme on Nuclear Power Plant Safety 2019 - 2022 (SAFIR2022). The authors would also like to thank J. Rantala, T. Lehtikuusi, M. Mattila and J. Lukin for their valuable contributions to this study. Publisher Copyright: {\textcopyright} 2019 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, EnvDeg. All rights reserved. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.; 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, EnvDeg 2019, ENVDEG 2019 ; Conference date: 18-08-2019 Through 22-08-2019",

year = "2019",

language = "English",

pages = "156--164",

booktitle = "19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors",

publisher = "American Nuclear Society (ANS)",

address = "United States",

}

Huotilainen, C, Ehrnstén, U, Ahonen, M & Hänninen, H 2019, Effect of thermal aging on microstructure and hardness of industrial heats of Alloy 690. in 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors. American Nuclear Society (ANS), pp. 156-164, 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, EnvDeg 2019, Boston, United States, 18/08/19.

Effect of thermal aging on microstructure and hardness of industrial heats of Alloy 690. / Huotilainen, Caitlin; Ehrnstén, Ulla; Ahonen, Matias et al.
19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors. American Nuclear Society (ANS), 2019. p. 156-164.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

TY - GEN

T1 - Effect of thermal aging on microstructure and hardness of industrial heats of Alloy 690

AU - Huotilainen, Caitlin

AU - Ehrnstén, Ulla

AU - Ahonen, Matias

AU - Hänninen, Hannu

N1 - Funding Information: The authors would like to thank EPRI for providing the Alloy 690 materials investigated in this study. This work was performed within the framework of the Thermal ageing and EAC research for plant life management (THELMA) project funded by the Finnish Research Programme on Nuclear Power Plant Safety 2015 - 2018 (SAFIR2018) and the Thermal aging of Alloy 690 and high-nickel alloys (TAAN) project funded by the Finnish Research Programme on Nuclear Power Plant Safety 2019 - 2022 (SAFIR2022). The authors would also like to thank J. Rantala, T. Lehtikuusi, M. Mattila and J. Lukin for their valuable contributions to this study. Publisher Copyright: © 2019 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, EnvDeg. All rights reserved. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2019

Y1 - 2019

N2 - Alloy 690 is a high-chromium nickel-base alloy used in various primary coolant system components and for steam generator tubes in many nuclear power plants. A thermal treatment is typically applied for Alloy 690 components, giving the material a better resistance to stress corrosion cracking, compared to mill-annealed condition, due to fine grain boundary carbides of type M23C6. The effect of thermal aging at 400 ◦C was investigated in four different heats of Alloy 690. After 5000 h and 10 000 h of aging, one of the materials showed a significant increase in hardness, whereas the three other heats did not show a measurable effect of aging. Microstructural and hardness characterizations were performed, on both initial and aged material, by applying optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, microhardness and nanoindentation measurements, in order to study the microstructural features causing the observed increase in hardness.

AB - Alloy 690 is a high-chromium nickel-base alloy used in various primary coolant system components and for steam generator tubes in many nuclear power plants. A thermal treatment is typically applied for Alloy 690 components, giving the material a better resistance to stress corrosion cracking, compared to mill-annealed condition, due to fine grain boundary carbides of type M23C6. The effect of thermal aging at 400 ◦C was investigated in four different heats of Alloy 690. After 5000 h and 10 000 h of aging, one of the materials showed a significant increase in hardness, whereas the three other heats did not show a measurable effect of aging. Microstructural and hardness characterizations were performed, on both initial and aged material, by applying optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, microhardness and nanoindentation measurements, in order to study the microstructural features causing the observed increase in hardness.

UR - http://www.scopus.com/inward/record.url?scp=85080077793&partnerID=8YFLogxK

M3 - Conference article in proceedings

SP - 156

EP - 164

BT - 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors

PB - American Nuclear Society (ANS)

T2 - 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, EnvDeg 2019

Y2 - 18 August 2019 through 22 August 2019

ER -

Effect of thermal aging on microstructure and hardness of industrial heats of Alloy 690

Abstract

Conference

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TAAN: Thermal Aging of Alloy 690 and a high Ni Alloy

Cite this

Effect of thermal aging on microstructure and hardness of industrial heats of Alloy 690

Abstract

Conference

Other files and links

Fingerprint

Projects

TAAN: Thermal Aging of Alloy 690 and a high Ni Alloy

Cite this