High temperature damage as an indicator of operating conditions and residual creep life

Pertti Auerkari, Jorma Salonen, Stefan Holmström, Anssi Laukkanen, L. Laaksonen, S. Mäkinen, V. Väänänen, R. Nikkarila

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Abstract

Damage due to creep and associated mechanisms is typically life-limiting in the pressure retaining hot sections of power boilers, requiring inspections to support the condition and life assessment.
Since a single local failure can result in a shutdown, it is important to find the critical hot spots that will determine the time to next failure, and to evaluate the condition at those spots.
This paper aims to demonstrate the characteristic damage in terms of in-service condition and related clues for life assessment. In particular, the appearance of microstructural degradation, internal oxidation and intergranular creep cavitation can indicate the path and extent of deviations from the expected status in components.
Examples are shown on ferritic boiler steels, with degradation and damage proceeding through somewhat comparable stages regardless of the material grade.
Hence although there are large differences e.g. in the creep strength between alloys, the operating conditions should largely compensate for the differences in the mechanical properties, and the predicted life fraction is not a strong function of the material grade for the same level of in-service damage.
However, uncompensated residual differences between materials also occur and are discussed with examples.
Original languageEnglish
Title of host publicationproceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11
Place of PublicationSendai, Japan
PublisherJapan Institute of Metals (JIM)
Pages1-4
ISBN (Print)978-488-90340-7-3
Publication statusPublished - 2012
MoE publication typeA4 Article in a conference publication
Event12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11 - Kyoto, Japan
Duration: 27 May 201231 May 2012

Conference

Conference12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11
Abbreviated titleJIMIS 11
CountryJapan
CityKyoto
Period27/05/1231/05/12

Fingerprint

Creep
Boilers
Internal oxidation
Degradation
Cavitation
Temperature
Inspection
Mechanical properties
Steel

Cite this

Auerkari, P., Salonen, J., Holmström, S., Laukkanen, A., Laaksonen, L., Mäkinen, S., ... Nikkarila, R. (2012). High temperature damage as an indicator of operating conditions and residual creep life. In proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11 (pp. 1-4). Sendai, Japan: Japan Institute of Metals (JIM).
Auerkari, Pertti ; Salonen, Jorma ; Holmström, Stefan ; Laukkanen, Anssi ; Laaksonen, L. ; Mäkinen, S. ; Väänänen, V. ; Nikkarila, R. / High temperature damage as an indicator of operating conditions and residual creep life. proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11. Sendai, Japan : Japan Institute of Metals (JIM), 2012. pp. 1-4
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abstract = "Damage due to creep and associated mechanisms is typically life-limiting in the pressure retaining hot sections of power boilers, requiring inspections to support the condition and life assessment. Since a single local failure can result in a shutdown, it is important to find the critical hot spots that will determine the time to next failure, and to evaluate the condition at those spots. This paper aims to demonstrate the characteristic damage in terms of in-service condition and related clues for life assessment. In particular, the appearance of microstructural degradation, internal oxidation and intergranular creep cavitation can indicate the path and extent of deviations from the expected status in components. Examples are shown on ferritic boiler steels, with degradation and damage proceeding through somewhat comparable stages regardless of the material grade. Hence although there are large differences e.g. in the creep strength between alloys, the operating conditions should largely compensate for the differences in the mechanical properties, and the predicted life fraction is not a strong function of the material grade for the same level of in-service damage. However, uncompensated residual differences between materials also occur and are discussed with examples.",
author = "Pertti Auerkari and Jorma Salonen and Stefan Holmstr{\"o}m and Anssi Laukkanen and L. Laaksonen and S. M{\"a}kinen and V. V{\"a}{\"a}n{\"a}nen and R. Nikkarila",
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Auerkari, P, Salonen, J, Holmström, S, Laukkanen, A, Laaksonen, L, Mäkinen, S, Väänänen, V & Nikkarila, R 2012, High temperature damage as an indicator of operating conditions and residual creep life. in proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11. Japan Institute of Metals (JIM), Sendai, Japan, pp. 1-4, 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11, Kyoto, Japan, 27/05/12.

High temperature damage as an indicator of operating conditions and residual creep life. / Auerkari, Pertti; Salonen, Jorma; Holmström, Stefan; Laukkanen, Anssi; Laaksonen, L.; Mäkinen, S.; Väänänen, V.; Nikkarila, R.

proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11. Sendai, Japan : Japan Institute of Metals (JIM), 2012. p. 1-4.

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

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T1 - High temperature damage as an indicator of operating conditions and residual creep life

AU - Auerkari, Pertti

AU - Salonen, Jorma

AU - Holmström, Stefan

AU - Laukkanen, Anssi

AU - Laaksonen, L.

AU - Mäkinen, S.

AU - Väänänen, V.

AU - Nikkarila, R.

PY - 2012

Y1 - 2012

N2 - Damage due to creep and associated mechanisms is typically life-limiting in the pressure retaining hot sections of power boilers, requiring inspections to support the condition and life assessment. Since a single local failure can result in a shutdown, it is important to find the critical hot spots that will determine the time to next failure, and to evaluate the condition at those spots. This paper aims to demonstrate the characteristic damage in terms of in-service condition and related clues for life assessment. In particular, the appearance of microstructural degradation, internal oxidation and intergranular creep cavitation can indicate the path and extent of deviations from the expected status in components. Examples are shown on ferritic boiler steels, with degradation and damage proceeding through somewhat comparable stages regardless of the material grade. Hence although there are large differences e.g. in the creep strength between alloys, the operating conditions should largely compensate for the differences in the mechanical properties, and the predicted life fraction is not a strong function of the material grade for the same level of in-service damage. However, uncompensated residual differences between materials also occur and are discussed with examples.

AB - Damage due to creep and associated mechanisms is typically life-limiting in the pressure retaining hot sections of power boilers, requiring inspections to support the condition and life assessment. Since a single local failure can result in a shutdown, it is important to find the critical hot spots that will determine the time to next failure, and to evaluate the condition at those spots. This paper aims to demonstrate the characteristic damage in terms of in-service condition and related clues for life assessment. In particular, the appearance of microstructural degradation, internal oxidation and intergranular creep cavitation can indicate the path and extent of deviations from the expected status in components. Examples are shown on ferritic boiler steels, with degradation and damage proceeding through somewhat comparable stages regardless of the material grade. Hence although there are large differences e.g. in the creep strength between alloys, the operating conditions should largely compensate for the differences in the mechanical properties, and the predicted life fraction is not a strong function of the material grade for the same level of in-service damage. However, uncompensated residual differences between materials also occur and are discussed with examples.

M3 - Conference article in proceedings

SN - 978-488-90340-7-3

SP - 1

EP - 4

BT - proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11

PB - Japan Institute of Metals (JIM)

CY - Sendai, Japan

ER -

Auerkari P, Salonen J, Holmström S, Laukkanen A, Laaksonen L, Mäkinen S et al. High temperature damage as an indicator of operating conditions and residual creep life. In proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11. Sendai, Japan: Japan Institute of Metals (JIM). 2012. p. 1-4