Comparison of transition temperature criteria applied for KLST and ISO-V type Charpy specimens

Tapio Planman, Matti Valo, Kim Wallin

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

Abstract

A great deal of test data have been obtained on reactor pressure vessel steels using the standard Charpy-V test. Although more advanced test methods, based on elastic-plastic fracture mechanics, are both recommendable and already in use in the surveillance programmes of some nuclear power plants (NPPs), Charpy tests are still required, e.g., by regulatory guides. Besides the normal-size (ISO-V) Charpy specimen (10*10*55 mm3), various types of sub-size specimens have been introduced. One standardised sub-size specimen being in use is the so-called KLST specimen, the size of which is 3*4*27 mm3 with 1 mm central notch (DIN 50 115). So far the test data published for the KLST specimen, as well as sub-size specimens in general, is still limited. The results from small specimen testing are typically used for evaluating the fracture behaviour of the ISO-V Charpy specimen and if there are no test results available for the correlation, as there usually is not, a general correlation has to be applied to evaluate the fracture behaviour of the ISO-V specimen. The availability of a sub-size specimen depends therefore significantly on how reliably this relationship has been established. Impact test data measured with different specimens have been correlated using some appropriate criterion (or criteria) and since a total transition curve is normally measured, there are several ones available. The criterion can be a fixed energy or lateral expansion level describing the transition temperature or the level can be derived from the upper-shelf energy (USE). In general, the proposed criterion can be divided into two groups: those derived from the dimensions of the specimens and those derived empirically from experimental data. Test data measured with ISO-V and KLST -type Charpy specimens are discussed and the validity of two proposed, basically different transition temperature criteria and the resulting differences in the temperatures, that are inevitable because of the different size ligaments, studied. Specimens' capability to describe consistently the transition temperature shift characteristic of ferritic steels due to irradiation and recovery annealing is discussed as well. The data consists of the test results published previously [1] and more recent test data measured at VTT with KLST-type specimens for non-irradiated and irradiated FFA, JFL and JRQ pressure vessel steels in an IAEA Co-ordinated research programme.
Original languageEnglish
Title of host publicationRATU2: The Finnish Research Programme on the Structural Integrity of Nuclear Power Plants
Subtitle of host publicationSynthesis of achievements 1995-1998
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Pages77-90
ISBN (Electronic)951-38-5264-4
ISBN (Print)951-38-5263-6
Publication statusPublished - 1998
MoE publication typeA4 Article in a conference publication
EventRATU2: The Finnish Research Programme on the Structural Integrity of Nuclear Power Plants: Synthesis of achievements 1995−1998 - Espoo, Finland
Duration: 7 Dec 19987 Dec 1998

Publication series

NameVTT Symposium
PublisherVTT
Number190
ISSN (Print)0357-9387
ISSN (Electronic)1455-0873

Conference

ConferenceRATU2: The Finnish Research Programme on the Structural Integrity of Nuclear Power Plants
CountryFinland
CityEspoo
Period7/12/987/12/98

Fingerprint

Superconducting transition temperature
Steel structures
Ligaments
Ferritic steel
Fracture mechanics
Nuclear power plants
Availability
Irradiation
Annealing
Plastics
Recovery
Testing
Temperature

Cite this

Planman, T., Valo, M., & Wallin, K. (1998). Comparison of transition temperature criteria applied for KLST and ISO-V type Charpy specimens. In RATU2: The Finnish Research Programme on the Structural Integrity of Nuclear Power Plants: Synthesis of achievements 1995-1998 (pp. 77-90). Espoo: VTT Technical Research Centre of Finland. VTT Symposium, No. 190
Planman, Tapio ; Valo, Matti ; Wallin, Kim. / Comparison of transition temperature criteria applied for KLST and ISO-V type Charpy specimens. RATU2: The Finnish Research Programme on the Structural Integrity of Nuclear Power Plants: Synthesis of achievements 1995-1998. Espoo : VTT Technical Research Centre of Finland, 1998. pp. 77-90 (VTT Symposium; No. 190).
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abstract = "A great deal of test data have been obtained on reactor pressure vessel steels using the standard Charpy-V test. Although more advanced test methods, based on elastic-plastic fracture mechanics, are both recommendable and already in use in the surveillance programmes of some nuclear power plants (NPPs), Charpy tests are still required, e.g., by regulatory guides. Besides the normal-size (ISO-V) Charpy specimen (10*10*55 mm3), various types of sub-size specimens have been introduced. One standardised sub-size specimen being in use is the so-called KLST specimen, the size of which is 3*4*27 mm3 with 1 mm central notch (DIN 50 115). So far the test data published for the KLST specimen, as well as sub-size specimens in general, is still limited. The results from small specimen testing are typically used for evaluating the fracture behaviour of the ISO-V Charpy specimen and if there are no test results available for the correlation, as there usually is not, a general correlation has to be applied to evaluate the fracture behaviour of the ISO-V specimen. The availability of a sub-size specimen depends therefore significantly on how reliably this relationship has been established. Impact test data measured with different specimens have been correlated using some appropriate criterion (or criteria) and since a total transition curve is normally measured, there are several ones available. The criterion can be a fixed energy or lateral expansion level describing the transition temperature or the level can be derived from the upper-shelf energy (USE). In general, the proposed criterion can be divided into two groups: those derived from the dimensions of the specimens and those derived empirically from experimental data. Test data measured with ISO-V and KLST -type Charpy specimens are discussed and the validity of two proposed, basically different transition temperature criteria and the resulting differences in the temperatures, that are inevitable because of the different size ligaments, studied. Specimens' capability to describe consistently the transition temperature shift characteristic of ferritic steels due to irradiation and recovery annealing is discussed as well. The data consists of the test results published previously [1] and more recent test data measured at VTT with KLST-type specimens for non-irradiated and irradiated FFA, JFL and JRQ pressure vessel steels in an IAEA Co-ordinated research programme.",
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Planman, T, Valo, M & Wallin, K 1998, Comparison of transition temperature criteria applied for KLST and ISO-V type Charpy specimens. in RATU2: The Finnish Research Programme on the Structural Integrity of Nuclear Power Plants: Synthesis of achievements 1995-1998. VTT Technical Research Centre of Finland, Espoo, VTT Symposium, no. 190, pp. 77-90, RATU2: The Finnish Research Programme on the Structural Integrity of Nuclear Power Plants, Espoo, Finland, 7/12/98.

Comparison of transition temperature criteria applied for KLST and ISO-V type Charpy specimens. / Planman, Tapio; Valo, Matti; Wallin, Kim.

RATU2: The Finnish Research Programme on the Structural Integrity of Nuclear Power Plants: Synthesis of achievements 1995-1998. Espoo : VTT Technical Research Centre of Finland, 1998. p. 77-90 (VTT Symposium; No. 190).

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

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T1 - Comparison of transition temperature criteria applied for KLST and ISO-V type Charpy specimens

AU - Planman, Tapio

AU - Valo, Matti

AU - Wallin, Kim

PY - 1998

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N2 - A great deal of test data have been obtained on reactor pressure vessel steels using the standard Charpy-V test. Although more advanced test methods, based on elastic-plastic fracture mechanics, are both recommendable and already in use in the surveillance programmes of some nuclear power plants (NPPs), Charpy tests are still required, e.g., by regulatory guides. Besides the normal-size (ISO-V) Charpy specimen (10*10*55 mm3), various types of sub-size specimens have been introduced. One standardised sub-size specimen being in use is the so-called KLST specimen, the size of which is 3*4*27 mm3 with 1 mm central notch (DIN 50 115). So far the test data published for the KLST specimen, as well as sub-size specimens in general, is still limited. The results from small specimen testing are typically used for evaluating the fracture behaviour of the ISO-V Charpy specimen and if there are no test results available for the correlation, as there usually is not, a general correlation has to be applied to evaluate the fracture behaviour of the ISO-V specimen. The availability of a sub-size specimen depends therefore significantly on how reliably this relationship has been established. Impact test data measured with different specimens have been correlated using some appropriate criterion (or criteria) and since a total transition curve is normally measured, there are several ones available. The criterion can be a fixed energy or lateral expansion level describing the transition temperature or the level can be derived from the upper-shelf energy (USE). In general, the proposed criterion can be divided into two groups: those derived from the dimensions of the specimens and those derived empirically from experimental data. Test data measured with ISO-V and KLST -type Charpy specimens are discussed and the validity of two proposed, basically different transition temperature criteria and the resulting differences in the temperatures, that are inevitable because of the different size ligaments, studied. Specimens' capability to describe consistently the transition temperature shift characteristic of ferritic steels due to irradiation and recovery annealing is discussed as well. The data consists of the test results published previously [1] and more recent test data measured at VTT with KLST-type specimens for non-irradiated and irradiated FFA, JFL and JRQ pressure vessel steels in an IAEA Co-ordinated research programme.

AB - A great deal of test data have been obtained on reactor pressure vessel steels using the standard Charpy-V test. Although more advanced test methods, based on elastic-plastic fracture mechanics, are both recommendable and already in use in the surveillance programmes of some nuclear power plants (NPPs), Charpy tests are still required, e.g., by regulatory guides. Besides the normal-size (ISO-V) Charpy specimen (10*10*55 mm3), various types of sub-size specimens have been introduced. One standardised sub-size specimen being in use is the so-called KLST specimen, the size of which is 3*4*27 mm3 with 1 mm central notch (DIN 50 115). So far the test data published for the KLST specimen, as well as sub-size specimens in general, is still limited. The results from small specimen testing are typically used for evaluating the fracture behaviour of the ISO-V Charpy specimen and if there are no test results available for the correlation, as there usually is not, a general correlation has to be applied to evaluate the fracture behaviour of the ISO-V specimen. The availability of a sub-size specimen depends therefore significantly on how reliably this relationship has been established. Impact test data measured with different specimens have been correlated using some appropriate criterion (or criteria) and since a total transition curve is normally measured, there are several ones available. The criterion can be a fixed energy or lateral expansion level describing the transition temperature or the level can be derived from the upper-shelf energy (USE). In general, the proposed criterion can be divided into two groups: those derived from the dimensions of the specimens and those derived empirically from experimental data. Test data measured with ISO-V and KLST -type Charpy specimens are discussed and the validity of two proposed, basically different transition temperature criteria and the resulting differences in the temperatures, that are inevitable because of the different size ligaments, studied. Specimens' capability to describe consistently the transition temperature shift characteristic of ferritic steels due to irradiation and recovery annealing is discussed as well. The data consists of the test results published previously [1] and more recent test data measured at VTT with KLST-type specimens for non-irradiated and irradiated FFA, JFL and JRQ pressure vessel steels in an IAEA Co-ordinated research programme.

M3 - Conference article in proceedings

SN - 951-38-5263-6

T3 - VTT Symposium

SP - 77

EP - 90

BT - RATU2: The Finnish Research Programme on the Structural Integrity of Nuclear Power Plants

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Planman T, Valo M, Wallin K. Comparison of transition temperature criteria applied for KLST and ISO-V type Charpy specimens. In RATU2: The Finnish Research Programme on the Structural Integrity of Nuclear Power Plants: Synthesis of achievements 1995-1998. Espoo: VTT Technical Research Centre of Finland. 1998. p. 77-90. (VTT Symposium; No. 190).