Cyclic softening of tempered ferritic-martensitic steel P91

Jaromir Janousek, Stefan Holmström, Rami Pohja

Research output: Contribution to conferenceConference articleScientific

Abstract

For the ferritic-martensitic steel P91 cyclic softening has been identified as important factor in the assessments of creep-fatigue in nuclear components. Better understanding of the cyclic softening is needed as it is believed to be the main contributor for the complex material behavior encountered in creep-fatigue testing. In fast reactor components the main life shortening load cycles are from thermal fluctuations causing through-wall stress gradients. The main objective of this work (as a Task in the European project MATISSE) is to perform tailored experiments and to develop models for understanding and predicting the cyclic-softening of P91. The supporting experimental program produces data for calibration and validations of the developed models. An existing elasto-viscoplasticity model simulates the key mechanisms such as decrease in dislocation density, increase in sub-grain size and recovering phenomena. The model will be modified to also incorporate the effect of hold time on the cyclic softening.
Original languageEnglish
Publication statusPublished - 2015
Event31th Conference with International Participation on Computational Mechanics - Spicák, Czech Republic
Duration: 9 Nov 201511 Nov 2015

Conference

Conference31th Conference with International Participation on Computational Mechanics
CountryCzech Republic
CitySpicák
Period9/11/1511/11/15

Fingerprint

Martensitic steel
Ferritic steel
Creep testing
Viscoplasticity
Fatigue testing
Fast reactors
Creep
Fatigue of materials
Calibration
Experiments

Keywords

  • cyclic softening
  • creep-fatigue
  • P91 steel

Cite this

Janousek, J., Holmström, S., & Pohja, R. (2015). Cyclic softening of tempered ferritic-martensitic steel P91. Paper presented at 31th Conference with International Participation on Computational Mechanics, Spicák, Czech Republic.
Janousek, Jaromir ; Holmström, Stefan ; Pohja, Rami. / Cyclic softening of tempered ferritic-martensitic steel P91. Paper presented at 31th Conference with International Participation on Computational Mechanics, Spicák, Czech Republic.
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abstract = "For the ferritic-martensitic steel P91 cyclic softening has been identified as important factor in the assessments of creep-fatigue in nuclear components. Better understanding of the cyclic softening is needed as it is believed to be the main contributor for the complex material behavior encountered in creep-fatigue testing. In fast reactor components the main life shortening load cycles are from thermal fluctuations causing through-wall stress gradients. The main objective of this work (as a Task in the European project MATISSE) is to perform tailored experiments and to develop models for understanding and predicting the cyclic-softening of P91. The supporting experimental program produces data for calibration and validations of the developed models. An existing elasto-viscoplasticity model simulates the key mechanisms such as decrease in dislocation density, increase in sub-grain size and recovering phenomena. The model will be modified to also incorporate the effect of hold time on the cyclic softening.",
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author = "Jaromir Janousek and Stefan Holmstr{\"o}m and Rami Pohja",
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Janousek, J, Holmström, S & Pohja, R 2015, 'Cyclic softening of tempered ferritic-martensitic steel P91' Paper presented at 31th Conference with International Participation on Computational Mechanics, Spicák, Czech Republic, 9/11/15 - 11/11/15, .

Cyclic softening of tempered ferritic-martensitic steel P91. / Janousek, Jaromir; Holmström, Stefan; Pohja, Rami.

2015. Paper presented at 31th Conference with International Participation on Computational Mechanics, Spicák, Czech Republic.

Research output: Contribution to conferenceConference articleScientific

TY - CONF

T1 - Cyclic softening of tempered ferritic-martensitic steel P91

AU - Janousek, Jaromir

AU - Holmström, Stefan

AU - Pohja, Rami

N1 - LIS: Extended 2 page abstracts reviewed

PY - 2015

Y1 - 2015

N2 - For the ferritic-martensitic steel P91 cyclic softening has been identified as important factor in the assessments of creep-fatigue in nuclear components. Better understanding of the cyclic softening is needed as it is believed to be the main contributor for the complex material behavior encountered in creep-fatigue testing. In fast reactor components the main life shortening load cycles are from thermal fluctuations causing through-wall stress gradients. The main objective of this work (as a Task in the European project MATISSE) is to perform tailored experiments and to develop models for understanding and predicting the cyclic-softening of P91. The supporting experimental program produces data for calibration and validations of the developed models. An existing elasto-viscoplasticity model simulates the key mechanisms such as decrease in dislocation density, increase in sub-grain size and recovering phenomena. The model will be modified to also incorporate the effect of hold time on the cyclic softening.

AB - For the ferritic-martensitic steel P91 cyclic softening has been identified as important factor in the assessments of creep-fatigue in nuclear components. Better understanding of the cyclic softening is needed as it is believed to be the main contributor for the complex material behavior encountered in creep-fatigue testing. In fast reactor components the main life shortening load cycles are from thermal fluctuations causing through-wall stress gradients. The main objective of this work (as a Task in the European project MATISSE) is to perform tailored experiments and to develop models for understanding and predicting the cyclic-softening of P91. The supporting experimental program produces data for calibration and validations of the developed models. An existing elasto-viscoplasticity model simulates the key mechanisms such as decrease in dislocation density, increase in sub-grain size and recovering phenomena. The model will be modified to also incorporate the effect of hold time on the cyclic softening.

KW - cyclic softening

KW - creep-fatigue

KW - P91 steel

M3 - Conference article

ER -

Janousek J, Holmström S, Pohja R. Cyclic softening of tempered ferritic-martensitic steel P91. 2015. Paper presented at 31th Conference with International Participation on Computational Mechanics, Spicák, Czech Republic.