PSI - Issue 52

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

Procedia Structural Integrity 52 (2024) 259–266

© 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi It was found that long-term creep exposition led to coarsening of the size of M 23 C 6 carbides and their precipitation at the grain boundary, which promotes intergranular creep cavitation and thus reduces the creep lifetime of the steel. The acoustic emission (AE) method was applied to monitor the formation and the rate of propagation of cracks arising from creep damage. This nondestructive method is able to detect in advance the degradation processes leading to high temperature component failure. The necessity for nondestructive examination rather than destructive investigation to identify creep damage is emphasized. Abstract For pipeline systems operating for a long time in thermal and/or power plants at high temperature and pressure, the degree of creep degradation is a key factor for their safe operation. The advanced 9% chromium creep-resistant P92 steel is now widely used in modern power plant boiler pipes operated at steam temperatures up to 650 °C. In this work, the relationship between creep deformation and damage have been analysed. Constant load tensile creep tests were conducted at 600 °C under different applied stresses. The microstructure evolution after creep loading was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that long-term creep exposition led to coarsening of the size of M 23 C 6 carbides and their precipitation at the grain boundary, which promotes intergranular creep cavitation and thus reduces the creep lifetime of the steel. The acoustic emission (AE) method was applied to monitor the formation and the rate of propagation of cracks arising from creep damage. This nondestructive method is able to detect in advance the degradation processes leading to high temperature component failure. The necessity for nondestructive examination rather than destructive investigation to identify creep damage is emphasized. Keywors: creep; P92 steel; creep deformation and fracture mechanisms; acoustic emission 1. Introduction The advanced tungsten and boron-modified creep-resistant 9%Cr ferritic P92 steel (ASTM Grade P92) is currently considered as a candidate material for fossil and nuclear power plants (Klueh, (2005), Mayer and Masuyama, (2008), Fracture, Damage and Structural Health Monitoring Study of Creep Damage in P92 Steel Using Acoustic Emission Jiri Dvorak a,* , Petr Kral a , Vaclav Sklenicka a , Marie Kvapilova a , Jan Sifner b , Vaclav Koula b , Marie Ohankova c Fracture, Damage and Structural Health Monitoring Study of Creep Damage in P92 Steel Using Acoustic Emission Jiri Dvorak a,* , Petr Kral a , Vaclav Sklenicka a , Marie Kvapilova a , Jan Sifner b , Vaclav Koula b , Marie Ohankova c a Institute of Physics of Materials, Czech Academy of Sciences, Zizkova 513/22, Brno 616 00, Czech Republic b DAKEL - technical diagnostics center ZD Rpety, Ohrobecka 408/3, Prague 142 00, Czech Republic c UJP Praha, a.s., Nad Kaminkou 1345, Prague, 156 10, Czech Republic a Institute of Physics of Materials, Czech Academy of Sciences, Zizkova 513/22, Brno 616 00, Czech Republic b DAKEL - technical diagnostics center ZD Rpety, Ohrobecka 408/3, Prague 142 00, Czech Republic c UJP Praha, a.s., Nad Kaminkou 1345, Prague, 156 10, Czech Republic Abstract For pipeline systems operating for a long time in thermal and/or power plants at high temperature and pressure, the degree of creep degradation is a key factor for their safe operation. The advanced 9% chromium creep-resistant P92 steel is now widely used in modern power plant boiler pipes operated at steam temperatures up to 650 °C. In this work, the relationship between creep deformation and damage have been analysed. Constant load tensile creep tests were conducted at 600 °C under different applied stresses. The microstructure evolution after creep loading was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Keywors: creep; P92 steel; creep deformation and fracture mechanisms; acoustic emission 1. Introduction The advanced tungsten and boron-modified creep-resistant 9%Cr ferritic P92 steel (ASTM Grade P92) is currently considered as a candidate material for fossil and nuclear power plants (Klueh, (2005), Mayer and Masuyama, (2008),

* Corresponding author. Tel.: +420-532-290-397. E-mail address: dvorak@ipm.cz * Corresponding author. Tel.: +420-532-290-397. E-mail address: dvorak@ipm.cz

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi 10.1016/j.prostr.2023.12.027 2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi 2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi