TEM examination of the effect of post-irradiation annealing on 7.7 dpa AISI 304 stainless steel

Wade Karlsen, Mykola Ivanchenko, Janne Pakarinen, Torill Karlsen

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

Abstract

Analytical transmission electron microscopy (ATEM) was used to examine the effect of post-irradiation annealing (PIA) on radiation-induced segregation (RIS) at the grain boundaries of 7.7 dpa AISI 304 stainless steel. The grain boundary profiles and the irradiation damage were analysed in the as-irradiated state and after PIA of 6 hours at 500 °C and after 25 hours at 500°C and 550°C by using transmission electron microscopy (TEM). As a main conclusion from the TEM examinations, the effects of PIA were found to be relatively small after only 6 hours, while after 25 hours of PIA at both 500 and 550°C, RIS was almost recovered and only marginal deviation in chemical composition could be found near the GB. The as-irradiated state showed extreme RIS values of Si 4.9 wt%, Cr 14.7 wt%, Ni 23.4 wt%, and P 1.4 wt%., while upon PIA for 6 hours the extreme values for RIS were Si 3.9 wt%, Cr 16.0 wt%, Ni 21 wt%, and P 0.9 wt%. After 6 hours annealing at 500°C dislocation loops start to grow, while dislocation density remains of the same order of magnitude. After annealing for 25 hours at 500°C the average size of dislocation loops remains nearly the same, while dislocation density was reduced almost by one fold. In the areas where dislocation density was found to be the lowest some features, which can most likely be attributed to stacking fault tetrahedral (SFT) were found. Annealing at even higher temperature (550°C) affected the average size of the dislocation loops, making them almost twice as large as well as resulting in a very broad distribution of dislocation sizes. Density of dislocations is also reduced by one fold in comparison to the as irradiated condition and leads to formation of SFT's, which could be consistently found in the specimen. None of the applied PIA treatments had caused formation of voids.
Original languageEnglish
Title of host publicationProceedings of Fontevraud 8
Number of pages11
Publication statusPublished - 2014
MoE publication typeA4 Article in a conference publication
EventFontevraud 8: Conference on Contribution of Materials Investigations and Operating Experience to LWRs' Safety, Performance and Reliability - Avignon, France
Duration: 15 Sep 201418 Sep 2014

Conference

ConferenceFontevraud 8
CountryFrance
CityAvignon
Period15/09/1418/09/14

Fingerprint

stainless steels
examination
transmission electron microscopy
irradiation
annealing
radiation
grain boundaries
crystal defects
voids
chemical composition
damage
deviation
profiles

Keywords

  • transmission electron microscopy
  • radiation induced segregation
  • post irradiation annealing

Cite this

@inproceedings{28f5ed76ee3b4819b8d4f4b10f57c44f,
title = "TEM examination of the effect of post-irradiation annealing on 7.7 dpa AISI 304 stainless steel",
abstract = "Analytical transmission electron microscopy (ATEM) was used to examine the effect of post-irradiation annealing (PIA) on radiation-induced segregation (RIS) at the grain boundaries of 7.7 dpa AISI 304 stainless steel. The grain boundary profiles and the irradiation damage were analysed in the as-irradiated state and after PIA of 6 hours at 500 °C and after 25 hours at 500°C and 550°C by using transmission electron microscopy (TEM). As a main conclusion from the TEM examinations, the effects of PIA were found to be relatively small after only 6 hours, while after 25 hours of PIA at both 500 and 550°C, RIS was almost recovered and only marginal deviation in chemical composition could be found near the GB. The as-irradiated state showed extreme RIS values of Si 4.9 wt{\%}, Cr 14.7 wt{\%}, Ni 23.4 wt{\%}, and P 1.4 wt{\%}., while upon PIA for 6 hours the extreme values for RIS were Si 3.9 wt{\%}, Cr 16.0 wt{\%}, Ni 21 wt{\%}, and P 0.9 wt{\%}. After 6 hours annealing at 500°C dislocation loops start to grow, while dislocation density remains of the same order of magnitude. After annealing for 25 hours at 500°C the average size of dislocation loops remains nearly the same, while dislocation density was reduced almost by one fold. In the areas where dislocation density was found to be the lowest some features, which can most likely be attributed to stacking fault tetrahedral (SFT) were found. Annealing at even higher temperature (550°C) affected the average size of the dislocation loops, making them almost twice as large as well as resulting in a very broad distribution of dislocation sizes. Density of dislocations is also reduced by one fold in comparison to the as irradiated condition and leads to formation of SFT's, which could be consistently found in the specimen. None of the applied PIA treatments had caused formation of voids.",
keywords = "transmission electron microscopy, radiation induced segregation, post irradiation annealing",
author = "Wade Karlsen and Mykola Ivanchenko and Janne Pakarinen and Torill Karlsen",
note = "Project code: 85618",
year = "2014",
language = "English",
booktitle = "Proceedings of Fontevraud 8",

}

Karlsen, W, Ivanchenko, M, Pakarinen, J & Karlsen, T 2014, TEM examination of the effect of post-irradiation annealing on 7.7 dpa AISI 304 stainless steel. in Proceedings of Fontevraud 8. Fontevraud 8, Avignon, France, 15/09/14.

TEM examination of the effect of post-irradiation annealing on 7.7 dpa AISI 304 stainless steel. / Karlsen, Wade; Ivanchenko, Mykola; Pakarinen, Janne; Karlsen, Torill.

Proceedings of Fontevraud 8. 2014.

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

TY - GEN

T1 - TEM examination of the effect of post-irradiation annealing on 7.7 dpa AISI 304 stainless steel

AU - Karlsen, Wade

AU - Ivanchenko, Mykola

AU - Pakarinen, Janne

AU - Karlsen, Torill

N1 - Project code: 85618

PY - 2014

Y1 - 2014

N2 - Analytical transmission electron microscopy (ATEM) was used to examine the effect of post-irradiation annealing (PIA) on radiation-induced segregation (RIS) at the grain boundaries of 7.7 dpa AISI 304 stainless steel. The grain boundary profiles and the irradiation damage were analysed in the as-irradiated state and after PIA of 6 hours at 500 °C and after 25 hours at 500°C and 550°C by using transmission electron microscopy (TEM). As a main conclusion from the TEM examinations, the effects of PIA were found to be relatively small after only 6 hours, while after 25 hours of PIA at both 500 and 550°C, RIS was almost recovered and only marginal deviation in chemical composition could be found near the GB. The as-irradiated state showed extreme RIS values of Si 4.9 wt%, Cr 14.7 wt%, Ni 23.4 wt%, and P 1.4 wt%., while upon PIA for 6 hours the extreme values for RIS were Si 3.9 wt%, Cr 16.0 wt%, Ni 21 wt%, and P 0.9 wt%. After 6 hours annealing at 500°C dislocation loops start to grow, while dislocation density remains of the same order of magnitude. After annealing for 25 hours at 500°C the average size of dislocation loops remains nearly the same, while dislocation density was reduced almost by one fold. In the areas where dislocation density was found to be the lowest some features, which can most likely be attributed to stacking fault tetrahedral (SFT) were found. Annealing at even higher temperature (550°C) affected the average size of the dislocation loops, making them almost twice as large as well as resulting in a very broad distribution of dislocation sizes. Density of dislocations is also reduced by one fold in comparison to the as irradiated condition and leads to formation of SFT's, which could be consistently found in the specimen. None of the applied PIA treatments had caused formation of voids.

AB - Analytical transmission electron microscopy (ATEM) was used to examine the effect of post-irradiation annealing (PIA) on radiation-induced segregation (RIS) at the grain boundaries of 7.7 dpa AISI 304 stainless steel. The grain boundary profiles and the irradiation damage were analysed in the as-irradiated state and after PIA of 6 hours at 500 °C and after 25 hours at 500°C and 550°C by using transmission electron microscopy (TEM). As a main conclusion from the TEM examinations, the effects of PIA were found to be relatively small after only 6 hours, while after 25 hours of PIA at both 500 and 550°C, RIS was almost recovered and only marginal deviation in chemical composition could be found near the GB. The as-irradiated state showed extreme RIS values of Si 4.9 wt%, Cr 14.7 wt%, Ni 23.4 wt%, and P 1.4 wt%., while upon PIA for 6 hours the extreme values for RIS were Si 3.9 wt%, Cr 16.0 wt%, Ni 21 wt%, and P 0.9 wt%. After 6 hours annealing at 500°C dislocation loops start to grow, while dislocation density remains of the same order of magnitude. After annealing for 25 hours at 500°C the average size of dislocation loops remains nearly the same, while dislocation density was reduced almost by one fold. In the areas where dislocation density was found to be the lowest some features, which can most likely be attributed to stacking fault tetrahedral (SFT) were found. Annealing at even higher temperature (550°C) affected the average size of the dislocation loops, making them almost twice as large as well as resulting in a very broad distribution of dislocation sizes. Density of dislocations is also reduced by one fold in comparison to the as irradiated condition and leads to formation of SFT's, which could be consistently found in the specimen. None of the applied PIA treatments had caused formation of voids.

KW - transmission electron microscopy

KW - radiation induced segregation

KW - post irradiation annealing

M3 - Conference article in proceedings

BT - Proceedings of Fontevraud 8

ER -