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Title: Radiation induced segregation and precipitation behavior in self-ion irradiated Ferritic/Martensitic HT9 steel

Abstract

In this study, Ferritic/Martensitic (F/M) HT9 steel was irradiated to 20 displacements per atom (dpa) at 600 nm depth at 420 and 440 °C, and to 1, 10 and 20 dpa at 600 nm depth at 470 °C using 5 MeV Fe++ ions. The characterization was conducted using ChemiSTEM and Atom Probe Tomography (APT), with a focus on radiation induced segregation and precipitation. Ni and/or Si segregation at defect sinks (grain boundaries, dislocation lines, carbide/matrix interfaces) together with Ni, Si, Mn rich G-phase precipitation were observed in self-ion irradiated HT9 except in very low dose case (1 dpa at 470 °C). Some G-phase precipitates were found to nucleate heterogeneously at defect sinks where Ni and/or Si segregated. In contrast to what was previously reported in the literature for neutron irradiated HT9, no Cr-rich α' phase, χ-phases, η phase and voids were found in self-ion irradiated HT9. The difference of observed microstructures is probably due to the difference of irradiation dose rate between ion irradiation and neutron irradiation. In addition, the average size and number density of G-phase precipitates were found to be sensitive to both irradiation temperature and dose. With the same irradiation dose, the average size of G-phase increasedmore » whereas the number density decreased with increasing irradiation temperature. Within the same irradiation temperature, the average size increased with increasing irradiation dose.« less

Authors:
ORCiD logo [1];  [2];  [2];  [1]
  1. North Carolina State Univ., Raleigh, NC (United States)
  2. Univ. of Oxford (United Kingdom)
Publication Date:
Research Org.:
Univ. of Michigan, Ann Arbor, MI (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1353271
Alternate Identifier(s):
OSTI ID: 1426234
Grant/Contract Number:
NE0000639
Resource Type:
Journal Article: Published Article
Journal Name:
Journal of Nuclear Materials
Additional Journal Information:
Journal Volume: 491; Journal Issue: C; Journal ID: ISSN 0022-3115
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; F/M steel, HT9, Ion irradiation, Radiation-induced segregation & precipitation, G-phase, ChemiSTEM, APT

Citation Formats

Zheng, Ce, Auger, Maria A., Moody, Michael P., and Kaoumi, Djamel. Radiation induced segregation and precipitation behavior in self-ion irradiated Ferritic/Martensitic HT9 steel. United States: N. p., 2017. Web. doi:10.1016/j.jnucmat.2017.04.040.
Zheng, Ce, Auger, Maria A., Moody, Michael P., & Kaoumi, Djamel. Radiation induced segregation and precipitation behavior in self-ion irradiated Ferritic/Martensitic HT9 steel. United States. doi:10.1016/j.jnucmat.2017.04.040.
Zheng, Ce, Auger, Maria A., Moody, Michael P., and Kaoumi, Djamel. Mon . "Radiation induced segregation and precipitation behavior in self-ion irradiated Ferritic/Martensitic HT9 steel". United States. doi:10.1016/j.jnucmat.2017.04.040.
@article{osti_1353271,
title = {Radiation induced segregation and precipitation behavior in self-ion irradiated Ferritic/Martensitic HT9 steel},
author = {Zheng, Ce and Auger, Maria A. and Moody, Michael P. and Kaoumi, Djamel},
abstractNote = {In this study, Ferritic/Martensitic (F/M) HT9 steel was irradiated to 20 displacements per atom (dpa) at 600 nm depth at 420 and 440 °C, and to 1, 10 and 20 dpa at 600 nm depth at 470 °C using 5 MeV Fe++ ions. The characterization was conducted using ChemiSTEM and Atom Probe Tomography (APT), with a focus on radiation induced segregation and precipitation. Ni and/or Si segregation at defect sinks (grain boundaries, dislocation lines, carbide/matrix interfaces) together with Ni, Si, Mn rich G-phase precipitation were observed in self-ion irradiated HT9 except in very low dose case (1 dpa at 470 °C). Some G-phase precipitates were found to nucleate heterogeneously at defect sinks where Ni and/or Si segregated. In contrast to what was previously reported in the literature for neutron irradiated HT9, no Cr-rich α' phase, χ-phases, η phase and voids were found in self-ion irradiated HT9. The difference of observed microstructures is probably due to the difference of irradiation dose rate between ion irradiation and neutron irradiation. In addition, the average size and number density of G-phase precipitates were found to be sensitive to both irradiation temperature and dose. With the same irradiation dose, the average size of G-phase increased whereas the number density decreased with increasing irradiation temperature. Within the same irradiation temperature, the average size increased with increasing irradiation dose.},
doi = {10.1016/j.jnucmat.2017.04.040},
journal = {Journal of Nuclear Materials},
number = C,
volume = 491,
place = {United States},
year = {Mon Apr 24 00:00:00 EDT 2017},
month = {Mon Apr 24 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.jnucmat.2017.04.040

Citation Metrics:
Cited by: 2works
Citation information provided by
Web of Science

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  • In this study, Ferritic/Martensitic (F/M) HT9 steel was irradiated to 20 displacements per atom (dpa) at 600 nm depth at 420 and 440 °C, and to 1, 10 and 20 dpa at 600 nm depth at 470 °C using 5 MeV Fe++ ions. The characterization was conducted using ChemiSTEM and Atom Probe Tomography (APT), with a focus on radiation induced segregation and precipitation. Ni and/or Si segregation at defect sinks (grain boundaries, dislocation lines, carbide/matrix interfaces) together with Ni, Si, Mn rich G-phase precipitation were observed in self-ion irradiated HT9 except in very low dose case (1 dpa at 470more » °C). Some G-phase precipitates were found to nucleate heterogeneously at defect sinks where Ni and/or Si segregated. In contrast to what was previously reported in the literature for neutron irradiated HT9, no Cr-rich α' phase, χ-phases, η phase and voids were found in self-ion irradiated HT9. The difference of observed microstructures is probably due to the difference of irradiation dose rate between ion irradiation and neutron irradiation. In addition, the average size and number density of G-phase precipitates were found to be sensitive to both irradiation temperature and dose. With the same irradiation dose, the average size of G-phase increased whereas the number density decreased with increasing irradiation temperature. Within the same irradiation temperature, the average size increased with increasing irradiation dose.« less
  • Ferritic/Martensitic (F/M) steels with high Cr content posses the high temperature strength and low swelling rates required for advanced nuclear reactor designs. Radiation induced segregation (RIS) occurs in F/M steels due to solute atoms preferentially coupling to point defect fluxes to defect sinks, such as grain boundaries (GBs). The RIS response of F/M steels and austenitic steels has been shown to be dependent on the local structure of GBs but has only been demonstrated in ion irradiated specimens. A 9 wt. % Cr model alloy steel was irradiated to 3 dpa using neutrons at the Advanced Test Reactor (ATR) tomore » determine the effect of neutron radiation environment on the RIS-GB structure dependence. This investigation found the relationship between GB structure and RIS is also active for F/M steels irradiated using neutrons. The data generated from the neutron irradiation is also compared to RIS data generated using proton irradiations on the same heat of model alloy.« less
  • Ferritic/Martensitic (F/M) steels with high Cr content posses the high temperature strength and low swelling rates required for advanced nuclear reactor designs. Radiation induced segregation (RIS) occurs in F/M steels due to solute atoms preferentially coupling to point defect fluxes which migrate to defect sinks, such as grain boundaries (GBs). The RIS response of F/M steels and austenitic steels has been shown to be dependent on the local structure of GBs where low energy structures have suppressed RIS responses. This relationship between local GB structure and RIS has been demonstrated primarily in ion-irradiated specimens. A 9 wt.% Cr model alloymore » steel was irradiated to 3 dpa using neutrons at the Advanced Test Reactor (ATR) to determine the effect of a neutron radiation environment on the RIS response at different GB structures. This investigation found the relationship between GB structure and RIS is also active for F/M steels irradiated using neutrons. The data generated from the neutron irradiation is also compared to RIS data generated using proton irradiations on the same heat of model alloy.« less
  • Abstract not provided.