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Title: Ion-irradiation-induced microstructural modifications in ferritic/martensitic steel T91

Authors:
ORCiD logo; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE)
OSTI Identifier:
1396924
Grant/Contract Number:
NE0008291; AC02-06CH11357; AC07-051D14517
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Nuclear Materials
Additional Journal Information:
Journal Volume: 490; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-04 15:28:01; Journal ID: ISSN 0022-3115
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Liu, Xiang, Miao, Yinbin, Li, Meimei, Kirk, Marquis A., Maloy, Stuart A., and Stubbins, James F. Ion-irradiation-induced microstructural modifications in ferritic/martensitic steel T91. Netherlands: N. p., 2017. Web. doi:10.1016/j.jnucmat.2017.04.047.
Liu, Xiang, Miao, Yinbin, Li, Meimei, Kirk, Marquis A., Maloy, Stuart A., & Stubbins, James F. Ion-irradiation-induced microstructural modifications in ferritic/martensitic steel T91. Netherlands. doi:10.1016/j.jnucmat.2017.04.047.
Liu, Xiang, Miao, Yinbin, Li, Meimei, Kirk, Marquis A., Maloy, Stuart A., and Stubbins, James F. 2017. "Ion-irradiation-induced microstructural modifications in ferritic/martensitic steel T91". Netherlands. doi:10.1016/j.jnucmat.2017.04.047.
@article{osti_1396924,
title = {Ion-irradiation-induced microstructural modifications in ferritic/martensitic steel T91},
author = {Liu, Xiang and Miao, Yinbin and Li, Meimei and Kirk, Marquis A. and Maloy, Stuart A. and Stubbins, James F.},
abstractNote = {},
doi = {10.1016/j.jnucmat.2017.04.047},
journal = {Journal of Nuclear Materials},
number = C,
volume = 490,
place = {Netherlands},
year = 2017,
month = 7
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on May 18, 2018
Publisher's Accepted Manuscript

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  • In this paper, in situ transmission electron microscopy investigations were carried out to study the microstructural evolution of ferritic/martensitic steel T91 under 1 MeV Krypton ion irradiation up to 4.2 x 10(15) ions/cm(2) at 573 K, 673 K, and 773 K. At 573 K, grown-in defects are strongly modified by black dot loops, and dislocation networks together with black-dot loops were observed after irradiation. At 673 K and 773 K, grown-in defects are only partially modified by dislocation loops; isolated loops and dislocation segments were commonly found after irradiation. Post irradiation examination indicates that at 4.2 x 1015 ions/cm(2), aboutmore » 51% of the loops were a(0)/2 < 111 > type for the 673 K irradiation, and the dominant loop type was a(0)< 100 > for the 773 K irradiation. Finally, a dispersed barrier hardening model was employed to estimate the change in yield strength, and the calculated ion data were found to follow the similar trend as the existing neutron data with an offset of 100-150 MPa. (C) 2017 Elsevier B.V. All rights reserved.« less
  • Microstructural evolution of P92 ferritic/martensitic steel irradiated by Ar{sup +} ion beams at doses from 0.6 to 230 displacements per atom (dpa) at room temperature was investigated with conventional transmission electron microscope technique. Selected-area electron diffraction combined with bright-field and dark-field contrast image indicated that carbide/matrix interfaces were more easily damaged. The carbide peripheries became partly amorphous at irradiation dose of 2.3 dpa and were almost complete amorphous at the dose of 11.5 dpa. The small carbides would re-precipitate in matrices at 34.5 dpa. Energy dispersive X-ray analysis revealed that segregation of Cr and W and depletion of Fe inmore » carbides occurred under irradiation. With the irradiation dose increasing, the irradiation induced segregation and depletion became more severe, which would influence mechanical properties of the steel. - Research Highlights: {yields} Carbide/matrix interfaces in P92 ferritic/martensitic steel were easily damaged. {yields} Small carbides re-precipitated in matrices after higher dose irradiation. {yields} Segregation of Cr and W and depletion of Fe in carbides occurred after irradiation.« less
  • Irradiation damage in P92 ferritic/martensitic steel irradiated by Ar{sup +} ion beams to 7 and 12 dpa at elevated temperatures of 290 Degree-Sign C, 390 Degree-Sign C and 550 Degree-Sign C has been investigated by transmission electron microscopy, scanning electron microscopy and atomic force microscopy. The precipitate periphery (the matrix/carbide interface) was amorphized only at 290 Degree-Sign C, while higher irradiation temperature could prevent the amorphization. The formation of the small re-precipitates occurred at 290 Degree-Sign C after irradiation to 12 dpa. With the increase of irradiation temperature and dose, the phenomenon of re-precipitation became more severe. The voids inducedmore » by irradiation were observed after irradiation to 7 dpa at 550 Degree-Sign C, showing that high irradiation temperature ({>=} 550 Degree-Sign C) was a crucial factor which promoted the irradiation swelling. Energy dispersive X-ray analysis revealed that segregation of Cr and W in the voids occurred under irradiation, which may influence mechanical properties of P92 F/M steel. - Graphical Abstract: High density of small voids, about 2.5 nm in diameter, was observed after irradiation to 12 dpa at 550 Degree-Sign C, which was shown in panel a (TEM micrograph). As shown in panel b (SEM image), a large number of nanometer-sized hillocks were formed in the surface irradiated at 550 Degree-Sign C, and the mean size was {approx} 30 nm. The formation of the nanometer-sized hillocks might be due to the voids that appeared as shown in TEM images (panel a). High irradiation temperature ({>=} 550 Degree-Sign C) was a crucial factor for the formation of void swelling. Highlights: Black-Right-Pointing-Pointer Small carbides re-precipitated in P92 matrix irradiated to 12 dpa at 290 Degree-Sign C. Black-Right-Pointing-Pointer High density of voids was observed at 550 Degree-Sign C. Black-Right-Pointing-Pointer Segregation of Cr and W in voids occurred under irradiation.« less
  • Reduced activation ferritic/martensitic steels (RAFs) are leading candidates for blanket and first wall of fusion reactors where effects of displacement damage and helium production are important subjects to be investigated. To obtain systematic and accurate information of microstructural response under fusion environment, dual-ion irradiation method was applied. In order to estimate the microstructural response under fusion neutron irradiation environment, ion-beam irradiation was carried out with helium and metallic self ions. The study is focused on JLF-1 single- and dial-ion irradiated up to 60 dpa at 693, 743 and 793 K. The damage rate and helium injection rate were 1.0 xmore » 10{sup -3} dpa/sec and 15 x 10{sup -3} appm He/sec. At 743 K, void cavity structure was observed under dual-ion irradiation where the contribution of void structure on hardening was not so significant. Irradiation hardening and swelling were depended for the case of dual-ion irradiation. It is attempted to quantitatively relate the dislocation and cavities to the irradiation induced hardening.« less
  • HCM12A is an advanced nominal 12Cr ferritic?martensitic steel designed for higher temperature operation and is under consideration for application in core components in Generation IV nuclear energy systems. This work provides information on the hardening and microstructural changes in HCM12A after irradiation using 2.0 MeV protons at 400 *C to 10 dpa and at 500 *C to 3 dpa, and using 5 MeV Ni-ions at 500 *C to 50 dpa. Following irradiation, changes in hardness were measured using Vickers hardness indentation, changes in microstructure and phase stability were studied using transmission electron microscopy, and changes in microchemistry were measured usingmore » scanning Auger microscopy and analytical electron microscopy. The hardness at 400 *C increases by roughly 70% and saturates by roughly 5 dpa. The microstructural changes contributing to this hardness increase are mainly the formation of precipitate phases. Hardness increases are much smaller at 500 *C. Chromium is enriched at grain boundaries prior to irradiation, likely due to grain boundary carbides, and increases further during irradiation at least partially due to radiation-induced segregation.« less