Comparison Between 590 Mev Proton Irradiation and Neutron Irradiation on the F82H Ferritic/Martensitic Steel

1998 ◽  
Vol 540 ◽  
Author(s):  
R. Schäublin ◽  
M. Victoria
Keyword(s):  
Single Dose ◽  
Electron Microscope ◽  
Neutron Irradiation ◽  
Proton Irradiation ◽  
Fusion Reactor ◽  
Martensitic Steel ◽  
Fission Neutron ◽  
First Wall ◽  
Defect Clusters ◽  
Transmission Electron

AbstractThe microstructure of the low activation F82H ferritic/martensitic steel, which is a candidate for future fusion reactor first wall, has been studied in order to determine the differences between 590 MeV proton irradiations and fission neutron irradiations. A range of doses and temperatures are investigated. The present work focuses on the microstructure of irradiation induced defect clusters for cases of proton irradiations to doses up to 1.7 dpa, and for neutron irradiation to a single dose of 2.5 dpa. The irradiation temperatures were 40°C and 250°C in the case of the proton irradiation and 250°C in the case of the neutron irradiation. In the case of the proton irradiation no defects are observed in the transmission electron microscope in the case of the 0.45 dpa dose, while they start to be clearly visible for doses higher than about 1.0 dpa. In the case of the neutron irradiation a high density of defects and small loops is evidenced. These preliminary results are presented here.

Radiation Damage Related to Fusion Reactors Materials

1982 ◽  
Vol 40 ◽  
pp. 584-587
Author(s):  
J. L. Brimhall
Keyword(s):  
Radiation Damage ◽  
Fusion Reactor ◽  
Fission Neutron ◽  
Energy Spectra ◽  
Radiation Environment ◽  
Fission Reactor ◽  
Transmission Electron ◽  
Damage States ◽  
Reactor Materials ◽  
Fission Reactors

Transmission electron microscopy has long been used to study the microstructual evolution in materials as a result of radiation damage. The radiation environment in a fusion reactor is unlike that in well-studied fission reactors, therefore unique microstructures in fusion reactor materials may occur. The fusion reactor energy spectra will be strongly peaked at 14 MeV, whereas typical fission neutron energy spectra are peaked in the range 0.5 to 1.0 MeV We need to know how this higher energy neutron spectra in a fusion reactor will perturb the radiation damage states normally observed in fission reactor irradiations.

Dislocation–grain boundary interactions in martensitic steel observed through in situ nanoindentation in a transmission electron microscope

2004 ◽  
Vol 19 (12) ◽  
pp. 3626-3632 ◽  
Author(s):  
T. Ohmura ◽  
A.M. Minor ◽  
E.A. Stach ◽  
J.W. Morris
Keyword(s):  
Electron Microscope ◽  
Grain Boundary ◽  
Transmission Electron Microscope ◽  
Critical Stress ◽  
Martensitic Steel ◽  
High Angle ◽  
Block Boundary ◽  
Density Of Dislocations ◽  
Transmission Electron

Dislocation–interface interactions in Fe–0.4 wt% C tempered martensitic steel were studied through in situ nanoindentation in a transmission electron microscope (TEM). Two types of boundaries were imaged in the dislocated martensitic structure: a low-angle (probable) lath boundary and a coherent, high-angle (probable) block boundary. In the case of a low-angle grain boundary, the dislocations induced by the indenter piled up against the boundary. As the indenter penetrated further, a critical stress appeared to have been reached, and a high density of dislocations was suddenly emitted on the far side of the grain boundary into the adjacent grain. In the case of the high-angle grain boundary, the numerous dislocations that were produced by the indentation were simply absorbed into the boundary, with no indication of pileup or the transmission of strain. This surprising observation is interpreted on the basis of the crystallography of the block boundary.

High Temperature Strength of Three ODS Ferritic/ Martensitic Steels

2007 ◽  
Vol 345-346 ◽  
pp. 1011-1014 ◽  
Author(s):  
Han Ki Yoon ◽  
Akihiko Kimura
Keyword(s):  
High Temperature ◽  
Fusion Reactor ◽  
Martensitic Steel ◽  
Operating Temperature ◽  
Oxide Dispersion Strengthened ◽  
High Temperature Strength ◽  
Martensitic Steels ◽  
First Wall ◽  
Wall Structures ◽  
Interesting Approach

Oxide dispersion strengthened (ODS) materials is leading candidates for blanket/first-wall structures of the fusion reactor. ODS materials for structure application in fusion rector would allow to increase the operating temperature to approximately 650. Therefore, this work focused on the optimization of metallurgical features to improve high temperature strength and elongation through understanding of contents of Cr and Al. In the study, the three kinds of ODS steels such as 19Cr-ODS (K1), 13Cr-Al-ODS (K2) and 19Cr-Al-ODS (K4) with Y2O3 content of 0.37wt% have been produced. And tensile test were performed on three ODS ferritic/martensitic steel between RT, 300, 400 and 600Dispersion hardening represents an interesting approach to improve the mechanical properties at elevated temperature, as they are foreseen in the future fusion reactor It has been successfully demonstrated that it is possible to expanse the temperature range for the application of fusion reactor.

TEM Evidence for the Ejection of Matter by Energetic Displacement Cascades

1977 ◽  
Vol 35 ◽  
pp. 36-37
Author(s):  
K.L. Merkle
Keyword(s):  
Fusion Reactor ◽  
Surface Erosion ◽  
Defect Structures ◽  
First Wall ◽  
Neutron Bombardment ◽  
Defect Clusters ◽  
Displacement Cascades ◽  
The Past ◽  
Multiple Defect

At the first wall of a D-T fusion reactor very energetic displacement cascades will be produced. These cascades are initiated by 14 MeV neutron recoils of energies near 100 keV and above. Such cascades can also be produced by selfion bombardment. TEM has served in the past as a valuable tool in investigations of cascade defect structures; also quantitative correlations between cascades produced by energetic self ions and 14 MeV neutrons have been established.1 Qualitatively Figs. 1 and 2 show strong similarities between 200 keV self ion cascades and cascades produced by 14 MeV neutron bombardment of Au. Most clusters visible in Fig. 1 and 2 are thought to result from the collapse of depleted zones. The presence of multiple defect clusters is indicative of subcascade formation.The intersection of an energetic cascade with a surface will lead to the ejection of atoms or clusters of atoms. This problem of surface erosion has recently found considerable attention.

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