Void Swelling Resistance in Fe-Cr Alloys at 200 DPA

1994 ◽  
Vol 373 ◽  
Author(s):  
D. S. Gelles
Keyword(s):  
Irradiation Temperature ◽  
The Other ◽  
Dislocation Network ◽  
Fast Breeder Reactor ◽  
Ferritic Alloys ◽  
Density Measurements ◽  
Void Swelling

AbstractMicrostructural examinations have been performed on a series of binary Fe-Cr alloys irradiated to 200 dpa at 425°C in a fast breeder reactor. The alloy compositions rangedfrom 3% to 18% Cr in 3% Cr increments, and the irradiation temperature corresponded to the peak swelling condition for this alloy class. Density measurements showed swelling levels as high as 7.4%, with the highest swelling found in the Fe-9Cr and Fe-6Cr alloys. Microstructural examinations revealed that the highest swelling conditions contained welldeveloped voids, often as large as 100 nm, and a dislocation network comprised of both a2 <111> and <100> Burgers vectors. Swelling was lower in the other alloys, and the swelling reduction could be correlated with increased precipitation. These results are considered in light of the current theories for low swelling in ferritic alloys, but no theory is available to completely explain the results.

The effect of radiation-induced segregation on void swelling in electron-irradiated austenitic Fe-Cr-Ni-Ti-P Alloy

1990 ◽  
Vol 48 (4) ◽  
pp. 932-933
Author(s):  
H. Watanabe ◽  
T. Muroga ◽  
N. Yoshida
Keyword(s):  
Temperature Dependence ◽  
Electron Irradiation ◽  
Irradiation Temperature ◽  
The Other ◽  
Austenitic Steels ◽  
Nickel Concentration ◽  
In Situ Observation ◽  
Void Swelling ◽  
Radiation Induced

It has been reported that the void swelling in austenitic steels at higher temperatures is enhanced by a nickel depletion in matrix . The objective of the present study is to understand the effect of solute addition on void swelling, in association with microchemical changes, in austenitic steels during electron irradiation.Four types of model alloys (Fe-16Cr-17Ni, Fe-16Cr-17Ni-0.25Ti, Fe- 16Cr-17Ni-0.1P, Fe-16Cr-17Ni-0.25Ti-0.IP) and JPCA-2 were used in this study. Irradiation and in-situ observation were carried out with 1.0 MeV electrons utilizing JEM-1000 of HVEM Lab. Kyushu Univ.Fig. 1 shows the irradiation temperature dependence of nickel concentration in matrix after irradiated at 2 dpa. The ternary alloy and alloys containing phosphorus(or titanium) only show a strong nickel depletion in matrix due to nickel segregation to defect sinks. Our previous results about void swelling in these alloys showed that the temperature, where nickel depletion in matrix became prominent, corresponded to that of maxium void swelling. On the other hand, void swelling and the nickel depletion were not detected in Fe-16Cr-17Ni-0.25Ti-0.IP and JPCA-2.

Void Swelling of Ferritic Alloys Bombarded with Nickel Ions

2009 ◽  
pp. 809-809-15 ◽  
Author(s):  
WG Johnston ◽  
T Lauritzen ◽  
JH Rosolowski ◽  
AM Turkalo
Keyword(s):  
Nickel Ions ◽  
Ferritic Alloys ◽  
Void Swelling

scholarly journals Radio Recombination Lines from Starburst Galaxies: High and Low Density Ionized Gas

2002 ◽  
Vol 199 ◽  
pp. 243-244
Author(s):  
N.R. Mohan ◽  
K.R. Anantharamaiah ◽  
W.M. Goss
Keyword(s):  
Flux Density ◽  
Hii Regions ◽  
Starburst Galaxies ◽  
High Density ◽  
The Other ◽  
Low Density ◽  
Ionized Gas ◽  
Density Measurements ◽  
Radio Recombination Lines ◽  
Upper Limits

Radio recombination lines (RRL) at 8 GHz and 15 GHz detected from four starburst galaxies are shown to arise in compact high density HII regions, which are undetectable below ∼4 GHz. Detection of an RRL at 1.4 GHz towards one galaxy and upper limits in the other three are consistent with the presence of an equal amount of low density diffuse gas. Continuum flux density measurements using the GMRT will be important in constraining the properties of the diffuse gas.

Effects of ALPS on Mechanical Property in Bainitic Steels

2014 ◽  
Vol 783-786 ◽  
pp. 926-931 ◽  
Author(s):  
Kiyomichi Nakai ◽  
Sanae Konishi ◽  
Tatsuaki Sakamoto ◽  
Sengo Kobayashi
Keyword(s):  
Unit Area ◽  
Nucleation Site ◽  
The Other ◽  
Dislocation Network ◽  
Slip Systems ◽  
Square Root ◽  
Deformation Strain ◽  
Bainitic Steels ◽  
Average Size ◽  
Strength And Toughness

Aggregate of bainite laths with almost parallel slip systems between neighboring bainite laths, hereafter referred to as ALPS, has great effect on the improvement of mechanical properties in steels. Elongation increases remarkably with increasing the number of bainite laths within an ALPS. When a bainite lath begins to deform, the neighboring bainite lath also easily deforms to relax the deformation strain, because of good parallelism between their slip systems. Under the cooperative deformation of bainite laths, the area of interface between neighboring bainite laths increases during deformation. The increase in the area of interface between neighboring bainite laths suppresses localization of dislocations at the interface, that is, dislocation density per unit area of the interface between neighboring bainite laths hardly increases, resulting in the suppression of nucleation of cracks at the interface between neighboring bainite laths. Ductile fracture would occur along the boundary between ALPSs. It could be suggested that larger ALPS and/or ALPS consisting of large number of bainite laths induce larger elongation in steels.On the other hand, it has been reported that tensile strength increases in proportion to inverse of square root ofd, thedbeing the average size of bainite laths [1]. In order to form fine bainite lath, dislocation network instead of inclusion in austenite was utilized as nucleation site for bainite lath. Great barriers to be overcome exist for the improvement of both strength and toughness. An idea for the improvement of both strength and toughness is shown in this study.

Transmission electron microscope observations of rectangular dislocation networks in an Al70Co15Ni15 decagonal quasicrystal

1993 ◽  
Vol 8 (2) ◽  
pp. 286-290 ◽  
Author(s):  
Yanfa Yan ◽  
Renhui Wang
Keyword(s):  
Electron Microscope ◽  
Electron Diffraction ◽  
Transmission Electron Microscope ◽  
The Other ◽  
Dislocation Network ◽  
Decagonal Quasicrystal ◽  
Twofold Axis ◽  
Decagonal Phase ◽  
Diffraction Contrast ◽  
Transmission Electron

The electron diffraction contrast of two types of rectangular dislocation networks in an Al70Co15Ni15 decagonal quasicrystal has been analyzed. One type of dislocation network consists of two dislocation sets whose Burgers vectors are parallel to the tenfold axis A10 and a twofold axis A2D. The other type of dislocation network consists of two dislocation sets whose Burgers vectors are parallel to the A10 and the other twofold axis of A2P. The characteristics of the diffraction contrast of the dislocation networks in the Al–Co–Ni decagonal phase are similar to those in conventional crystals.

Effect of irradiation temperature on void swelling of China Low Activation Martensitic steel (CLAM)

2008 ◽  
Vol 59 (3) ◽  
pp. 344-347 ◽  
Author(s):  
Fei Zhao ◽  
Jiansheng Qiao ◽  
Yina Huang ◽  
Farong Wan ◽  
Soumei Ohnuki
Keyword(s):  
Martensitic Steel ◽  
Irradiation Temperature ◽  
Void Swelling

scholarly journals Influence of irradiation temperature on void swelling in NiCoFeCrMn and NiCoFeCrPd

2019 ◽  
Vol 158 ◽  
pp. 57-61 ◽  
Author(s):  
Tai-ni Yang ◽  
Chenyang Lu ◽  
Gihan Velisa ◽  
Ke Jin ◽  
Pengyuan Xiu ◽  
...  
Keyword(s):  
Irradiation Temperature ◽  
Void Swelling

Regular Dislocation Networks in Si. Part II: Luminescence

2007 ◽  
Vol 131-133 ◽  
pp. 503-510 ◽  
Author(s):  
Teimuraz Mchedlidze ◽  
T. Wilhelm ◽  
X. Yu ◽  
Tzanimir Arguirov ◽  
G. Jia ◽  
...  
Keyword(s):  
The Other ◽  
Dislocation Network ◽  
Light Reflection ◽  
Induced Current ◽  
Excitation Light ◽  
Radiative Transitions ◽  
Recombination Centers ◽  
Precipitate Layer ◽  
Precipitate Density

Regular dislocation networks formed as a result of the direct bonding of Cz-Si wafers with oxide remnants on the pre-bonding surfaces were investigated. Besides the dislocation network, oxide precipitates were detected at the bonding interface. The precipitate density across the network was ~5×1010 cm-2, except small irregularly distributed circular areas, several mm in diameter, where the density was remarkably lower (<5×108 cm-2). The dislocation network structure was not affected by the change in the precipitate density. Photoluminescence spectroscopy (PL) and light beam induced current (LBIC) mapping were applied for characterization of such dislocation networks. For the locations with high precipitate density, PL signal from dislocations and that from the band-to-band transitions were enhanced. On the other hand, the LBIC results indicated that oxide precipitates are active recombination centers and thus should suppress the observed radiative transitions. The controversy can be explained in the assumption that the D-band PL signal increases due to scattering of excitation light by the precipitates and due to related expansion of the excitation area of the dislocation network. The light reflection from the precipitate layer also enhances the detected band-to-band PL signal. The shape of PL spectra from the samples in the range of photon energies 0.75 – 1.15 eV was not influenced by the oxide precipitates.

Application of the System Based Code Concept to the Determination of In-Service Inspection Requirements

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Shigeru Takaya ◽  
Tai Asayama ◽  
Yoshio Kamishima ◽  
Hideo Machida ◽  
Daigo Watanabe ◽  
...  
Keyword(s):  
Defect Detection ◽  
Structural Integrity ◽  
The Other ◽  
Fast Breeder Reactor ◽  
Plant Safety ◽  
New Process ◽  
Service Inspection

A new process for determination of in-service inspection (ISI) requirements was proposed on the basis of the system based code concept to realize effective and rational ISI by properly taking into account plant-specific features. The proposed process consists of two complementary evaluations, one focusing on structural integrity and the other one on detectability of defects before they would grow to an unacceptable size in light of plant safety. If defect detection was not feasible, structural integrity evaluation would be required under sufficiently conservative hypothesis. The applicability of the proposed process was illustrated through an application to the existing prototype fast breeder reactor, Monju.

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