Refine your search:     
Report No.
 - 
Search Results: Records 1-4 displayed on this page of 4
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Atomistic modeling of hardening in spinodally-decomposed Fe-Cr binary alloys

Suzudo, Tomoaki; Takamizawa, Hisashi; Nishiyama, Yutaka; Caro, A.*; Toyama, Takeshi*; Nagai, Yasuyoshi*

Journal of Nuclear Materials, 540, p.152306_1 - 152306_10, 2020/11

 Times Cited Count:8 Percentile:76.65(Materials Science, Multidisciplinary)

Spinodal decomposition in thermally aged Fe-Cr alloys leads to significant hardening, which is the direct cause of the so-called 475C-embrittlement. To illustrate how spinodal decomposition induces hardening by atomistic interactions, we conducted a series of numerical simulations as well as reference experiments. The numerical results indicated that the hardness scales linearly with the short-range order (SRO) parameter, while the experimental result reproduced this relationship within statistical error. Both seemingly suggest that neighboring Cr-Cr atomic pairs essentially cause hardening, because SRO is by definition uniquely dependent on the appearance probability of such pairs. A further numerical investigation supported this notion, as it suggests that the dominant cause of hardening is the pinning effect of dislocations passing over such Cr-Cr pairs.

Journal Articles

Hardening in thermally-aged Fe-Cr binary alloys; Statistical parameters of atomistic configuration

Suzudo, Tomoaki; Nagai, Yasuyoshi*; Schwen, D.*; Caro, A.*

Acta Materialia, 89, p.116 - 122, 2015/05

 Times Cited Count:12 Percentile:51.75(Materials Science, Multidisciplinary)

By exploiting Monte Carlo methodology and molecular dynamics, we computationally simulate the spinodal decomposition of iron-chromium binary alloys and analyze the relationship between the increase of yield stress induced by the phase separation phenomenon, and statistical parameters of the atomistic configuration. We successfully model the experimentally-discovered proportional relationship between the hardness and the variation parameter (or V), and also found that the adequacy of the parameter V as an empirical indicator of hardening is limited, because it does not properly capture short-range atomistic configurations that influence the hardening. We suggest that the short-range-order parameter has more potential to become universal descriptor of the phenomenon.

Oral presentation

Atomistic modeling of hardening in thermally-aged Fe-Cr binary alloys

Suzudo, Tomoaki; Nagai, Yasuyoshi*; Toyama, Takeshi*; Takamizawa, Hisashi; Nishiyama, Yutaka; Caro, A.*

no journal, , 

The hardening in phase-separated Fe-Cr binary alloys is a direct cause of so-called 475$$^{circ}$$C embrittlement. We here conduct a series of atomistic simulations with reference experiments to establish a model of the hardening phenomenon caused by spinodal decomposition. The result indicated that the hardness predicted by the simulations linearly scales with the short-range order (SRO) parameter and have a good agreement with those by the experiments. We also found that the linear relation is aging-temperature independent while the relation of the hardening to the well-known variation parameter varies with the annealing temperature. This finding has a practical merit, that is, the SRO parameter can be a good index to monitor ongoing hardening of steels and to estimate their lifetime.

Oral presentation

Modeling study of hardening in thermally-aged Fe-Cr alloys

Suzudo, Tomoaki; Nagai, Yasuyoshi*; Toyama, Takeshi*; Takamizawa, Hisashi; Nishiyama, Yutaka; Caro, A.*

no journal, , 

It is widely known that iron-chromium (Fe-Cr) binary alloys undergo spinodal decomposition when they are thermally aged because of miscibility gap, and that this microstructural evolution causes hardening and loss of ductility; this is a direct cause of so-called 475C embrittlement. In the present study, we computationally simulated the spinodal decomposition using a Monte Carlo (MC) method and evaluated the increase in hardness through the examination of the interaction between an edge dislocation and Cr-rich phases by exploiting molecular dynamics methodology. We also conduct a series of reference experiments to verify the established model of this hardening phenomenon. The result indicates that the short-range order parameter is a universal parameter to describe the hardening and that it is a better index than the well-known variation parameter. We consider that the short-range order parameter can be applied to the prediction of materials' lifetime.

4 (Records 1-4 displayed on this page)
  • 1