A two-site mean field model of discontinuous dynamic recrystallization

Autor: Swarup Bag, Roland E. Logé, P. Bernard, Ke Huang
Přispěvatelé: Centre de Mise en Forme des Matériaux (CEMEF), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Discontinuous dynamic recrystallization
Surrounding materials
Dynamic recrystallization
02 engineering and technology
Flow stress
Topology
01 natural sciences
Stainless steel
[SPI.MAT]Engineering Sciences [physics]/Materials
Topological information
Mean field models
New model
General Materials Science
Grain boundary migrations
Grain boundary migration
Strain hardening
010302 applied physics
Strain rate
Recrystallization (metallurgy)
Mechanics
021001 nanoscience & nanotechnology
Condensed Matter Physics
Constitutive law
Physical phenomena
Grain size
Inverse methodology
Mechanics of Materials
Nucleation
Grain boundary
0210 nano-technology
Dislocation densities
Materials science
Experimental data
Recrystallized grains
Modelling
Recrystallization kinetics
0103 physical sciences
Mean field theory
Thermo-mechanical
Grain boundary strengthening
Initial grain size
Mechanical Engineering
Metallurgy
Relative weights
Stainless steels
Strain hardening exponent
Stress-strain curves
Grain boundaries
Grain size and shape
Zdroj: Materials Science and Engineering: A
Materials Science and Engineering: A, Elsevier, 2011, 528 (24), pp.7357-7367. ⟨10.1016/j.msea.2011.06.023⟩
ISSN: 0921-5093
DOI: 10.1016/j.msea.2011.06.023⟩
Popis: International audience; The paper describes a new model of discontinuous dynamic recrystallization (DDRX) which can operate in constant or variable thermomechanical conditions. The model considers the elementary physical phenomena at the grain scale such as strain hardening, recovery, grain boundary migration, and nucleation. The microstructure is represented through a set of representative grains defined by their size and dislocation density. It is linked to a constitutive law giving access to the polycrystal flow stress. Interaction between representative grains and the surrounding material is idealized using a two-site approach whereby two homogeneous equivalent media with different dislocation densities are considered. Topological information is incorporated into the model by prescribing the relative weight of these two equivalent media as a function of their volume fractions. This procedure allows accounting for the well-known necklace structures. The model is applied to the prediction of DDRX in 304 L stainless steel, with parameters identified using an inverse methodology based on a genetic algorithm. Results show good agreement with experimental data at different temperatures and strain rates, predicting recrystallization kinetics, recrystallized grain size and stress-strain curve. Parameters identified with one initial grain size lead to accurate results for another initial grain size without introducing any additional parameter.
Databáze: OpenAIRE
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