Novel Approach to Model Static Recrystallization of Austenite during Hot-Rolling of Nb-Microalloyed Steel: Effect of Precipitates

2016

Metall Mater Trans A

In the present work, we introduce a state parameter-based microstructure evolution model, which incorporates the effect of solute atoms and precipitates on recrystallization kinetics. The model accounts for local precipitate coarsening at grain boundaries, which promotes an average grain boundary movement even if the Zener pinning force exceeds the driving force for recrystallization. The impact of solute drag on the grain boundary mobility as well as simultaneous precipitation is discussed in detail. The model is validated on experimental data on recrystallization in V-micro-alloyed steel, where excellent agreement is achieved.

Section: Introductionmentioning

confidence: 99%

A Model for Static Recrystallization with Simultaneous Precipitation and Solute Drag

2016

Metall Mater Trans A

“…Consequently, this process is comparable in nature to the movement of an interface through a viscous medium, which can be expressed by a characteristic mobility governed by the kinetics of local coarsening. In contrast to most other modeling approaches [2][3][4][5][6][7], in the present work, the Zener pressure, P Z , is therefore not incorporated in the driving force term for recrystallization but accounted for indirectly in an effective grain boundary mobility, expressed in terms of a weighted superposition of an obstacle-free mobility, M free , representing the mobility of the grain boundary in the absence of precipitates, and a pinned mobility, M pinned , describing the effective mobility of the grain boundary in the presence of particles subject to the mechanism of local coarsening, as…”

Section: Model For Simultaneous Recrystallization and Precipitationmentioning

confidence: 95%

“…Although the experimentally observed completion of recrystallization is commonly attributed to precipitate coarsening and the accompanying reduction of the Zener pressure, its kinetics is not related to conventional Ostwald ripening, but to some faster coarsening mechanism. In a recent contribution [7], the assumption of local coarsening along the pinned grain boundaries has been suggested, however, no corresponding local coarsening model has been formulated, there.…”

Section: Introductionmentioning

confidence: 99%

A state parameter-based model for static recrystallization interacting with precipitation

Sherstnev

Modelling Simul. Mater. Sci. Eng.

2016

In the present work, we develop a state parameter-based model for the treatment of simultaneous precipitation and recrystallization based on a single-parameter representation of the total dislocation density and a multi-particle multi-component framework for precipitation kinetics. In contrast to conventional approaches, the interaction of particles with recrystallization is described with a non-zero grain boundary mobility even for the case where the Zener pressure exceeds the driving pressure for recrystallization. The model successfully reproduces the experimentally observed particle-induced recrystallization stasis and subsequent continuation in micro-alloyed steel with a single consistent set of input parameters. In addition, as a state parameter-based approach, our model naturally supports introspection into the physical mechanisms governing the competing recrystallization and recovery processes.

“…with the Boltzmann constant, k B . In their simulations, Rehman and Zurob [11,31] observe that the growth rate of subgrains is slowed down by dissolved atoms. Therefore, they introduce a model that correlates the rate of subgrain growth with the mean distance of solute atoms.…”

Section: Boundary Mobilitymentioning

confidence: 99%

Modeling Static Recrystallization in Al-Mg Alloys

2020

Metall Mater Trans A

In the present work, the influence of Mg on recrystallization kinetics in Al is analyzed by computer simulation. A comprehensive state parameter-based microstructure model is developed, which describes recrystallization in terms of nucleation and growth. The mechanism of solute drag is fully incorporated, thus accounting for the decrease of grain boundary mobility in the presence of impurity atoms. On the basis of the present approach, the solute binding energy between Mg atoms and grain boundaries is assessed and compared to experimentally measured values. Furthermore, the influence of Mg on dislocation production during strain hardening is modeled. The simulations of the composition and temperature-dependent recrystallization kinetics are verified on experimental studies where excellent agreement is achieved. Both simulation and experiment show that increasing Mg content first decelerates and, later on, accelerates recrystallization kinetics.