3D numerical modeling of dynamic recrystallization under hot working: Application to Inconel 718

Dynamic recrystallisation model in precipitation-hardened superalloys as a tool for the joint design of alloys and forming processes

“…1, it constitutes an improvement over the previous model which did not take pinning by γ′ into account, since it allows to predict recrystallisation during subsolvus processing. Being fully composition-dependent through composition and phase constitution, it allows a predictive evaluation of DRX behaviour in new alloys, unlike other models that are material-specific [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”

“…This may be achievable if a model is available, capable of predicting DRX features as a function of alloy compositionand hence phase constitution -as well as of processing conditions (temperature, strain rate, strain). Most models, however, provide a description of microstructural evolution using fitted parameters and are not predictive regarding the influence of composition [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. For instance, some authors [8][9][10][11][12][13][14] have used parameterised equations, mostly relying on or deriving from the Zener-Hollomon parameter, to describe the high temperature flow stress of different superalloys, the dependence of grain size on temperature, strain rate, and/or the evolution of the recrystallised fraction with strain.…”

“…The latter is considered as a continuous medium with averaged properties [20], or as a homogenised medium made of fractions of recrystallised and non-recrystallised grains having different properties [21]. Calculating the evolution of individual grains can also be made without a mean field approach, by simulating a large and representative set of grains by a cellular automaton [22][23][24]. Nevertheless, all the abovementioned approaches [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] share the common feature that model parameters have to be fitted to each specific alloy, so that predictions cannot be extended to different alloy compositions unless model parameters have been fitted again.…”

Analysis of deformation and microstructure evolution during the cogging process of Waspaloy alloy

“…Their high flow stress and high recrystallization temperature narrow the forging temperature range to 1000-1100 o C, hence the implementation of forging technologies for these alloys still faces a number of major technological problems [3]. For developing the optimal thermo-mechanical deformation conditions for nickel-based alloys in order to obtain the required microstructure in finished products under industrial conditions, simulations of the process of forging at high deformation temperatures, considering variable process parameters (temperature, strain and strain rate), are necessary [4]. By controlling changes in the thermo-mechanical state of the deformation zone in the Waspaloy alloy blank forging process, the mechanical and functional properties of products can be significantly influenced.…”

Some Facts We Can Learn from Analytical Modeling of DDRX in Pure Metals and Solid Solutions

“…Various approaches have been proposed for modeling DDRX in the past: after some analytical pioneering works [1,2], Monte Carlo calculations were published by Rollett and co-workers [3][4][5]. Several researchers used as an alternative cellular automata, although the latter are more adapted for describing static than dynamic recrystallization for strain has to be introduced in a somewhat artificial way [6,7], or by coupling the cellular automaton (for static recrystallization) with finite element computations (for deformation) [8]. More recently, the level set finite element technique has been introduced, which allows a full field description of the material during static [9] or dynamic [10] recrystallization.…”