Growth Of New Grains Research Articles

Unveiling the recrystallization mechanism and kinetics parameters in cold-rolled dual-phase stainless steel using differential scanning calorimetry

The present work aims to assess the Recrystallization mechanism and Kinetics parameters in Cold-Rolled Dual-Phase stainless steel. For this purpose, Differential Scanning Calorimetry was used over a range of 5–20 K/mn of heating rate, to identify the classical kinetic parameters such as recrystallization temperature, activation energy, and growth mechanism following 90 % reduction in thickness. The findings revealed that the recrystallization temperature increased with rising heating rates within the range [706.8–732] for the ferrite phase, as well as [1282.0–1360.3] K for the austenite phase. The estimated activation energies for ferrite and austenite recrystallization fell within the range of [207.2 ± 1.4–220.1 ± 2.5] kJ/mol and [220.2 ± 2.0–241.1 ± 4.0] kJ/mol, respectively. The Avrami parameter approached half-unity for both ferrite and austenite recrystallized phases for which results can be interpreted to be chiefly responsible for a general mechanism involving the growth of new grains with appreciable initial volume through a diffusion-controlled process.

Hot deformation behaviors and microstructure evolution of a supersaturated nickel-based superalloy

The hot deformation behaviors and microstructure evolution of a supersaturated Ni-based superalloy GH4742 were investigated by isothermal compression tests. The deformation temperature range encompassed γ' sub-solvus (1000–1075 °C) and super-solvus (1100–1150 °C), with strain rates ranging from 0.001 s−1 to 1 s−1. Separate Arrhenius-type constitutive equations were established considering the re-precipitation of the γ' phase. The correlation coefficient between the calculated stresses and the experimental data was as high as 0.997, which indicated that the rheological behaviors of the material during hot deformation processes could be accurately analyzed by the constitutive relationship. Additionally, the activation energies for the γ + γ' two-phase region and the γ single region were calculated to be 949.08 kJ.mol−1 and 437.66 kJ.mol−1, respectively. Microstructural analysis revealed that the partial dynamic recrystallisation (DRX) occurred in the γ' sub-solvus regime whereas the full DRX occurred in the γ' super-solvus regime. The low DRX fractions in the γ' sub-solvus regime were attributed to the presence of near-spherical re-precipitated γ' phase, which effectively suppresses the nucleation and growth of new grains. The deformed grains were oriented in the <101> direction parallel to the compression direction. Meanwhile, the non-monotonic relationship between the degrees of DRX and strain rate was observed due to the adiabatic temperature rise. The retarding effects of solute elements on the grain growth in the γ' super-solvus regime were determined by comparing the recrystallized grain sizes from theoretical analysis and experiment values. This work can provide guidance for understanding the deformation behaviors of the alloy and achieving desired microstructures.

A novel strategy creating serrated grain boundaries to improve ductility in a Fe–Cr–Al alloy

Grain boundaries serration has long been regarded as a way to improve mechanical properties at high temperatures in alloys. However, the traditional method of creating serrated grain boundaries (SGBs), solution treatment followed by slow cooling, could induce a significant coarsening behavior of the second phase, thereby adversely affecting the properties. In this work, a new strategy is proposed to obtain numerous irregular SGBs without producing coarser Laves precipitates (<400 nm) in Fe–Cr–Al alloys, in which these SGBs are formed through recrystallization annealing of a warm-rolled microstructure featuring kink bands (KBs). These SGBs can be divided into two types: low amplitude SGBs (LA-SGBs, in the range of 1∼10 μm), and high amplitude SGBs (HA-SGBs, over 20 μm). Through SEM and quasi in-situ EBSD observation, and combined with the Taylor factor model, the formation mechanism of irregular SGBs is revealed in detail. The pinning effect of Laves phase precipitated during annealing on the grain boundaries migration induces the formation of LA-SGBs. On the other hand, the discrepancy in deformation stored energy between the matrix and the KBs promotes the special nucleation and growth of new grains, thus resulting in the formation of HA-SGBs. Moreover, tensile tests are conducted at 298 K and 873 K. SGBs can significantly enhance ductility while maintaining strength, exhibiting an increase of 52.1% and 41.1% respectively. Compared to straight grain boundaries, at 298 K, SGBs can reduce the accumulation of the GNDs in the vicinity of themselves through the unique strain-hardening behavior mediated by high-density dislocation walls (HDDWs), alleviate the stress concentration, make the plastic strain distributions more uniform, and thus retard the crack initiation. As the deformation temperature rises to 873 K, the improved ductility is mainly ascribed to the deflection and passivation effects of SGBs on crack propagation during straining from necking to fracture while their effects on the strain-hardening stage are weakened.

Influence of carbon content on static recrystallization behavior of 50% cold-rolled Fe-18Mn-9Cr-2Al-xC steels

Recrystallization behavior during annealing at various temperatures was investigated for 50% cold-rolled Fe-18Mn-9Cr-2Al-xC steels with C contents varying between 0 and 0.5 wt%. Nucleation of recrystallization occurred near randomly in the carbon-free steel, whereas increasing the carbon contents promoted preferential nucleation at carbides formed along the grain boundaries through the particle stimulated nucleation mechanism. New grains in the carbon-free steel grow freely at the expense of deformed grains until the end of recrystallization during which migration of recrystallization front was blocked by the elongated δ-ferrites. For the carbon-added steels, on the other hand, (Cr,Mn)23C6 carbides and FeAl intermetallics formed during annealing and pre-existing carbides at grain boundaries pinned the recrystallization front, and thereby suppressing the growth of new grains and developing a distinct necklace structure. Recrystallization of the carbon-added steels completed only after carbides were dissolved at higher temperatures around 900 °C. It is noteworthy that it is not the carbon atom itself in solid solution but carbides that promotes nucleation of recrystallization and subsequently suppressed growth of new grains. It was also found that tensile properties of the cold-rolled steels restored nearly to those prior to cold rolling, i.e., in as-annealed state. It is concluded that recrystallization kinetics, special distribution of new grains, and texture of the cold-rolled Fe-18Mn-9Cr-2Al-xC steels are significantly affected by the carbon contents. In addition, restoration of tensile properties of cold-rolled steels by recrystallization suggests that many repetitive thermomechanical processing are applicable to the steels for forming into a desire shape.

High throughput construction for the deformation mechanism diagram and dynamic recrystallization of a bimodal‐sized particle‐reinforced Ti‐2.5Zr‐2Al‐1(Si,C) titanium alloy

AbstractAn in situ autogenous particle‐reinforced Ti‐2.5Zr‐2Al‐1(Si,C) titanium alloy is prepared by vacuum induction melting. The wide range of an effective strain between 0.2 and 1.2 and the corresponding microstructure are obtained by the double‐cone high‐throughput compression test and finite element simulation. The deformation mechanism diagram with strains of 0.2–1.2 and strain rates of 0.7–1.5 s−1 at 900°C is constructed. When the strain rate is 1.3 s−1, dynamic recovery occurs in the small strain range (&lt;0.377), dynamic recrystallization (DRX) occurs in the medium strain range (0.377–1.182), and deformation instability occurs in the large strain range (&gt;1.182), resulting in the deformation bands. High‐angle annular dark field and high‐resolution transmission electron microscopy are used to determine the existence of bimodal particle distribution, namely micron‐scale TiC particles and nano‐scale Ti5Si3 and (Zr, Si) particles. The average radius of the (Zr, Si) nanoparticles measured by small angle neutron scattering is 19.3 nm, and the volume fraction is 0.35%. DRX grains with an average size of 0.49 μm are obtained at 900°C, strain rate of 1.3 s−1, and strain of about 0.6. Micron‐scale particles stimulated DRX nucleation, while nanoscale particles hindered the growth of new grains, resulting in grain refinement.

Effect of welding current and Laves phase on the microstructures and mechanical properties of GTAW joints for ZC63 magnesium alloy

Gas tungsten arc welding (GTAW) is used to successfully join ZC63 magnesium alloy extruded plates. The effect of welding current and Laves phase on the microstructures and mechanical properties of the welded joints were studied. It was found that when the welding heat input is low, the grains in the heat affected zone (HAZ) of the welded joints of ZC63 alloy with low recrystallization fraction will not grow significantly. This is due to the fact that the heat energy of the HAZ in the welding process is mostly consumed in the process of recrystallization nucleation and growth of new grains. Besides, compared to base metal (BM), The HAZ and fusion zone (FZ) present greater randomness of grain orientation and weaker crystallographic texture. With the increase of welding current, the mechanical properties of the welded joints decrease. The welded joints exhibit the most excellent properties when the welding current is 90 A (the UTS is 229 MPa, the YS is 100 MPa, and the EL is 12.6%). The FZ is the weakest position of the welded joints. The Laves phases are distributed in a continuous network at the grain boundaries in the FZ. Under the stress, the Laves phases are the initiation of crack, which eventually causes intergranular fracture of the welded joints.

Microstructure evolution and grain refinement mechanism of fine-grained Mg-Gd-Y-Zn-Zr alloy during multi-directional forging

Fine-grained Mg-8.59Gd-3.85Y-1.14Zn-0.49Zr alloy was subjected to multi-directional forging (MDF). The corresponding grain refinement mechanism was analyzed by observing the microstructure before and after MDF, and the evolution mechanism of various phases and texture states was discussed. The results showed that the 9 passes MDF with deformation temperature of 350 ℃ and strain rates of 0.01 s−1 and 0.1 s−1 can further refine the grain structure. The average grain size decreases to 2.95 µm at the strain rate of 0.1 s−1. The refinement of the grain structure is dominated by dynamic recrystallization (DRX), while the β phase maintains the refinement results through the pinning effect. The main refinement mechanism of the original equiaxed grains is discontinuous dynamic recrystallization (DDRX), and the growth of the original equiaxed grains and new grains is hindered by the β phases. The dissolution of lamellar structures and continuous dynamic recrystallization (CDRX) at the deflected lamellar long-period stacking ordered (LPSO) lead to the fracture and refinement of large-sized deformed grains, while the β phases precipitated precede CDRX can hinder the growth of new grains. The effect of the deformation temperature on the grain refinement is more notable than that of the strain rate owing to the significant difference in the number of β phases at different temperatures. Because of the low nucleation rate and high dissolution rate associated with the high temperature sensitivity, the number of β phases is low at 400 ℃ and can not effectively maintain the refinement results. The random orientation of DRX grains and change in the load direction of each pass promote the weakening of the basal texture, making the MDFed microstructure exhibits multitextured components.

Perspectives of Microstructure Refinement of Aluminum and Its Alloys by the Reciprocating Extrusion (Cyclic Extrusion Compression-CEC).

This paper presents a study on the perspectives of structure refinement of aluminum and its alloys by reciprocating extrusion (cyclic extrusion compression—CEC). The study included Al99.5 and Al99.992 aluminum and AlMg5 and AlCu4Zr alloy. Aluminum and alloys were deformed by reciprocating extrusion (CEC) in the strain range ϕ = 0.42 (1 CEC cycle) to ϕ = 59.8 (67 CEC cycles). After deformation, the structure of the specimens was investigated by optical microscopy (OM) and transmission electron microscopy (TEM), which revealed that the primary mechanism of hardening, over the range of applied strains, was the result of the propagation of shear bands throughout the specimens. The intersection of shear bands was found to divide the volume of the specimens into nano and microvolumes with dimensions limited by the width of the microbands. Due to structure renewal processes such as polygonization and dynamic geometric recrystallization, the formed micro and nano volumes were transformed into nano and micrograins with large misorientation angles. In terms of the occurrence of grain microstructure, a sustained uniform level of hardening was found, which was defined as steady-state flow. The research has shown that the steady state of flow is a result of the competitive interaction between the processes of hardening and structure renewal. The higher the metal purity, the higher the intensity of the structure renewal processes was. The formation of new grains and their growth under dynamic and post-dynamic recrystallization was observed in Al99.992 aluminum, in which high purity of the metal and high strain accumulation caused the growth of new grains at room temperature.

Role of temperature and precipitates on the evolution of microstructure and texture during grain growth of Mg–3Al–0.2Ce alloy

ABSTRACT Mg–3Al–0.2Ce alloys were subjected to annealing at temperatures ranging from 200 to 450°C for different periods to evaluate the microstructure and texture developments in the alloy. The grain growth exponent of n = 13 and the activation energy for grain growth, Q = 75 kJmol−1 were observed. A large number of precipitates were observed in the samples. They were found to be Mg17Al12, Al8Mn5, Al11Mn4, Al11Ce3, Al3Ce, Al4Ce, Mg17Ce2, Al10Mn7Ce2, Mg2Ce, Mg3Ce, and Mg12Ce, as confirmed by electron probe microanalysis (EPMA) and X-ray Diffraction (XRD). The precipitates were further found to be dissolved or disappeared with an increase in the temperature of annealing. As a result, the grain boundary mobility was enhanced during annealing at high temperatures and increased the grain growth of the samples. The initial basal texture in the alloy was observed to be tilted (by ∼ 30°) towards the transverse direction of the samples during annealing. Such a texture weakening in the alloy during annealing was attributed to the nucleation and growth of new grains formed in the deformed zone surrounding the precipitates.

Additive Manufacturing of Compositionally-Graded AISI 316L to CoCrMo Structures by Directed Energy Deposition

In the present study, compositionally-graded structures of AISI 316L and CoCrMo alloy are manufactured by powder-based laser-beam directed energy deposition (DED-LB). Through a process-integrated adjustment of powder flow, in situ alloying of the two materials becomes feasible. Thus, a sharp and a smooth transition with a mixture of both alloys can be realized. In order to investigate the phase formation during in situ alloying, a simulation approach considering equilibrium calculations is employed. The findings reveal that a precise compositional as well as functional gradation of the two alloys is possible. Thereby, the chemical composition can be directly correlated with the specimen hardness. Moreover, phases, which are identified by equilibrium calculations, can also be observed experimentally using scanning electron microscopy (SEM) and energy-dispersive X-ray-spectroscopy (EDS). Electron backscatter diffraction (EBSD) reveals epitaxial grain growth across the sharp transition region with a pronounced &lt;001&gt;-texture, while the smooth transition acts as nucleus for the growth of new grains with &lt;101&gt;-orientation. In light of envisaged applications in the biomedical sector, the present investigation demonstrates the high potential of an AISI 316L/CoCrMo alloy material combination.

Effect of electric pulse treatment on the structure and hardness of nickel deformed at room and liquid nitrogen temperatures

The influence of the energy of electro-pulse processing (EPP) on the structure and hardness of pure nickel deformed at room and liquid nitrogen temperatures is studied. The metal was subjected to isothermal rolling with a strain of 90% and subsequent EPP with integral current densities Kj in the range from 0.06 to 0.19×105 A2s/mm4 corresponding to the calculated temperature range of 130-925°C. It was found that decreasing the rolling temperature of Ni resulted in a more uniform and less misoriented nanocellular structure and a 15-20 HV higher hardness. Subsequent EPP decreased the hardness due to recovery, discontinuous recrystallization with the formation of annealed twins and growth of new grains. It is revealed that a more uniform fine-grained structure with a smaller grain size is formed in the cryorolled metal in a narrower interval and at less EPP energies.

Computer Simulation Study on Dynamic Recrystallization Mechanism of Magnesium Alloy during Compound Deformation

The evolution law of dynamic recrystallization structure in the process of indentation-flattening compound deformation technology (IFCDT) of AZ31 magnesium alloy was studied. A computer simulation method for dynamic recrystallization structure evolution process was proposed based on cellular automata theory (CA method). Firstly, the material model of cellular automata method is established. Secondly, the performance parameters and compound deformation parameters of AZ31 magnesium alloy were determined. Finally, the dynamic recrystallization process of AZ31 magnesium alloy during compound deformation was analyzed. During the compound deformation of AZ31 magnesium alloy, the dynamic recrystallization mechanism is initial state, nucleation of new grains, generation of new grains, growth of new grains, continuous growth of new grains, and covering of original large grains. Compared simulation results with experimental results, the maximum relative errors is 15.4%. It is proved that cellular automaton method may be used to predict the microstructure evolution of AZ31 magnesium alloy during indentation-flattening compound deformation.

The Effect Of Heating Temperature On The Hardness, Microstructure And V-Bending Spring Back Results On Commercial Steel Plate

The need for low carbon steel plate sheets with relatively thin thickness measurements in Indonesia is currently quite high, especially in supporting the automotive industry, the electronics industry, the food industry, beverages, and household appliances. To fulfill this, raw materials for low carbon steel plate sheets that have high formability and are not easily cracked in critical areas of the desired model are required. For this reason, research on the effect of temperature variations in heat treatment on hardness, microstructure and spring back of V-bending results on steel plates with a plate thickness of 0.8 mm. The research method used was a laboratory experimental method. The heat treatment is carried out with temperature variations of 710, 820 and 9300C with a holding time of 60 minutes. Tests carried out on specimens are hardness testing, microstructure testing, and spring back V-bending results on steel plates. The results of this study indicate a decrease in the spring back angle where the smallest spring back angle in the bending process is on the 9300C plate which is 1,040. The value of the hardness results from V-bending has increased significantly. The increase in the value of hardness because the plate has an atom shift or dislocation by shear stress (slip) due to plastic deformation on the plate. The highest hardness value is on the 7100C plate which is 154.67 HV or has an increase of 14,291% of the pre-bending plate. The lowest hardness value is on the 9300C plate which is 125.33 HV, its hardness increases 4.4% against the pre-bending plate. Heat treatment also causes changes in the microstructure of the plates from the process of regulation and reshaping of crystals to the growth of new grains which have implications for changes in mechanical properties and formability of the workpiece.

Study on Non-Isothermal Transformation of Ti-6Al-4V in Solution Heating Stage

In order to understand the non-isothermal transformation behavior of Ti-6Al-4V titanium alloy in the continuous heating stage of solution treatment, thermal dilatometry tests with heating rates of 0.1~0.8 °C/s were designed. The conversion between the expansion amount and the transformed volume fraction was realized by the lever principle, and the transformation characteristics of α + β → β were quantified based on the Kissinger-Akahira-Sunose (KAS) theory and the modified Johnson–Mehl–Avrami (JMA) model. The results show that the phase transformation kinetics curves present typical “S” patterns, and the element diffusion transformation controls the nucleation and growth of new grains during the transformation of α + β → β. The phase transformation interval gradually moves to high temperature regions with the increase of heating rates, and the phase transformation activation energy is 445.5 kJ·mol−1. The phase transformation process is divided into three stages according to the relationship between the Avrami exponent n and the transformed volume fraction fT. These three stages correspond to different stages of grain nucleation or growth.

Microstructure and Texture Evolution During Thermomechanical Processing of Al0.25CoCrFeNi High-Entropy Alloy

Microstructure and texture evolution was studied in a Al0.25CoCrFeNi high-entropy alloy after cold work and subsequent isochronal annealing treatments. The alloy was synthesized by arc-melting and the resulting ingots were cold rolled up to two different thickness reductions: 50 pct and 80 pct. The alloy was then annealed for 1 hour at 973 K, 1073 K, 1173 K, and 1273 K. The final microstructures were analyzed using X-ray diffraction, scanning electron microscopy, and electron backscatter diffraction and the results were correlated with hardness measurements. The sample reduced by 80 pct recrystallized at a lower temperature than the sample reduced by 50 pct, confirming the influence of the deformation degree on the rate of nucleation and growth of new grains. The recrystallized microstructures revealed equiaxed grains with a high density of twins, which is typical of metals with low stacking fault energy. Twins were also observed in the as-rolled samples, suggesting that twinning precedes shear banding during deformation of this alloy. This accounts for the strength of the {110} 〈112〉 brass texture component in the cold rolled samples.

The operative dynamic recrystallization mechanism of austenite during the transient deformation in a Ni-30%Fe model alloy

Effect of strain rate and its discontinuous changes on dynamic recrystallization (DRX) behaviours of a Ni-30%Fe austenitic model alloy were investigated by hot compression tests. The results show that, during deformation at slow strain rates, DRX occurs with discontinuous nature, i.e. the DRX nuclei preferentially appear along initial grain boundaries followed by a quick growth through the strain-induced boundary migration (SIBM). Interestingly, during the further deformation after an abrupt increase in the strain rate, it can be found that the subgrains which developed in the first stage of deformation would gradually transform into new DRX grains. Therefore, in spite of the low stacking fault energy austenite, the continuous DRX (CDRX) is indeed possible to be activated during the transient deformation. The strain-induced sub-boundaries developed in the first deformation stages are believed to transform into higher-angle boundaries easily in further straining after abrupt increase of the strain rate. By this way, the CDRX mechanism in austenite is significantly promoted. Moreover, the local growth of new grains also plays an important role in this dynamic softening process.

Quasi in-situ EBSD characterization of the evolution of microtexture and microstructure in non-oriented electrical steels during cold rolling and annealing

Non-oriented electrical steel sheets are extensively used to manufacture core laminations for electric motors. The microstructure and crystallographic texture of the final thin sheets have a significant effect on the magnetic quality of the lamination core. Controlling the development of microstructure and texture during thermomechanical processing of these steels is of great practical importance. Although the final microstructure and texture of the steel sheets are affected by all the processing procedures employed, cold rolling and final annealing have the most direct effect since these are usually the final steps to process the steel. Although much effort has been made to study the evolution of microstructure and texture in non-oriented electrical steels, the formation mechanisms of the final microstructure and texture during annealing (especially grain growth) are still not completely understood, which is partially due to the fact that it is very difficult to directly investigate these processes using conventional characterization techniques. In this research, a quasi in-situ electron backscatter diffraction (EBSD) technique was presented, which enabled the tracking of the changes of the morphology and orientation of individual grains during cold rolling and the subsequent annealing process. The experiments revealed the rotations of individual grains under plane strain compression, and tracked the formation of nuclei from the deformed matrix and the growth of new grains during the recrystallization process. The results provided valuable insights into the evolution of microstructure and microtexture during cold rolling and annealing of non-oriented electrical steels, and helped understand the mechanisms that govern the nucleation and grain growth during recrystallization.

Effect of stacking fault and amorphous boundary on plastic deformation mechanism of dual-phase nanostructure Mg alloys

Dual-phase nanostructure model is an effective method to improve the plasticity of Mg alloys. Here, molecular dynamics simulation is performed to investigate the influence of stacking fault (SF) and amorphous boundary (AB) on the deformation mechanism of dual-phase crystal/amorphous nanostructure Mg alloys under tensile loading. The results show that with the increase of AB spacing, the plastic deformation mode of dual-phase nanostructure Mg alloys containing SFs with large SF spacing converts from the generation and growth of new grains in crystalline phase to the plastic deformation dominated by amorphous phase. When the AB spacing reaches a critical value, the plastic deformation of dual-phase nanostructure Mg alloys is completely provided by amorphous phase, and the crystalline phase hardly participates in plastic deformation. However, the results also indicate that when the SF spacing in the crystalline phase is relatively small, the crystalline phase still contributes to the plastic deformation of Mg alloys to a certain extent, even if the AB spacing is large. These analysis shed light on that the introduction of SFs may promote the formation of new grains, and the deformation mechanism of dual-phase nanostructured Mg alloys is not only related to the AB spacing of amorphous phase, but also to the SF spacing of crystalline phase.

Hot torsion behavior of SP-700 near beta titanium alloy in single and dual phase regions

Abstract Hot deformation behavior of the SP-700 alloy is studied through continuous and interrupted hot torsion testing carried out at 850 and 1 000 °C at different pass-strains and inter-pass times. The flow curves of SP-700 alloy showed the discontinuous yield stress, which is followed by the steady state region. The dominant mechanism of softening in hot deformation at 1 000 °C was dynamic recrystallization (DRX), whereas at 850 °C serration and tanglement of the grain boundaries were observed. Nevertheless, the microstructure of the sample twisted at 850 °C indicated the occurrence of DRX and the formation of fine grains in the vicinity of grain boundaries and triple points by the bulging mechanism. With an increase in the pass-strain of interrupted torsion at 1 000 °C, due to the increase in driving force for nucleation and growth of new grains, the kinetics of static restoration increased. However, due to the completion of DRX, the kinetics rate of static restoration at steady state strain (∊ s) was lower than that of the former state. The β → α phase transformation at 850 °C was found to be another factor contributing in fractional softening.

Consistency of dynamic recrystallization models from the perspective of physical metallurgy and continuum mechanics

AbstractDynamic recrystallization (DRX) is characterized by the nucleation and growth of new grains, which takes place concurrently to plastic deformation. DRX processes are used in industrial hot forming operations to control the microstructure and properties of the workpiece. Various models have been developed that consider the coupled evolution of microstructure and flow stress during hot deformation processes, some from a perspective of physical metallurgy, some from continuum mechanics. It is widely accepted that the onset of DRX is characterized by an inflection point of the strain hardening rate as a function of stress. This criterion was derived by Poliak and Jonas using results from the thermodynamics of irreversible processes. The present paper analyses the conditions that need to be met by DRX models to be consistent with the criterion by Poliak and Jonas. It is shown that for models which use classical Avrami kinetics to describe the evolution of the recrystallized volume fraction, the Avrami exponent should exceed a value of 3 to ensure that the Poliak‐Jonas criterion is not violated. Based on this observation, a framework for consistent DRX kinetics is presented and discussed. (© 2017 Wiley‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)