Cellular Automaton Modeling of Dynamic Recrystallisation Microstructure Evolution for 316LN Stainless Steel

2016 ◽  
Vol 693 ◽  
pp. 548-553 ◽  
Author(s):  
Hai Peng Ji ◽  
Li Ge Zhang ◽  
Jing Liu ◽  
Tai Yong Wang
Keyword(s):  
Dynamic Recrystallization ◽  
Cellular Automaton ◽  
Grain Growth ◽  
Volume Fraction ◽  
Von Neumann ◽  
Modeling Methodology ◽  
Average Grain Size ◽  
Dynamic Recrystallisation ◽  
Ca Model ◽  
Kinetic Transformation

Based on the theoretical model and physical mechanism of dynamic recrystallization (DRX) in metal materials, the dislocation density change, nucleation and grain growth model during the process of DRX are taken into account. And according to the nucleation driven by dislocation and grain growth kinetic, transformation rules are made. A modeling methodology coupling fundamental metallurgical principles based on amended nucleation rate with the cellular automaton (CA) technique is here derived to simulate the 316LN.The two-dimensional CA model uses quadrilateral element and periodic boundary condition and Von-Neumann neighbor type. The influence of strain, strain rate and deformation temperature on dynamic recrystallization volume fraction and average grain size are analyzed on the basis of established CA model.

scholarly journals Modeling of Dynamic Recrystallization Behavior of As-Extruded AM50 Magnesium Alloy during Hot Compression by a Cellular Automaton Method

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 75
Author(s):  
Dayu Shu ◽  
Jing Wang ◽  
Menghao Jiang ◽  
Gang Chen ◽  
Liwei Lu ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Cellular Automaton ◽  
Volume Fraction ◽  
Strain Rate Range ◽  
Dynamic Recrystallization Behavior ◽  
Ca Model ◽  
Cellular Automaton Method ◽  
Experimental Values

The dynamic recrystallization (DRX) behavior of as-extruded AM50 magnesium alloy was modelled and simulated by a cellular automaton (CA) method. Isothermal compression experiments were conducted, and the characteristic parameters in the CA model were obtained by the testing stress–strain flow curves in a wide temperature range of 250–450 °C and strain rate range of 0.001–10 s−1. The flow stress, DRX volume fraction and DRX grain size of the as-extruded AM50 magnesium alloy were predicted by CA simulation. The results showed that the DRX behavior of the studied magnesium alloy was susceptive with the temperature and strain rate; meanwhile, the prediction results were approximate to the experimental values, indicating that the developed CA model can make a confident estimation on the DRX behavior of the as-extruded AM50 magnesium alloy in high temperature conditions.

Modeling and Simulation of Dynamic Recrystallization of GCr15 Steel Using Cellular Automaton Method

2013 ◽  
Vol 750 ◽  
pp. 156-159 ◽  
Author(s):  
Xiao Hu Deng ◽  
Zhou De Qu ◽  
Li Wen Zhang ◽  
Dong Ying Ju
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Cellular Automaton ◽  
Volume Fraction ◽  
Accurate Determination ◽  
Structural Evolution ◽  
Bearing Steel ◽  
Gcr15 Steel ◽  
Gcr15 Bearing Steel ◽  
Ca Model

A modified two-dimensional (2-D) cellular automaton (CA) model was constructed to simulate dynamic recrystallization (DRX) process of GCr15 steel. Particle stimulated nucleation (PSN) was incorporated into the CA model to determine the influence of dispersed particles on the nucleation of DRX. In addition, the model included the effects of particles on increasing the dislocation density and pinning the grain boundaries for accurate determination of micro-structural evolution during DRX. The model was applied to simulate the DRX process of GCr15 bearing steel. DRX grain size and volume fraction were simulated using the CA model. The simulated results indicated that the simulated stable grain size of particle-containing model is closer to measured value than particle-free model. It was observed that DRX kinetics depends on both thermo-mechanical parameters and initial grain sizes. The calculated results were compared with the experimental findings in GCr15 bearing steel, the predictions show very good agreement with the experimental results.

Study on Dynamic Recrystallization Behavior in Deformed Austenite of 52100 Steel by Using JMAK-Model

2013 ◽  
Vol 275-277 ◽  
pp. 1833-1837
Author(s):  
Ke Lu Wang ◽  
Shi Qiang Lu ◽  
Xin Li ◽  
Xian Juan Dong
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Volume Fraction ◽  
True Strain ◽  
Strain And Strain Rate ◽  
Average Grain Size ◽  
Dynamic Recrystallization Behavior ◽  
Simulation And Experiment ◽  
Good Agreement

A Johnson-Mehl-Avrami-Kolmogorov (JMAK)-model was established for dynamic recrystallization in hot deformation process of 52100 steel. The effects of hot deformation temperature, true strain and strain rate on the microstructural evolution of the steel were physically studied by using Gleeble-1500 thermo-mechanical simulator and the experimental results were used for validation of the JMAK-model. Through simulation and experiment, it is found that the predicted results of DRX volume fraction, DRX grain size and average grain size are in good agreement with the experimental ones.

scholarly journals Finite Element Analysis of Dynamic Recrystallization of Casting Slabs during Hot-Core Heavy Reduction Rolling Process

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 181
Author(s):  
Haijun Li ◽  
Tianxiang Li ◽  
Meina Gong ◽  
Zhaodong Wang ◽  
Guodong Wang
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Volume Fraction ◽  
Rolling Process ◽  
Reduction Ratio ◽  
Secondary Development ◽  
Innovative Technology ◽  
Element Analysis ◽  
The Core ◽  
Average Grain Size

Hot-core heavy reduction rolling (HHR2) is an innovative technology, where a two-high rolling mill is installed after the solidification end of a strand, which can significantly eliminate the core defects of the slab. The mill exhibits a heavy reduction ratio, which promotes the dynamic recrystallization (DRX) of the slab. This study aims to optimize the parameters of the HHR2 process considering the effect of DRX on microstructure homogeneity. The secondary development of commercial software DEFORM-3D is conducted to calculate the deformation and DRX behavior of HHR2 for different reduction ratios. The parameters of DRX volume fraction and DRX grain size are compared, and finer DRX grains are obtained when the greater reduction ratios are conducted in HHR2. Then, corresponding to the deformation conditions in the HHR2, the thermal–mechanical simulations are conducted on the Gleeble3800 to obtain the average grain sizes before and after this process. When the reduction amount increases from 20 mm to 50 mm, the difference of average grain size between the core and the surface reduces by 52%. In other words, appropriately enhancing the reduction ratio is helpful to reduce the average austenite grain and promote the microstructure uniformity of the slab. These results provide some valuable information on the design of deformation parameters for HHR2.

Simulation of Ideal Grain Growth Using the Multi-Phase-Field Model

2007 ◽  
Vol 558-559 ◽  
pp. 1177-1181 ◽  
Author(s):  
Philippe Schaffnit ◽  
Markus Apel ◽  
Ingo Steinbach
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Phase Field ◽  
Large Scale ◽  
Field Model ◽  
Three Dimensional ◽  
Phase Field Model ◽  
Two Dimensions ◽  
Von Neumann ◽  
Average Grain Size

The kinetics and topology of ideal grain growth were simulated using the phase-field model. Large scale phase-field simulations were carried out where ten thousands grains evolved into a few hundreds without allowing coalescence of grains. The implementation was first validated in two-dimensions by checking the conformance with square-root evolution of the average grain size and the von Neumann-Mullins law. Afterwards three-dimensional simulations were performed which also showed fair agreement with the law describing the evolution of the mean grain size against time and with the results of S. Hilgenfeld et al. in 'An Accurate von Neumann's Law for Three-Dimensional Foams', Phys. Rev. Letters, 86(12)/2685, March 2001. Finally the steady state grain size distribution was investigated and compared to the Hillert theory.

scholarly journals Effects of Repetitive Upsetting Extrusion on the Microstructure and Texture of GWZK124 Alloy under Different Starting Temperatures

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2437
Author(s):  
Guanshi Zhang ◽  
Zhimin Zhang ◽  
Yingze Meng ◽  
Zhaoming Yan ◽  
Xin Che ◽  
...  
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Grain Refinement ◽  
Volume Fraction ◽  
Bimodal Microstructure ◽  
Continuous Dynamic Recrystallization ◽  
Average Grain Size ◽  
Second Phases ◽  
Continuous Dynamic ◽  
Weak Texture

The effects of repetitive upsetting extrusion under different starting temperatures on the microstructure and texture of GWZK124 alloy were investigated. The results clearly showed that the particles and second phases induced dynamic recrystallization (DRX), which can be explained by the particle-stimulated nucleation (PSN) mechanism. It was shown that grain refinement during repetitive upsetting extrusion (RUE) is dominated by a complicated combination of continuous dynamic recrystallization and discontinuous dynamic recrystallization. The RUEed alloys under different starting temperatures exhibited a bimodal microstructure comprising fine DRXed grains with weak texture and coarse deformed grains with strong texture. The DRXed grains could weaken the texture. As the RUE starting temperature decreased, the average grain size increased and the volume fraction of DRXed grains decreased.

Modeling of Dynamic Recrystallization Process in AZ31 Magnesium Alloy Using Cellular Automaton Method

2015 ◽  
Vol 833 ◽  
pp. 19-22
Author(s):  
Xiao Hu Deng ◽  
Dong Ying Ju ◽  
Xiao Dong Hu ◽  
Hong Yang Zhao
Keyword(s):  
Dynamic Recrystallization ◽  
Grain Growth ◽  
Grain Morphology ◽  
Mg Alloy ◽  
Recrystallization Process ◽  
Az31 Mg Alloy ◽  
Dynamic Recrystallization Behavior ◽  
Ca Model ◽  
Grain Growth Model ◽  
Experimental Findings

A modified 2-D CA model has been developed to simulate dynamic recrystallization behavior of Magnesium (Mg) alloy during hot deformation processing. Based on the fact that Mg has an HCP crystal structure with six-fold symmetry, the model employs the hexagonal CA lattice. The initial microstructure with prescribed grain size was generated by a normal grain growth algorithm. The DRX model consists of dislocation density evolution model, DRX nucleation model and recrystallization grain growth model. DRX grain morphology and size, flow curve were simulated by the present model. The calculated results were compared with the available experimental findings in AZ31 Mg alloy, the predictions show very good agreement with the experimental results.

scholarly journals Simulation of Dynamic Recrystallization Behavior under Hot Isothermal Compressions for as-extruded 3Cr20Ni10W2 Heat-Resistant Alloy by Cellular Automaton Model

2018 ◽  
Vol 37 (7) ◽  
pp. 635-647 ◽  
Author(s):  
Le Li ◽  
Li-yong Wang
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Cellular Automaton ◽  
Deformation Temperature ◽  
Experimental Result ◽  
Recrystallization Behavior ◽  
Dynamic Recrystallization Behavior ◽  
Ca Model ◽  
Recrystallized Grain Size

AbstractIn order to study dynamic recrystallization behavior of the as-extruded 3Cr20Ni10W2 under isothermal compression conditions, a cellular automaton (CA) model was applied to simulate hot compression. Analysis on the strain–stress curves indicates that dynamic recrystallization is the main softening mechanism for the 3Cr20Ni10W2 when the deformation occurred in the temperature range of 1203–1303 K with an interval of 50 K and strain rate range of 0.01–10 s−1. The deformation temperature and strain rate have a significant influence on the dynamically recrystallized grain size. Subsequently, a CA model is established to simulate the dynamic recrystallization behaviors of the studied alloy. The simulated results show that the mean grain size increases with the increased deformation temperature and decreases with the increased strain rate, which is consistent with the experimental result. In addition, the average absolute relative error, which is 13.14%, indicates that the process of the dynamic recrystallization and the dynamically recrystallized grain size can be well predicted by the present CA model.

Dynamic recrystallization and microstructure evolution of AZ31 magnesium alloy produced by extrusion through rotating container

2016 ◽  
Vol 30 (01) ◽  
pp. 1550261 ◽  
Author(s):  
Feng Li ◽  
Nan Bian ◽  
Yongchao Xu ◽  
Xiang Zeng
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Theoretical Basis ◽  
Volume Fraction ◽  
Az31 Magnesium Alloy ◽  
Average Grain Size ◽  
Distribution Uniformity ◽  
Equiaxed Grains

In order to research the dynamic recrystallization (DRX) and grain refinement mechanisms in the process of extrusion through the rotating container, hot compression experiment of AZ31 magnesium alloy was carried out. Through the combination of experimental data and Yada empirical model, the DRX model of AZ31 magnesium alloy was established. Based on this DRX model, the numerical simulation of AZ31 magnesium alloy extrusion through the rotating container process was performed. The research results indicated, with the same process parameters of conventional extrusion, the shear stress increased significantly at the same position during the process of extrusion through the rotating container. This stress change promoted the occurrence of DRX and the increased recrystallization volume fraction. The average grain size obviously decreased. The equiaxed grains increased and the distribution uniformity was improved. These characteristics provided a theoretical basis for a better understanding of the enhanced comprehensive mechanical properties during the extrusion through the rotating container.

Modeling of Grain Structure Evolution and its Impact on the Reliability of Al(Cu) Thin Film Interconnects

1997 ◽  
Vol 490 ◽  
Author(s):  
S. P. Riege ◽  
V. Andleigh ◽  
C. V. Thompson ◽  
H. J. Frost
Keyword(s):  
Grain Growth ◽  
Volume Fraction ◽  
Grain Structure ◽  
Structure Evolution ◽  
2D Simulation ◽  
Grain Structures ◽  
Average Grain Size ◽  
Interconnect Reliability ◽  
Bamboo Structure ◽  
Cu Thin Film

ABSTRACTWe have extended a 2D simulation of grain growth to treat the effects of precipitates on the evolution of interconnect grain structures during post-patterning processing. It is known from experiments that different annealing histories result in different precipitate sizes and locations. Precipitates capture and effectively pin grain boundaries and inhibit grain growth and evolution toward bamboo structures. We find that even a small volume fraction of precipitates prevent an interconnect strip from reaching the fully bamboo structure by retarding grain growth and lowering the average grain size. At a late stage of evolution, cluster regions are pinned by precipitates on both sides, preventing further transformation to the by far more reliable bamboo structure. The results from grain growth simulations have been used with our electromigration simulator MTT/EmSim to investigate the dependence of interconnect reliability on linewidth and precipitate distribution. We find that in lines with precipitates the bamboo structure is not reached during post-pattern annealing even if the line width is smaller than the average grain diameter. Furthermore, it is found that while Cu in solid solution improves interconnect reliability, Al2Cu precipitates can inhibit post-patterning grain structure evolution to more reliable bamboo or near-bamboo structures so much that similar lines made of pure Al would be more reliable. Linked grain structure evolution and electromigration simulations allow process optimization for maximum interconnect reliability.

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