Mathematical Modeling of Critical Condition for Dynamic Recrystallization

Chen, Fei; Feng, Guowei; Cui, Zhenshan

doi:10.1016/j.proeng.2014.10.027

Cited by 12 publications

(6 citation statements)

References 13 publications

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“…Chen et al [125] have presented a new model to describe the flow stress up to the peak of the σ-ε curves and, applying the SDC [14,29], the authors derive an expression to calculate the critical strain ratio R ε . In this case, the flow curve up to the peak stress was modeled using the following equation:…”

Section: Calculation Of the Critical Strain Ratio By Applying Constitmentioning

confidence: 99%

“…Chen et al [125] have developed a model used to predict the stress-strain curves of X12 an ultra-super-critical rotor steel. By applying Equation 29, R ε is determined to be equal to 0.43, which is in agreement with the experimental value obtained using the approach reported by Najafizadeh and Poliak [113].…”

Section: Calculation Of the Critical Strain Ratio By Applying Constitmentioning

confidence: 99%

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Critical Strain for Dynamic Recrystallisation. The Particular Case of Steels

Varela-Castro

Cabrera

Prado

2020

Metals

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The knowledge of the flow behavior of metallic alloys subjected to hot forming operations has particular interest for metallurgists in the practice of industrial forming processes involving high temperatures (e.g., rolling, forging, and/or extrusion operations). Dynamic recrystallisation (DRX) occurs during high temperature forming over a wide range of metals and alloys, and it is known to be a powerful tool that can be used to control the microstructure and mechanical properties. Therefore, it is important to know, particularly in low stacking fault energy materials, the precise time at which DRX is available to act. Under a constant strain rate condition, and for a given temperature, such a time is defined as a critical strain (εc). Unfortunately, this critical value is not always directly measurable on the flow curve; as a result, different methods have been developed to derive it. Focused on carbon and microalloyed steels subjected to laboratory-scale testing, in the present work, the state of art on the critical strain for the initiation of DRX is reviewed and summarized. A review of the different methods and expressions for assessing the critical strain is also included. The collected data are well suited to feeding constitutive models and computational codes.

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Section: Calculation Of the Critical Strain Ratio By Applying Constitmentioning

confidence: 99%

Section: Calculation Of the Critical Strain Ratio By Applying Constitmentioning

confidence: 99%

Critical Strain for Dynamic Recrystallisation. The Particular Case of Steels

Varela-Castro

Cabrera

Prado

2020

Metals

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“…In literature, several methods to predict the critical strain and stress based on computational or experimental approaches are reported [35]- [40]. For example, Cram et al [41] found the critical conditions for the nucleation of the DDRX using a physical-based model by coupling polyphase and grain growth models.…”

Section: Critical Stress and Strainmentioning

confidence: 99%

Thermomechanical response of additively manufactured Inconel 718 during hot torsion tests

Yadav,

Rigo,

Arvieu

et al. 2023

Int J Adv Manuf Technol

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In this study, we have investigated the microstructural changes during deformation of the SLM samples printed Inconel 718 using hot torsion tests. Prior to thermomechanical testing, the as-built samples are homogenized at 850°C for 2 h in Ar atmosphere followed by air cooling. Hot torsion tests are performed at temperatures of 850, 1000 and 1100°C, and at strain rates of 0.01, 0.1 and 1 s − 1 . It is observed that the dynamic recrystallization mechanism progresses with the evolution of annealing twins which is quanti ed by the increase in % of annealing twins during thermomechanical deformation. It is observed that samples deformed at 850°C for strain rates of 0.01 and 0.1 s − 1 shows brittle like fracture and no dynamic recrystallization. However, the samples deformed at 1000 and 1100°C for strain rates of 0.01, 0.1 and 1 s − 1 shows typical stress strain curves obtained for dynamic recrystallization. It is noted that the peak stress decreases with an increase in the temperature and increases with an increase in the strain rate. Alongside, an activation energy (Q) of 379.62 KJ/mol for SLMed Inconel 718 samples is calculated which agrees with the reported values in the literature for Hot compression tests.

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“…Now the developed equations will be: The critical strain ratio (ε c /ε p = 0.632) of present Fe-Cr-Ni alloy was found to be higher than critical strain ratio of single phase austenitic steels (ε c /ε p = 0.48-0.52). [42][43][44] This is expected to be due to the presence of two phases in the microstructure as compared to the single-phase austenitic steel. The applied strain gets partitioned into both the phases and both have different crystal structure and deformation response.…”

Section: G T Gv Hmentioning

confidence: 99%

Strain Rate Sensitivity Behaviour of a Chrome-Nickel Austentic-Ferritic Stainless Steel and its Constitutive Modelling

et al. 2018

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In the present investigation, the plastic flow curves and work softening behaviour of a dual phase Fe-Cr-Ni alloy during hot deformation (low to intermediate temperature range, 948 K (675°C) to 1 248 K (975°C)) along with concurrent microstructural development were investigated. The flow stress increased with the increase in strain rate and decreased with the increase in deformation temperature. The single peak characteristic appearing in all the flow curves indicated that dynamic recrystallization (DRX) was the dominant softening mechanism in the later stage of deformation. The critical strain for DRX initiation was ε c = 0.632ε p and the peak strain (ε p ) were expressed through the Zener-Hollomon parameter (Z). For flow stress modelling, an Arrhenius type constitutive model was established to predict the flow stress behaviour during hot deformation. The results showed that the calculated flow curves agreed reasonably well with the experimental results. The microstructural analysis using optical microscopy indicated that all the deformed structures exhibited elongated grains similar to that of parent microstructure and some equiaxed grains (resulting from DRX in the austenite phase). The fraction of equiaxed grains (in austenite) increased with the deformation temperature. At low Z, the ferrite phase accommodates the strain and dynamic recovery was the prominent restoration process. At high Z, austenite controlled the deformation mechanism and DRX was the likely cause for microstructural refinement. The iso-strain rate sensitivity (m) contour map was used to determine the optimum regime of high temperature workability.

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Mathematical Modeling of Critical Condition for Dynamic Recrystallization

Cited by 12 publications

References 13 publications

Critical Strain for Dynamic Recrystallisation. The Particular Case of Steels

Critical Strain for Dynamic Recrystallisation. The Particular Case of Steels

Thermomechanical response of additively manufactured Inconel 718 during hot torsion tests

Strain Rate Sensitivity Behaviour of a Chrome-Nickel Austentic-Ferritic Stainless Steel and its Constitutive Modelling

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