Constitutive modeling for predicting peak stress characteristics during hot deformation of hot isostatically processed nickel-base superalloy

Kumar, Sanjeev; Raghu, T.; Bhattacharjee, P.P.; Rao, G. Appa; Borah, Utpal

doi:10.1007/s10853-015-9200-0

Cited by 80 publications

(12 citation statements)

References 43 publications

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“…The surface temperature increased with increasing strain rate ( Figure 3c), and for 5 s −1 at 1080 • C it even exceeded the carbide solvus (1100 • C), but the test times were too short to allow for any significant carbide dissolution. The increase in temperature due to adiabatic heating agrees with similar studies [26,36].…”

Section: Methodssupporting

confidence: 90%

Dynamic and Post-Dynamic Recrystallization of Haynes 282 below the Secondary Carbide Solvus

Eriksson

Colliander

2021

Metals

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Thermomechanical processes, such as forging, are important steps during manufacturing of superalloy components. The microstructural development during processing, which controls the final component properties, is complex and depends on e.g., applied strain, strain rate and temperature. In this study, we investigate the effect of process parameters on the dynamic and post-dynamic recrystallization during hot compression of Ni-base superalloy Haynes 282. Specifically, we address the effect of deformation below the grain boundary carbide solvus temperature. During deformation, discontinuous and continuous dynamic recrystallization was observed at the grain boundaries, and particle-stimulated nucleation occurred at primary carbides. Strain rate was determined to be the governing factor controlling the recrystallization fraction for strain rates up to 0.5 s−1 above which adiabatic heating became the dominating factor. Careful examination of the temperature development during deformation showed that the response of the closed-loop temperature control system to adiabatic heating can have important effects on the interpretation of the observed behavior. During a 90 s post-deformation hold, grain growth and an increasing fraction of twin boundaries significantly changed the deformation-induced microstructure and texture. The microstructure developed during post-dynamic recrystallization was mainly controlled by the temperature and only weakly coupled to the prior deformation step.

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Section: Methodssupporting

confidence: 90%

Dynamic and Post-Dynamic Recrystallization of Haynes 282 below the Secondary Carbide Solvus

Eriksson

Colliander

2021

Metals

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“…The observed behavior is typical in alloys showing the occurrence of DRX during hot deformation [38,[44][45][46]. Moreover, it is observed that the peak stress decreases as the temperature increases, which is a conventional behavior and consistent with other reports for nickel-based superalloys [47][48][49][50]. Flow curves of IN718 alloy obtained at the temperature of 1100 °C and at various strain rates from 0.001 to 1 s −1 are also displayed in Fig.…”

Section: Stress-strain Curvessupporting

confidence: 88%

Dynamic recrystallization mechanisms and twining evolution during hot deformation of Inconel 718

Azarbarmas

Aghaie-Khafri

Cabrera

et al. 2016

Materials Science and Engineering: A

193

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The hot deformation behavior of an IN718 superalloy was studied by isothermal compression tests under the deformation temperature range of 950–1100 °C and strain rate range of 0.001–1 s-1 up to true strains of 0.05, 0.2, 0.4 and 0.7. Electron backscattered diffraction (EBSD) technique was employed to investigate systematically the effects of strain, strain rate and deformation temperature on the subgrain structures, local and cumulative misorientations and twinning phenomena. The results showed that the occurrence of dynamic recrystallization (DRX) is promoted by increasing strain and deformation temperature and decreasing strain rate. The microstructural changes showed that discontinuous dynamic recrystallization (DDRX), characterized by grain boundary bulging, is the dominant nucleation mechanism in the early stages of deformation in which DRX nucleation occurs by twining behind the bulged areas. Twin boundaries of nuclei lost their ¿3 character with further deformation. However, many simple and multiple twins can be also regenerated during the growth of grains. The results showed that continuous dynamic recrystallization (CDRX) is promoted at higher strains and large strain rates, and lower temperatures, indicating that under certain conditions both DDRX and CDRX can occur simultaneously during the hot deformation of IN718.Peer ReviewedPostprint (author's final draft

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“…10 that the peak stress and the steady-state stress have linear relationship especially for samples compressed at low strain rates. Although in the in literature, there are reports of using both the peak stress [54] and the steady-state stress [16] for formulating the constitutive equations, one should notice that it is not often possible to determine the steady state stress accurately and the adiabatic heating can drop the flow stress at high strain rates. Therefore, it seems that it is better to use the peak stress in constitutive equations rather than steady state stresses.…”

Section: Constitutive Equations Based On Sellars Modelsmentioning

confidence: 99%

Microstructural evolution and constitutive equations of Inconel 718 alloy under quasi-static and quasi-dynamic conditions

et al. 2016

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The deformation behavior of IN718 superalloy was investigated using the hot compression tests in the temperature range of 950-1100 °C, and strain rates covering the quasi-static to the quasi-dynamic regions (0.001-10 s-1). The shape of flow curves as well as the corresponding work hardening rates analysis was utilized to reveal the dynamic recrystallization (DRX) phenomena. DRX was the dominant restoration mechanism in the whole temperature and strain rate domains, which was characterized by the optical and EBSD images. Extended flow softening was observed at high strain rates due to the adiabatic heating and dislocations interaction. In addition to the assessment the capability of Sellars equations, a new constitutive equation based on the multiple variable regression analysis was proposed for modeling the peak stress as a function of strain rate and temperature. Besides the simple form of the proposed model, it has a good accuracy for predicting the peak stress.The deformation behavior of IN718 superalloy was investigated using the hot compression tests in the temperature range of 950-1100 °C, and strain rates covering the quasi-static to the quasi-dynamic regions (0.001-10 s-1). The shape of flow curves as well as the corresponding work hardening rates analysis was utilized to reveal the dynamic recrystallization (DRX) phenomena. DRX was the dominant restoration mechanism in the whole temperature and strain rate domains, which was characterized by the optical and EBSD images. Extended flow softening was observed at high strain rates due to the adiabatic heating and dislocations interaction. In addition to the assessment the capability of Sellars equations, a new constitutive equation based on the multiple variable regression analysis was proposed for modeling the peak stress as a function of strain rate and temperature. Besides the simple form of the proposed model, it has a good accuracy for predicting the peak stress.Peer ReviewedPostprint (published version

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Constitutive modeling for predicting peak stress characteristics during hot deformation of hot isostatically processed nickel-base superalloy

Cited by 80 publications

References 43 publications

Dynamic and Post-Dynamic Recrystallization of Haynes 282 below the Secondary Carbide Solvus

Dynamic and Post-Dynamic Recrystallization of Haynes 282 below the Secondary Carbide Solvus

Dynamic recrystallization mechanisms and twining evolution during hot deformation of Inconel 718

Microstructural evolution and constitutive equations of Inconel 718 alloy under quasi-static and quasi-dynamic conditions

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