Evolution of Microstructure and Texture During Hot Compression of a Ni-Fe-Cr Superalloy

Coryell, Stephen; Findley, Kip O.; Mataya, M. C.; Brown, E. L.

doi:10.1007/s11661-011-0889-3

Cited by 57 publications

(13 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It appears that the grains in the Alloy A in the as-annealed sample have stronger orientations (Figure 5a, a double fiber texture with 110 and 111 ) compared to Alloy B (Figure 5b, a fiber texture with 100 ) [41]. Alloy A also exhibits a fiber compression texture 110 , which is consistent with other materials that have face-centered cubic crystal structures [43]. This is also consistent with stress-strain curves for the deformation tests (Figure 3).…”

Section: Microstructure Analysis 421 Microstructure Before Deformationsupporting

confidence: 56%

Effect of Trace Magnesium Additions on the Dynamic Recrystallization in Cast Alloy 825 after One-Hit Hot-Deformation

Al-Saadi

Hulme-Smith

et al. 2020

Metals

View full text Add to dashboard Cite

Alloy 825 is widely used in several industries, but its useful service life is limited by both mechanical properties and corrosion resistance. The current work explores the effect of the addition of magnesium on the recrystallization and mechanical behavior of alloy 825 under hot compression. Compression tests were performed under conditions representative of typical forming processes: temperatures between 1100 and 1250 °C and at strain rates of 0.1–10 s−1 to a true strain of 0.7. Microstructural evolution was characterized by electron backscattered diffraction. Dynamic recrystallization was found to be more prevalent under all test conditions in samples containing magnesium, but not in all cases of conventional alloy 825. The texture direction ⟨101⟩ was the dominant orientation parallel to the longitudinal direction of casting (also the direction in which the samples were compressed) in samples that contained magnesium under all test conditions, but not in any sample that did not contain magnesium. For all deformation conditions, the peak stress was approximately 10% lower in material with the addition of magnesium. Furthermore, the differences in the peak strain between different temperatures are approximately 85% smaller if magnesium is present. The average activation energy for hot deformation was calculated to be 430 kJ mol−1 with the addition of magnesium and 450 kJ mol−1 without magnesium. The average size of dynamically recrystallized grains in both alloys showed a power law relation with the Zener–Hollomon parameter, DD~Z−n, and the exponent of value, n, is found to be 0.12. These results can be used to design optimized compositions and thermomechanical treatments of alloy 825 to maximize the useful service life under current service conditions. No experiments were conducted to investigate the effects of such changes on the service life and such experiments should now be performed.

show abstract

Section: Microstructure Analysis 421 Microstructure Before Deformationsupporting

confidence: 56%

Effect of Trace Magnesium Additions on the Dynamic Recrystallization in Cast Alloy 825 after One-Hit Hot-Deformation

Al-Saadi

Hulme-Smith

et al. 2020

Metals

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

“…The DRX is classified into two categories according to phenomenological classification, i.e., DDRX and CDRX. [ 41 ] The process of CDRX is considered as a dominant nucleation mechanism for the nickel‐based superalloy at low temperature and high strain rate, as discussed previously. It involves the procedures of LAGB array and rearrangement of dislocations during hot deformation.…”

Section: Discussionmentioning

confidence: 99%

“…[40] It is also widely reported that the formation of annealing twins can lower the boundary energy of growing grain and increase the mobility of the grain boundary. [41] Thus, the process of DRX is promoted by the Σ3 boundary. Specifically, the anomalous grain growth may result in nucleation in subgrain boundaries with misorientation lower than 2 at 1200 C. At high temperatures, the migration of grain boundaries leads to abnormal growth between grains, and cell masses will gradually form inside the growing grains, leading to nucleation of a large number of subgrain boundaries.…”

Section: Drx Behavior Of Ni-based Superalloymentioning

confidence: 99%

See 1 more Smart Citation

Hot Deformation Behavior and Dynamic Recrystallization Nucleation Mechanisms of Inconel 625 during Hot Compressive Deformation

Jia

Sun

Ji³

et al. 2021

Adv Eng Mater

View full text Add to dashboard Cite

High‐temperature compression deformation behavior of the Inconel 625 alloy is investigated using hot compression tests. The results regarding the flow behaviors and hot processing map indicate that the optimum condition for plastic deformation is determined to be at temperatures higher that 1050 °C and strain rate from 1 to 10 s−1. Herein, the hot compression microstructure evolution is characterized by electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) techniques. The results indicate that the dynamic recrystallization (DRX) mechanism is different under different compression deformation conditions. At low temperatures (<1100 °C), continuous dynamic recrystallization (CDRX) with subgrain rotation plays a dominant role in the DRX process. However, as the temperature rises beyond 1100 °C, discontinuous dynamic recrystallization (DDRX) with a bulging boundary induced by twinning becomes dominant in the dynamic recrystallization process. The findings provide a theoretical basis for the optimization of the thermoplastic processing of nickel‐based superalloys.

show abstract

“…It was interesting to note that a load drop and secondary yield point were visible on the flow curves of the initial deformation stage at the strain rate of 10 −1 s −1 (Figure 2c,d). This phenomenon is also observed in Ti60 alloy [26] and superalloys [27,28], which could be caused by microstrain dynamic strain aging. Figure 2d,h shows that the flow curves with dynamic recrystallization characteristics were observed at the strain rate of 10 −3 s −1 , indicating that the alloys with two different grain sizes had undergone dynamic recrystallization under these deformation conditions.…”

Section: Methodsmentioning

confidence: 64%

Initial β Grain Size Effect on High-Temperature Flow Behavior of Tb8 Titanium Alloys in Single β Phase Field

Yang

Tan

et al. 2019

Metals

View full text Add to dashboard Cite

The high-temperature flow behavior of TB8 titanium alloys with two different grain sizes was investigated in this present work. Results show that a significant characteristic of stress drop is visible at the start stage of the hot deformation process when the strain rates are 100 and 10−1 s−1. With the further increasing of strain, the flow stress initially rises to a maximum value and subsequently attains a plateau for the strain rates of 100 s−1 and a slight decrease for the strain rates of 10−1 s−1. Only dynamic recovery occurs under these deformation conditions. When the strain rates drop to 10−3 s−1, the dynamic recrystallization takes place during hot deformation. The values of deformation activation energy and materials constants at different strains were calculated. The processing maps at different strains were established for the fine- and coarse-grained alloys. The optimal processing parameter for hot processing was attained to be 900 °C/10−3 s−1 for fine-grained alloys and 950 °C/10−3 s−1 for coarse-grained alloys, respectively.

show abstract

Evolution of Microstructure and Texture During Hot Compression of a Ni-Fe-Cr Superalloy

Cited by 57 publications

References 23 publications

Effect of Trace Magnesium Additions on the Dynamic Recrystallization in Cast Alloy 825 after One-Hit Hot-Deformation

Effect of Trace Magnesium Additions on the Dynamic Recrystallization in Cast Alloy 825 after One-Hit Hot-Deformation

Hot Deformation Behavior and Dynamic Recrystallization Nucleation Mechanisms of Inconel 625 during Hot Compressive Deformation

Initial β Grain Size Effect on High-Temperature Flow Behavior of Tb8 Titanium Alloys in Single β Phase Field

Contact Info

Product

Resources

About