Hot deformation behavior and dynamic recrystallization of GH690 nickel-based superalloy

2020 ◽  
Vol 847 ◽  
pp. 156507 ◽  
Author(s):  
Yingjie Li ◽  
Ying Zhang ◽  
Zhiying Chen ◽  
Zhongchao Ji ◽  
Hongyang Zhu ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Hot Deformation Behavior ◽  
Nickel Based Superalloy

A Novel Unified Dislocation-Density Based Model for Hot Deformation Behavior of a Nickel-Based Superalloy

2016 ◽  
Vol 853 ◽  
pp. 117-121 ◽  
Author(s):  
Y.C. Lin ◽  
Dong Xu Wen
Keyword(s):  
Grain Size ◽  
Dislocation Density ◽  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Metallic Materials ◽  
Hot Deformation Behavior ◽  
Nickel Based Superalloy ◽  
Size Evolution

In hot forming processes, metallic materials often undergo a series of plastic deformation and heat treatments. Hot working parameters, including deformation temperature, strain rate, and strain, exert great impacts on hot deformation behavior of alloys. Work hardening (WH), dynamic recovery (DRV), dynamic recrystallization (DRX), phase transformation, and metadynamic recrystallization (MDRX) often take place, and affect hot deformation behavior of metallic materials. Therefore, a comprehensive investigation on the intrinsic interactions between microstructural evolution and hot deformation behavior is necessary. In this study, a novel unified dislocation-density based model is presented to characterize the hot deformation behavior of a nickel-based superalloy In the Kocks-Mecking model, a new softening item is proposed to represent the impacts of dynamic recrystallization behavior on dislocation density evolution. The grain size evolution and dynamic recrystallization kinetics are incorporated into the developed model. Material parameters of the developed model are calibrated by a derivative-free method in MATLAB toolbox. Comparisons for the experimental and predicted results confirm that the developed unified model can accurately reproduce the hot deformation behavior, DRX kinetics, and grain size evolution in wide scope of initial grain size, deformation temperature, and strain rate.

scholarly journals Hot Deformation Behavior Considering Strain Effects and Recrystallization Mechanism of an Al-Zn-Mg-Cu Alloy

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1743 ◽  
Author(s):  
Lei Luo ◽  
Zhiyi Liu ◽  
Song Bai ◽  
Juangang Zhao ◽  
Diping Zeng ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Processing Parameters ◽  
Strain Rate Range ◽  
Hot Compression ◽  
Processing Maps ◽  
Hot Deformation Behavior ◽  
Recrystallization Mechanism ◽  
Cu Alloy

The hot deformation behavior of an Al-Zn-Mg-Cu alloy was investigated by hot compression test at deformation temperatures varying from 320 to 440 °C with strain rates ranging from 0.01 to 10 s−1. The results show that the Mg(Zn, Cu)2 particles as a result of the sufficient static precipitation prior to hot compression have an influence on flow softening. A constitutive model compensated with strain was developed from the experimental results, and it proved to be accurate for predicting the hot deformation behavior. Processing maps at various strains were established. The microstructural evolution demonstrates that the dominant dynamic softening mechanism stems from dynamic recovery (DRV) and partial dynamic recrystallization (DRX). The recrystallization mechanism is continuous dynamic recrystallization (CDRX). The microstructure observations are in good agreement with the results of processing maps. On account of the processing map and microstructural observation, the optimal hot processing parameters at a strain of 0.6 are at deformation temperature range of 390–440 °C and strain rate range of 0.010–0.316 s−1 with a peak efficiency of 0.390.

scholarly journals Hot Deformation Behavior of Cu–Sn–La Polycrystalline Alloy Prepared by Upcasting

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3739
Author(s):  
Siming Hua ◽  
Pingze Zhang ◽  
Zili Liu ◽  
Lin Yang
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Testing Machine ◽  
Shear Bands ◽  
Strain Curve ◽  
Extrusion Process ◽  
Hot Deformation Behavior ◽  
Polycrystalline Alloy ◽  
Promising Application

In this study, the hot deformation of a Cu–0.55Sn–0.08La (wt.%) alloy was studied using a Gleeble-3180 testing machine at deformation temperatures of 400–700 °C and various strain rates. The stress–strain curve showed that the hot deformation behavior of the Cu–0.55Sn–0.08La (wt.%) alloy was significantly affected by work hardening, dynamic recovery, and dynamic recrystallization. The activation energy Q was 261.649 kJ·mol−1 and hot compression constitutive equation was determined as  ε˙=[sinh(0.00651σ)]10.2378·exp(33.6656−261.649RT). The microstructural evolution of the alloy during deformation at 400 °C revealed the presence of both slip and shear bands in the grains. At 700 °C, dynamic recrystallization grains were observed, but recrystallization was incomplete. In summary, these results provide the theoretical basis for the continuous extrusion process of alloys with promising application prospects in the future.

Effect of pre-treatment on hot deformation behavior and processing map of an aged nickel-based superalloy

2015 ◽  
Vol 649 ◽  
pp. 1075-1084 ◽  
Author(s):  
Dao-Guang He ◽  
Y.C. Lin ◽  
Ming-Song Chen ◽  
Jian Chen ◽  
Dong-Xu Wen ◽  
...  
Keyword(s):  
Hot Deformation ◽  
Deformation Behavior ◽  
Processing Map ◽  
Hot Deformation Behavior ◽  
Nickel Based Superalloy ◽  
Pre Treatment

scholarly journals Effect of Nitrogen Content on Hot Deformation Behavior and Grain Growth in Nuclear Grade 316LN Stainless Steel

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ming-wei Guo ◽  
Zhen-hua Wang ◽  
Ze-an Zhou ◽  
Shu-hua Sun ◽  
Wan-tang Fu
Keyword(s):  
Stainless Steel ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Grain Growth ◽  
Strain Rate Sensitivity ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Rate Sensitivity ◽  
Processing Maps ◽  
Hot Deformation Behavior

316LN stainless steel with 0.08%N (08N) and 0.17%N (17N) was compressed at 1073–1473 K and 0.001–10 s−1. The hot deformation behavior was investigated using stress-strain curve analysis, processing maps, and so forth. The microstructure was analyzed through electron backscatter diffraction analysis. Under most conditions, the deformation resistance of 17N was higher than that of 08N. This difference became more pronounced at lower temperatures. The strain rate sensitivity increased with increasing temperature for types of steel. In addition, the higher the N content, the higher the strain rate sensitivity. Hot deformation activation energy increased from 487 kJ/mol to 549 kJ/mol as N concentration was increased from 0.08% to 0.17%. The critical strain for initiation of dynamic recrystallization was lowered with increasing N content. In the processing maps, both power dissipation ratio and unstable region increased with increasing N concentration. In terms of microstructure evolution, N promoted dynamic recrystallization kinetic and decreased dynamic recrystallization grain size. The grain growth rate was lower in 17N than in 08N during heat treatment. Finally, it was found that N favored twin boundary formation.

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