Hot Deformation Behavior and Mechanism of Alloy Inconel 625

2010 ◽  
Vol 650 ◽  
pp. 186-192
Author(s):  
Q.J. Yu ◽  
Wen Ru Sun ◽  
M. Cai ◽  
X.J. Wu ◽  
Shou Ren Guo ◽  
...  
Keyword(s):  
Grain Size ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Critical Strain ◽  
Peak Flow ◽  
Inconel 625 ◽  
Hot Deformation Behavior ◽  
Inconel 625 Alloy

The hot deformation behavior and microstructure of rolled Inconel 625 alloy have been studied from 930°C to 1180°C, and at strain rate from 10 s-1 to 80 s-1, respectively. The results indicate that, as deformation temperature rises, both peak flow stress (PFS) and recrystallization critical strain (RCS) decrease; as the strain rate increases, the PFS is enhanced, but the RCS drops. When the deformation temperature is within 1100°C and 1180°C, the grain size coarsens markedly with the temperature increasing. When the deformation temperature is lower than 1100°C，a higher strain rate is helpful for grain refinement. However, when the temperature is beyond 1100°C,the effect of strain rate on the grain size is reduced.

Hot Deformation Behavior and Microstructure of U720Li Alloy

2013 ◽  
Vol 709 ◽  
pp. 143-147 ◽  
Author(s):  
Tao Wang ◽  
Zhao Li ◽  
Shu Hong Fu ◽  
Yong Zhang ◽  
Yu Xin Zhao ◽  
...  
Keyword(s):  
Grain Size ◽  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Primary Phase ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Fine Grain ◽  
Lower Strain

The hot deformation behavior of U720Li was investigated by isothermal compression tests at temperature ranging from 1060-1180°C and strain rate from 0.001s-1 to 20s-1. The flow stress-strain curves and microstructures were investigated and a constitutive equation was established. It is found that flow stress is sensitive to stain rate and deformation temperature greatly. The higher stain rate resultes in a larger fluctuation in flow stress. The hot deformation activation energy is determined to be 552.8kJ/mol. Grain size increases with increasing temperature and decreases firstly and then increases with increasing strain rate. U720Li alloy should be deformed below the solve temperature of γ primary phase with lower strain rate in order to obtain the even and fine grain size.

Hot Deformation Behavior and Microstructure Evolution of a DC Cast Hypereutectic Al-Si Alloy

2012 ◽  
Vol 151 ◽  
pp. 332-336
Author(s):  
Ke Zhun He ◽  
Fu Xiao Yu ◽  
Da Zhi Zhao ◽  
Liang Zuo
Keyword(s):  
Strain Rate ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Peak Stress ◽  
Strain Rate Range ◽  
Hot Deformation Behavior ◽  
Strong Function ◽  
Primary Si

The hot deformation behavior and microstructure evolution of a DC cast hypereutectic Al-Si alloy was studied in the temperature range of 400-500 °C and strain rate range of 0.001-1 s-1. The results show that the as-cast microstructure of the alloy consists of polygonal primary Si particles and α-aluminum dendritic halos with Al-Si eutectics and intermetallic compounds segregated into the interdendritic regions. The flow stress of the alloy is a strong function of temperature and strain rate, and the peak stress is increased with the decrease of deformation temperature and the increase of strain rate. All the true stress-true stain curves in the experiments exhibit dynamic softening. The fracture frequency of primary Si particle is decreased with the increase of deformation temperature and the decrease of strain rate. The dynamic flow softening is mainly as a result of dynamic recrystallization.

scholarly journals Characterization of Hot Deformation Behavior and Dislocation Structure Evolution of an Advanced Nickel-Based Superalloy

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 920 ◽  
Author(s):  
Zhihao Yao ◽  
Hongying Wang ◽  
Jianxin Dong ◽  
Jinglin Wang ◽  
He Jiang ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Flow Instability ◽  
Processing Condition ◽  
Constitutive Relationship ◽  
Structure Evolution ◽  
Hot Deformation Behavior

The hot deformation behavior of an advanced nickel-based Haynes282 superalloy was systematically investigated employing isothermal compression tests in the sub-solvus and super-solvus temperature with various strain rates. The influence of deformation temperature and strain rate on the microstructure was studied by transmission electron microscope. The results reveal that the interaction between work hardening and dynamic softening did not reach equilibrium under lower deformation temperature and higher strain rate. The active energy of alloy is around 537.12 kJ/mol and its hot deformation constitutive relationship equation was expressed. According to the processing map and microstructure observations, two unsafe flow instability domains should be avoided. The optimum hot processing condition for homogeneous and fine dynamic recrystallization grains are obtained. TEM micrograph observations indicated that deformation temperature and strain rate affected recrystallization by affecting the evolution of dislocation substructures within the alloy. The nucleation and growth of DRX grains can be promoted by the relatively high deformation temperature and low strain rate. The main mechanism of dynamic recrystallization nucleation preferred to discontinuous dynamic recrystallization and the typical feature of discontinuous dynamic recrystallization showed grain boundary migration nucleation. The findings improve the understanding of hot deformation behavior and dislocation substructures evolution of the superalloy, which benefits the accurate control of microstructures of nickel-based superalloys, and tailors the properties of final components used in the land-based gas turbine.

Hot Deformation Behavior of A390 Hypereutectic Al-Si Alloy

2013 ◽  
Vol 749 ◽  
pp. 88-95 ◽  
Author(s):  
Xiao Gang Hu ◽  
Bi Cheng Yang ◽  
Jun Xu ◽  
Hai Jun Wang
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Primary Silicon ◽  
Simulation Test ◽  
Hot Deformation Behavior ◽  
Deformation Activation Energy ◽  
Relationship Of ◽  
The Relationship

The hot deformation behavior of hypereutectic aluminium-silicon alloy was investigated by thermal simulation test at the deformation temperature of 330-480 and the strain rate of 0.1-10s-1using the Gleeble-1500 thermal mechanical simulator. The relationship of flow stress, temperature and strain rate was appropriately described by the deformation constitutive equation, and the deformation activation energy is 187.418 KJ/mol. In addition, the microstructures of these specimens were analyzed and the result showed that the inhomogeneous deformation enhances with increasing strain rate and decreasing deformation temperature, and the presence of primary silicon had a strong influence on the uneven deformation.

Hot deformation behavior and dynamic recrystallization constitutive modeling of Al–Cu–Mg powder compacts processed by extrusion at elevated temperatures

2020 ◽  
pp. 146442072097132
Author(s):  
Katti Bharath ◽  
Asit Kumar Khanra ◽  
MJ Davidson
Keyword(s):  
Powder Metallurgy ◽  
Flow Stress ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Relative Density ◽  
Constitutive Equations ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Peak Flow ◽  
Hot Deformation Behavior

The deformation behavior of Al–Cu–Mg sintered preforms has been investigated by extrusion in the temperature range of 450–550°C and strain rate range of 0.1–0.3 s−1, respectively. The aim of this study is to analyze the effect of initial preform relative density on the hot deformation behavior and to model and predict the flow stress of extruded samples using constitutive equations. The true stress–strain curves exhibit three stages of deformation, which represent work hardening, dynamic recovery, and dynamic recrystallization during deformation at different temperatures, strain rates, and initial preform relative densities of 70%, 80%, and 90%, respectively. The results show that the flow stress values are influenced by initial preform relative density, deformation temperature, and strain rate. Microstructural examination of extruded specimens has been performed by optical microscopy and scanning electron microscopy. Arrhenius-type constitutive equations are developed to predict the flow stress of hot-extruded powder metallurgy processed aluminum alloy (Al–4%Cu–0.5%Mg). Zener–Hollomon parameter is used to explain the relationship between peak flow stress, temperature, and strain rate in an exponential equation containing the deformation activation energy and material constants. Subsequently, the statistical indicators correlation coefficient ( R) and the average absolute relative error are assessed to confirm the validity of constitutive equations. The results indicate the experimental and predicted peak flow stress values are in good agreement, which indicate the accuracy and reliability of the developed model for powder metallurgy processed Al–4%Cu–0.5%Mg preforms.

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.

The effects of temperature and strain rate on the hot deformation behavior of AISI H10 tool steel

2020 ◽  
Vol 118 (1) ◽  
pp. 107
Author(s):  
Maryam Kamali Ardakani ◽  
Maryam Morakabati
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Tool Steel ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Strain Rates ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Temperature Range

The hot deformation behavior of a H10 hot work tool steel was studied by performing hot compression tests over the temperature range of 900 to 1200 °C and strain rates of 0.001–1 s−1 and total strain of 0.7. At temperatures below 1100 °C, the grain size is fine and below 20 μm. In this temperature range, grain size increase with temperature due to dissolution of carbides. Then by increasing temperature to 1150 and 1200 °C, the grain size is increased significantly due to growth of grains. The study on the effect of strain rate showed that at constant temperature of 1000 °C, the grain size increased from 4.8 to 6 μm with increasing strain rate from 0.001 to 1 s−1. Also, this increase in the strain rate at temperature of 1100 °C lead to increase the grain size from 5.9 to 17 μm, due to the occurrence of dynamic recrystallization. At 1200 °C growth of grains causes to decrease grain size from 112 to 87 μm by increasing strain rate. According to the microstructural investigations, at the temperatures of 1000 and 1100 °C and strain rates of 0.01 and 0.1 s−1 dynamic recrystallization was the main softening mechanism. As a result, the most suitable range for hot deformation was obtained at the temperature range of 1000–1100 °C and strain rates of 0.01–0.1 s−1.

Flow Stress Behavior of the Normalized and Tempered as-Cast 42CrMo Steel during Hot Deformation

2011 ◽  
Vol 314-316 ◽  
pp. 2560-2564 ◽  
Author(s):  
Hui Ping Qi ◽  
Yong Tang Li ◽  
Jia Fu ◽  
Zhi Qi Liu
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Deformation Process ◽  
True Stress ◽  
Hot Deformation Behavior ◽  
Simulation Experiments ◽  
42Crmo Steel

The purpose of this study is to find the hot deformation behavior of as-cast 42CrMo steel. The thermal simulation experiments of as-cast 42CrMo steel were done on the Gleeble-1500 thermo-mechanical simulation machine. The hot deformation behavior of as-cast 42CrMo steel was analyzed. The true stress-strain curves in hot deformation at different deformation temperature (850°C,950°C,1050°C,1150°C), different strain rate (0.05S-1, 0.5 S-1, 1 S-1,5 S-1) were obtained. The influence rules of the deformation temperature and strain rate on the curves were analyzed. The analysis shows that the true stress increases with increase of deformation temperature and decrease of stain rate. The hot deformation behavior of as-cast 42CrMo steel was compared with forged 42CrMo steel. The results show that the flow stress of as-cast 42CrMo steel during hot deformation was higher than that of the forged 42CrMo steel. Compared to the forged 42CrMo steel, the dynamic recrystallization in as-cast 42CrMo steel during hot deformation is more difficult to occur. The above conclusions have significant theoretical and practical meanings for the design of hot deformation process of as-cast 42CrMo steel.

Hot Deformation Behavior and Microstructure Evolution of GH625 Superalloy Tube during Extrusion Process

2011 ◽  
Vol 291-294 ◽  
pp. 640-644
Author(s):  
Qing Miao Guo ◽  
De Fu Li ◽  
Sheng Li Guo ◽  
Guo Ling Xie
Keyword(s):  
Strain Rate ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Flow Behavior ◽  
Outer Wall ◽  
Extrusion Process ◽  
Compression Tests ◽  
Hot Deformation Behavior

Flow behavior and microstructures of GH625 superalloy were investigated by hot compression tests. Then the GH625 superalloy tube was hot extruded according to the hot deformation behavior, and the microstructures of different position of extruded tube was also analyzed. The results show that the actual deformation temperature of the specimen deformed at a strain rate of 10.0s-1 is higher than the preset temperature, resulting in a deformation thermal effect. Thus, the microstructure evolution of GH625 superalloy is controlled both by the strain rate and deformation temperature. It is also found that the GH625 superalloy tube can be successfully fabricated with a stable extrusion speed of 40 mm·s-1, extrusion ratio of 4.1 and preheating temperature of 1200°C. The microstructure of extruded tube was obviously fined due to the occurrence of dynamic recrystallization(DRX). Different degrees of DRX were observed in outer wall, center and inner wall of the tube, which is similar to that in the head, middle and tail of the tube. An extruded tube containing fully DRX grains can be obtained by cutting the head and tail of the tube, and machining a small amount of the inner wall.

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