Peak Efficiency Of Power Dissipation Research Articles

Delineating the role of dynamic and static recrystallization during hot working of nickel-based superalloy (IN600)

In the presented research, the dynamic working of nickel-based (IN600) superalloy was performed and the micro-mechanisms affecting the deformation behaviour were closely monitored, particularly the role of static and dynamic recrystallization. Hot deformation flow stress response indicated an increase in the true stress value with an increase in strain rate and decrease in temperature. The constitutive calculations indicated that deformation progressed mainly due to dislocation climb motion. The hot workability map indicated a peak power dissipation efficiency (PDE) of 0.39 in two working domains. The microstructural evolution in the hot deformed specimens depicted a consistent increase in dynamic softening at temperature ≥ 1000 °C, whereas, a steady decline in the extent of dynamic softening is observed with increase in strain rate from 0.01 s−1 to 1 s−1. The mechanism for microstructural evolution in this range (0.01–1 s−1) was identified as discontinuous dynamic recrystallization (DDRX). Moreover, at the highest strain rate of 10 s−1, a sudden surge in the recrystallization fraction was observed, which was attributed to the combined effect of DDRX and static recrystallization (SRX). Additionally, this study shows that the presence of twin boundaries (TBs) contributes to dynamic softening by serving as sites for nucleation of strain-free grains.

Hot Deformation Behavior of a Novel Cr–Mo–V Hot Work Die Steel

Herein, high‐temperature hot compression tests are carried out to investigate the hot deformation behavior of a novel Cr–Mo–V hot work die steel. Meanwhile, a strain compensation Arrhenius constitutive equation is created, and the fitting correlation coefficient R between the experimental and predicted values is 0.98921, with a mean average absolute relative error (AARE) of 3.82%. According to the results, the hot deformation constitutive equation of the novel Cr–Mo–V steel can predict the flow stress of hot deformation with high accuracy. Furthermore, the equations for critical stress (strain), peak stress (strain), and Zener–Holomon parameters are constructed, and they demonstrate a satisfactory linear fit. Additionally, a hot processing map of the novel Cr–Mo–V steel is developed at strains of 0.4, 0.5, 0.6, and 0.7. By analyzing the hot processing map and viewing the microstructure, this study concludes that the optimal hot processing parameters of the novel Cr–Mo–V steel are 1050–1150 °C and 0.8–1 s−1 at a strain of 0.7, with a peak power dissipation efficiency of nearly 0.68.

An investigation on the hot workability and microstructural evolution of a novel dual-phase Mg–Li alloy by using 3D processing maps

Hot compression tests of a novel dual-phase Mg–Li alloy were performed in temperature range of 200–400 °C and strain rate range of 0.01–10s−1. 2D and 3D processing maps were established using Prasad's and Murty's instability criteria (methods) based on the dynamic materials model. It was found that one instability region obtained based on Prasad's instability criterion exist in the domain of power dissipation efficiency at a strain of 0.7. Prasad's and Murty's instability criteria are difficult to accurately characterize the instability characteristics of the alloy. The accuracy processing map rectified was obtained by means of Murty's and Prasad's instability criteria and microstructural analysis. On the basis of the processing map rectified, the optimum hot working parameters were obtained to be the temperature range of 320–400 °C and strain rate range of 0.01–0.4s−1 with the peak power dissipation efficiency. In this domain, the α phase undergone dynamic recrystallization (DRX) and dynamic recovery (DRV). The β-phase occurred DRX during the hot deformation. The instability regions lie in the temperature range of 200–250 °C with strain rate range of 0.01–1s−1 and the temperature range of 200–312 °C with strain rate range of 1–10s−1. Microstructural observations indicate that characteristics of the flow instabilities were flow localization, deformation twinning, the adiabatic shear bands and macro/micro cracking. The rectified processing map was successfully verified by the hot rolling test. The rectified processing map could accurately characterize workability characteristics of a novel dual-phase Mg–Li alloy and could be used for the optimization of hot working process parameters.

Hot Deformation Behavior and 3D Processing Maps of Mn18Cr18N Steel

The isothermal hot deformation behavior in the ranges of 1023–1473 K (750–1200 °C) and 0.001–10 s−1 for 0.53 wt% N‐bearing Mn18Cr18N steel is studied with a Gleeble‐3500 thermomechanical simulator. The results indicate that the peak stress decreases with decreasing strain rate and increasing temperature. The calculated deformation activation energy of the experimental steel is 449.118 kJ mol−1 by regression analysis. At the same time, 3D processing maps are established based on experimental data and the principles of the dynamic materials model. The domain of stable deformation gradually expands with the increase in strain, while the instability region shrinks accordingly. From the microstructure of specimens and the processing maps established, it is clear that dynamic recrystallization emerges in the peak power dissipation efficiency domain, 1000–1150 °C/0.002–0.1 s−1, which is the optimum region of hot working of the steel.

Hot deformation behaviors of AZ91 magnesium alloy: Constitutive equation, ANN-based prediction, processing map and microstructure evolution

The hot deformation behavior in an AZ91 magnesium alloy was studied using Arrhenius model and Back-Propagation Artificial Neural Network (BP-ANN) approaches. The hot compression tests of AZ91 alloy were performed on the MMS-300 simulator at deformation temperatures and strain rates in the range of 473–623 K and 0.001 s −1 - 1 s −1 , respectively. The results indicated that the BP-ANN model has higher accuracy than Arrhenius model and the correlation coefficient is as high as 0.99341. The processing map is divided into three parts: machinable area (A), instability area I (INS I) (B) and instability area II (INS II) (C). The instability mode of areas B and C gradually changes from cracks to holes with the increase of temperature or the decrease of strain rate. The stable hot-deformation conditions with peak efficiency of power dissipation were concentrated in the range of 523 K, 0.01 s −1 , 573 K, 0.01 s −1 , 623 K, 0.001–1 s −1 , respectively. With the increase of temperature, the deformation mechanism changed from twinning to dynamic recrystallization (DRX), which is discontinuous dynamic recrystallization (DDRX). Due to DRX,< 0001 > // CD texture intensity increased with the increase of temperature, and then decreased. ● BP-ANN is used to predict stress and strain. ● Instability mode: crack and hole. ● Deformation mechanism: twinning, slip and DRX.

Hot Deformation Behavior and Microstructural Evolution Based on the Processing Map of Dual-Phase Mg-Li Based Alloy.

The deformation behavior of the as-extruded Mg-Li-Al-Zn-Si alloy was studied by conducting a hot compression test, with a temperature range of 180–330 °C and a strain rate range of 0.01–10 s−1. The constitutive relationship of flow stress, temperature, and strain rate was expressed by the Zener–Hollomon parameter and included the Arrhenius term. By considering the effect of strain on the material constants, the flow stress at 240–330 °C could be precisely predicted with the constitutive equation (incorporating the influence of strain). A processing map was established at the strain of 0.7. The unsafe domains that are characterized by uneven microstructures were detected at low temperatures (<230 °C) or high temperatures (>280 °C), with high strain rates (>1 s−1). The optimum hot deformation region was obtained at a medium temperature (270–300 °C), with a peak power dissipation efficiency of 0.44. The microstructural evolution in different domains is investigated. The unstable domains are characterized by a non-uniform flow behavior and uneven microstructure. The observation showed that the dynamic recrystallization (DRX) process could easily occur at the safe domain with high power dissipation efficiency. For the α-phase, some features of continuous dynamic recrystallization can be found. The triple points serve as prominent nucleation sites for the β-phase DRX grains and the growth in the grains was carried out by subgrain boundary migration. The microstructure exhibits characteristics of discontinuous dynamic recrystallization.

Hot deformation behavior and microstructure evolution of an Fe–30Cr–2Mo ultra-pure super ferritic stainless steel

The hot deformation behavior and microstructure evolution of an Fe–30Cr–2Mo ultra-pure super ferritic stainless steel were investigated at the temperature range of 950–1150 °C and strain rate varying from 0.01 to 10 s−1. A strain compensated constitutive equation based on the Arrhenius-type model was established to predict the flow stress. The hot processing map based on the dynamic materials model was achieved to identify the optimum processing parameters. In addition, the features of microstructure evolution combined with the processing map were systematically investigated. The experimental results revealed that the flow stress increased with decreasing deformation temperature or increasing strain rate. Dynamic recovery was confirmed to be the predominant softening mechanism. The values of flow stress predicted by the strain compensated constitutive equation agreed well with the experimental values. The extent of dynamic recrystallization and recrystallized grain size increased with increasing deformation temperature or decreasing strain rate, and the continuous dynamic recrystallization was attributed to be the predominant mechanism of recrystallization during hot deformation. The optimum hot working parameters were determined to be the deformation temperature of 1070–1150 °C and strain rate of 0.1–1 s−1 with a peak power dissipation efficiency of 42%.

Hot deformation behavior and mechanism of a new metastable β titanium alloy Ti–6Cr–5Mo–5V–4Al in single phase region

Abstract A new metastable β titanium alloy Ti–6Cr–5Mo–5V–4Al (Ti-6554) has shown good application potential in large parts. In order to study the hot deformation behavior and mechanism of the Ti-6554 alloy in the β single phase region, hot compression tests were carried out at temperatures of 800–950 °C and strain rates of 0.001–10 s−1 on the Gleeble-3500 thermal simulation machine. Strain-compensated Arrhenius constitutive model was used to predict the flow behavior of the alloy, and the correlation coefficient between the experimental and predicted values reached 0.982. Based on the hot processing map, it was found that the instability region was mainly concentrated in the high strain rate area, and the peak efficiency of power dissipation (η) region occurs in the temperature range of 913–928 °C and the strain rate of 0.001–0.0025 s-1. There was an obvious DRX phenomenon in the stability region, while the instability region was dominated by deformation band (DB) and flow localization (FL). The continuous dynamic recrystallization (CDRX) by progressive rotation of subgrains and discontinuous dynamic recrystallization (DDRX) by grain boundaries bulging could be observed. DDRX mainly occurred in high temperature and low strain rate regions, while the CDRX process occurred in the high strain rate region. As the η decreased, the deformation mechanism changed from DDRX to CDRX and further to dynamic recovery (DRV), DB, FL.

Hot deformation behavior and processing map of a new type Mg-6Zn-1Gd-1Er alloy

The hot deformation behavior of a new type Mg-6Zn-1Gd-1Er alloy was investigated in the temperature range of 180 ℃–380 ℃ and strain rate of 10−3 s−1–10 s−1 with the Gleeble-3500 thermal simulation testing machine. The true stress-strain curves showed that flow stress increased with the increasing of strain rate and decreasing of temperature. The constitutive equations based on hyperbolic sine equation were used to demonstrate the flow stress of two intervals of medium-high and low temperature deformation for this alloy. Processing maps were developed based on the experimental data of true strains of 0.2, 0.4, 0.6 and 0.8, which the optimal processing parameters were determined as 330 ℃–380 ℃ and 0.001 s−1–0.1 s−1. Microstructure analysis based on the strain rate corresponding to peak efficiency of power dissipation of processing map found that twinning was the dominate deformation mechanisms during low temperature deformation. With the increasing of temperature, a typical necklace-typed microstructure resulted by continuous dynamic recrystallization (CDRX) was formed. When the temperature was up to 380 ℃, the electron backscatter diffraction (EBSD) results of stable region showed that a typical discontinuous dynamic recrystallization (DDRX) and CDRX were the main deformation mechanisms, and formation a strong<0001>//CD texture together with secondary weaker texture component. At the instability region, it can be found that CDRX and twinning were the main deformation mechanisms, and an obvious bimodal texture formed at 380 ℃/10 s−1.

Hot deformation behaviours and spheroidization mechanisms of Ti-5322 alloy during hot compression

The hot deformation behavior of Ti-5322 alloy are researched at compression temperatures range of 750–1050 °C and strain rate range of 0.01–10 s−1, to optimize its hot workability. Processing map analysis and microstructure observations reveal that the optimal processing parameters of Ti-5322 alloy are temperatures of 750–825 °C and strain rates of 0.01–0.05 s−1, and temperatures of 925–975 °C and strain rates of 0.01–1 s−1. The peak efficiency of power dissipation can reach 40% owing to the transformation from α phase to β phase, spheroidization behavior and dynamic recrystallization of the β phase. The dynamic recrystallization was the primary form of microstructure evolution above 900 °C, while the spheroidization of α phase below 900 °C. The spheroidization of α lamellae can be attributed to the instability of subgrain boundaries appeared in the α phase during hot deformation. The β phase wadges into the α/α subgrain boundary and α/β interface migration induced the α phase spheroidization. In addition, three instability domains are detected in the processing maps, which confirmed by the presence of microstructures with wedge cracking and adiabatic shear bands.

Constitutive Equation and Hot Processing Map of a Nitrogen-Bearing Martensitic Stainless Steel

The hot deformation behavior of a nitrogen-bearing martensitic stainless steel was researched by the isothermal compression test in the temperature range of 950–1150 °C and strain rate range of 0.01–10 s−1 with a Gleeble-3800 thermal-mechanical simulating tester. A strain compensated sine-hyperbolic Arrhenius-type constitutive equation was developed to describe the relationship between true stress and deformation parameters such as temperature, strain rate and true strain. The hot deformation activation energy is calculated to be from 407 to 487 KJ mol−1. It is validated by the standard statistical parameters that the established constitutive equation can accurately predict the true stress. The processing maps at different true strains were constructed based on the dynamic material model (DMM) and the true stress data obtained from the hot compression tests. Two unstable regions which should be avoided during hot working were observed from the processing map. In addition, the optimum hot working parameters are located in the domain of 1000–1150 °C/0.1–1 s−1 with the peak power dissipation efficiency of 39.9%, in which complete dynamic recrystallization (DRX) occurs.

The hot deformation behavior and 3D processing maps of 25Cr2Ni4MoV steel for a super-large nuclear-power rotor

According to the characteristics of open die forging for heavy forgings, the compression tests in the temperature range of 1373−1523 K and strain rate range of 0.001−0.1 s −1 were finished for investigating the hot deformation behavior of 25Cr2Ni4MoV steel for a super-large nuclear-power rotor. The deformation activation energy was calculated about 356.79 KJ/ mol. The 3D processing maps were established based on dynamic materials model to reveal the hot workability. According to the processing maps, when the strain is less than 0.5, the processing map were strongly influenced by the temperature, strain rate and strain. At the strain of 0.9, the processing map was divided into four regions for researching the microstructure evolution. Defects such as mixed grain and large grain were observed at relatively high or low strain rates. 25Cr2Ni4MoV steel is not suitable to be processed at temperatures exceeding 1473 K. The optimum hot working domain was the area of 1378−1423 K/0.0067 s -1 -0.01 s -1 with a peak power dissipation efficiency of about 0.5.

Hot Deformation Characteristics and Processing Map of 1Cr12Ni2Mo2WVNb Martensitic Stainless Steel

Herein, the hot deformation behavior of 1Cr12Ni2Mo2WVNb martensitic stainless steel is investigated through the high‐temperature thermal compression test. Meanwhile, a strain‐compensated Arrhenius constitutive equation is established. The correlation coefficient R between the predicted value and the experimental value is 0.994, and the average absolute relative error (AARE) (%) value is calculated to be 3.7845%. These results show that the improved constitutive model of 1Cr12Ni2Mo2WVNb steel achieves a higher accuracy in predicting the flow stress value. Moreover, the equation regarding the peak stress (strain), the critical stress (strain), and the Zener–Holomon parameter is constructed, which exhibits good linearity. In addition, the hot processing maps of 1Cr12Ni2Mo2WVNb steel under the strains of 0.3, 0.4, 0.5, and 0.6 are also established, respectively, based on the compression test. According to the processing map and microstructural observation, it is concluded that the optimal processing conditions for 1Cr12Ni2Mo2WVNb steel are determined as follows: a temperature of 1070–1100 °C, a strain rate of 0.8–1 s−1, and a peak power dissipation efficiency of about 0.34.

The hot deformation behavior, microstructure evolution and texture types of as-cast Mg–Li alloy

Abstract In this study, aiming to systematically investigate the hot deformation mechanism, microstructure evolution and texture types of Mg–5Li–3Al–2Zn (LAZ532) alloy, and confirm the optimum constitutive model and hot working conditions of LAZ532 alloy. The hot compression test of LAZ532 alloy was performed on Gleeble-3500 simulator at deformation temperatures and strain rates in the range of 200 °C –350 °C and 0.001 s−1–1 s−1, respectively. The experimental results showed that the established optimum constitutive model could accurately predict the hot deformation behavior of LAZ532 alloy, and the stable hot-deformation zones with peak efficiency of power dissipation were concentrated in the zones range of 300 °C , 1 s−1, 0.001 s−1–0.01 s−1 and 350 °C , 0.01 s−1–0.1 s−1, respectively. By observing the microstructure of the alloy showed that the dynamic recrystallization (DRX) mechanism could be considered to be discontinuous dynamic recrystallization (DDRX), and the recrystallization degree increases with the increasing of deformation temperatures or decreasing of strain rates. Moreover, based on EBSD analysis, it was found that both the deformed microstructure and recrystallization microstructure in the alloy had a //CD texture, and a few {10 1 ¯ 2} extension twins were observed in the coarse deformed grains.

Characterization of Ti-25.5Al-13.5Nb-2.8Mo-1.8Fe Alloy Hot Deformation Behavior Through Processing Map

The isothermal compression tests of Ti-25.5Al-13.5Nb-2.8Mo-1.8Fe (at.%) alloys were executed under the deformation temperature ranges of 950-1100 C with the strain rate ranges of 0.001-1 s-1, for total height reduction of 0.5. The isothermal compression deformation behavior was investigated based on flow stress curves, dynamic model analysis. The processing map of Ti-25.5Al-13.5Nb-2.8Mo-1.8Fe alloy was obtained for the optimum hot process parameters. The calculated value of Q (activation energy) was 634.5 kJ/mol. The constitutive model of the alloy was constructed. Based on DMM and the Prasad flow instability criteria, the hot processing map was established with strain of 0.7. The deformation mechanisms were interpreted by microstructural observation within both stable and instability zones. Processing map showed a stable region under the deformation temperature ranges of 950-1100 C with the strain rate ranges of 0.001-1 s-1. One certain maximum power dissipation efficiency value was approximately 43 % occurred at 950 C/0.001 s-1. Another peak power dissipation efficiency value was about 58 % at 1050 C/0.001 s-1. Both areas were the optimum processing regions. Furthermore, while the strain rate value exceeded 1 s-1, the alloy sustained deformation instability phenomenon, such as shearing band or flow localization.

Hot Deformation Characteristics and Processing Map Analysis of Pre-Forged AZ80 Magnesium Alloy

The hot deformation behavior of pre-forged AZ80 magnesium alloy is investigated by the isothermal compression tests at temperatures of 523–683 K and strain rates of 0.0001–0.1 s−1, and analyzed by the processing maps for guiding isothermal die forging. Flow localization and even cracking occurs at low temperatures and high strain rates, where shear deformation degree shows a positive correlation with the $$\xi \left( {\dot{\varepsilon }} \right)$$ value. Two stability regions with high efficiency is found out by the processing maps. At common stability region with high temperatures and low strain rates, peak power dissipation efficiency does not represent optimum deformation condition as reported in other materials. A Z parameter criterion is introduced for parameters optimization. javascript:void(0); a new stability domain of 523–590 K and 0.0001–0.01 s−1 is observed, which is typical for fine microstructure composed of equiaxed clean α-Mg grains and big particles both about 1 µm (573 K/0.01 s−1). Super plasticity is speculated to occur at that condition.

Hot Deformation Behavior and Processing Map of a Cu-Bearing 2205 Duplex Stainless Steel

The hot deformation behavior and processing map of Cu-bearing 2205 duplex stainless steel (2205-Cu DSS) were investigated at temperatures of 950–1150 °C and strain rates of 0.01–10 s−1. The effects of Cu addition and different deformation parameters on deformation behavior were, respectively, characterized by analyzing flow curves, constitutive equations and microstructures. The results indicated that the shapes of flow curves strongly depended on the volume fraction of two phases. When deformed at low strain rate, DRV in ferrite was prompted with increase in the temperature and was further developed to continuous DRX. At high strain rate, flow localization preferentially occurred in ferrite at low deformation temperature due to the strain partitioning and relatively less fraction of ferrite. The activation energy for 2205-Cu DSS was 452 kJ/mol and was found to connect with the variation of strain, strain rate and deformation temperature. The optimum hot deformation parameters for 2205-Cu DSS were obtained in the temperature range of 1100–1150 °C and strain rate range of 0.1–1 s−1 with a peak power dissipation efficiency of 41%. Flow localization was the main way to lead to flow instability. Meanwhile, the Cu-rich precipitates were generated within a few ferrite grains when deformed at temperature lower than 1000 °C. The interaction between dislocations and Cu-rich precipitates at high strain rate, as well as the limited DRV in ferrite and DRX in austenite, contributed to the complex microstructure and flow behavior.

Characterization of Microstructural Evolution for a Near-α Titanium Alloy with Different Initial Lamellar Microstructures

The effects of initial lamellar thickness on microstructural evolution and deformation behaviors of a near-α Ti-5.4Al-3.7Sn-3.3Zr-0.5Mo-0.4Si alloy were investigated during isothermal compression in α + β phase field. Special attention was paid to microstructural conversion mechanisms for α lamellae with different initial thicknesses. The deformation behaviors, including flow stress, temperature sensitivity, and strain rate sensitivity, and processing maps and their dependence on initial lamellar thickness were discussed. The detailed microstructural characterizations in different domains of the developed processing maps were analyzed. The results showed that the peak efficiency of power dissipation decreased with increasing initial lamellar thickness. The interaction effects with different extents of globularization, elongating, kinking, and phase transformation of lamellar α accounted for the variation in power dissipation. The flow instability region appeared to expand more widely for thicker initial lamellar microstructures during high strain rate deformation due to flow localization and local lamellae kinking. The electron backscatter diffraction (EBSD) analyses revealed that the collaborative mechanism of continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) promoted the rapid globularization behavior for the thinnest acicular initial microstructure, whereas in case of the initial thick lamellar microstructure, CDRX leading to the fragmentation of lamellae was the dominant mechanism throughout the deformation process.

Effects of second phases on deformation behavior and dynamic recrystallization of as-cast Mg-4.3Li-4.1Zn-1.4Y alloy during hot compression

Hot compression and dynamic recrystallization (DRX) behavior corresponding to the second phases of as-cast Mg-4.3Li-4.1Zn-1.4Y (wt.%) alloy was investigated in the range of 250–450 °C and 0.001–10 s−1. True strain-true stress curves showed typical characteristics DRX process. Constitutive relationship yielded an average activation energy (Q) and stress exponent (n) of 147.183 kJ/mol and 5.49, respectively. The hot deformation was mainly controlled by climb of edge dislocations, which turned into cross-slip of screw dislocations at ≥400 °C. The volume fraction of second phases changed the dislocation movement and resulted in the variation of the rate-controlling mechanism. The peak power dissipation efficiency (η) was observed at 450 °C/0.1 s−1 (32%), and the corresponding uniform and fine microstructure was attributed to the dynamic precipitation and complete DRX from uniformly distributed second phase particles. A wide flow instability region was observed at all temperatures and relatively high strain rates, corresponding to the non-uniform microstructure of the incomplete DRX and deformation band composed of ultrafine DRXed grains, which resulted from local distributed second phase particles. DRX process was attributed to the nucleation at second phase particles by the mechanism of particle stimulated nucleation (PSN), and the incomplete DRX process was accompanied by the dynamic recovery (DRV) process.

High-Temperature Deformation Behavior of Ti-6Al-2Sn-4Zr-2Mo Alloy with Lamellar Microstructure Under Plane-Strain Compression

High-temperature plane-strain compression of a Ti-6Al-2Sn-4Zr-2Mo (Ti-6242) alloy with a lamellar structure was applied by a thermal simulation machine Gleeble 3800 at a temperature of 1223-1370 K and a strain rate of 0.01-10 s−1. Constitutive relations between the flow stress and strain at different temperatures and strain rates were constructed based on the Arrhenius equation. Processing maps based on the dynamic material model at strains of 0.5, 1.0, and 1.25 were also constructed to analyze the mechanism and instability of high-temperature deformation. Dynamic recrystallization was found to occur at 1223-1313 K and 0.01-0.1 s−1, with a peak efficiency of power dissipation of 70%. Observations of the microstructure demonstrated that α platelets and dynamic globularization were responsible for dynamic softening in the α + β phase field. Flow instability behaviors occurred at 1263-1343 K/1.78-10 s−1, 1233-1283 K/0.1-3.16 s−1, and 1353-1373 K/0.56-1.78 s−1, and adiabatic shear bands and microcracks were observed in these domains. Thus, for the lamellar Ti-6242 alloy, the recommended hot rolling parameters were 1243-1333 K and 0.01-0.1 s−1. Electron backscattered diffraction results revealed that the dynamic restoration mechanism in the β phase field was dynamic recovery when the strain rate was as high as 10 s−1.