Kinetics of Dynamic Recrystallization of 18 Ni Maraging Steels

2016 ◽  
Vol 850 ◽  
pp. 13-20 ◽  
Author(s):  
Ni Li ◽  
Fei Zhao ◽  
Huan Zhang ◽  
Yong Hai Ren
Keyword(s):  
Dynamic Recrystallization ◽  
Peak Stress ◽  
Strain Rates ◽  
Recrystallization Behavior ◽  
Compression Tests ◽  
Flow Curves ◽  
Maraging Steels ◽  
Dynamic Recrystallization Behavior ◽  
Characteristic Values ◽  
Kinetics Of

The dynamic recrystallization behavior of 18 Ni maraging steels was investigated by hot compression tests at temperatures ranging from 900 °C to 1100 °C and strain rates ranging from 0.001 to 1 s-1. Based on the flow curves from the tests, the effects of temperatures and strain rates on the dynamic recrystallization behavior were analyzed. The strain-hardening rates versus stress curves were used to determine to the critical strain, the peak stress (strain), the saturated stress and the steady stress. With the assistance of the process parameters, constitutive equations were obtained and the activation energy was determined to be 413544.96 J/mol. The dependence of the characteristic values on Zener-Hollomon was found. The dynamic recrystallization kinetics model of the tested steels was constructed and the validity was confirmed based on the experimental results.

Dynamic Recrystallization Behavior of Mg-Gd-Y-Zr Alloy during Hot Compression

2016 ◽  
Vol 849 ◽  
pp. 181-185 ◽  
Author(s):  
Shi Lun Yu ◽  
Yong Hao Gao ◽  
Chu Ming Liu ◽  
Hong Chao Xiao
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Volume Fraction ◽  
Peak Stress ◽  
Critical Conditions ◽  
Recrystallization Behavior ◽  
Compression Tests ◽  
Dynamic Recrystallization Behavior ◽  
Increasing Temperature ◽  
The Cost

Dynamic recrystallization behavior of Mg-8.0Gd-3.0Y-0.5Zr (wt.%) alloy and the critical conditions corresponding to the onset of dynamic recrystallization were investigated using uniaxial compression tests conducted at temperatures ranging from 350 °C to 500 °C and strain rates ranging from 0.001 s-1 to 1 s-1. Results show that increasing temperature and/or decreasing strain rate can enhance the process of dynamic recrystallization of Mg-8.0Gd-3.0Y-0.5Zr alloy and lower the peak stress and corresponding strain. However, decreasing temperature and/or increasing strain rate can promote the occurrence of twin dynamic recrystallization (TDRX) within the original grains at the cost of reducing the total volume fraction of dynamically recrystallized grains in the microstructure. Besides, the critical stress and strain corresponding to the onset of dynamic recrystallization of Mg-8.0Gd-3.0Y-0.5Zr at 400 °C and 0.1 s-1 are 173MPa and 0.13, respectively.

Effect of Deformation Conditions on Dynamic Recrystallization of As-Cast GH625 Alloy

2015 ◽  
Vol 816 ◽  
pp. 620-627
Author(s):  
Hao Yu Wang ◽  
Jian Xin Dong ◽  
Mai Cang Zhang ◽  
Lei Zheng ◽  
Zhi Hao Yao ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Process Design ◽  
Deformation Process ◽  
Strain Rates ◽  
Recrystallization Behavior ◽  
Compression Tests ◽  
Volume Percent ◽  
Dynamic Recrystallization Behavior ◽  
Continuous Recrystallization

High temperature compression tests at a deformation temperature range of 1273K~1473K with various strain rates of 0.01s-1~0.1s-1 on as-cast GH625 alloy were carried out, aiming at the current research status that the deformation process of cogging and the recrystallization behavior of ingot are still in the study. The results indicated that the recrystallization nuclei of ingot formed not only along the original grain boundaries, but also in the interdendrite. Dynamic recrystallization volume percent increased with the increase of temperature and the decrease of strain rate. When the temperature was high and strain rate was low, the dynamic recrystallization behavior of as-cast GH625 alloy was dominated by discontinuous recrystallization. However, when the temperature was low and strain rate was high, continuous recrystallization also existed. These results can provide some reliable experimental support for the cogging process design.

Dynamic Recrystallization Behavior of AISI 420 Stainless Steel under Hot Compression

2014 ◽  
Vol 0 (0) ◽  
Author(s):  
Y. Cao ◽  
H.S. Di ◽  
R.D.K. Misra
Keyword(s):  
Stainless Steel ◽  
Dynamic Recrystallization ◽  
Deformation Behavior ◽  
Hot Compression ◽  
Strain Rates ◽  
Recrystallization Behavior ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Aisi 420 ◽  
Dynamic Recrystallization Behavior

AbstractHot deformation behavior of AISI 420 stainless steel was studied under hot compression tests in the temperature range of 950 to 1150 °C and strain rates of 0.01 s

Dynamic Recrystallization Behavior of a New Lead-Free Machinable Brass during Hot Deformation

2015 ◽  
Vol 817 ◽  
pp. 444-448
Author(s):  
Chun Lei Gan ◽  
Kai Hong Zheng ◽  
Hai Yan Wang ◽  
Wen Jun Qi ◽  
Nan Zhou
Keyword(s):  
Dynamic Recrystallization ◽  
Peak Stress ◽  
Lead Free ◽  
Strain Rates ◽  
Compression Tests ◽  
Stress Strain ◽  
Rate Versus ◽  
Dynamic Recrystallization Behavior ◽  
Compression Data ◽  
Strain Hardening Rate

The dynamic recrystallization (DRX) behavior of the new lead-free machinable brass was investigated by compression tests on a Gleeble-1500 thermal mechanics simulator in the temperatures range of 823-973 K and strain rates ranging from 0.01 to 1 s-1. On the basis of the hot compression data, critical stress (strain) or peak stress (strain) were determined with the assistance of the strain hardening rate versus stress curves. The dynamic recrystallization kinetics model of the lead-free machinable brass was established to evaluate the DRX behavior. The results will be beneficial to optimizing hot working processes of this new lead-free machinable brass.

scholarly journals Dynamic recrystallization behavior of the Ta-containing TiAl alloy in isothermal deformation

2020 ◽  
Vol 321 ◽  
pp. 12008
Author(s):  
Y.Y. Luo ◽  
X.N. Mao ◽  
H.Y. Yang ◽  
Y.F. Yin ◽  
Z.Z. Zhao ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Tial Alloy ◽  
Grain Boundary Sliding ◽  
Strain Rates ◽  
Recrystallization Behavior ◽  
Compression Process ◽  
Dynamic Recrystallization Behavior ◽  
Boundary Sliding ◽  
Mechanical Twins

The dynamic recrystallization behavior of as-cast Ti-46.5Al-3Ta-2Cr-0.2W alloy during isothermal compression process with nominal deformation of 50% and strain rates from 0.01s to 1s was investigated by electron microscopy. The results showed that the deformation mechanism of this alloy can be concluded as grain boundary sliding and mechanical twins, which induce the final dynamic recrystallization. The phase boundary bulging was found to be the major nucleation mechanism responsible for the lamellar globularization and the formation of recrystallized γ grains inside the lamellar colony under the high strain rate. The recrystallized γ grains induced by the twinning is the main mechanism for refining α2 lamellar microstructures under low strain rate.

Flow Behavior and Dynamic Recrystallization of BT25y Titanium Alloy During Hot Deformation

2018 ◽  
Vol 37 (2) ◽  
pp. 181-192 ◽  
Author(s):  
Xuemei Yang ◽  
Hongzhen Guo ◽  
Zekun Yao ◽  
Shichong Yuan
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Volume Fraction ◽  
Flow Behavior ◽  
Strain Rates ◽  
Recrystallization Behavior ◽  
Lower Strain ◽  
Deformation Activation Energy ◽  
Strain Data ◽  
Dynamic Recrystallization Behavior

AbstractThe high-temperature plastic deformation and dynamic recrystallization behavior of BT25y alloy were investigated within the deformation temperatures of 1,213–1,293 K and strain rates of 0.001–1.0 s–1 on a Gleeble-1500 thermo-mechanical simulator. Results showed that the dynamic recrystallization (DRX) mechanism played an important role in the hot deformation of BT25y alloy. Based on the regression analysis of the true stress–strain data, the stress exponent and deformation activation energy of BT25y alloy were calculated to be 3.4912 and 288.0435 kJ/mol, respectively. The θ-σ and dθ/dσ–σ curves were plotted to further obtain the critical stress and critical strain for the occurrence of DRX. Based on the analysis results, the DRX kinetic model was established. The model was validated by the comparison between predicted and experimental volume fraction of DRX. As the DRX evolution was sensitive to deformation temperature and strain rate, quantities of dynamically recrystallized grains appeared at higher temperatures and lower strain rates.

scholarly journals Hot Deformation Behavior and Processing Maps of Fe-30Mn-0.11C Steel

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1940 ◽  
Author(s):  
Jianmei Kang ◽  
Yuhui Wang ◽  
Zhimeng Wang ◽  
Yiming Zhao ◽  
Yan Peng ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
True Strain ◽  
Peak Stress ◽  
Strain Rates ◽  
Processing Maps ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
High Deformation

Hot deformation behavior of Fe-30Mn-0.11C steel was investigated. Hot compression tests were carried out at various temperatures ranging from 800 °C to 1200 °C and at different strain rates of 0.01 s−1 to 10 s−1. The constitutive equation based on peak stress was established. Hot processing maps at different strains and recrystallization diagrams were also established and analyzed. The results show that dynamic recrystallization easily occur at high deformation temperatures and low strain rates. Safe and unstable zones are determined at the true strain of 0.6 and 0.7, and the hot deformation process parameters of partial dynamic recrystallization of the tested steel are also obtained.

The Dynamic Recrystallization of Hot-Deformed Austenite in a Micro-Alloyed Steel

2012 ◽  
Vol 724 ◽  
pp. 287-290
Author(s):  
Yuan She ◽  
Zhao Hui Zhang ◽  
Jun Yang ◽  
Jian Tao Ju
Keyword(s):  
Dynamic Recrystallization ◽  
Peak Stress ◽  
Controlled Rolling ◽  
Alloyed Steel ◽  
Compression Tests ◽  
Austenite Grain Size ◽  
Alloyed Element ◽  
Deformation Equation ◽  
Dynamic Recrystallization Behavior ◽  
Micro Alloyed Steel

As the dynamic recrystallization (DRX) behavior of hot-deformed austenite is the basis of determining controlled rolling schedule for steel, in the present work, the dynamic recrystallization behavior of austenite of a 0.22%C-1.30%Mn-0.04%Nb micro-alloyed steel was investigated by means of high temperature compression tests on the Thermecmastor-Z simulator. By the analysis of true stress-strain curves at different deformation stages, the hot deformation equation of austenite was established for the steel. As a result, the energy to induce recrystallization of austenite for the steel is 419.1 kJmol-1, as it was influenced by the drag effect of micro-alloyed element Nb in solid solution. The ratio (σc/σp) of critical stress σc (where DRX occurs) to peak stress σp is 0.93 while the ratio (εc/εp) of critical strain εc to peak stress εp is 0.52 for the steel. The austenite grain size of dynamic recrystallization of the micro-alloyed steel is refined by decreasing the deformation temperature and improving the stain rate.

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