Study on the Constitutive Equation of High-Temperature of High-Elastic Cu-20.0Ni-5.0Sn-0.25Zn-0.22Mn Alloy

2019 ◽  
Vol 956 ◽  
pp. 169-178
Author(s):  
Geng Sheng Cai ◽  
Zhi Hong Cai ◽  
Fu Ping Liu ◽  
Hua Gang Yu
Keyword(s):  
High Temperature ◽  
Constitutive Equation ◽  
Strain Rate ◽  
True Stress ◽  
Temperature Dependent ◽  
Stress Strain ◽  
Thermal Compression ◽  
Compression Deformation ◽  
Dual Stage ◽  
Stage Division

The high-elastic Cu-20.0Ni-5.0Sn-0.25Zn-0.22Mn alloy was designed and prepared using a 830°C/2h+850°C/2h dual-stage homogenization annealing process. The true stress-strain curves of well annealed Cu-20.0Ni-5.0Sn-0.25Zn-0.22Mn alloy were plotted as a function of compressive temperature and strain rate. The results showed that the stage division of thermal compression deformation is temperature dependent, which involves work hardening, dynamic recovery and recrystallization stages. The maximum value of the true stress increases as the strain rate gets larger, but decreases as the deformation temperature rises. The high temperature compression deformation process of the alloy is a thermal activated process, and the corresponding constitutive equation of the true stress-strain is established.

Hot Compression Deformation Behavior of Spray-Formed AlSn20Cu Alloy

2021 ◽  
Vol 1035 ◽  
pp. 189-197
Author(s):  
Bao Ying Li ◽  
Bao Hong Zhu
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Phase Distribution ◽  
True Stress ◽  
Hot Compression ◽  
Test Machine ◽  
Hot Compression Deformation ◽  
Compression Deformation

The hot deformation behavior of spray-formed AlSn20Cu alloy during hot compression deformation was studied, and the constitutive equation of AlSn20Cu alloy was established. The samples of spray-formed AlSn20Cu alloy were compressed on Gleeble-3500 thermal simulation test machine. The error of the true stress caused by adiabatic heating effect in the experiment was corrected. The constitutive equation of spray-formed AlSn20Cu alloy could be represented by Zener-Hollomon parameter in a hyperbolic sine function. The results showed that the deformation temperatures and strain rates had a notable effect on the true stress of the alloy. At the identical deformation temperature, the true stress increased with the increase of strain rate. When the strain rate was constant, the stress decreased with the increase of deformation temperature. After hot compression deformation, the tin phase was elongated along the direction perpendicular to the compression axis with short strips and blocks. With the increase of deformation temperature and the decrease of strain rate, Sn phase distribution became more homogeneous.

Thermal Deformation Behavior and Critical Conditions of Dynamic Recrystallization of QCr0.8 Alloy

2019 ◽  
Vol 944 ◽  
pp. 38-45
Author(s):  
Shu Yu Yang ◽  
Qiang Song Wang ◽  
Guo Liang Xie ◽  
Dong Mei Liu ◽  
Fang Liu
Keyword(s):  
Constitutive Equation ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Thermal Deformation ◽  
Processing Map ◽  
Critical Conditions ◽  
Temperature Deformation ◽  
Thermal Compression ◽  
Compression Deformation

In this paper, the flow stresses, the constitutive equation, processing map and the critical conditions of dynamic recrystallization (DRX) of the hot forged QCr0.8 alloy are studied by hot compressive test in the 750-900°C temperature and 0.01-10s-1 strain rate ranges using Gleeble-1500D thermo-mechanical simulator. The compression reduction of thermal compression deformation is 50%. The results show that the thermal deformation temperatures and strain rates have a significant effect on the high temperature deformation behavior of the alloy. The higher the temperature, the smaller the strain rate and the easier the DRX of the alloy is found.The peak stresses of the alloy decreases with the increase of temperature and increases with the increase of the strain rates.The flow stresses during hot deformation can be described by a hyperbolic sine function. The activation energy Q of the thermal compression deformation is determined to be 370.8KJ/mol. The constitutive equation and processing map of the alloy are established. Critical strains of DRX εc are studied by the inflection point characteristic of the lnθ-ε curve of the alloy and the corresponding minimum value of the ∂θ (∂θ)/∂ε-ε curve.

Characterization of High Temperature Deformation Behavior of BFe10-1-2 Cupronickel Alloy Using Orthogonal Analysis

2017 ◽  
Vol 36 (7) ◽  
pp. 701-710
Author(s):  
Jun Cai ◽  
Kuaishe Wang ◽  
Xiaolu Zhang ◽  
Wen Wang
Keyword(s):  
High Temperature ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Deformation Behavior ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Compression Tests ◽  
Statistical Parameters ◽  
Orthogonal Analysis

AbstractHigh temperature deformation behavior of BFe10-1-2 cupronickel alloy was investigated by means of isothermal compression tests in the temperature range of 1,023~1,273 K and strain rate range of 0.001~10 s–1. Based on orthogonal experiment and variance analysis, the significance of the effects of strain, strain rate and deformation temperature on the flow stress was evaluated. Thereafter, a constitutive equation was developed on the basis of the orthogonal analysis conclusions. Subsequently, standard statistical parameters were introduced to verify the validity of developed constitutive equation. The results indicated that the predicted flow stress values from the constitutive equation could track the experimental data of BFe10-1-2 cupronickel alloy under most deformation conditions.

Mechanical Behavior and Constitutive Equation of Concrete under High-Temperature Dynamical Conditions

2011 ◽  
Vol 228-229 ◽  
pp. 303-308
Author(s):  
Bin Jia ◽  
Zheng Liang Li ◽  
Jun Lin Tao ◽  
Chun Tao Zhang
Keyword(s):  
High Temperature ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
Test Data ◽  
Dynamical Behavior ◽  
Hardening Effect ◽  
Failure Evolution ◽  
Different Temperatures ◽  
Strain Rate Hardening

SPHB tests of concrete under different temperatures and various loading conditions are completed, and high-temperature dynamical behavior of concrete is obtained. Dynamical mechanical behavior of concrete with high temperature is affected by not only the strain rate effect, but also the high temperature weakening effect, and the strain rate hardening effect is coupled with high temperature weakening effect, but the latter has greater influence. Concrete failure evolution is described on basis of the damage factor, the intercoupling strain rate hardening effect and temperature weakening effect are simply set as mutually independent factors, each parameter is respectively fitted with test data, finally, concrete constitutive equation under high-temperature dynamical conditions is established, and comparative analysis with test data are conducted, indicating good coincidence with test results.

scholarly journals Hot Deformation Behavior and Constitutive Modeling of H13-Mod Steel

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 846 ◽  
Author(s):  
Changmin Li ◽  
Yuan Liu ◽  
Yuanbiao Tan ◽  
Fei Zhao
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
High Strain ◽  
Flow Behavior ◽  
Peak Stress ◽  
Strain Rates ◽  
Hot Deformation Behavior ◽  
Stress Strain

The H13-mod steel optimized by composition and heat treatment has reached the performance index of the shield machine hob. The hot deformation behavior of the H13-mod steel was investigated by compression tests in the temperature range from 900 to 1150 °C and the strain rate range from 0.01 to 10 s−1. The true stress-strain curve showed that the rising stress at the beginning of deformation was mainly caused by work hardening. After the peak stress was attained, the curve drop and the flow softening phenomenon became more obvious at low strain rates. The flow behavior of the H13-mod steel was predicted by a strain-compensated Arrhenius-type constitutive equation. The relationship between the material constant in the Arrhenius-type constitutive equation and the true strain was established by a sixth-order polynomial. The correlation coefficient between the experimental value and the predicted value reached 0.987, which indicated that the constitutive equation can accurately estimate the flow stress during the deformation process. A good linear correlation was achieved between the peak stress (strain), critical stress (strain) and the Zener‒Hollomon parameters. The processing maps of the H13-mod steel under different strains were established. The instability region was mainly concentrated in the high-strain-rate region; however, the microstructure did not show any evidence of instability at high temperatures and high strain rates. Combined with the microstructure and electron backscattered diffraction (EBSD) test results under different deformations, the optimum hot working parameters were concluded to be 998–1026 °C and 0.01–0.02 s−1 and 1140–1150 °C and 0.01–0.057 s−1.

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

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1502
Author(s):  
Xiao Li ◽  
Lifeng Hou ◽  
Yinghui Wei ◽  
Zhengyan Wei
Keyword(s):  
Stainless Steel ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Hot Deformation ◽  
Processing Map ◽  
Martensitic Stainless Steel ◽  
True Strain ◽  
True Stress ◽  
Hot Working ◽  
Compression Tests

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.

Viscoplastic Constitutive Equation of High-Density Polyethylene

2007 ◽  
Vol 340-341 ◽  
pp. 1097-1102 ◽  
Author(s):  
Yukio Sanomura ◽  
Mamoru Mizuno
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
High Density Polyethylene ◽  
Kinematic Hardening ◽  
Constant Strain Rate ◽  
Strain Curve ◽  
High Density ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Creep Theory

A viscoplastic constitutive equation based on the kinematic hardening creep theory of Malinin-Khadjinsky and the nonlinear kinematic hardening rule of Armstrong-Frederick is formulated to describe the inelastic behavior of high-density polyethylene under various loading. The gentle progress of back stress by the introduction of loading surface in the viscoplastic strain space and smaller material constant under unloading can be expressed. Material constants are identified by various stress-strain curves under compression at constant strain rate and creep curves under compression at constant stress. The viscoplastic model can describe stress-strain curve under compression with change in strain rate and shear stress-strain curve including unloading. The model can qualitatively describe stress-strain curves under compression with changed strain rate including unloading, but it is quantitatively insufficient.

Flow Stress Behaviour of TWIP Steel during the Hot Compression Deformation

2011 ◽  
Vol 194-196 ◽  
pp. 1235-1241
Author(s):  
Qiang Liu ◽  
De Jun Li ◽  
Feng Shou Shangguan ◽  
Yao Rong Feng ◽  
Ke Tong
Keyword(s):  
Flow Stress ◽  
Hot Deformation ◽  
Twip Steel ◽  
Linear Regression Analysis ◽  
Typical Feature ◽  
True Stress ◽  
Hot Compression ◽  
Stress Strain ◽  
Hot Compression Deformation ◽  
Compression Deformation

The hot deformation behavior of Fe-25Mn-3Si-3Al TWIP steel were investigated by isothermal single-pass compression on Gleeble-3500 thermal simulator at the temperature range of 900°C to 1100°C and the strain rate range of 0.01s-1to 1s-1. The results showed that the true stress-strain curves of Fe-25Mn-3Si-3Al steel had a typical feature which often appears during the hot deformation process of metals and alloys with high stacking fault energies. In true stress-strain curves, No obvious flow stress peak was observed. With the increase of strain, flow stress reaches the saturation value, indicating that the hot deformations of these conditions are dynamic recovery. The hot compression deformation of Fe-25Mn-3Si-3Al steel can be represented by Arrhenius model. The constitutive equation of Fe-25Mn-3Si-3Al steel under hot compression deformation is calculated by a linear regression analysis. The activation energy for hot deformation of the experimental steel is 422.51kJ/mol.

Projection of Extrusion Force of Spray-Formed Al-25wt%Si with High Temperature Compression

2007 ◽  
Vol 539-543 ◽  
pp. 374-379 ◽  
Author(s):  
C.H. Chiang ◽  
Chi Y.A. Tsao
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Compressive Stress ◽  
Al Alloys ◽  
Extrusion Force ◽  
Strain Rates ◽  
Direct Extrusion ◽  
Compressive Tests

The extrusion forces of the spray-formed Al-25wt%Si alloy at various strain rates and temperatures were calculated with the flow stresses obtained from high temperature compressive tests. The compressive stress-strain curves of the spray-formed Al-25wt%Si at various temperatures and strain rates were determined and discussed. The constitutive equation of strain rate as a function of stress and temperature described by, n Q RT A e ' / sinh( ) − ε& = ασ for the spray-formed Al-25wt%Si alloy, was established. The activation energy and constants in the constitutive equation were discussed and compared to other Al alloys. A direct extrusion experiment was employed to evaluate the extrusion loads vs. ram displacement at various temperatures and strain rates. By applying the constitutive equation, the extrusion loads were calculated and compared to the experimental ones for various temperatures and strain rates. The accuracy of the calculated results compared to the experimental results was discussed.

A novel phenomenological constitutive model for Ti-6Al-4V at high temperature conditions and quasi-static strain rates

2021 ◽  
pp. 095441002098599
Author(s):  
Mohammad Mahdi Ashrafian ◽  
Seyed Ali Hosseini Kordkheili
Keyword(s):  
High Temperature ◽  
Constitutive Model ◽  
Power Law ◽  
Phenomenological Approach ◽  
Strain Rates ◽  
Temperature Dependent ◽  
Stress Strain ◽  
Strain Behavior ◽  
Temperature Conditions ◽  
Cook Model

Phenomenological constitutive modeling of Ti-6Al-4V at temperatures between 923 and 1023 K under 0.0005–0.05 s−1 quasi-static rates is studied based on a phenomenological approach. For this purpose, the Johnson–Cook constitutive model is revisited. At low temperature conditions under moderate to high strain rates, the material’s stress–strain curves are the most similar to power-law function. Contrary to this, at high temperature conditions under low to moderate strain rates, the saturation-type function well describes the stress–strain curves. On the other hand, it is illustrated that the Johnson–Cook constitutive model is feeble to predict the material’s behavior correctly. Accordingly, in this study, a viscoplastic temperature-dependent constitutive model is developed. The strain rate hardening as well as thermal softening of the developed model is the same as the Johnson–Cook model. But a temperature-dependent strain hardening function is proposed in which both the saturation-type and power-law hardening behaviors of the material are implemented. In comparison with the Johnson–Cook model, the new constitutive model’s fidelity in capturing the titanium behavior is depicted. At last, by considering an Arrhenius-type phenomenological constitutive model, it is noted that the developed constitutive model has the best correctness in predicting the Ti-6Al-4V stress–strain behavior at high temperature conditions under quasi-static rates.

Sign in / Sign up

Export Citation Format

Share Document