Constitutive Relationship of TRIP780 Steel in Quenching Process

2012 ◽  
Vol 572 ◽  
pp. 261-266
Author(s):  
Qiang Cao ◽  
Qing Dong Zhang ◽  
Chao Yang Sun
Keyword(s):  
Flow Stress ◽  
Tensile Tests ◽  
Constitutive Relationship ◽  
Uniaxial Tensile ◽  
Proposed Model ◽  
Quenching Process ◽  
Gleeble 3500 ◽  
Increasing Temperature ◽  
Relationship Of ◽  
The Impact

To characterize the mechanical behavior of TRIP780 steel in quenching process, Uniaxial tensile tests are performed on Gleeble-3500 thermo-simulation machine at temperature 323K~1073K and corresponding stress-strain curves are obtained. The results show that flow stress is affected by deformation temperature significantly and declines with increasing temperature. Based on simplified and modified Zerrilli-Armstrong model, the impact factor of temperature with quadratic polynomial fitting is introduced and the constitutive relationships with temperature dependent are established. The accuracy of the constitutive equations is verified and the flow stress predicted by the proposed model is consistent with experimental results. Therefore, the constitutive model can be applied for numerical simulation of quenching process.

Thermal Deformation Behavior and Constitutive Equation of Highly Alloyed Superalloy Udimet720Li

2013 ◽  
Vol 747-748 ◽  
pp. 703-708 ◽  
Author(s):  
Tao Wang ◽  
Shu Hong Fu ◽  
Zhao Li ◽  
Yong Zhang ◽  
Yu Xin Zhao ◽  
...  
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Thermal Deformation ◽  
True Strain ◽  
True Stress ◽  
Constitutive Relationship ◽  
Deformation Activation Energy ◽  
Gleeble 3500 ◽  
Relationship Of

Hot compressive deformation of Udimet720Li alloy was carried out on Gleeble-3500 thermal mechanical simulator. The flow stress behavior of Udimet720Li alloy during hot compression was studied in the temperature range of 1100-1160 and at a strain rate of 0.001-1s -1. The results showed that the flow stress was controlled by both strain rate and deforming temperature. The flow stress decreased with the increase of deforming temperature, while increased with the increase of strain rate. The change of flow stress with deformation thermal parameters was revealed from true stress-true strain curves, and constitutive relationship of Udimet720Li alloy was obtained on the base of Arrhenius equations and the deformation activation energy was calculated.

scholarly journals A Flow Stress Model of 300M Steel for Isothermal Tension

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 252
Author(s):  
Rongchuang Chen ◽  
Shiyang Zhang ◽  
Xianlong Liu ◽  
Fei Feng
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Tensile Deformation ◽  
Flow Behavior ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Model Parameters ◽  
Average Deviation ◽  
Cross Sectional ◽  
300M Steel

To investigate the effect of hot working parameters on the flow behavior of 300M steel under tension, hot uniaxial tensile tests were implemented under different temperatures (950 °C, 1000 °C, 1050 °C, 1100 °C, 1150 °C) and strain rates (0.01 s−1, 0.1 s−1, 1 s−1, 10 s−1). Compared with uniaxial compression, the tensile flow stress was 29.1% higher because dynamic recrystallization softening was less sufficient in the tensile stress state. The ultimate elongation of 300M steel increased with the decrease of temperature and the increase of strain rate. To eliminate the influence of sample necking on stress-strain relationship, both the stress and the strain were calibrated using the cross-sectional area of the neck zone. A constitutive model for tensile deformation was established based on the modified Arrhenius model, in which the model parameters (n, α, Q, ln(A)) were described as a function of strain. The average deviation was 6.81 MPa (6.23%), showing good accuracy of the constitutive model.

Effect of Fast Annealing on Microstructure and Mechanical Properties of Non-Oriented Al-Si Low C Electrical Steels

2007 ◽  
Vol 560 ◽  
pp. 29-34 ◽  
Author(s):  
Emmanuel Gutiérrez C. ◽  
Armando Salinas-Rodríguez ◽  
Enrique Nava-Vázquez
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Room Temperature ◽  
Tensile Tests ◽  
Rate Of Change ◽  
Uniaxial Tensile ◽  
Electrical Steels ◽  
Offset Yield Strength ◽  
Microstructure And Mechanical Properties ◽  
Increasing Temperature

The effects of heating rate and annealing temperature on the microstructure and mechanical properties of cold rolled Al-Si, low C non-oriented electrical steels are investigated using SEM metallography and uniaxial tensile tests. The experimental results show that short term annealing at temperatures up to 850 °C result in microstructures consisting of recrystallized ferrite grains with sizes similar to those observed in industrial semi-processed strips subjected to long term batch annealing treatments. Within the temperature range investigated, the grain size increases and the 0.2% offset yield strength decreases with increasing temperature. It was observed that the rate of change of grain size with increasing temperature increases when annealing is performed at temperatures greater than Ac1 (~870 °C). This effect is attributed to Fe3C dissolution and rapid C segregation to austenite for annealing temperatures within the ferrite+austenite phase field. This leads to faster ferrite growth and formation of pearlite when the steel is finally cooled to room temperature. The presence of pearlite at room temperature decreases the ductility of samples annealed at T > Ac1.

Tensile Deformation Behavior of 5A90 Al-Li Alloy Sheet at Elevated Temperature

2011 ◽  
Vol 66-68 ◽  
pp. 70-75 ◽  
Author(s):  
Gao Shan Ma ◽  
Song Yang Zhang ◽  
Han Ying Wang ◽  
Min Wan
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Tensile Deformation ◽  
Alloy Sheet ◽  
Hot Forming ◽  
Uniaxial Tensile ◽  
Sensitivity Index ◽  
Tensile Deformation Behavior ◽  
Increasing Temperature

Uniaxial tensile deformation behavior of 5A90 aluminium-lithium alloy sheet is investigated in the hot forming with the temperature range of 200-450°C and strain rate range of 0.3×10-3-0.2×10-1s-1. It is found that the flow stress of 5A90 Al-Li alloy in uniaxial tension increase with increasing strain rate and decrease with increasing temperature, however, the tendency of total elongation is just the reverse, and the optimum forming temperature is 400°C. The strain rate sensitivity index (m-value) remarkably increases with increasing temperature for a given strain rate. It is shown that 5A90 Al-Li alloy sheet displays the sensitivity to the strain rate at elevated temperatures. For a given strain rate, the strain hardening index (n-value) decreases with increasing temperature, whereas the n-value increases above 350°C. The constitutive equation of stress, strain and strain rate for 5A90 Al-Li alloy at any temperature is obtained by fitting the experimental data, which gave a good flow stress model for the FEM simulation of hot forming.

scholarly journals Strain Rate-Dependent Constitutive and Low Stress Triaxiality Fracture Behavior Investigation of 6005 Al Alloy

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Yong Peng ◽  
Xuanzhen Chen ◽  
Shan Peng ◽  
Chao Chen ◽  
Jiahao Li ◽  
...  
Keyword(s):  
Flow Stress ◽  
Plastic Strain ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Equivalent Plastic Strain ◽  
Stress Triaxiality ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Stress States

In order to study the dynamic and fracture behavior of 6005 aluminum alloy at different strain rates and stress states, various tests (tensile tests at different strain rates and tensile shearing tests at five stress states) are conducted by Mechanical Testing and Simulation (MTS) and split-Hopkinson tension bar (SHTB). Numerical simulations based on the finite element method (FEM) are performed with ABAQUS/Standard to obtain the actual stress triaxialities and equivalent plastic strain to fracture. The results of tensile tests for 6005 Al show obvious rate dependence on strain rates. The results obtained from simulations indicate the feature of nonmonotonicity between the strain to fracture and stress triaxiality. The equivalent plastic strain reduces to a minimum value and then increases in the stress triaxiality range from 0.04 to 0.30. A simplified Johnson-Cook (JC) constitutive model is proposed to depict the relationship between the flow stress and strain rate. What is more, the strain-rate factor is modified using a quadratic polynomial regression model, in which it is considered to vary with the strain and strain rates. A fracture criterion is also proposed in a low stress triaxiality range from 0.04 to 0.369. Error analysis for the modified JC model indicates that the model exhibits higher accuracy than the original one in predicting the flow stress at different strain rates. The fractography analysis indicates that the material has a typical ductile fracture mechanism including the shear fracture under pure shear and the dimple fracture under uniaxial tensile.

Tensile testing low density multilayers: Aluminum/titanium

1998 ◽  
Vol 13 (10) ◽  
pp. 2902-2909 ◽  
Author(s):  
D. Josell ◽  
D. van Heerden ◽  
D. Read ◽  
J. Bonevich ◽  
D. Shechtman
Keyword(s):  
Thin Films ◽  
Yield Stress ◽  
Tensile Testing ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Low Density ◽  
Multilayer Thin Films ◽  
Bilayer Thickness ◽  
Relationship Of ◽  
The Relationship

Yield stresses, ultimate tensile strengths, and specific strengths of aluminum/titanium multilayer thin films are determined from the results of uniaxial tensile tests. The plasticity in the stress-strain curves, the nature of the fracture surfaces, and the relationship of the yield stress and the bilayer thickness are discussed. Properties are compared with those of other multilayer materials published in the literature.

scholarly journals Stochastic Constitutive Relationship of Self-Compacting Concrete under Uniaxial Compression

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Xiao Li ◽  
Zhi Shan ◽  
Zhiwu Yu ◽  
Jing Gao ◽  
Jianfeng Mao
Keyword(s):  
Uniaxial Compression ◽  
Practical Method ◽  
Constitutive Relationship ◽  
Experimental Investigations ◽  
Chain Model ◽  
Self Compacting Concrete ◽  
Mechanical Responses ◽  
Cyclic Compression ◽  
Proposed Model ◽  
Relationship Of

Experimental investigations on self-compacting concrete (SCC) under uniaxial monotonic and cyclic compression taking into account the stochastic constitutive relationship were reported and conducted. By introducing a practical method on plasticity characterization into the fiber bundle-plastic chain model, a new constitutive model based on the statistic damage approach for describing the stochastic mechanical responses of SCC under uniaxial compression was proposed. The comparison between the experimental results and the predictions demonstrated that the proposed model was able to characterize the salient features for SCC under both uniaxial monotonic and cyclic compression. Furthermore, the stochastic evolution (SE) of SCC under uniaxial compression and a comparison between the SCC and normally vibrated concrete (NVC) in certain aspects were analyzed and discussed; it was concluded that the stochastic constitutive relationship of SCC under compression can be understood by a media process of transition from microscale to macroscale.

Studies on the Stress-Strain Relationship Bovine Cortical Bone Based on Ramberg–Osgood Equation

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
N. K. Sharma ◽  
M. D. Sarker ◽  
Saman Naghieh ◽  
Daniel X. B. Chen
Keyword(s):  
Cortical Bone ◽  
Linear Regression Analysis ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Loading Conditions ◽  
Stress Strain ◽  
Strain Behavior ◽  
Nonlinear Stress ◽  
Strain Relationship ◽  
Relationship Of

Bone is a complex material that exhibits an amount of plasticity before bone fracture takes place, where the nonlinear relationship between stress and strain is of importance to understand the mechanism behind the fracture. This brief presents our study on the examination of the stress–strain relationship of bovine femoral cortical bone and the relationship representation by employing the Ramberg–Osgood (R–O) equation. Samples were taken and prepared from different locations (upper, middle, and lower) of bone diaphysis and were then subjected to the uniaxial tensile tests under longitudinal and transverse loading conditions, respectively. The stress–strain curves obtained from tests were analyzed via linear regression analysis based on the R–O equation. Our results illustrated that the R–O equation is appropriate to describe the nonlinear stress–strain behavior of cortical bone, while the values of equation parameters vary with the sample locations (upper, middle, and lower) and loading conditions (longitudinal and transverse).

Constitutive Modeling of the Rate-Dependent Behavior of Ti-6Al-4V Using an Arrhenius-Type Law

2012 ◽  
Vol 591-593 ◽  
pp. 949-954
Author(s):  
Jun Jie Xiao ◽  
Dong Sheng Li ◽  
Xiao Qiang Li ◽  
Chao Hai Jin ◽  
Chao Zhang
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Tensile Tests ◽  
Alloy Sheet ◽  
Uniaxial Tensile ◽  
Thin Wall ◽  
Rate Dependent ◽  
Hot Environment ◽  
Dependent Behavior ◽  
Element Simulation

Uniaxial tensile tests were performed on a Ti-6Al-4V alloy sheet over the temperature range of 923K-1023K with the strain rates of 5×10-4s-1-5×10-2s-1 up to a 25% length elongation of the specimen. The true stress-strain curves reveal that the flow stress decreases with the increase of the temperature and the decrease of the strain rate. In the same process, the accompanying softening role increases. It is found that the Ti-6Al-4V shows the features of non-linearity, temperature sensitivity and strain rate dependence in hot environment. Finally, an Arrhenius-type law has been established to predict the experimental data and the prediction precision was verified by the plotting of parameter and flow stress, which revealed that the error of stress exponent was only 4.99%. This indicates the flow stress model has high precision and can be used for the process design and the finite element simulation of hot forming thin-wall Ti-6Al-4V alloy components.

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