Uniaxial Cyclic Deformation Behaviors of 42CrMo Steel with Different Heat-Treatments

2007 ◽  
Vol 353-358 ◽  
pp. 555-558 ◽  
Author(s):  
Guo Zheng Kang ◽  
Zhao Li ◽  
Yu Jie Liu
Keyword(s):  
Strain Rate ◽  
Cyclic Deformation ◽  
Room Temperature ◽  
Annealed Sample ◽  
Cyclic Softening ◽  
Heat Treatments ◽  
Ratcheting Strain ◽  
42Crmo Steel ◽  
Deformation Behaviors ◽  
Cyclic Straining

The cyclic deformation behaviors of 42CrMo steel with different heat treatments were observed by uniaxial cyclic straining and stressing tests at room temperature. The cyclic softening/ hardening features of the tempered or annealed 42CrMo steel and their effects on the uniaxial ratcheting produced in asymmetrical cyclic stressing were discussed. It is concluded that the tempered 42CrMo steel shows significantly cyclic softening feature, but the annealed one is cyclic stabilizing. Different ratcheting behaviors are also observed. For the tempered 42CrMo steel, a special tertiary ratcheting behavior is observed and the previous cyclic straining greatly accelerates the evolution of ratcheting strain in subsequent cyclic stressing. In contrast, the annealed sample presents a stabilized ratcheting with nearly constant ratcheting strain rate after certain cycles, and the previous cyclic straining slightly influences the ratcheting in subsequent cyclic stressing.

Uniaxial and Multiaxial Cyclic Deformation Behaviors of SiCp/6061Al Alloy Composites

2007 ◽  
Vol 353-358 ◽  
pp. 1247-1250 ◽  
Author(s):  
Guo Zheng Kang ◽  
Yu Jie Liu
Keyword(s):  
Cyclic Deformation ◽  
Room Temperature ◽  
Cyclic Softening ◽  
Mean Stress ◽  
Ratcheting Strain ◽  
The Matrix ◽  
Deformation Behaviors ◽  
Sic Particulates ◽  
Cyclic Straining ◽  
Particulate Volume

The uniaxial/multiaxial cyclic deformation behaviors of SiCp/6061Al alloy composites with various particulate volume fractions were studied by uniaxial and multiaxial cyclic straining or stressing tests at room temperature. The cyclic softening/hardening features and ratcheting behaviors of T6-treated composites and un-reinforced matrix were discussed in different loading conditions. It is shown that the ratcheting also occurs in the composites under uniaxial and multiaxial asymmetrical cyclic stressing, and the ratcheting strain increases with stress amplitude and mean stress; however, the addition of SiC particulates into the matrix increases the resistance of the composite to ratcheting. The ratcheting depends greatly on the shapes of loading paths and mainly occurs in the direction of non-zero mean stress.

Uniaxial Cyclic Deformation Behavior of 6061Al Alloy and its Time-Dependence at Room and High Temperatures

2007 ◽  
Vol 345-346 ◽  
pp. 9-12 ◽  
Author(s):  
Guo Zheng Kang ◽  
Yu Jie Liu ◽  
Jun Ding
Keyword(s):  
High Temperatures ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Hold Time ◽  
Cyclic Softening ◽  
Loading Rates ◽  
Ratcheting Strain ◽  
Deformation Behaviors ◽  
Cyclic Straining ◽  
Stressing Rate

The cyclic deformation behavior of 6061Al-T6 alloy was studied by uniaxial cyclic straining or stressing tests at room and high temperatures. The cyclic softening/hardening feature of the material and its effect on the uniaxial ratcheting occurred under asymmetrical cyclic stressing were discussed. The cyclic deformation behaviors of the material presented at various loading rates and with certain peak and/or valley strain or stress holds were addressed. It is concluded from the experimental results that 6061Al-T6 alloy presents slightly cyclic softening feature, and its cyclic deformation is time-dependent even at room temperature. The ratcheting strain produced at lower stressing rate and with longer hold-time is apparently larger than that at higher stressing rate and with fewer hold-time. Some significant conclusions useful to construct the constitutive model to describe such cyclic deformation behaviors are obtained.

Strain-Rate-Dependent Deformation Behavior of Carbon-Black-Filled Rubber under Monotonic and Cyclic Straining

2007 ◽  
Vol 340-341 ◽  
pp. 1017-1024 ◽  
Author(s):  
Yoshihiro Tomita ◽  
K. Azuma ◽  
M. Naito
Keyword(s):  
Strain Rate ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Viscoelastic Deformation ◽  
Rate Dependent ◽  
Filled Rubber ◽  
Deformation Behaviors ◽  
Deformation Processes ◽  
The Individual ◽  
Cyclic Straining

The constitutive equation of rubber is derived by employing a nonaffine molecular chain network model for an elastic deformation behavior and the reptation theory for a viscoelastic deformation behavior. The results reveal the roles of the individual springs and dashpot, and the strain rate dependence of materials and disentanglement of molecular chains in the monotonic and cyclic deformation behaviors, particularly softening and hysteresis loss, that is, the Mullins effect, occurring in stress-stretch curves under cyclic deformation processes.

Strain Rate Dependent Micro- to Macroscopic Deformation Behavior of Carbon-Black Filled Rubber under Monotonic and Cyclic Straining

2007 ◽  
Vol 345-346 ◽  
pp. 53-56
Author(s):  
Yoshihiro Tomita ◽  
K. Azuma ◽  
M. Naito
Keyword(s):  
Carbon Black ◽  
Strain Rate ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Viscoelastic Deformation ◽  
Rate Dependent ◽  
Filled Rubber ◽  
Deformation Behaviors ◽  
The Individual ◽  
Cyclic Straining

A constitutive equation of rubber is derived by employing a nonaffine molecular chain network model for an elastic deformation behavior and the reptation theory for a viscoelastic deformation behavior. The results reveal the roles of the individual springs and dashpot, and the strain rate dependence of materials in the monotonic and cyclic deformation behaviors, particularly softening and hysteresis loss, that is, the Mullins effect, occurring in stress-stretch curves under cyclic deformation processes of carbon black filled rubber..

Experimental Observation on the Uniaxial Cyclic Deformation Behaviour of TA16 Titanium Alloy

2011 ◽  
Vol 415-417 ◽  
pp. 2318-2321 ◽  
Author(s):  
Qian Hua Kan ◽  
Wen Yi Yan ◽  
Guo Zheng Kang ◽  
Su Juan Guo
Keyword(s):  
Titanium Alloy ◽  
Cyclic Loading ◽  
Cyclic Deformation ◽  
Room Temperature ◽  
Stress Ratio ◽  
Stress Amplitude ◽  
Deformation Behaviour ◽  
Ratcheting Strain ◽  
Number Of Cycles ◽  
Stable Material

The cyclic deformation including the ratcheting of TA16 titanium alloy was investigated experimentally at room temperature. Experimental results under symmetrical strain-controlled cyclic loading with various strain amplitudes show that the responded stress amplitude keeps almost unchanged with the increasing number of cycles. It is concluded that TA16 titanium alloy can be regarded as a cyclic stable material. Remarkable ratcheting was also observed under asymmetrical stress-controlled cyclic loading, i.e., ratcheting strain increases with the increasing number of cycles. The ratcheting strain strongly depends on the stress level and increases with the increase of applied mean stress, stress amplitude and stress ratio. These findings are useful to reasonably model the cyclic deformation of TA16 titanium alloy.

Asymmetric Cyclic Deformation Behaviors of Hot-Rolled AZ91 Magnesium Alloy in Rolling Direction

2013 ◽  
Vol 712-715 ◽  
pp. 38-41
Author(s):  
Xiao Min Chen ◽  
Y.C. Lin ◽  
Zheng Hua Liu ◽  
Jian Chen
Keyword(s):  
Magnesium Alloy ◽  
Fatigue Failure ◽  
Cyclic Deformation ◽  
Fatigue Crack Initiation ◽  
Rolling Direction ◽  
Az91 Magnesium Alloy ◽  
Cycle Number ◽  
Ratcheting Strain ◽  
Deformation Behaviors ◽  
Az91 Magnesium

The cyclic deformation behaviors of hotrolled AZ91 magnesium alloy are studied by asymmetrical cyclic stresscontrolled experiments at room temperature. The ratcheting behavior and fatigue failure mechanism are discussed. Results show that: (1) The ratcheting strain increases sharply with the increase of cycle number at the initial stage, and then tends to be a constant after certain cycles. (2) The fatigue crack initiation and stable propagation regions are flat with lamellar structures, while the unstable propagation and rapid fracture regions are coarse with ductile dimples and tearing edges. (3) The residual twins can be seen as potential damage to fatigue failure of the material, due to its irreversibility of cyclic plastic deformation and damage to grain boundaries.

scholarly journals High-temperature Cyclic Deformation Behavior and Damage-coupled Unified Viscoplastic Constitutive Model for a Ductile Cast Iron QTRSi4Mo1

2021 ◽  
Author(s):  
Zhenxing Wu ◽  
Xuedong Chen ◽  
Zhichao Fan ◽  
Yu Zhou ◽  
Jinwen Yu ◽  
...  
Keyword(s):  
Cast Iron ◽  
Constitutive Model ◽  
Cyclic Deformation ◽  
Low Cycle Fatigue ◽  
Strain Range ◽  
Optimization Procedure ◽  
Cyclic Hardening ◽  
Cyclic Softening ◽  
Ductile Cast Iron ◽  
Deformation Behaviors

Isothermal low cycle fatigue tests for a ductile cast iron QTRSi4Mo1 were carried out at 500°C and 760°C. The results showed that it exhibited initial cyclic hardening followed by saturation at 500°C, while gradual cyclic softening occurred at 760°C due to a more pronounced creep effect. A damage-coupled unified viscoplastic constitutive model incorporating two nonlinear and one linear strain range-dependent drag stress components was developed, for modeling the distinct strain range-dependent deformation behaviors at different temperatures. In the model, a modified damage evolution law was introduced. Furthermore, the parameter identification approach for the unified viscoplastic model was proposed, including the initial estimates combined with the genetic algorithm-based global optimization procedure. The proposed model can simulate the strain range-dependent cyclic deformation behaviors and predict the LCF failure life of the investigated material.

Uniaxial Ratchetting of SiCP/6061Al Alloy Composites at Room and High Temperatures

2005 ◽  
Author(s):  
Guozheng Kang
Keyword(s):  
High Temperatures ◽  
Cyclic Deformation ◽  
Volume Fraction ◽  
Stress Amplitude ◽  
Cyclic Softening ◽  
Mean Stress ◽  
Ratcheting Strain ◽  
Macro Scale ◽  
The Matrix ◽  
Sic Particulates

The uniaxial strain cyclic characteristics and ratcheting behaviors of T6-treated SiCP/6061Al alloy composites were studied experimentally at room and high temperatures (573K). The cyclic softening/hardening and ratcheting behaviors of T6-treated composites and un-reinforced matrix were investigated in different loading conditions and with two volume fractions of SiC particulates. It is shown that the cyclic softening/ hardening and ratcheting behaviors of the composites are similar to those of the un-reinforced matrix in macro-scale, i.e., the ratcheting also occurs in the composites during the cyclic stressing with non-zero mean stress, and the ratcheting strain increases with the increasing of stress amplitude and mean stress; however, the addition of SiC particulates into the matrix increases the resistance of the composite to the ratcheting, and the ratcheting strain decreases as the volume fraction of SiC particulates increases. It can be also concluded that the cyclic deformation of the composites has a great temperature-dependence. Some significant conclusions are obtained, which are useful to construct a constitutive model to describe the cyclic deformation of the composites.

Softening Phenomenon during Compression Test in Nanograined Aluminum Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 3489-3492 ◽  
Author(s):  
Se Hyun Ko ◽  
Jin Man Jang ◽  
Won Sik Lee
Keyword(s):  
Plastic Deformation ◽  
Aluminum Alloys ◽  
Strain Rate ◽  
Strain Hardening ◽  
Compression Test ◽  
Room Temperature ◽  
Strain Rate Range ◽  
Rate Range ◽  
Cu Alloys ◽  
Deformation Behaviors

Al-Mg and Al-Mg-Cu alloys are known well to reveal superplasticity in tension at high temperatures. In this study, deformation behaviors of those alloys nanograined were investigated under compression test at room temperature. During plastic deformation softening phenomena occurred obviously in nanograined Al-1.5wt%Mg and Al-0.7wt%Mg-1.0wt%Cu alloys while slight strain hardening appeared in nanograined pure Al. These results suggest that the softening strongly depends on composition of alloys. The softening takes place over strain rate range from 10-4 up to 10-1.

Sign in / Sign up

Export Citation Format

Share Document