Dynamic Recrystallization Behavior of High Carbon Chromium Bearing Steel

2014 ◽  
Vol 584-586 ◽  
pp. 1011-1016
Author(s):  
Xiao Lei Zhang ◽  
Hui Li ◽  
Shi Xin Xu ◽  
Zhi Chao Li ◽  
Zhen Li Mi
Keyword(s):  
Flow Stress ◽  
Dynamic Recrystallization ◽  
Peak Stress ◽  
Bearing Steel ◽  
Peak Strain ◽  
Compression Tests ◽  
Gcr15 Bearing Steel ◽  
Dynamic Recrystallization Behavior ◽  
Gleeble 3500 ◽  
Relationship Of

The effect of process parameters on dynamic recrystallization of GCr15 bearing steel was investigated by a single-pass compression tests using Gleeble-3500 thermal simulator. The results indicate that the flow stress decreases with the increasing of temperature and the decreasing of strain rate. The dynamic recrystallization rate increases with the increasing of deformation temperature. By regression analysis, the mean activation energy and the stress exponent are determined to be 435.1KJ/mol-1and 5.0505 respectively. Meanwhile, the kinetic mathematical model of dynamic recrystallization and constitutive equation are established.The relationship of peak stress, peak strain and Z parameters is founded by using the data of flow stress curves.

scholarly journals Influence of Rare Earth on Dynamic Recrystallization Behavior of As-Cast 30Mn Steel

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Honghong Yan ◽  
Yong Hu ◽  
Dawen Zhao
Keyword(s):  
Rare Earth ◽  
Dynamic Recrystallization ◽  
Strain Rate Range ◽  
Compression Tests ◽  
Forming Process ◽  
Cast Slab ◽  
Forming Technology ◽  
Alloy Addition ◽  
Dynamic Recrystallization Behavior ◽  
Gleeble 3500

Based on casting-rolling compound forming process, the effect of rare earth on dynamic recrystallization (DRX) of as-cast 30Mn steel was investigated by the single-pass hot compression tests performed using a Gleeble-3500 thermomechanical simulator, and the deformation temperature range was 950°C–1150°C and strain rate range was 0.1–1 s−1. With the assistance of the process parameters, constitutive equations were used to obtain the activation energy and hot working equation. The dynamic recrystallization kinetics models of the tested steel were constructed. The results show that rare earth ferrosilicon alloy addition (0.2%, mass fraction) can delay the onset of DRX significantly and refine the hot deformation microstructures. All of the results indicate that the addition of rare earth into as-cast 30Mn steel is helpful to prepare excellent cast slab for the casting-rolling compound forming technology.

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.

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.

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.

Practical Acquisition and Application of Flow Stresses Emphasizing on Prediction Accuracy for Bearing Steel, STB2

2020 ◽  
Vol 830 ◽  
pp. 101-106
Author(s):  
Mohd Kaswandee Razali ◽  
Missam Irani ◽  
Man Soo Joun
Keyword(s):  
Flow Stress ◽  
Peak Stress ◽  
Bearing Steel ◽  
Peak Strain ◽  
Function Model ◽  
Model Flow ◽  
Stress Behaviors ◽  
Softening Coefficient ◽  
State Stress ◽  
Good Agreement

A phenomenological model presented by the authors in the previous study, which is a kind of two-region exponential function model, is used to describe flow stress behaviors of bearing steel, STB2. In this model, flow stress is calculated using two separated equations for hardening and softening regions. Peak stress, peak strain, hardening coefficient, steady state stress and softening coefficient are the required parameters for the model. These parameters are then either interpolated using linear regression or used to find some fitted functions of strain rate and temperature to identify the flow stress. The former is called the piecewise bi-linear function model (PLF model) while the latter the closed-form function model (CFF model). It has been shown that the flow stress curves of STB2 steel obtained by these two models are in good agreement with experimental results.

Dynamic Recrystallization Behavior of N08028 Corrosion Resistant Alloy

2014 ◽  
Vol 788 ◽  
pp. 396-405 ◽  
Author(s):  
Lei Wang ◽  
Feng Liu
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Kinetic Equations ◽  
Accurate Estimate ◽  
Compression Tests ◽  
Corrosion Resistant ◽  
Resistant Alloy ◽  
Dynamic Recrystallization Behavior ◽  
Corrosion Resistant Alloy ◽  
Relationship Of

The dynamic recrystallization (DRX) of N08028 corrosion resistant alloy was investigated by hot compression tests which were performed at the deformation temperatures from 1000°C to 1200°C and strain rate from 0.01s-1 to 1s-1 on a Gleeble-1500 thermo-mechanical simulator. The stress-strain curves at all strain rates showed the characteristics of DRX and exhibited a peak in the flow stress before reaching steady state. The microstructures after deformation demonstrated that DRX took place in all specimens. The results show that DRX occurs more easily with the decrease of strain rate and the increase of deformation temperature. By regression analysis, the activation energy in the entire range of deformation conditions, and the relationship of critical strain as well as strain for 50% DRX with deformation conditions were determined. A good agreement between the experimental and predicted results shows that the proposed DRX kinetic equations can give an accurate estimate of the DRX behavior in hot deformed N08028 corrosion resistant alloy.

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 Effect of Trace Magnesium Additions on the Dynamic Recrystallization in Cast Alloy 825 after One-Hit Hot-Deformation

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 36
Author(s):  
Munir Al-Saadi ◽  
Wangzhong Mu ◽  
Christopher N. Hulme-Smith ◽  
Fredrik Sandberg ◽  
Pär G. Jönsson
Keyword(s):  
Service Life ◽  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Cast Alloy ◽  
True Strain ◽  
Peak Strain ◽  
Compression Tests ◽  
Electron Backscattered Diffraction ◽  
Hollomon Parameter ◽  
Test Conditions

Alloy 825 is widely used in several industries, but its useful service life is limited by both mechanical properties and corrosion resistance. The current work explores the effect of the addition of magnesium on the recrystallization and mechanical behavior of alloy 825 under hot compression. Compression tests were performed under conditions representative of typical forming processes: temperatures between 1100 and 1250 °C and at strain rates of 0.1–10 s−1 to a true strain of 0.7. Microstructural evolution was characterized by electron backscattered diffraction. Dynamic recrystallization was found to be more prevalent under all test conditions in samples containing magnesium, but not in all cases of conventional alloy 825. The texture direction ⟨101⟩ was the dominant orientation parallel to the longitudinal direction of casting (also the direction in which the samples were compressed) in samples that contained magnesium under all test conditions, but not in any sample that did not contain magnesium. For all deformation conditions, the peak stress was approximately 10% lower in material with the addition of magnesium. Furthermore, the differences in the peak strain between different temperatures are approximately 85% smaller if magnesium is present. The average activation energy for hot deformation was calculated to be 430 kJ mol−1 with the addition of magnesium and 450 kJ mol−1 without magnesium. The average size of dynamically recrystallized grains in both alloys showed a power law relation with the Zener–Hollomon parameter, DD~Z−n, and the exponent of value, n, is found to be 0.12. These results can be used to design optimized compositions and thermomechanical treatments of alloy 825 to maximize the useful service life under current service conditions. No experiments were conducted to investigate the effects of such changes on the service life and such experiments should now be performed.

Constitutive Modeling for Flow Stress Behavior of Nimonic 80A Superalloy During Hot Deformation Process

2016 ◽  
Vol 35 (3) ◽  
pp. 327-336 ◽  
Author(s):  
Sendong Gu ◽  
Liwen Zhang ◽  
Chi Zhang ◽  
Wenfei Shen
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Hot Deformation ◽  
Critical Strain ◽  
Volume Fraction ◽  
Constitutive Models ◽  
Avrami Equation ◽  
Peak Strain ◽  
Compression Tests ◽  
Nimonic 80A

AbstractThe hot deformation characteristics of nickel-based alloy Nimonic 80A were investigated by isothermal compression tests conducted in the temperature range of 1,000–1,200°C and the strain rate range of 0.01—5 s–1on a Gleeble-1500 thermomechanical simulator. In order to establish the constitutive models for dynamic recrystallization (DRX) behavior and flow stress of Nimonic 80A, the material constantsα,nand DRX activation energyQin the constitutive models were calculated by the regression analysis of the experimental data. The dependences of initial stress, saturation stress, steady-state stress, dynamic recovery (DRV) parameter, peak strain, critical strain and DRX grain size on deformation parameters were obtained. Then, the Avrami equation including the critical strain for DRX and the peak strain as a function of strain was established to describe the DRX volume fraction. Finally, the constitutive model for flow stress of Nimonic 80A was developed in DRV region and DRX region, respectively. The flow stress values predicted by the constitutive model are in good agreement with the experimental ones, which indicates that the constitutive model can give an accurate estimate for the flow stress of Nimonic 80A under the deformation conditions.

Sign in / Sign up

Export Citation Format

Share Document