Dynamic Recrystallization Behavior and Softening Kinetics in 3Mn-1.5Al TRIP Steels

2011 ◽  
Vol 287-290 ◽  
pp. 330-333 ◽  
Author(s):  
Adam Grajcar ◽  
Roman Kuziak
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Large Fraction ◽  
Solute Drag ◽  
Vacuum Induction Furnace ◽  
Compression Tests ◽  
Hollomon Parameter ◽  
Trip Steels ◽  
Dynamic Recrystallization Behavior ◽  
Parameter Values

Two 0.17C-3Mn-1.5Al-0.2Si-0.2Mo steels with and without Nb microaddition were melted in a vacuum induction furnace. The steels are characterized by bainitic-martensitic structures with large fraction of retained austenite. To design a thermomechanical treatment for steels with required multiphase structures a knowledge of their hot deformation resistance and softening kinetics is of primary importance. The paper presents the results of the compression tests carried out at various temperatures and strain rates using the Gleeble simulator. A softening kinetics was determined in a double-hit compression test. It was found that the dynamic recrystallization was a process controlling work hardening of steels except for hot deformation conditions characterized by the highest Zener-Hollomon parameter values. Nb microalloyed steel has higher flow stresses and peak strains than the steel without Nb. A solute drag effect of niobium results also in a slower recrystallization kinetics for the Nb containing steel.

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.

scholarly journals Investigation on Dynamic Recrystallization Behavior of Martensitic Stainless Steel

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Facai Ren ◽  
Fei Chen ◽  
Jun Chen
Keyword(s):  
Stainless Steel ◽  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Martensitic Stainless Steel ◽  
Flow Curves ◽  
Hollomon Parameter ◽  
Temperature Range ◽  
Characteristic Points ◽  
Dynamic Recrystallization Behavior ◽  
Recrystallized Grain Size

The hot deformation behavior of X20Cr13 martensitic stainless steel was studied using the hot compression flow curves corresponding to the temperature range of 900–1150°C under strain rates from 0.01 to 10 s−1. A new mathematical model to estimate the flow stress under hot deformation conditions up to the peak of the flow curves was developed. The critical strains for initiation of dynamic recrystallization were also derived by the developed model. Furthermore, the effects of Zener-Hollomon parameter on the characteristic points of the flow curves were studied using the power law relation. The deformation activation energy obtained for this steel was 359.4 kJ/mol in the temperature range from 900°C to 1150°C. At the same time, the Avrami kinetic equation of dynamic recrystallization for X20Cr13 steel and the recrystallized grain size model were also established. Good agreement was obtained between the predictions and the experimental values.

Softening Kinetics in Nb-Microalloyed TRIP Steels with Increased Mn Content

2011 ◽  
Vol 314-316 ◽  
pp. 119-122 ◽  
Author(s):  
Adam Grajcar ◽  
Roman Kuziak
Keyword(s):  
Hot Deformation ◽  
Static Recrystallization ◽  
Solute Drag ◽  
Compression Tests ◽  
Trip Steels ◽  
Thermally Activated ◽  
Nb Microalloyed Steel ◽  
Mn Content ◽  
Kinetics Of ◽  
Thermally Activated Process

Two 5Mn-1.5Al TRIP steels with and without Nb microaddition were developed in the present study. The steels contain bainite, martensite, interlath retained austenite and martensite- austenite islands. The paper presents the results of the compression tests carried out at various temperatures using the Gleeble simulator. To analyze the kinetics of static recrystallization in these steels, a softening kinetics were determined in a double-hit compression test. It was found that the dynamic recovery is a main thermally activated process occurring during hot deformation. The Nb microalloyed steel has higher flow stresses and peak strains than the Nb-free steel. A solute drag effect of Nb results in a slower softening kinetics of Nb containing steel. The effects of Mn on the retardation of Nb(C,N) precipitation and hot deformation characteristics are also discussed.

Dynamic recrystallization behavior during hot deformation of as-cast 4Cr5MoSiV1 steel

2021 ◽  
Vol 56 (14) ◽  
pp. 8762-8777
Author(s):  
Yahui Han ◽  
Changsheng Li ◽  
Jinyi Ren ◽  
Chunlin Qiu ◽  
Shuaishuai Chen ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Recrystallization Behavior ◽  
Dynamic Recrystallization Behavior

The Constitutive Model for High Temperature Flow Behavior of SiC/6168Al Composite

2015 ◽  
Vol 1089 ◽  
pp. 37-41
Author(s):  
Jiang Wang ◽  
Sheng Li Guo ◽  
Sheng Pu Liu ◽  
Cheng Liu ◽  
Qi Fei Zheng
Keyword(s):  
Constitutive Model ◽  
Hot Deformation ◽  
Flow Behavior ◽  
Type Equation ◽  
Strain Rate Range ◽  
Compression Tests ◽  
Stress Strain ◽  
Hollomon Parameter ◽  
Proposed Model ◽  
Relationship Of

The hot deformation behavior of SiC/6168Al composite was studied by means of hot compression tests in the temperature range of 300-450 °C and strain rate range of 0.01-10 s-1. The constitutive model was developed to predict the stress-strain curves of this composite during hot deformation. This model was established by considering the effect of the strain on material constants calculated by using the Zenter-Hollomon parameter in the hyperbolic Arrhenius-type equation. It was found that the relationship of n, α, Q, lnA and ε could be expressed by a five-order polynomial. The stress-strain curves obtained by this model showed a good agreement with experimental results. The proposed model can accurately describe the hot flow behavior of SiC/6168Al composite, and can be used to numerically analyze the hot forming processes.

Constitutive Equation for 3104 Alloy at High Temperatures in Consideration of Strain

2016 ◽  
Vol 35 (6) ◽  
pp. 599-605 ◽  
Author(s):  
Fuqiang Zhen ◽  
Jianlin Sun ◽  
Jian Li
Keyword(s):  
Hot Deformation ◽  
Flow Behavior ◽  
Temperature Correction ◽  
Strain Rates ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Element Analysis ◽  
Hollomon Parameter ◽  
The Finite Element Analysis ◽  
Effects Of Temperature

AbstractThe flow behavior of 3104 aluminum alloy was investigated at temperatures ranging from 250°C to 500°C, and strain rates from 0.01 to 10 s−1 by isothermal compression tests. The true stress–strain curves were obtained from the measured load–stroke data and then modified by friction and temperature correction. The effects of temperature and strain rate on hot deformation behavior were represented by Zener–Hollomon parameter including Arrhenius term. Additionally, the influence of strain was incorporated considering the effect of strain on material constants. The derived constitution equation was applied to the finite element analysis of hot compression. The results show that the simulated force is consistent with the measured one. Consequently, the developed constitution equation is valid and feasible for numerical simulation in hot deformation process of 3104 alloy.

Study on Dynamic Recrystallization Behavior in Deformed Austenite of 52100 Steel by Using JMAK-Model

2013 ◽  
Vol 275-277 ◽  
pp. 1833-1837
Author(s):  
Ke Lu Wang ◽  
Shi Qiang Lu ◽  
Xin Li ◽  
Xian Juan Dong
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Volume Fraction ◽  
True Strain ◽  
Strain And Strain Rate ◽  
Average Grain Size ◽  
Dynamic Recrystallization Behavior ◽  
Simulation And Experiment ◽  
Good Agreement

A Johnson-Mehl-Avrami-Kolmogorov (JMAK)-model was established for dynamic recrystallization in hot deformation process of 52100 steel. The effects of hot deformation temperature, true strain and strain rate on the microstructural evolution of the steel were physically studied by using Gleeble-1500 thermo-mechanical simulator and the experimental results were used for validation of the JMAK-model. Through simulation and experiment, it is found that the predicted results of DRX volume fraction, DRX grain size and average grain size are in good agreement with the experimental ones.

scholarly journals Hot Deformation Behavior of a Ni-Based Superalloy with Suppressed Precipitation

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 605
Author(s):  
Franco Lizzi ◽  
Kashyap Pradeep ◽  
Aleksandar Stanojevic ◽  
Silvana Sommadossi ◽  
Maria Cecilia Poletti
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Hot Deformation ◽  
Strain Rates ◽  
Compression Tests ◽  
Deformation Bands ◽  
Stress Softening ◽  
Relative Stress ◽  
The Matrix ◽  
Thermomechanical Processes

Inconel®718 is a well-known nickel-based super-alloy used for high-temperature applications after thermomechanical processes followed by heat treatments. This work describes the evolution of the microstructure and the stresses during hot deformation of a prototype alloy named IN718WP produced by powder metallurgy with similar chemical composition to the matrix of Inconel®718. Compression tests were performed by the thermomechanical simulator Gleeble®3800 in a temperature range from 900 to 1025 °C, and strain rates scaled from 0.001 to 10 s−1. Flow curves of IN718WP showed similar features to those of Inconel®718. The relative stress softening of the IN718WP was comparable to standard alloy Inconel®718 for the highest strain rates. Large stress softening at low strain rates may be related to two phenomena: the fast recrystallization rate, and the coarsening of micropores driven by diffusion. Dynamic recrystallization grade and grain size were quantified using metallography. The recrystallization grade increased as the strain rate decreased, although showed less dependency on the temperature. Dynamic recrystallization occurred after the formation of deformation bands at strain rates above 0.1 s−1 and after the formation of subgrains when deforming at low strain rates. Recrystallized grains had a large number of sigma 3 boundaries, and their percentage increased with strain rate and temperature. The calculated apparent activation energy and strain rate exponent value were similar to those found for Inconel®718 when deforming above the solvus temperature.

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