scholarly journals Hot Deformation Process Analysis and Modelling of X153CrMoV12 Steel

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1125 ◽  
Author(s):  
Michal Krbaťa ◽  
Maroš Eckert ◽  
Daniel Križan ◽  
Igor Barényi ◽  
Ivana Mikušová
Keyword(s):  
Hot Deformation ◽  
Process Analysis ◽  
True Strain ◽  
Peak Stress ◽  
High Strength ◽  
True Stress ◽  
Point Of View ◽  
Plastic Behavior ◽  
Hollomon Parameter ◽  
Wide Range

Analysis of the high temperature plastic behavior of high-strength steel X153CrMoV12 was developed in the temperature range of 800–1200 °C and the deformation rate in the range of 0.001–10 s−1 to the maximum value of the true strain 0.9%. Microstructural changes were observed using light optical microscopy (LOM) as well as atomic force microscopy (AFM). The effect of hot deformation temperature on true stress, peak stress and true strain was evaluated from the respective flow curves. Based on these results, steel transformation was discussed from the dynamic recovery and recrystallization point of view. Furthermore, a present model, taking into account the Zener–Hollomon parameter, was developed to predict the true stress and strain over a wide range of temperatures and strain rates. Using constitutive equations, material parameters and activation energy were derived, which can be subsequently applied to other models related to hot deformation behavior of selected tool steels. The experimental data were compassed to the ones obtained by the predictive model with the correlation coefficient R = 0.98267. These results demonstrate an appropriate applicability of the model for experimental materials in hot deformation applications.

Simulated Research on Hot Forming Mechanism of Sour Service Drill Pipe Steel

2011 ◽  
Vol 704-705 ◽  
pp. 266-272
Author(s):  
Mei Juan Hu ◽  
Peng Wang ◽  
Li Hong Han ◽  
Xin Li Han
Keyword(s):  
Constitutive Equation ◽  
Hot Deformation ◽  
Pipe Steel ◽  
True Strain ◽  
Drill Pipe ◽  
Peak Stress ◽  
True Stress ◽  
Experimental Results ◽  
Strain Rates ◽  
Sour Service

The dynamic mechanical behaviors of as-cast sour service drill pipe steel under development during hot deformation were studied in this paper by using Gleeble-3500 thermal mechanical simulator. The compressions were carried out at the temperature of 900°C, 1000°C, 1100°C, 1200°C and strain rates of 10s-1, 1s-1and 0.1s-1. The compress degree was about 70%, and then the maximum true strain for each specimen was 1.2. The experimental results show that the peak stress was related to the compression temperatures and the strain rates. Through respectively analyzing and studying the true stress-true strain curves, the hot deformation constitutive equation and the deformation activation energy were obtained by regression analysis. The evolution of microstructures at various strain rates and temperatures was discussed. Experimental results can provide scientific basis for analyzing the hot deformation processes and controlling quality. Keywords: sour service drill pipe, hot compression, true stress-true strain, constitutive equation, microstructure

Dynamically recrystallized austenitic grain in a low carbon advanced ultra-high strength steel (A-UHSS) microalloyed with boron under hot deformation conditions

2012 ◽  
Vol 1485 ◽  
pp. 143-148 ◽  
Author(s):  
I. Mejía ◽  
E. García-Mora ◽  
G. Altamirano ◽  
A. Bedolla-Jacuinde ◽  
J. M. Cabrera
Keyword(s):  
Grain Size ◽  
Hot Deformation ◽  
High Strength Steel ◽  
Picric Acid ◽  
True Strain ◽  
Research Work ◽  
High Strength ◽  
Low Carbon ◽  
Ultra High Strength Steel ◽  
Wide Range

ABSTRACTThis research work studies the dynamically recrystallized austenitic grain size (Drec) in a new family of low carbon NiCrCuV advanced ultra-high strength steel (A-UHSS) microalloyed with boron under hot deformation conditions. For this purpose, uniaxial hot-compression tests are carried out in a low carbon A-UHSS microalloyed with different amounts of boron (14, 33, 82, 126 and 214 ppm) over a wide range of temperatures (950, 1000, 1050 and 1100°C) and constant true strain rates (10−3, 10−2and 10−1s−1). Deformed samples are prepared and chemically etched with a saturated aqueous picric acid solution at 80°C in order to reveal theDrecand examined by light optical (LOM) and scanning electron microscopy (SEM). TheDrecis related to the Zener-Hollomon parameter (Z), and thereafter theDrecdivided by Burger's vector (b) is related to the steady state stress (σss) divided by the shear modulus (µ) (Derby model). Results shown that theDrecin the current steels is fine (≈ 23 μm) and almost equiaxed, and the recrystallized grain size-flow stress relationship observed after of plastic deformation is consistent with the general formulation proposed by Derby. It is corroborated that boron additions to the current A-UHSS do not have meaningful influence on theDrec.

Study of Hot Deformation Behavior of 6082 Aluminum Alloy

2016 ◽  
Vol 877 ◽  
pp. 340-346 ◽  
Author(s):  
Peng Long Wang ◽  
Hai Tao Jiang ◽  
Rui Jie Zhang ◽  
Shi Yao Huang
Keyword(s):  
Aluminum Alloy ◽  
Strain Rate ◽  
Work Hardening ◽  
Hot Deformation ◽  
Processing Map ◽  
Peak Stress ◽  
True Stress ◽  
Stress Strain ◽  
Hollomon Parameter ◽  
6082 Aluminum Alloy

A set of hot deformation experiments 6082 aluminum alloy were carried out on the Gleeble-3500 thermal simulation machine. The true stress-strain curves were obtained in the condition of temperatures 425 ̊C,450 ̊C,475 ̊C and 500 ̊C, strain rate 0.01s-1, 0.1s-1, 1s-1 and 10s-1. At the low strain rate (0.01s-1, 0.1s-1), true stress-strain curves exhibited typical work hardening and flow softening features, but at the high strain rate (1s-1, 10s-1), true stress-strain curves just exhibited typical work hardening. The peak stress of current alloy decreased with temperature and increased with strain rate, which can be represented by a hyperbolic sine equation using the Zener-Hollomon parameter (Z). The processing map was calculated and analyzed according to dynamic materials mode (DMM). The processing map showed the reasonable hot working region of 6082 aluminum ally.

Dynamic Recrystallization of 18Ni(1700MPa) Maraging Steel During Hot Deformation

2012 ◽  
Vol 602-604 ◽  
pp. 441-447 ◽  
Author(s):  
Fei Zhao ◽  
Yong Hai Ren ◽  
Yan Yan
Keyword(s):  
Dynamic Recrystallization ◽  
Maraging Steel ◽  
Hot Deformation ◽  
Critical Stress ◽  
Critical Strain ◽  
True Strain ◽  
Peak Stress ◽  
True Stress ◽  
Strain Rates ◽  
High Deformation

Dynamic recrystallization(DRX) behaviors of 18Ni maraging steel during hot deformation have been investigated by single-pass thermo-mechanical simulative experiment at temperatures of 1173K-1323K and strain rates of 0.001s-1-1s-1. The results show that the true stress-true strain curves type of this alloy is DRX. The DRX in 18Ni maraging steel is easy to occur at low strain rates and high deformation temperatures. Using regression analysis, the activation energy(Q) for DRX of 18Ni maraging steel was calculated to be 413544.96J/mol. The constitutive equation of peak stress for DRX was also obtained. The mathematical models of critical stress and critical strain were finally established.

Evolution of Flow Stress and Microstructure in an Al-Zn-MgSeries Alloy during Hot Deformation

2007 ◽  
Vol 546-549 ◽  
pp. 965-970
Author(s):  
Jian Shen ◽  
Yong Heng ShangGuan ◽  
Xiao Dong Yan
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
Elevated Temperatures ◽  
Subgrain Size ◽  
True Strain ◽  
Large Angle ◽  
Peak Stress ◽  
Hollomon Parameter ◽  
Dislocation Generation

Evolution of flow stress and microstructures of an Al-Zn-Mg series alloy during deformation at elevated temperatures and large ranges of strain rates have been investigated by isothermal compression testing on Gleeble 1500 thermomechanical simulator. The results showed that the flow stress exhibited a characteristic of peak stress followed by smoothing out in the imposed strain rate and temperature ranges. The hot deformation of the alloy is a thermally activated process, which is controlled by rate-controlling mechanisms of dislocation generation and dislocation annihilation. The flow stress decreases with the increase of true strain at higher temperature and lower strain rate, indicating that dynamic softening dominates instead of strain hardening during hot deformation of the alloy. Microstructure observation revealed that typical subgrain cluster structures obviously developed in the original elongated grains of the alloy during hot deformation. The subgrain size of the alloy increased with deformation temperature and downturn of strain rate, where the Zener-Hollomon parameter increased. Fine equiaxed recrystallized grains with large-angle grain boundaries developed significantly in the alloy during hot compression at low Z values, implying activation of dynamic recrystallization.

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.

Taylor Cylinder Testing of High Strength Steels for Hard Target Warhead Applications

2009 ◽  
Author(s):  
Rachel Russo ◽  
Nicholas Dutton ◽  
Bart Baker ◽  
Karen Torres ◽  
Stanley E. Jones ◽  
...  
Keyword(s):  
Impact Test ◽  
True Strain ◽  
High Strength Steels ◽  
High Strength ◽  
True Stress ◽  
Dimensional Theory ◽  
One Dimensional ◽  
Cylinder Test ◽  
Taylor Impact ◽  
The One

A one-dimensional analysis of the Taylor impact test [4] has been used to estimate the quasi-static stress for several different alloys. One criticism of this work was the use of Taylor cylinder test data to estimate the quasi-static true stress/true strain compression diagram. The one-dimensional theory does accommodate this estimate. The purpose of this paper is to demonstrate that this process leads to acceptable results by analyzing a series of high, medium, and low strength materials.

scholarly journals Constitutive Descriptions and Restoration Mechanisms of a Fe-17Cr Alloy during Deformation at Temperatures of 700–1000 °C

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5022
Author(s):  
Fei Gao ◽  
Zilong Gao ◽  
Qiyong Zhu ◽  
Zhenyu Liu
Keyword(s):  
Shear Band ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Flow Behavior ◽  
Peak Stress ◽  
Type Model ◽  
Hollomon Parameter ◽  
Transmission Electron ◽  
Precession Electron Diffraction ◽  
Increasing Temperature

The deformation behavior for highly purified Fe-17Cr alloy was investigated at 700~1000 °C and 0.5~10 s−1. The microstructure evolution and corresponding mechanism during deformation were studied in-depth, using electron backscattering diffraction, transmission electron microscopy and precession electron diffraction. During deformation, dynamic recrystallization (DRX) occurred, along with extensive dynamic recovery, and the active DRX mechanism depended on deformation conditions. At higher Zener-Hollomon parameter (Z ≥ 5.93 × 1027 s−1), the development of the shear band was promoted, and then continuous DRX was induced by the formation and intersection shear band. At lower Zener-Hollomon parameter (Z ≤ 3.10 × 1025 s−1), the nucleation of the new grain was attributed to the combination of continuous DRX by uniform increase in misorientation between subgrains and discontinuous DRX by grain boundary bulging, and with increasing temperature, the effect of the former became weaker, whereas the effect of the latter became stronger. The DRX grain size increased with the temperature. For alleviating ridging, it seems advantageous to activate the continuous DRX induced by shear band through hot deformation with higher Z. In addition, the modified Johnson-Cook and Arrhenius-type models by conventional way were developed, and the modified Johnson-Cook model was developed, using the proposed way, by considering strain dependency of the material parameters. The Arrhenius-type model was also modified by using the proposed way, through distinguishing stress levels for acquiring partial parameter and through employing peak stress to determine the activation energy and considering strain dependency of only other parameters for compensating strain. According to our comparative analyses, the modified Arrhenius-type model by the proposed approach, which is suggested to model hot-deformation behavior for metals having only ferrite, could offer a more accurate prediction of flow behavior as compared to other developed models.

scholarly journals Hot Deformation Behavior and Processing Maps of Fe-30Mn-0.11C Steel

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1940 ◽  
Author(s):  
Jianmei Kang ◽  
Yuhui Wang ◽  
Zhimeng Wang ◽  
Yiming Zhao ◽  
Yan Peng ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
True Strain ◽  
Peak Stress ◽  
Strain Rates ◽  
Processing Maps ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
High Deformation

Hot deformation behavior of Fe-30Mn-0.11C steel was investigated. Hot compression tests were carried out at various temperatures ranging from 800 °C to 1200 °C and at different strain rates of 0.01 s−1 to 10 s−1. The constitutive equation based on peak stress was established. Hot processing maps at different strains and recrystallization diagrams were also established and analyzed. The results show that dynamic recrystallization easily occur at high deformation temperatures and low strain rates. Safe and unstable zones are determined at the true strain of 0.6 and 0.7, and the hot deformation process parameters of partial dynamic recrystallization of the tested steel are also obtained.

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