High Temperature Compression Deformation Behavior and Rheological Stress Model of HRB400

2013 ◽  
Vol 470 ◽  
pp. 310-315
Author(s):  
Yu Yan Liu ◽  
Jia Zhen Zang ◽  
Yang Wang ◽  
Sheng Hu

A series single-pass compression tests of HRB400 slab under the circumstances of different deformation temperature and deformation rate are carried out with Gleeble-1500D thermal simulation testing machine. The experimental results shows as follows. The true stress-true strain curves of the compression process are got from the tests. The state activation energy is 353.542kJ/mol and a mathematical model of high-temperature rheological stress is established. The calculated results by the rheological model are consistent with the experiments.

2013 ◽  
Vol 17 (5) ◽  
pp. 1523-1528
Author(s):  
Bao-Hua Jia ◽  
Wei-Dong Song ◽  
Hui-Ping Tang ◽  
Jian-Guo Ning

Isothermal compression tests of TC18 titanium alloy at the deformation temperatures ranging from 25?C to 800?C and strain rate ranging from 10-4 to 10-2 s-1 were conducted by using a WDW-300 electronic universal testing machine. The hot deformation behavior of TC18 was characterized based on an analysis of the true stress-true strain curves of TC18 titanium alloy. The curves show that the flow stress increases with increasing the strain rate and decreases with increasing the temperature, and the strain rate play an important role in the flow stress when increasing the temperatures. By taking the effect of strain into account, an improved constitutive relationship was proposed based on the Arrhenius equation. By comparison with the experimental results, the model prediction agreed well with the experimental data, which demonstrated the established constitutive relationship was reliable and can be used to predict the hot deformation behavior of TC18 titanium alloy.


2014 ◽  
Vol 922 ◽  
pp. 807-812 ◽  
Author(s):  
Robert Werner ◽  
Emanuel Schwaighofer ◽  
Martin Schloffer ◽  
Helmut Clemens ◽  
Janny Lindemann ◽  
...  

In the present study the high-temperature deformation behavior of a caste and subsequently HIPed β-solidifying γ-TiAl-based alloy with a nominal composition of Ti-43.5Al-4Nb-1Mo-0.1B (in at. %), termed TNM alloy, is investigated. At room temperature this alloy consists of ordered γ-TiAl, α2-Ti3Al and βo-TiAl phases. By increasing the temperature, α2and βodisorder to α and β, respectively. In order to get a better understanding of dynamic recovery and recrystallization processes during thermomechanical processing, isothermal compression tests on TNM specimens are carried out on a Gleeble®3500 simulator. These tests are conducted at temperatures ranging from 1100 °C to 1250 °C (in the α/α2+β/βo+γ phase field region) applying strain rates in the range of 0.005 s-1to 0.5 s-1up to a true strain of 0.9. The evolution of microstructure along with the dynamically recrystallized grain size during hot deformation is examined by scanning electron microscopy (SEM). The flow softening behavior after reaching the peak stress in the true stress-true strain curve is attributed to dynamic recrystallization. By using the Zener-Hollomon parameter as a temperature-compensated strain rate the dependence of flow stress on temperature and strain rate is shown to follow a hyperbolic-sine Arrhenius-type relationship.


2009 ◽  
Vol 1243 ◽  
Author(s):  
I. Mejía ◽  
S. González-Sala ◽  
J.M. Cabrera

ABSTRACTThis research work deals the influence of boron content on the high temperature deformation behavior of a low carbon advanced high strength steel (AHSS). For this purpose high temperature tensile and compression tests are carried out at different temperatures and constant true strain rates by using an Instron testing machine equipped with a radiant cylindrical furnace. Tensile tests are carried out at different temperatures (650, 750, 800, 900 and 1000°C) at a constant true strain rate of 0.001 s-1. Uniaxial hot compression tests are also performed over a wide range of temperatures (950, 1000, 1050 and 1100°C) and constant true strain rates (10-3, 10-2 and 10-1 s-1). In general, experimental results of hot tensile tests show an improvement of the hot ductility of the AHSS microalloyed with boron, although poor ductility at low temperatures (650 and 750°C). The fracture surfaces of the AHSS tested at temperatures showing the higher ductility (800, 900 and 1000°C) indicate that the fracture mode is a result of ductile failure, whereas in the region of poor ductility the fracture mode is of the ductile-brittle type failure. On the other hand, experimental results of hot compression tests show that both peak stress and peak strain tend to decrease in the AHSS microalloyed with boron, which indicates that boron generates a sort of solid solution softening effect in similar a way to other interstitial alloying elements in steel. Likewise, hot flow curves of the AHSS microalloyed with boron show an acceleration of the onset of dynamic recrystallization (DRX) and a delay of the recrystallization kinetics. Results are discussed in terms of boron segregation towards austenitic grain boundaries and second phase particles precipitation during plastic deformation and cooling.


2012 ◽  
Vol 538-541 ◽  
pp. 945-950 ◽  
Author(s):  
Jiang Kun Fan ◽  
Hong Chao Kou ◽  
Min Jie Lai ◽  
Bin Tang ◽  
Hui Chang ◽  
...  

The effects of processing parameters on deformation behavior of a new near β titanium alloy were investigated by using compression tests. The experiments were carried out in the Gleeble-3800 thermal and mechanical simulator in the temperature range of 770-970°C and strain rate range of 10-3-10s-1, and height direction reduction of 70%. The results show that the flow stress of Ti-7333 titanium alloy increases obviously with the strain and reaches a peak, then decreases to a steady value. The steady and peak stress significantly decreases with the increase of deformation temperature and decrease of strain rate. The flow stress model of Ti-7333 titanium alloy during high temperature deformation was established by using the regression method. The average relative difference between the calculated and experimental flow stress is 6.33%. The flow stress model can efficiently predict the deformation behavior of Ti-7333 titanium alloy during high temperature deformation.


2007 ◽  
Vol 551-552 ◽  
pp. 365-372 ◽  
Author(s):  
C.H. Park ◽  
Young Gun Ko ◽  
Chong Soo Lee ◽  
Kyung Tae Park ◽  
Dong Hyuk Shin ◽  
...  

High-temperature deformation behavior and microstructural evolution process of ELI Ti-6Al-4V alloy having martensite microstructure were investigated with the variation of strain, strain rate and temperature. A series of hot compression tests was carried out isothermally for martensite microstructure at the true strain range of 0.6 to 1.4, strain rate range of 10-3 s-1 to 1 s-1 and temperature range of 700 oC to 950 oC. The processing maps for martensite microstructures were constructed on the basis of dynamic materials model (DMM). At the strain rate higher than 10-2 s-1 and the temperature lower than 750 oC regions of flow instability such as adiabatic shear band and micro-cracking were observed. Also, after imposing an effective strain of ≈ 1.4, deformed microstructure showed the significant kinking/bending behavior of lamellae resulting in the dynamic globularization associated with the fragmentation of beta-phase. The effects of strain, strain rate and temperature for dynamic globularization were discussed based on the microstructure and efficiency of power dissipation.


Author(s):  
Sijia Zhong ◽  
Jianfeng Shi ◽  
Jinyang Zheng

Polyethylene (PE) pipes have been applied in transportation of key energy medium such as natural gas in the past decades. The mechanical property of PE is of great importance for better design and safer application of PE pipeline system. The large deformation behavior is a key character of PE, not only for its significant strain rate sensitivity, but also for localized necking process after yielding. In this paper, a new constitutive modeling method was proposed to charaterize the rate-denpendent large deformation behavior of PE, in which the true stress is regarded as a function of true stain and true strain rate alone. Uniaxial tensile tests of PE were conducted under various cross-head speeds, and a digital camera was used to record the real-time deformation of specimens. By separating the composite effect into respective effect of local true strain and strain rate on the local true stress in the necking region, a phenomenological model for describing the rate-dependent deformation behavior under uniaxial tension was ealstablished. Model results were validated and found in good agreement with experimental data.


2017 ◽  
Vol 36 (7) ◽  
pp. 701-710
Author(s):  
Jun Cai ◽  
Kuaishe Wang ◽  
Xiaolu Zhang ◽  
Wen Wang

AbstractHigh temperature deformation behavior of BFe10-1-2 cupronickel alloy was investigated by means of isothermal compression tests in the temperature range of 1,023~1,273 K and strain rate range of 0.001~10 s–1. Based on orthogonal experiment and variance analysis, the significance of the effects of strain, strain rate and deformation temperature on the flow stress was evaluated. Thereafter, a constitutive equation was developed on the basis of the orthogonal analysis conclusions. Subsequently, standard statistical parameters were introduced to verify the validity of developed constitutive equation. The results indicated that the predicted flow stress values from the constitutive equation could track the experimental data of BFe10-1-2 cupronickel alloy under most deformation conditions.


2019 ◽  
Vol 51 (1) ◽  
pp. 467-481
Author(s):  
Suwaree Chankitmunkong ◽  
Dmitry G. Eskin ◽  
Chaowalit Limmaneevichitr

Abstract Aluminum piston alloys of the AA4032 type are produced by direct-chill (DC) casting and subsequent forging; therefore, it is important to understand their thermomechanical behavior. In recent years, it was shown that additions of Cu and Er could improve mechanical properties of these alloys at room and high temperatures. In this work, we studied the constitutive behavior of AA4032-type alloys with and without Cu and Er additions. The experimental true stress–true strain curves were obtained by compression tests under various temperatures [683 K to 723 K (410 °C to 450 °C)] and strain rates (0.01 to 10 s−1) to determine constitutive parameters [strain-rate sensitivity, activation energy, and Zener–Hollomon (Z) parameter] for the hot deformation behavior of AA4032-type piston alloys with and without additions of Cu and Er. The flow stress decreased with increasing deformation temperature and decreasing strain rate. The results also showed that increasing the Cu content increased the flow stress over the applied range of deformation conditions due to solid-solution strengthening and the formation of primary Si particles, which led to an increase in the activation energy during hot deformation. Moreover, the main microstructural damage in the AA4032 alloy with 3.5 pct Cu was predominantly due to the cracking of primary Si particles. Additions of 0.4 pct Er and 3.5 pct Cu lower the activation energy of deformation, Q, as compared to the base alloy and the alloy with 3.5 pct Cu. The microstructures in the deformed specimens consisted of subgrains, recrystallized grains, and fine eutectic phases. The alloys containing Er demonstrated more polygonized grains at a low strain rate than the alloys without Er, indicating that Er hindered recrystallization development. The peak stress of the AA4032 alloy with 3.5 pct Cu alloy was higher than for the base AA4032 alloy and for the AA4032 alloy with 3.5 pct Cu and 0.4 pct Er additions, which was attributed to the prevalence of the work-hardening mechanism over the softening mechanism.


2012 ◽  
Vol 190-191 ◽  
pp. 517-521
Author(s):  
Bao Guo Yuan ◽  
Qiang Chen ◽  
Hai Ping Yu ◽  
Ping Li ◽  
Ke Min Xue ◽  
...  

Compression tests of the hydrogenated Ti6Al4V0.2H alloy were carried out using an Instron 5569 machine at room temperature. True stress-strain curves of the hydrogenated Ti6Al4V0.2H alloy under different compressive strains were obtained. Microstructure evolution of the hydrogenated Ti6Al4V0.2H alloy during the process of compression was investigated by optical microscopy and transmission electron microscopy. Results show that true stress-true strain curves of Ti6Al4V0.2H alloy have good repeatability. The deformation of grains, the dislocation density and slipping evolution during the process of compression are discussed.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1940 ◽  
Author(s):  
Jianmei Kang ◽  
Yuhui Wang ◽  
Zhimeng Wang ◽  
Yiming Zhao ◽  
Yan Peng ◽  
...  

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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