Characterization of Hot Workability of Boron-Added Modified 9Cr-1Mo Steel (P91B) Using Dynamic Materials Model

2015 ◽  
Vol 830-831 ◽  
pp. 325-328
Author(s):  
Marimuthu Arvinth Davinci ◽  
Dipti Samantaray ◽  
Utpal Borah ◽  
Shaju K. Albert ◽  
Arun Kumar Bhaduri
Keyword(s):  
Processing Map ◽  
Thermomechanical Processing ◽  
Strain Rates ◽  
Hot Workability ◽  
Isothermal Compression ◽  
Compression Tests ◽  
Microstructural Investigation ◽  
Dynamic Materials ◽  
Dynamic Materials Model

Elevated temperature workability of Boron added modified 9Cr-1Mo steel is studied in temperature range 1223-1473K and strain rates of 0.001-10s-1 using Dynamic Materials Model. Towards this end hot isothermal compression tests are carried out and the experimental results are used to obtain processing map. Extensive microstructural investigation is carried out to validate different domains of processing map. On the basis of the microstructurally validated processing map, parameters for the thermomechanical processing of P91B are recommended.

Hot Deformation Characterization of Mg-Sm-Zn-Zr Alloy Using Artificial Neural Network and 3D Processing Map

2016 ◽  
Vol 723 ◽  
pp. 252-257
Author(s):  
Ruo Han Chang ◽  
Zhong Yi Cai ◽  
Chao Jie Che
Keyword(s):  
Processing Map ◽  
Processing Parameters ◽  
Maximum Efficiency ◽  
Strain Rates ◽  
Hot Workability ◽  
Compression Tests ◽  
Bp Network ◽  
Wide Range ◽  
3D Processing ◽  
Zr Alloy

The true stress-strain data from isothermal hot compression tests on Gleeble-1500D thermo mechanical simulator, in a wide range of temperatures (350-450°C) and strain rates (0.001-1s-1), was employed to establish the PSO-BP network prediction model and 3D processing map of Mg-Sm-Zn-Zr alloy. It was found that the PSO-BP model could be efficient and accurate in predicting flow stress, most of relative errors were in the range of -4% to 6%, and the average relative error was found to be 1.52%. Then considering the effect of strain, the 3D processing map was established to characterize the hot workability of the alloy. The 3D processing map exhibited the maximum efficiency domain and the instability domain, which could be used to determine the optimal deformation conditions. The optimum processing parameters of Mg-Sm-Zn-Zr alloy were deformation temperatures of 400-450°C and strain rates of 0.003-0.1s-1.

Measurement of the Material State Including the Effects of Recovery and Recrystallization

2000 ◽  
Author(s):  
M. E. Bange ◽  
A. J. Beaudoin ◽  
M. G. Stout ◽  
S. R. MacEwen
Keyword(s):  
Elevated Temperatures ◽  
High Strain ◽  
Quantitative Measure ◽  
Experimental Program ◽  
Strain Rates ◽  
Compression Tests ◽  
State Variable ◽  
Mechanical Threshold ◽  
Material State

Abstract Deformation at elevated temperatures in combination with high strain rates leads to recovery and recrystallization in aluminum alloys. Previous work in recrystallization has emphasized the detailing of microstructural trend in progression from the deformed to the annealed state. In the following, we examine the effect of rate dependence on deformation on AA 5182 and AA 6061. It is demonstrated that identification of underlying microstructural mechanisms is critical. An experimental program is then outlined for characterization of recovery and recrystallization of AA 5182. Instantaneous hardening rate and flow stress are developed from interrupted compression tests. These data are used to establish a quantitative measure of recovery through evaluation of a state variable for work hardening, the mechanical threshold. It is intended that the results serve as a foundation for development of relations for evolution of a mechanical state variable in the presence of recrystallization. Such a framework is necessary for the practical prediction of interstand recrystallization in hot rolling operations.

The Optimal Selection of Extrusion Parameters of As-Cast TC27 Titanium Alloy Based on Processing-Map

2017 ◽  
Vol 898 ◽  
pp. 1134-1139
Author(s):  
Xue Fei Li ◽  
Ai Xue Sha ◽  
Xu Huang ◽  
Li Jun Huang
Keyword(s):  
Titanium Alloy ◽  
Flow Stress ◽  
Strain Rate ◽  
Processing Map ◽  
True Strain ◽  
Great Influence ◽  
Stable Condition ◽  
Dynamic Materials ◽  
Dynamic Materials Model ◽  
Selection Of

The hot deformation behavior of TC27 titanium alloy at the temperatures of 900-1150 °C and the strain rate of 0.01-10 s-1, the height reduction of 70%, was investigated in the isothermal compression test to identify the optimal extrusion parameters. The processing-map of TC27 titanium alloy was constructed based on dynamic materials model (DMM) and principle of Prasad*s instability. The conclusion shows that temperature and strain rate of deformation had a great influence on flow stress. At the beginning of deformation, the flow stress increased quickly with the augment of true strain and decreased slowly after flow stress reaching to the maximum value. Finally, flow stress tended to relatively stable condition. The flow stress decreased with the increase of temperature and increased with the increase of strain rate. The TC27 titanium alloy was sensitive to temperature and strain rate. Processing-map exhibited two peak efficiencies of power dissipation; one peak was 49% at 900°C/0.01 s-1, which dynamic recovery occured. The other peak was also 49% at 1050 °C /0.01s-1, which dynamic recrystallization occured in the domain. Besides, there were two instability areas in the processing-map which should be avoided during the extrusion. Therefore, in order to obtain the satisfactory properties, the parameters that 1050 °C and 0.01 s-1 were selected in the extrusion.

Hot working of SP-700 titanium alloy with lamellar α + β starting structure using a processing map

2020 ◽  
Vol 111 (4) ◽  
pp. 297-306
Author(s):  
Amir Hosein Sheikhali ◽  
Maryam Morakkabati
Keyword(s):  
Titanium Alloy ◽  
Strain Rate ◽  
Hot Deformation ◽  
Processing Map ◽  
Microstructural Analysis ◽  
Shear Bands ◽  
Alpha Phase ◽  
Strain Rates ◽  
Compression Tests ◽  
Temperature Range

Abstract In this study, hot deformation behavior of SP-700 titanium alloy was investigated by hot compression tests in the temperature range of 700-9508C and at strain rates of 0.001, 0.1, and 1 s-1. Final mechanical properties of the alloy (hot compressed at different strain rates and temperatures) were investigated using a shear punch testing method at room temperature. The flow curves of the alloy indicated that the yield point phenomenon occurs in the temperature range of 800- 9508C and strain rates of 0.1 and 1 s-1. The microstructural analysis showed that dynamic globularization of the lamellar α phase starts at 7008C and completes at 8008C. The alpha phase was completely eliminated from b matrix due to deformation- induced transformation at 8508C. The microstructure of specimens compressed at 8508C and strain rates of 0.001 and 0.1 s-1showed the serration of beta grain boundaries, whereas partial dynamic recrystallization caused a necklace structure by increasing strain rate up to 1 s-1. The specimen deformed at 7008C and strain rate of 1 s-1was located in the instability region and localized shear bands formed due to the low thermal conductivity of the alloy. The processing map of the alloy exhibited a peak efficiency domain of 54% in the temperature range of 780-8108C and strain rates of 0.001- 0.008 s-1. The hot deformation activation energy of the alloy in the α/β region (305.5 kJ mol-1) was higher than that in the single-phase β region (165.2 kJ mol-1) due to the dynamic globularization of the lamellar a phase.

Thermal Deformation Behavior and Processing Map of Al-Mg-Er Alloy

2018 ◽  
Vol 913 ◽  
pp. 30-36
Author(s):  
Ran Liu ◽  
Hui Huang ◽  
Ya Liu ◽  
Li Rong
Keyword(s):  
Flow Stress ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Material Model ◽  
Instability Criterion ◽  
Strain Rates ◽  
Processing Maps ◽  
Hot Workability ◽  
Compression Tests ◽  
Dynamic Material Model

To study the hot deformation behavior of Al-Mg-Er alloy, hot compression tests were conducted on a Gleeble-1500D thermal simulator at the temperature range of 200-500°C with the strain rates from 0.001 to 10s-1. With the increase in the deformation temperature and the decrease in strain rates, the flow stress of the Al-Mg-Er alloy decreased. Processing maps were constructed to study on hot workability characteristics. The results showed that the flow stress curves exhibited the typical dynamic recrystallization characteristics and the stress decreased with the increase of deformation temperature and the decrease of strain rate. Moreover, the processing maps were established on the basis of dynamic material model and Prasad’s instability criterion.

High Temperature Deformation Mechanisms and Processing Map for Hot Working of Cast-Homogenized Mg-3Sn-2Ca Alloy

2010 ◽  
Vol 638-642 ◽  
pp. 3616-3621 ◽  
Author(s):  
K.P. Rao ◽  
Y.V.R.K. Prasad ◽  
Norbert Hort ◽  
Karl Ulrich Kainer
Keyword(s):  
Strain Rate ◽  
Processing Map ◽  
Volume Fraction ◽  
Flow Instability ◽  
Back Stress ◽  
Hot Working ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Strain Rates ◽  
Compression Tests

The hot working behavior of Mg-3Sn-2Ca alloy has been investigated in the temperature range 300–500 oC and strain rate range 0.0003–10 s-1, with a view to evaluate the mechanisms and optimum parameters of hot working. For this purpose, a processing map has been developed on the basis of the flow stress data obtained from compression tests. The stress-strain curves exhibited steady state behavior at strain rates lower than 0.01 s-1 and at temperatures higher than 350 oC and flow softening occurred at higher strain rates. The processing map exhibited two dynamic recrystallization domains in the temperature and strain rate ranges: (1) 300–420 oC and 0.0003–0.003 s-1, and (2) 420–500 oC and 0.003–1.0 s-1, the latter one being useful for commercial hot working. Kinetic analysis yielded apparent activation energy values of 161 and 175 kJ/mole in domains (1) and (2) respectively. These values are higher than that for self-diffusion in magnesium suggesting that the large volume fraction of intermetallic particles CaMgSn present in the matrix generates considerable back stress. The processing map reveals a wide regime of flow instability which gets reduced with increase in temperature or decrease in strain rate.

Development of Processing Maps for 3003 Al Alloy

2011 ◽  
Vol 291-294 ◽  
pp. 306-310 ◽  
Author(s):  
Gui Qing Chen ◽  
Gao Sheng Fu ◽  
Wen Duan Yan ◽  
Chao Zeng Cheng ◽  
Ze Chang Zou
Keyword(s):  
Strain Rate ◽  
Flow Instability ◽  
Hot Working ◽  
Al Alloy ◽  
Processing Maps ◽  
Isothermal Compression ◽  
Instability Domain ◽  
Optimum Parameters ◽  
Dynamic Materials ◽  
Dynamic Materials Model

The 3003 Al alloy was deformed by isothermal compression in the range of deformation temperature 300-500 °C at strain rate 0.0l-10.0 s-1 with Gleeble-1500 thermal simulator. Processing maps at a strain of 0.6 for hot working were developed on a dynamic materials model. The maps exhibit a flow instability domain at about 300 °C-380 °C and 1.0-10.0 s-1. DRX occurs extensively in the temperature range of 450-500 °C and at the strain rate of 10.0 s-1. The optimum parameters of hot working for 3003 Al alloy at the strain of 0.6 are confined at 500 °C and 10.0 s-1 with the highest efficiency (37%).

Development of Processing Maps for Coiled Tubing Steel

2011 ◽  
Vol 415-417 ◽  
pp. 955-959
Author(s):  
Zhen Dong Zhang ◽  
Hai Tao Zhou ◽  
Xiang Hua Liu ◽  
Si Jun Li ◽  
Jie Dong ◽  
...  
Keyword(s):  
Strain Rate ◽  
Power Dissipation ◽  
Processing Map ◽  
Dynamic Recovery ◽  
Control Process ◽  
Stable Region ◽  
Coiled Tubing ◽  
Dynamic Materials ◽  
Hot Compression Test ◽  
Dynamic Materials Model

Hot compression test of coiled tubing steel is performed on Gleeble3500 at 1123K—1373K and strain rate from 0.001 to 5s-1. The hot deformation behavior of coiled tubing steel was characterized using processing map developed on the basis of the dynamic materials model. The processing map gives the flow instable region and the flow stable region in which the process of dynamic recovery (DRV) and the dynamic recrystallization (DRX) occur. In the processing map, the variation of the efficiency of the power dissipation is plotted as a function of temperature and the strain rate. According to the processing map, the coiled tubing steel is rolled by The Thermo-Mechanical-Control-Process (TMCP), and finally it is obtained that the yield strength and tensile strength of coiled tubing steel are 565MPa and 685MPa respectively, and the elongation percentage is 32.1%.

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