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constitutive equation and hot processing maps of Al-5Ti-1B master alloy

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Rare Metals 2018年第8期37卷 668-674页

作者： Fu-Wei Kang Jie Zhou Zhi-Wei Wang Xue-Min Zhang Yi-Cheng Feng Er-Jun Guo School of Materials Science and Engineering Harbin Universityof Science and Technology Harbin 150040 China Harbin Dong An Engine Group Corporation Ltd. Aviation Industry Corporation of China Harbin 150066 China

The isothermal compression tests of A1-5Ti- 1B master alloy were conducted on the thermal mechanical simulator Gleeble-1500D at the deformation temperature range of 300-450 ℃,the strain rate range of 0.01- 10.00 s^-l, and the engineering strain of 50 %. The effects of deformation temperatures and strain rates on the flow stress were analyzed by the true stress-true strain curves. The result indicates that the flow stress increases with the increase of strain rate, while it decreases with the increase of temperature. The hot deformation activation energy of A1-5Ti-IB master alloy is calculated to be 250.9 kJ.mol^-1, and the constitutive equation is established as ε=1.97 x lO^19[sinh（O.O15δ）^11.14exp（-250.9/RT）, and the validity of this constitutive equation is verified. Based on dynamic material model （DMM） criterion, the hot processing map of AI-5Ti-1B master alloy is obtained. The optimum hot extrusion conditions are determined as deformation temperature of 400℃ and strain rate of 1.00 s^-1, and the flow instability only appears at the temperature range of 300-340℃ at the base of the hot processing map.

关键词： Al-5Ti-1B master alloy Flow stress constitutive equation Hot processing map

constitutive equation Models of Hot-Compressed T122 Heat Resistant Steel

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Journal of Iron and Steel Research(International) 2012年第6期19卷 53-58页

作者： CAO Jin-rong LIU Zheng-dong CHENG Shi-chang YANG Gang XIE Jian-xin Tianjin Pipe Group Corporation Technical Center Tianjin 300301China Central Iron and Steel Research Institute Beijing 100081China University of Science and Technology Beijing Beijing 100083China

Based on dislocation reaction theory and Avrami equation, a constitutive equation model was developed to describe dynamic recovery and dynamic recrystallization during hot deformation of T122 heat resistant steel, which have taken the effect of dynamic strain aging into account. Uniaxial hot compression test had been carried out over a wide range of strain rate （0.01 to 10 s-1 ） and temperature （900 to 1 200 ~C） with the help of Gleeble 3500. Obtained experimental data was applied to determine the material parameters in proposed constitutive equations of T122 steel, by using the non-linear least square regress optimization method. The calculated constitutive equations are quantita- tively in good agreement with experimentally measured curves and microstructure observation. It shows that propose constitutive equation T122 steel is able to be used to predict flow stress of T122 steel during hot deformation in aus- tenite temperature scope.

关键词： hot deformation dislocation constitutive equation T122 heat resistant steel

constitutive equation OF CO-ROTATIONAL DERIVATIVE TYPE FOR ANISOTROPIC-VISCOELASTIC FLUID

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Acta Mechanica Sinica 2004年第1期20卷 46-53页

作者：韩式方 Res.Lab.of Non-Newtonian Fluid Mechanics Chengdu Institute of Computer ApplicationChinese Academy of SciencesChengdu 610041China

A constitutive equation theory of Oldroyd fluid B type,i.***.the co-rotational derivative type,is developed for the anisotropic-viscoelastic fluid of liquid crystalline(LC)polymer.Analyzing the influence of the orientational motion on the material behavior and neglecting the influence,the constitutive equation is applied to a simple case for the hydrodynamic motion when the orientational contribution is neglected in it and the anisotropic relaxation,retardation times and anisotropic viscosi- ties are introduced to describe the macroscopic behavior of the anisotropic LC polymer fluid.Using the equation for the shear flow of LC polymer fluid,the analytical expressions of the apparent viscosity and the normal stress differences are given which are in a good agreement with the experimental results of Baek et al.For the fiber spinning flow of the fluid,the analytical expression of the extensional viscosity is given.

关键词： constitutive equation anisotropic-viscoelastic fluid liquid crystalline polymer nonNewtonian flow co-rotational derivative anisotropic material functions shear flow extensional flow

constitutive equation and hot deformation characteristic of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy with equiaxed microstructure

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Rare Metals 2007年第S1期26卷 88-93页

作者： HUANG Lujun,GENG Lin,LI Aibin,WANG Guisong,and SHI Lei School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China Harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China

The hot deformation behavior of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy with equiaxed microstructure was characterized in the temperature range of 900～1060 ℃ and strain rate range of 10-3～10 s-1.The experimental results indicate that the plastic deformation behavior of the titanium alloys is rather sensitive to temperature and strain rate.In the α+β phase temperature region,all of the stress-strain curves exhibit different degrees of the flow softening after a peak stress.In the β phase temperature region,the titanium alloy shows a stress softening at high strain rates and a steady flow stress at low strain rates.On the basis of the peak stress data,the constitutive equations were constructed in the α+β phase temperature region and β phase temperature region,respectively.Activation energy parameters were calculated to be 344.923 kJ·mol-1 in the β phase temperature region and 628.3 kJ·mol-1 in the α+β phase temperature region.Microstructure of the compressed specimens in water-quenched conditions was found to be quite dependent on the conditions of deformation.

关键词： constitutive equation hot deformation Ti-6.5Al-3.5Mo-1.5Zr-0.3Si

Development of constitutive equation and Processing Maps for IN706 Alloy

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Acta Metallurgica Sinica(English Letters) 2014年第2期27卷 198-204页

作者： Shuo Huang Lei Wang Xintong Lian Beijiang Zhang Guangpu Zhao Key lab for Anisotropy and Texture of Materials Northeastern University Department of High-temperature Materials Central Iron and Steel Research Institute

The hot deformation behavior of IN706 has been investigated by means of hot compression tests in the temperature range of 900-1150℃ and strain rate range of 0.001-1 s^-1. The constitutive equation was developed on the basis of experimental data. Power dissipation efficiency （η） and instability parameter （4） maps were evaluated using the principles of the dynamic material model. Furthermore, the EBSD microstructure analysis was performed for validation, revealing that η was closely associated with the mechanism of dynamic recrystallization （DRX）. Microstructure transition map was composed of contour plots of η, 4, and DRX. The DRX domain zones and instable zones were identified in the processing map and were classified based on η. In a view of microstructure refinement and workability improvement, the optimum processing should be selected in the temperature range of 970-1025 ~C and the strain rate range of 0.08-0.01 s^-1.

关键词： IN706 alloy constitutive equation Power dissipation efficiency Flow instability Processing map

constitutive equation of Superalloy In718 in Hammer Forging Process

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Journal of Iron and Steel Research(International) 2001年第1期8卷 50-54页

作者： HU Jian-ping Chongqing Iron & Steel Design Inst Chongqing 400013 Peoples R China Cent Iron & Steel Res Inst Beijing 100081 Peoples R China Thyssen Unformtech GMBH D-42859 Remscheid Germany

A constitutive equation reflecting the flow behavior of Superalloy In718 during the counter-blow hammer forging process was developed in terms of the relationship of flow stress and hot-deformation parameters,such as strain,strain rate,and deformation temperature.A new simplified approach for the complex multi-pass stress-strain curves has been attempted.The simulation curves calculated by constitutive equation are consistent with the experimental data.

关键词： Superalloy In718 constitutive equation hammer forging

Research on constitutive equation of DIWA353 steel used in hemisphere head of power station nearby recrystallization temperature

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Journal of Harbin Institute of Technology(New Series) 2011年第6期18卷 39-43页

作者：侯珍秀王新庆董恺琛李世魁蔡多谋李晓红 Dept.of Electrical Engineering Harbin Institute of Technology Harbin Boiler Co.Ltd.

To simulate the DIWA353 steel used in boiler nearby recrystallization temperature accurately by using finite element,the high temperature constitutive model of this material must be researched firstly.Thermal simulation experimental machine is used to do the high temperature hot compression experiments for the DIWA353 steel used in boiler under different strain rates and temperatures nearby recrystallization temperature.Multi-bank data of true stress-true strain is gotten,and the hot deformation activation energy of DIWA353 is obtained,and the constitutive equation of steady-state flow stress under the circumstance of high temperature is constructed.The results show that DIWA353 steel is positive strain rate sensitized material when it is at temperature of 850-1050 ℃,and the steady-state flow stress decreases with the increase of deformation temperature,but increases with the increase of strain rate.

关键词： boiler head recrystallization temperature constitutive equation numerical simulation strain rate

constitutive equation WITH ORDERED PARAMETERS FOR VISCOELASTIC MATERIAL CONTAINING DEFECTS

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Acta Mechanica Solida Sinica 1997年第1期10卷 11-27页

作者： Yuan Longwei(Institute of Rheological Mechanics,Xiangtan University,Xiangtan 411105,China) Institute of Rheological Mechanics Xiangtan University Xiangtan 411105 China

Based on the experimental results of local temperature field formed in the evolution period of defects, the defect field is defined by this internal temperature field. The evolutionary processes of statistically correlative meso-scopic defects are analysed with the growth rate and nucleation rate of the meso-defect, and it is deemed that the dynamic failure process of the viscoelastic material with defects can be quantitatively described by the normal method of the procedure of heat wave transmission. The defect field is regarded as a complex system of the union of the real sets and null sets, its main characteristics depending on the stratum hypothesis about the activities of the subsystems of the highest stratum described by ordered parameters. The fluctuation of ordered parameters is demonstrated by means of the projection operator method. The constitutive equation with ordered parameters for the meso-defect evolutionary state of viscoelastic material with defects is deduced from the nonlinear rheological dynamic approach, and its solution is obtained.

关键词： rheology of bodies with defects constitutive equation local temperature field heat waves ordered parameter stratum system

constitutive equation of Laminated Veneer Lumber (LVL) at Large Deformation Condition

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Forestry Studies in China 2003年第3期5卷 39-41页

作者： Li Ning Sun Yanling Wang Shujuan Lu Zhenyou School of Technology Beijing Forestry UniversityBeijing 100083P.R.China

The stress-strain relation of laminated veneer lumber (LVL) was established by the method of regression, and its constitutive equation at large deformation and constant loading conditions was given to predict the stat... 详细信息

关键词： laminated veneer lumber (LVL) constitutive equation large deformation