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Simulation of bulk metal forming processes using one-step finite element approach based on deformation theory of plasticity 被引量:2
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作者 王鹏 董湘怀 傅立军 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第2期276-282,共7页
The bulk metal forming processes were simulated by using a one-step finite element(FE)approach based on deformation theory of plasticity,which enables rapid prediction of final workpiece configurations and stress/stra... The bulk metal forming processes were simulated by using a one-step finite element(FE)approach based on deformation theory of plasticity,which enables rapid prediction of final workpiece configurations and stress/strain distributions.This approach was implemented to minimize the approximated plastic potential energy derived from the total plastic work and the equivalent external work in static equilibrium,for incompressibly rigid-plastic materials,by FE calculation based on the extremum work principle.The one-step forward simulations of compression and rolling processes were presented as examples,and the results were compared with those obtained by classical incremental FE simulation to verify the feasibility and validity of the proposed method. 展开更多
关键词 bulk metal forming plastic deformation theory finite element method one-step forward simulation rigid-plastic materials
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THE HOT DEFORMATION BEHAVIOR AND DYNAMIC RECRYSTALLIZATION MODEL OF 35CrMo STEEL 被引量:5
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作者 B.Zhang H.B.Zhang +1 位作者 X.Y.Ruan Y.Zhang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2003年第3期183-191,共9页
The isothermal single-stage compression of 35CrMo structural steel has been carried out by using Gleeble 1500 simulator at the temperature range of 950℃ to 1150℃ and strain rate range of 0.01s-1 to 10s-1. The effect... The isothermal single-stage compression of 35CrMo structural steel has been carried out by using Gleeble 1500 simulator at the temperature range of 950℃ to 1150℃ and strain rate range of 0.01s-1 to 10s-1. The effect of hot deformation parameters, such as strain rate, deformed temperature and initial grain size on the flow stress behavior was investigated. The activation energy of tested alloy was calculated, which is 378.16kJ/mol; The relationships between the peak stress (σp), the peak stain (εp), the critical strain (εc) and Z parameter were established. The micro structure evolution shows the pre-existing austenite grain boundaries constitute the principal nucleation sites for dynamic recrystallization (DRX), and the initial austenite grain size affects the grain size of DRX slightly. The kinetic mathematical model of DRX of 35CrMo is: XDRX=1-exp(-3.23-2.28) and Ddyn = 2.252× 10Z-0.22. 展开更多
关键词 dynamic recrystallization deformation activation energy stress/strain curve grain size
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Cold extrusion deformation behavior of medium carbon steel after quenching and tempering
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作者 胡成亮 赵震 +2 位作者 尹冠人 袁兆峰 徐祥龙 《中国有色金属学会会刊:英文版》 CSCD 2009年第S3期552-557,共6页
By taking 40Cr as a specific object, cold extrusion deformation behavior of medium carbon steel after quenching and tempering was studied by experimental works. The influence of deformation extent (10%-50%), cone angl... By taking 40Cr as a specific object, cold extrusion deformation behavior of medium carbon steel after quenching and tempering was studied by experimental works. The influence of deformation extent (10%-50%), cone angle of die (90 °-120 °), hardness after quenching and tempering (HRC21-29) and lubricated condition on the forming load was analyzed. The results show that there is no central bursting and micro crack in the inner of the extruded specimen, and the forming quality is good. The double-peak phenomenon takes place at the front-end of the specimen; the double-peak index increases with deformation extent, and larger deformation can avoid the double-peak phenomenon. The deformation extent is the most important influencing factor, and the lubricated condition almost has no influence, which means that the phosphate coating plus soap process is still a proper lubrication method for cold extrusion of medium carbon steel after quenching and tempering. By investigating the microscopic structure before and after deformation, the initial equiaxed grain is elongated in the extrusion direction, and this feature is more significant at the front-end of specimen. 展开更多
关键词 MEDIUM carbon steel QUENCHING and TEMPERING COLD EXTRUSION deformation behavior microstructure
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Analysis of Sheet Metal Extrusion Process Using Finite Element Method
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作者 Xin-Cun Zhuang Hua Xiang Zhen Zhao 《International Journal of Automation and computing》 EI 2010年第3期295-302,共8页
Sheet bulk metal forming processes have been widely developed to the facilitate manufacture of complicated 3D parts. However, there is still not enough know-how available. In this paper, as one of the typical sheet bu... Sheet bulk metal forming processes have been widely developed to the facilitate manufacture of complicated 3D parts. However, there is still not enough know-how available. In this paper, as one of the typical sheet bulk metal forming processes, the sheet metal extrusion process was studied. A reasonable finite element method (FEM) model of sheet metal extrusion process taking the influence of flow-stress curve with wide range of plastic strain and ductile damage into consideration was established and simulated by an arbitrary Lagrangian-Eulerian (ALE) FEM implemented in MSC.Marc. Validated by comparing the results with experiment, some phenomenological characteristics, such as metal flow behavior, shrinkage cavity, and the influence of different combinations of diameter of punch, diameter of extrusion outlet, and diameter of pre-punched hole were analyzed and concluded, which can be used as theoretical fundamental for the design of the sheet metal extrusion process. 展开更多
关键词 Sheet bulk metal forming EXTRUSION ductile damage arbitrary Lagrangian-Eulerian (ALE) metal flow behavior.
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Single gate optimization for plastic injection mold 被引量:8
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作者 LI Ji-quan LI De-qun +1 位作者 GUO Zhi-ying LV Hai-yuan 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第7期1077-1083,共7页
This paper deals with a methodology for single gate location optimization for plastic injection mold. The objective of the gate optimization is to minimize the warpage of injection molded parts, because warpage is a c... This paper deals with a methodology for single gate location optimization for plastic injection mold. The objective of the gate optimization is to minimize the warpage of injection molded parts, because warpage is a crucial quality issue for most injection molded parts while it is influenced greatly by the gate location. Feature warpage is defined as the ratio of maximum displacement on the feature surface to the projected length of the feature surface to describe part warpage. The optimization is combined with the numerical simulation technology to find the optimal gate location, in which the simulated annealing algorithm is used to search for the optimum. Finally, an example is discussed in the paper and it can be concluded that the proposed method is effective. 展开更多
关键词 Injection mold Gate location OPTIMIZATION Feature warpage
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A new flow stress model based on Arrhenius equation to track hardening and softening behaviors of Ti6Al4V alloy 被引量:9
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作者 Fu-Hui Zhu Wei Xiong +1 位作者 Xi-Feng Li Jun Chen 《Rare Metals》 SCIE EI CAS CSCD 2018年第12期1035-1045,共11页
The conventional Arrhenius-type model was adopted to identify the deformation characteristic of Ti6 A14 V(TC4) titanium alloy based on the stress-strain curves of isothermal compression test. A new flow stress model b... The conventional Arrhenius-type model was adopted to identify the deformation characteristic of Ti6 A14 V(TC4) titanium alloy based on the stress-strain curves of isothermal compression test. A new flow stress model based on Arrhenius equation was proposed for TC4,which is composed of peak flow stress(PFS) prediction and strain compensation. The predicted PFS is set as a reference to derive the flow stress model at any strain ranging from approximately 0 to 0.7. The predictability and efficiency among the proposed model, conventional model,and an existing physical-based model of TC4 were comparatively evaluated. It is found that the newly proposed model can simultaneously track the hardening and softening behaviors of TC4 through a single expression while the other existing models are only valid in the softening region.Besides, the wider application range and acceptable accuracy of the new model have been achieved by fewer material constants with much-simplified modeling procedure than the other models. 展开更多
关键词 Flow stress model Arrhenius equation Hot deformation Flow behavior Titanium alloy
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Review on modeling and simulation of microstructure evolution during dynamic recrystallization using cellular automaton method 被引量:7
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作者 ZHU HuaJia CHEN Fei +1 位作者 ZHANG HaiMing CUI ZhenShan 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2020年第3期357-396,共40页
The macro-mechanical properties of metal and alloy are largely depended on their chemical composition and microstructures resulting from the complicated processing and heat treatment history in industrial production. ... The macro-mechanical properties of metal and alloy are largely depended on their chemical composition and microstructures resulting from the complicated processing and heat treatment history in industrial production. During these thermoplastic processes, dynamic recovery, dynamic recrystallization, static recovery and static recrystallization are the key microstructural evolution mechanisms. Accurate prediction and precise control of the microstructural evolution are of great importance for designers to achieve excellent mechanical properties for metals and alloys through hot working. Up to date, dynamic recrystallization has been recognized as a powerful mechanism for grain refinement. In-depth understanding of the microstructural evolution of dynamic recrystallization and furthermore to accurately predict and control the microstructure evolution during dynamic recrystallization process has become a research focus in the field of plastic processing. Cellular automaton(CA) method has been commonly employed to simulate the microstructure evolution of dynamic recrystallization due to its unique advantages,for example, it is easier to represent topological features and more realistically reflect the grain boundary migration process. In this paper, the basic ideas and characteristics of the CA method are briefly introduced. The physical mechanisms of dynamic recrystallization are summarized. Meanwhile, the state-of-the-art overview of the CA method of simulating the DRX process is introduced. Furthermore, this paper points out several problems that need to be solved urgently and prospects the development trend of the CA method for simulating the microstructure evolution in dynamic recrystallization. 展开更多
关键词 cellular automaton MICROSTRUCTURE RECRYSTALLIZATION
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Microstructure and performance evaluations on Q&P hot stamping parts of several UHSS sheet metals 被引量:5
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作者 HAN XianHong ZHONG YaoYao +2 位作者 TAN ShuLin DING YaNan CHEN Jun 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2017年第11期1692-1701,共10页
Hot stamping(press hardening) is widely used to fabricate safety components such as door beams and B pillars with increased strength via quenching. However, parts that are hot-stamped from ultra-high-strength steel(UH... Hot stamping(press hardening) is widely used to fabricate safety components such as door beams and B pillars with increased strength via quenching. However, parts that are hot-stamped from ultra-high-strength steel(UHSS) have very limited elongation,i.e., low ductility. In the present study, a novel variant of hot stamping technology called quenching-and-partitioning(Q&P) hot stamping was developed. This approach was tested on several UHSS sheet metals, and it was confirmed that this method can be used to overcome the drawbacks associated with conventional hot stamping. The applicability of Q&P hot stamping to each of these steels was also assessed. The part properties and performances of three widely used ultra-high-strength sheet metals, B1500 HS,27 SiMn, and TRIP780, were evaluated through tensile testing and microstructural observations. The results demonstrated that the ductility of Q&P hot-stamped sheet metals was notably higher than that of the conventionally hot-stamped parts because Q&P hot stamping gives rise to a dual-phase structure of both martensite and austenite. Further, material tests demonstrated that the Q&P treatment had positive effects on all three selected materials, of which TRIP780 had the best ductility and the highest value of the product of strength and plasticity. Scanning electron microscopy images indicated that the silicon in the steels could limit the formation of cementite and would, therefore, improve the mechanical properties of Q&P hot-stamped products. 展开更多
关键词 ultra-high-strength steel hot stamping quenching and partitioning process high ductility
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Modeling Flow Stress of 70Cr3Mo Steel Used for Back-Up Roll During Hot Deformation Considering Strain Compensation 被引量:3
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作者 REN Fa-cai CHEN Jun 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2013年第11期118-124,共7页
A constitutive model incorporating the influence of strain developed based on the Arrhenius equation by considering the variation of material constants as a fifth polynomial function of strain is presented. Materials ... A constitutive model incorporating the influence of strain developed based on the Arrhenius equation by considering the variation of material constants as a fifth polynomial function of strain is presented. Materials con- stants are fit to data from hot compression tests of 70Cr3Mo steel used for back-up roll at the temperatures from 1 173 to 1 473 K and strain rates from 0.01 to 10 s ~ by using a Gleeble-1500D thermo-mechanieal simulator. The de- veloped constitutive model is then used to predict the flow stress under all the tested conditions. The statistical pa- rameters of correlation coefficient and average absolute relative error are used to analyze the predictable efficiency and the values are 0. 997 and 3. 64%, respectively. The results show a good agreement between experimental stress and predicted stress. 展开更多
关键词 70Cr3Mo steel hot deformation flow stress constitutive modeling strain compensation
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Rapid Finite Element Analysis of Bulk Metal Forming Process Based on Deformation Theory
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作者 WANG Peng DONG Xiang-huai FU Li-jun 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2009年第5期23-28,42,共7页
The one-step finite element method (FEM), based on plastic deformation theory, has been widely used to simulate sheet metal forming processes, but its application in bulk metal forming simulation has been seldom inv... The one-step finite element method (FEM), based on plastic deformation theory, has been widely used to simulate sheet metal forming processes, but its application in bulk metal forming simulation has been seldom investigated, because of the complexity involved. Thus, a bulk metal forming process was analyzed using a rapid FEM based on deformation theory. The material was assumed to be rigid-plastic and strain-hardened. The constitutive relationship between stress and total strain was adopted, whereas the incompressible condition was enforced by penalty function. The geometrical non-linearity in large plastic deformation was taken into consideration. Furthermore, the force boundary condition was treated by a simplified equivalent approach, considering the contact history. Based on constraint variational principle, the deformation FEM was proposed. The one-step forward simulation of axisymmettic upsetting process was performed using this method. The results were compared with those obtained by the traditional incremental FEM to verify the feasibility of the proposed method. 展开更多
关键词 bulk metal forming finite element method (FEM) deformation theory rapid simulation
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Fracture morphologies of a hot stamped steel and comparisons with several sheet metals
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作者 Shu-lin Tan Kun Yang +1 位作者 Ya-nan Ding Xian-hong Han 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2017年第6期634-640,共7页
Hot stamping has been widely used in car industry to produce safety components. Most existing re- searches focused on the stamping and quenching process, but less on the mechanical properties of stamped parts. The fra... Hot stamping has been widely used in car industry to produce safety components. Most existing re- searches focused on the stamping and quenching process, but less on the mechanical properties of stamped parts. The fracture behaviors of hot stamped boron steel B1500HS have been studied, and other four commonly used sheet metals with different strengths, including Q235, TRIP780, QP980 and MS1300, were also introduced for comparison. Both uniaxial tests and mechanical trimming tests were performed, and the fracture surfaces under different stress states were observed and discussed. The SEM observations showed that the fracture models are closely related to the stress states, i. e., the tensile surfaces have ductile rupture characters while the trimming surfaces have brittle rupture characters. Compared with other steels, the quenched boron steel has smaller dimple size accompa- nied by shear planes in the tensile surface, and has smaller burnish zone in the trimming surface, and its cutting surface with 'S' like shape is also very different with others. Furthermore, two fitted em pirical models were derived to describe the quantitative correlations between the average dimple diam- eter and the steel strength and between the percentage of burnish zone and the steel strength. 展开更多
关键词 Hot stamped steelFracture morphologyTensile testMechanical trimming testSteel comparison
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Overview on the Prediction Models for Sheet Metal Forming Failure:Necking and Ductile Fracture 被引量:5
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作者 Qi Hu Feifei Zhang +1 位作者 Xifeng Li Jun Chen 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2018年第3期259-289,共31页
The formability of the material determines the amount of available deformation before failure and thus is important for the production of various structural components in industries. The workability of materiMs is com... The formability of the material determines the amount of available deformation before failure and thus is important for the production of various structural components in industries. The workability of materiMs is commonly evaluated by different forms of failure mod- els during sheet metal forming (SMF) processes. In order to provide a whole picture about the prediction models for SMF failure, necking-related formability and ductile fracture-related forma- bility studies in SMF processes are systematically summarized, the applicability and limitation of each model are highlighted, and the link between forming limit diagram and ductile fracture criterion is pointed out, Conclusions about some critical issues on failure in SMF are made. 展开更多
关键词 NECKING Ductile fracture Failure model Sheet metal forming
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