Simulation to Static Recrystallization of Nb Micro Alloyed Steel by Cellular Automaton

2011 ◽  
Vol 418-420 ◽  
pp. 1622-1628
Author(s):  
Ying Zhi ◽  
Xiang Hua Liu ◽  
Zhen Fan Wang
Keyword(s):  
Cellular Automaton ◽  
Static Recrystallization ◽  
Grain Shape ◽  
Volume Fraction ◽  
Processing Parameters ◽  
Alloyed Steel ◽  
Simulation Results ◽  
Micro Alloyed Steel ◽  
The Impact ◽  
Temperature Strain

The model of cellular automaton (CA) for simulating the static recrystallization of Nb micro alloyed steel after hot deformation was established. The static precipitation of micro alloyed elements on the impact of static recrystallization was considered in the mode. The microstructure evolution of austenite static recrystallization of Nb micro alloyed steel was simulated dynamically, such as the the volume fraction, kinetics curve of static recrystallization, dislocation density and grain shape, were quantitatively, accurately and visually described. According to the simulation results by cellular automaton, the effects of the deformation temperature, strain rate, and other processing parameters on the microstructure of the austenite static recrystallization of Nb micro alloyed steel were analyzed. The simulation results could provide a theoretical reference for the control of the microstructure and property of Nb micro alloyed steel.

Modeling Recrystallization for 3D Multi-Pass Forming Processes

2007 ◽  
Vol 558-559 ◽  
pp. 1201-1206 ◽  
Author(s):  
Mihaela Teodorescu ◽  
Patrice Lasne ◽  
Roland E. Logé
Keyword(s):  
Numerical Simulation ◽  
Grain Size ◽  
Present Model ◽  
Static Recrystallization ◽  
Volume Fraction ◽  
The Other ◽  
Finite Element Code ◽  
3D Numerical Simulation ◽  
Fraction Distribution ◽  
Simulation Results

The present work concerns the simulation of metallurgical evolutions in 3D multi-pass forming processes. In this context, the analyzed problem is twofold. One point refers to the management of the microstructure evolution during each pass or each inter-pass period and the other point concerns the management of the multi-pass aspects (different grain categories, data structure). In this framework, a model is developed and deals with both aspects. The model considers the microstructure as a composite made of a given (discretized) number of phases which have their own specific properties. The grain size distribution and the recrystallized volume fraction distribution of the different phases evolve continuously during a pass or inter-pass period. With this approach it is possible to deal with the heterogeneity of the microstructure and its evolution in multi-pass conditions. Both dynamic and static recrystallization phenomena are taken into account, with typical Avrami-type equations. The present model is implemented in the Finite Element code FORGE2005®. 3D numerical simulation results for a multi-pass process are presented.

scholarly journals Impact of Traffic Sign on Pedestrians’ Walking Behavior

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hui Xiong ◽  
Pingfu Yao ◽  
Xuedong Guo ◽  
Chenglong Chu ◽  
Wuhong Wang
Keyword(s):  
Cellular Automaton ◽  
Critical Level ◽  
Critical Distance ◽  
Pedestrian Flow ◽  
Traffic Sign ◽  
Walking Behavior ◽  
Simulation Results ◽  
Walking Environment ◽  
The Impact

To study the impact of traffic sign on pedestrian walking behavior, the paper applies cellular automaton to simulate one-way pedestrian flow. The channel is defined as a rectangle with one open entrance and two exits of equal width. Traffic sign showing that exit is placed with some distance in the middle front of the two exits. In the simulation, walking environment is set with various input density, width of exit, width and length of the channel, and distance of the traffic sign to exit. Simulation results indicate that there exists a critical distance from the traffic sign to exit for a given channel layout. At the critical distance, pedestrian flow fluctuates. Below such critical distance, flow is getting larger with the increase of input density. However, the flow drops sharply when the input density is over a critical level. If the distance is a little bit further than the critical distance, the largest flow occurs and the flow can remain steady no matter what input density will be.

The Impact Factors of Numerical Computation to Cavitating Flow

2011 ◽  
Vol 88-89 ◽  
pp. 404-407
Author(s):  
Wei Bao Xu ◽  
Chao Wang ◽  
Miao He ◽  
Sheng Huang ◽  
Xin Chang
Keyword(s):  
Volume Fraction ◽  
Turbulence Models ◽  
Cavity Flow ◽  
Impact Factors ◽  
Wall Function ◽  
Forming Process ◽  
Wall Functions ◽  
Simulation Results ◽  
Rsm Model ◽  
The Impact

Steady cavity flow of 2-D hydrofoil is simulated by CFD software. The impacts of different cavitation models, turbulence models and wall functions to the numerical simulation results are analyzed. The pressure distributing curve and volume fraction distributing map are obtained through detailed analysis to cavity flow under different cavity number. The analysis results show that those cavitation models simulate the origination and forming process of cavity preferably, which match experiment values closely. However, there are some differences among the results of those different cavitation models in the cavity closing area. The results of RNGmodel and the RSM model are more uniformity with the experiment values, but there is large distinctive between the result of the standard and the experiment values. The results of the standard wall function and the non-equilibrium wall function which have distinction with the experiment values are closed, but the enhanced wall function is the most accurate.

Impact of Processing Parameters and Tapering of Injection Chamber Walls in Resin Injection Pultrusion

2007 ◽  
Vol 15 (7) ◽  
pp. 507-519 ◽  
Author(s):  
A.L. Jeswani ◽  
J.A. Roux
Keyword(s):  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Injection Pressure ◽  
Processing Parameters ◽  
Fibre Volume ◽  
Fibre Reinforcement ◽  
Resin Injection ◽  
Resin Injection Pultrusion ◽  
The Impact

This study seeks to improve the wet-out and thus the quality of the pultruded part in the tapered injection pultrusion process. Complete wet-out of the dry fibre reinforcement by the liquid resin depends strongly on the processing parameters. Process parameters modelled were: fibre pull speed, fibre volume fraction and resin viscosity. In this work a 3-D finite volume technique was developed to simulate the flow of polyester resin through the glass rovings. The results show the impact of the tapering of the injection chamber walls on the minimum injection pressure necessary to achieve complete fibre matrix wet-out and the resin pressure at the injection chamber exit. Important chamber design information is presented.

scholarly journals Investigation of Impact Strength and Hardness of UHMW Polyethylene Composites Reinforced with Nano-Hydroxyapatite Particles Fabricated by Friction Stir Processing

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1041 ◽  
Author(s):  
Imran Khan ◽  
Ghulam Hussain ◽  
Khalid A Al-Ghamdi ◽  
Rehan Umer
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Friction Stir Processing ◽  
Volume Fraction ◽  
Polymeric Materials ◽  
Processing Parameters ◽  
Rockwell Hardness ◽  
Friction Stir ◽  
The Impact ◽  
Polyethylene Composites

The impact strength and surface properties of polymeric materials are of critical importance in various engineering applications. Friction stir processing (FSP) is a novel method for the fabrication of composite materials with superior mechanical properties. The main objective of this study is to investigate the impact strength and Rockwell hardness of UHMW polyethylene composites reinforced with nano-hydroxyapatite particles fabricated through FSP. The spindle speed (ω), tool traverse speed (f), volume fraction (v) of strengthening material and shoulder temperature (T) were key processing parameters. The analysis of variance (ANOVA) indicated that the selected processing parameters were significant. Microscopic investigations unveiled that high levels of (v, f) and low levels of (T, ω) caused agglomeration of the reinforcing particles and induced voids and channels, which consequently reduced the impact strength and hardness of the manufactured composite. However, medium conditions of processing parameters exhibited better distribution of particles with minimum defects, and hence resulted in better mechanical properties. Finally, the models to predict the impact strength and hardness are proposed and verified. Sets of process parameters favorable to maximize the impact strength and Rockwell hardness were worked out, which were believed to increase the impact strength, Rockwell hardness number, and ultimate tensile strength by 27.3%, 5.7%, and 11.2%, respectively.

Effect of Processing Parameters on the Hot Compressive Deformation Behavior of 20CrMnTiH

2011 ◽  
Vol 399-401 ◽  
pp. 1693-1696 ◽  
Author(s):  
Cheng Liang Hu ◽  
Ying Zhang ◽  
Zhen Zhao ◽  
Zhi Liang Zhang
Keyword(s):  
Strain Rate ◽  
Deformation Temperature ◽  
Processing Parameters ◽  
Significant Degree ◽  
Main Process ◽  
Compression Tests ◽  
Gear Steel ◽  
Stress Maximum ◽  
The Impact ◽  
Temperature Strain

20CrMnTiH is widely used as gear steel because of its good hardenability. Based on the Taguchi technique, an L9 orthogonal array was arranged, and the three main process parameters were deformation temperature, strain rate and strain, and their levels were in the range of 850oC~1050oC, 0.1 s-1~10s-1 and 0.2~0.8 respectively. Nine hot compression tests were carried out on a GLEEBLE 1500 simulator, and the stress-strain curves and microstructures were investigated. The experimental results showed that deformation temperature was the most significant parameter of flow stress maximum followed by strain rate and strain, and the impact significant degree of on the grain size after compression was shown in the following: deformation temperature > strain > strain rate.

Simulation of Martensitic Transformation of High Strength and Elongation Steel by Cellular Automaton

2014 ◽  
Vol 1004-1005 ◽  
pp. 235-238 ◽  
Author(s):  
Ying Zhi ◽  
Wei Jie Liu ◽  
Xiang Hua Liu
Keyword(s):  
Martensitic Transformation ◽  
Cellular Automaton ◽  
Microstructure Evolution ◽  
Retained Austenite ◽  
Volume Fraction ◽  
High Strength ◽  
Continuous Cooling ◽  
Simulation Results

The model of cellular automaton (CA) for simulating the martensitic transformation of the high strength and elongation steel during quenching was established. The microstructure evolution of martensitic transformation of high strength and elongation steel during continuous cooling was simulated dynamically, in terms of parameters such as the volume fraction and morphology of the martensite and retained austenite were quantitatively, accurately and visually described. The simulation results could provide a theoretical reference for the control of the microstructure and property of high strength and elongation steel.

scholarly journals Designing Q&P Process for Experimental Steel with 0.47 % Carbon Content

2014 ◽  
Vol 887-888 ◽  
pp. 257-261 ◽  
Author(s):  
Vít Pileček ◽  
Hana Jirková ◽  
Bohuslav Mašek
Keyword(s):  
Retained Austenite ◽  
Volume Fraction ◽  
High Strength ◽  
Heat Treating ◽  
Processing Parameters ◽  
Austenitizing Temperature ◽  
The Third ◽  
Martensitic Microstructure ◽  
The Impact ◽  
Correct Processing

The Q&P process (Quenching and Partitioning) is a heat treating method for high-strength low-alloyed steels. It delivers the desired combinations of high strength and adequate ductility. These properties are achieved thanks to the unique martensitic microstructure with a certain volume fraction of stable retained austenite. Retained austenite imparts plasticity to the otherwise brittle martensitic structure. Optimum mechanical properties are achieved by using correct processing parameters and chemistry of the material. The experimental material was a steel with 0.47 % carbon alloyed with silicon, manganese and chromium. The purpose of the effort was to optimise the heat treating parameters in order to obtain a strength level above 2000 MPa and an elongation of no less than 10%. In the first step, the appropriate austenitizing temperature was identified. In the second, effects of various quenching temperatures and cooling rates on the microstructure evolution were explored. In the third, the impact of raising the partitioning temperature on stabilization of retained austenite was examined. Adjustment of the parameters led to a strength of more than 2300 MPa and an elongation of 8 %.

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