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Microstructure Simulation for Heavy Backup Roll

Author: ZhangZuo
Tutor: ChenXueWen
School: Henan University of Science and Technology
Course: Materials Processing Engineering
Keywords: Large forgings 45Cr4NiMoV steel Finite Element Numerical Simulation Cellular Automata Microstructure
CLC: TG316
Type: Master's thesis
Year: 2011
Downloads: 142
Quote: 0
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Abstract

Large forgings as key pieces of basic parts has been widely used in various aspects of the equipment manufacturing. The production of large forgings is an important part of the heavy machinery manufacturing, the production level of the species, weight, grade, quantity, and production equipment, etc., are important aspects of the flag of a country's economic strength and industrial development level. Applications for large forgings decided to work under the complex conditions of service, and forgings have better intrinsic quality and the use of performance. Therefore, the production of large forgings and research requirements to the development of scientific, modern direction. Finite element simulation technology is not only used for the prediction and control of internal mechanical properties of the forging forming process, and the changes in the process of forging internal microstructure gradually deepening through forecast Forging Process microstructure evolution, in order to control the production process thermodynamic conditions and material forming process parameters to achieve control of the microstructure evolution of the forming process, and eventually get the ideal of forgings organization with good mechanical properties. Numerical simulation technology in the field of forging, not only greatly reduce the cost of production, and the forging by traditional qualitative to the quantitative research design changes to the scientific design experience. Firstly physics experiments by Gleeble-1500D thermal simulation compression the research supporting the roller material 45Cr4NiMoV steel thermal compression stress and strain changes in the relationship between the deformation process, the experimental results to establish the material stress-strain curve model; analysis of thermal compression peak stress and strain rate material deformation process temperature relationship, the results show that: the peak stress decreased with increasing deformation temperature, the same temperature, the greater the strain rate, the peak stress variation of material during high temperature deformation, microstructure evolution is closely related; and according to the different temperature thermal compression process, different strain rates peak strain values ??change, the material critical strain model. On the basis of the material model in physics experiments, using Deform-3D finite element analysis software simulation support roller upsetting drawing process, and analyze different tool width under stress forgings surface temperature distribution and core part, equivalent strain state obtained reasonable backup roll upsetting and stretching process scheme. Use of support rollers thermal compression experimental data and material critical strain model, and the establishment of a two-dimensional cellular automata dynamically recrystallized model; dynamic recrystallization process of the support roll upsetting pull deformation Deform-3D Microstructure module simulation analysis, summarize temperature, strain, the relationship between the dislocation density and other factors and dynamic recrystallization is: should be caused by the increase of the variable of the dislocation density increases, the formation of new nuclei to provide power for dynamic recrystallization; nucleation process partial dislocation can be released; the same time under the action of high temperatures and uneven dislocation energy, new nuclei grow rapidly. This process cycle occurs throughout the upsetting and stretching deformation process. Therefore, sufficient upsetting pull than, to ensure sufficient strain forgings core part that is thoroughly forging through the billet heart, is to ensure that revolutionized forging cast structure the uniform ideal grain prerequisite. Pull on 45Cr4NiMoV large supporting roller upsetting simulation analysis of the process as well as its dynamic recrystallization microstructure forecast results with theoretical basis consistent basis for the formulation of a large backup roll forgings forging process parameters.

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CLC: > Industrial Technology > Metallurgy and Metal Craft > Metal pressure processing > Forging, forging and blacksmith > Forging process
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