Q＆P钢中碳配分的有限元数值模拟
发布时间：2022-08-01 13:32
近些年来,汽车厂商在汽车上越来越多的使用热成形件。热成形件拥有很好的碰撞性能并能降低能耗。22MnB5热成形QP钢最有望达到此目的,其成分及多相组织特点能提高汽车服役性能。基于此,对热成形QP钢的研发需要弄清其性能及生产技术。对此钢种的制造工艺包括淬火配分热处理,使其增加强度同时不降低钢构件的塑性。经HS-QP处理后组织为马氏体基体和富碳的残余奥氏体。目前,研究者们致力于寻找生产低成本HS-QP钢的最合适的生产参数。本研究使用Galerkin有限元方法分析淬火配分（QP）过程中碳从马氏体扩散到奥氏体的过程。不同于经典的或复杂的扩散场模型,本研究选用基于化学势和成分的非线性控制方程。此模型被用于模拟1步法和2步法QP处理过程中的碳扩散行为。模拟中设定奥氏体与马氏体相界面不移动。模拟结果与0.8 Si-22MnB5淬火配分处理后的用磁性法测的残余奥氏体量（RA）的实验结果进行了对比。模拟结果预测并揭示了碳和硅的含量对最终淬火组织中的残余奥氏体含量的影响。
【文章页数】：55 页
【学位级别】：硕士
【文章目录】：
摘要
ABSTRACT
Nomenclature
CHAPTER 1: INTRODUCTION
1.1 Motivation
1.2 Aim and objectives of the current research
1.3 Outline
CHAPTER 2: COMPREHENSIVE REVIEW OF LITERATURE
2.1 Theory of Quenching & Partitioning in steels
2.1.1 Martensite
2.1.2 Retained austenite
2.1.3 Governing equation
2.1.4 Initial, boundary conditions and assumptions
CHAPTER 3: MODELLING IMPLEMENTATION
3.1 Finite element method
3.2 Finite difference time stepping
3.3 Numerical simulation
3.3.1 Finite element implementation
3.3.2 The time stepping scheme
3.4 Methodology to determine the Volume fraction of RA
3.4.1 Simulation conditions
3.5 Verification of the model
CHAPTER 4: EXPERIMENTAL WORK
4.1 Microscopy
4.1.1 Light Optical Microscopy (LOM)
4.1.2 Scanning Electron Microscopy (SEM)
4.1.3 Electron Backscatter Diffraction (EBSD)
4.2 Magnetisation measurements
4.3 X-Ray Diffraction (XRD)
4.4 Microindentation hardness testing
4.5 Tensile testing
4.6 Microstructure characterization
4.7 Mechanical properties
CHAPTER 5: RESULTS AND DISCUSSION
5.1 Computational results
5.1.1 Effect of Si content
5.1.2 Effect of C content
5.2 Model validation
5.2.1 Comparison with Thermo-Calc (DICTRA)
5.2.2 Comparison with experimental data
CHAPTER 6: CONCLUSIONS AND PERSPECTIVES
6.1 Conclusions
6.2 Further research
REFERENCES
ACKNOWLEDGEMENT
LIST OF PUBLICATIONS
【参考文献】：
期刊论文
[1]Q＆P钢配分过程中的组织演变[J]. 庄宝潼,唐荻,江海涛,米振莉. 北京科技大学学报. 2012(11)
本文编号：3667541
【文章页数】：55 页
【学位级别】：硕士
【文章目录】：
摘要
ABSTRACT
Nomenclature
CHAPTER 1: INTRODUCTION
1.1 Motivation
1.2 Aim and objectives of the current research
1.3 Outline
CHAPTER 2: COMPREHENSIVE REVIEW OF LITERATURE
2.1 Theory of Quenching & Partitioning in steels
2.1.1 Martensite
2.1.2 Retained austenite
2.1.3 Governing equation
2.1.4 Initial, boundary conditions and assumptions
CHAPTER 3: MODELLING IMPLEMENTATION
3.1 Finite element method
3.2 Finite difference time stepping
3.3 Numerical simulation
3.3.1 Finite element implementation
3.3.2 The time stepping scheme
3.4 Methodology to determine the Volume fraction of RA
3.4.1 Simulation conditions
3.5 Verification of the model
CHAPTER 4: EXPERIMENTAL WORK
4.1 Microscopy
4.1.1 Light Optical Microscopy (LOM)
4.1.2 Scanning Electron Microscopy (SEM)
4.1.3 Electron Backscatter Diffraction (EBSD)
4.2 Magnetisation measurements
4.3 X-Ray Diffraction (XRD)
4.4 Microindentation hardness testing
4.5 Tensile testing
4.6 Microstructure characterization
4.7 Mechanical properties
CHAPTER 5: RESULTS AND DISCUSSION
5.1 Computational results
5.1.1 Effect of Si content
5.1.2 Effect of C content
5.2 Model validation
5.2.1 Comparison with Thermo-Calc (DICTRA)
5.2.2 Comparison with experimental data
CHAPTER 6: CONCLUSIONS AND PERSPECTIVES
6.1 Conclusions
6.2 Further research
REFERENCES
ACKNOWLEDGEMENT
LIST OF PUBLICATIONS
【参考文献】：
期刊论文
[1]Q＆P钢配分过程中的组织演变[J]. 庄宝潼,唐荻,江海涛,米振莉. 北京科技大学学报. 2012(11)
本文编号：3667541
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