摘要高强度钢板的使用是实现汽车轻量化、提高汽车安全性能的重要途径之一。由于高强度钢板在常温下强度高、变形抗力大、延展性差，采用常规的冷冲压成形方式很难成形。因此，高强度钢板的热冲压成形技术应运而生。热冲压成形技术是先将高强度钢板加热到奥氏体化状态并保温然后成形及冷却的一种新的冲压成形工艺。由于高温可以使材料发生微观组织转变，成形之后再由模具对其进行冷却淬火，使之转变为马氏体，从而强度得到大大提高。本论文以BR1500HS高强度钢板为研究对象，利用实验研究与DEFORM-3D有限元模拟软件相结合的方法，建立高强度钢板的热成形工艺进行热-力-相变耦合分析，阐述板料在成形过程中的温度场和应力场的分布和变化特点，为热冲压模具的设计、汽车轻量化和安全化设计提供有价值的参考。6455
关键词：高强度钢板； 轻量化； 热冲压成形； 有限元模拟； 热-力-相变耦合
Abstract
The application of high strength steel (HSS) is very important in automotive light weighting industry and promoting passive security. However, because of the high stress,、deformation resistance and poor malleability of high strength steel, it is very hard to be formed by the method of cold punch, so the hot stamping technology emerged for demands. The hot stamping of HSS is a new forming process which heats the metal beyond the re-crystal temperature, then forming and quenching the part in mould to obtain high strength part. Because of high temperature, the material microstructure transferred into Austenite, for quenching after forming, the microstructure switch to Martensite, thus the mechanical strength has been improved greatly. This paper takes the HSS BR1500HS as research object, using combining DEFORM-3D—method of numerical simulation and test to establish base on thermos-mechanical-metallurgical coupled analysis method. The distribution and persification in metal sheet during the process are presented and effect of the initial the temperature field and stress field. It was obtained for the purpose of proving some theoretical proofs for hot stamping tools designing、light weighting industry and passive security.
Key Words：high strength steel； light weighting； hot stamping； numerical simulation； thermos-mechanical-metallurgical coupled
目 录
摘 要 I
Abstract II
1 绪论 1
1.1 高强度钢板热冲压成形国内外研究现状 2
1.1.1 汽车用高强度钢板现状 2
1.1.2 高强度钢板热冲压成形工艺现状 2
1.2 板料冲压成形有限元分析介绍 4
1.3 研究的目的及意义 6
1.4 研究的主要内容 7
2 高强度钢板的性能研究 8
2.1 前言 8
2.2 实验材料 8
2.3 实验设备 9
2.4 实验方案 10
2.4.1 等温拉伸实验 10
2.4.2 非等温拉伸实验 11
2.5 实验结果与分析 11
2.6 结论 17
2.7 热成形本构方程 17
2.7.1 试验材料与方案 18
2.7.2 试验结果 19
2.7.3 结果分析 20
3 高强度钢板热成形数值模拟 22
3.1 前言 22
3.2 零件模型建立 22
3.2.1 材料模型 22
3.2.2 网格划分 23
3.3 边界条件 24
3.3.1 机械接触 24
3.3.2 热边界 25
3.3.3 加载 25 热-力-相变耦合下BR1500HS高强度钢热成形数值模拟:http://www.751com.cn/cailiao/lunwen_4030.html