【作者】 张红；

【导师】 周惦武； 何艾君；

【作者基本信息】 湖南大学 ， 车辆工程， 2014， 硕士

【摘要】 通过对现代汽车开发流程及其关键技术的分析和研究，归纳和沉淀知识和经验，构建基于知识和经验的满足现代轿车车身正向开发的基础材料参数数据库,是轿车车身数据库必不可少的重要组成部分。为构建轿车车身用基础材料参数数据库，本文在对车身材料进行分类与整理的基础上，根据车身零件种类、结构和制造工艺的差异，基于车身设计所用材料的关键参数，选取轿车安全结构件，用DP600双相钢作为研究对象，采用试验与仿真结合的方法，利用MTS810材料试验机、卧式金相显微镜、扫描电镜、HyperMesh、LS-dyna、Dynaform商业软件等手段，对DP600双相钢的力学性能、金相组织、晶粒大小、晶粒取向分布、织构类型及拉延筋、压边力、冲压方向等工艺参数对成形件质量的影响进行了系统研究，构建了计算反求基本模型，修正了工程应力—应变曲线，研究结果期望为轿车车身的正向开发提供技术支持。根据准静态拉伸试验，得到DP600双相钢的应力-应变曲线与基本力学性能参数；构建准静态单向拉伸的数值计算模型，根据试验过程的约束及部分参数的前处理，通过计算反求修正应力-应变曲线。通过金相组织分析，发现DP600双相钢主要有铁素体与马氏体两相组成，其中高韧性的马氏体以岛状形式分布在高延性的铁素体的基体上；通过电子背散射衍射(EBSD)对比分析了DP600双相钢钢板表层、1/4层和中心层相的体积分数、晶粒大小、晶粒取向和织构，发现三个层面的晶粒大小、晶粒取向与相的总体积分数变化不大；中心层分布较多的(111)织构对DP600双相钢冲压性能的提高十分有利，而铁素体与马氏体两相的体积分数、形态、大小与分布对DP600双相钢力学性能起决定作用。基于DP600双相钢力学性能和成形性能的分析，建立轿车安全结构件B柱冲压仿真模型，研究了拉延筋、压边力等工艺参数对冲压成形件质量的影响，得到设置开式拉延筋的布置方式等合适工艺参数，并给出了控制冲压成形件质量的工艺优化措施。更多还原

【Abstract】 Through the analysis and research of modern automobile development processesand the key technologies of that, and then summarized and precipitation knowledgeand experience, build the basic material parameters database based on the knowledgeand experience and could meet a modern automobile body original design, which Is animportant part of the car body database. To build the basic material parametersdatabase of automobile body, this article based on the classification and finishing ofbody materials, according to the difference in body parts type, structure andmanufacturing process, and the key parameters of the body materials, selected the carsecurity structure Dual phase steel DP600as the research object, adopted the methodof simulation analysis combined with test, systematically studied the Impact on thequality of molded parts by using MTS810material testing machine, horizontalmetallographic microscope, scanning electron microscopy (SEM), the commercialsoftware HyperMersh, ls-dyna, Dynaform, to research the effect of mechanicalproperties of the DP600Dual phase steel, the microstructure, the grain size, grainorientation distribution, the types of texture and the process parameters inmanufacturing processes of drawbeads, BHF and the direction of stamping, and builtthe basic model and calculating reverse results, Fix the engineering stress-straincurves, and the results of the article are expected to provided technical support forautomobile body original design.On the basis of Quasi-static tensile test, the paper obtain the stress-strain curvesand the basic parameters of the mechanical properties of DP600, built numericcalculation model of quasi-tensile test. According to the constraints of the test and thepre-treatment of some parameters, based on the reverse calculation, ix the stress-strain curves of DP600.Microstructure analysis indicated that DP600is mainly made up of ferrite andmartensite. and Martensite of high impact toughness is distributed island-formed inthe ferrite of high ductility. By EBSD test comparative analysis of volume fraction,grain size，orientation and texture in the surface layer,1/4layer and center layer ofDP600high strength steel, the grain size, orientation and volume fraction of the abovethree layer is similar, the (111) texture which distributed more in the center layer is infavor of improvement of stamping performance of DP600, and the volume fraction,morphology, size and distribution of ferrite and martensite play a decisive role in the mechanical properties of DP600.On the basis of analysis of mechanical properties and formability of DP600, builtstamping simulation model of automotive security structure B pillar, study the effectsof the process parameters such as drawbeads, BHF on the quality of stamping parts,get the appropriate process parameters of setting layout of open drawbeads, and givesprocess optimization measures of the quality controlling of stamping parts.更多还原