电阻点焊工艺参数对高强钢焊接性能的影响研究

发布时间：2018-06-13 10:08

本文选题：汽车 + 高强钢　；参考：《华东理工大学》2016年硕士论文

【摘要】：为了满足汽车行业的轻量化制造和强度需求,越来越多的高强钢被运用于车身结构。车身结构一般采用焊接方式进行连接,电阻点焊因其成本低、易于控制、适于自动焊接等特点成为了车身焊接中最广泛使用的焊接方法。因此,电阻点焊质量是保证白车车身整体强度极为重要的一环,而点焊工艺参数的选取对点焊质量的控制显得尤为重要。本文选取点焊焊接三要素：焊接电流、焊接压力、焊接时间作为研究对象,分析了这三个焊接工艺参数对高强钢-低碳钢焊接组合质量的影响规律。采用拉伸实验和剪切实验测定点焊的抗拉强度和剪切强度,基于正交实验设计方法,采用极差分析和方差分析得到焊接三要素对电焊性能的影响规律和影响程度。采用显微金相分析方法,研究了焊接工艺参数对点焊显微金相组织的影响规律。结果表明：焊接电流、焊接压力和焊接时间都需要维持在一个合适的水平,过大和过小都不利于形成良好的点焊形貌。另外,汽车车身上点焊的焊点布置形式对汽车总体的结构强度和抗冲击性能有着显著的影响,本文基于有限元方法分析了不同的焊点分布形式对搭接构件的强度的影响,得到了最优的焊点布置形式并对其进行了讨论。
[Abstract]:In order to meet the demand of lightweight manufacturing and strength of automobile industry, more and more high-strength steels are used in body structure. The welding method is generally used to connect the body structure. The resistance spot welding has become the most widely used welding method in the body welding because of its low cost, easy to control, suitable for automatic welding and so on. Therefore, resistance spot welding quality is very important to ensure the overall strength of the white car body, and the selection of spot welding process parameters is particularly important to the control of spot welding quality. In this paper, three factors of spot welding: welding current, welding pressure and welding time are selected as the research object, and the influence of these three welding process parameters on the welding quality of high strength steel and low carbon steel is analyzed. The tensile strength and shear strength of spot welding were measured by tensile test and shear test. Based on the orthogonal design method, the influence law and degree of the three factors of welding on the welding properties were obtained by means of range analysis and variance analysis. The effect of welding parameters on the microstructure of spot welding was studied by means of metallographic analysis. The results show that the welding current, welding pressure and welding time need to be maintained at a suitable level, too large and too small are not conducive to the formation of a good spot welding morphology. In addition, the pattern of spot welding on the automobile body has a significant effect on the overall structural strength and impact resistance of the vehicle. This paper analyzes the influence of different distribution forms of solder joint on the strength of the lap member based on the finite element method. The optimal solder joint arrangement is obtained and discussed.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG453.9

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