DP590双相钢激光胶接点焊接头的疲劳强度分析

第9卷第7期有色金属工程 Vol. 9,No. 7 2 0 1 9 年7 月Nonferrous Metals Engineering July 2019

doi:10. 3969/j.issn.2095-1744. 2019. 07. 003

DP590双相钢激光胶接点焊接头的疲劳强度分析

翟停停，曾凯，孙鑫宇，易金权，冯煜阳

(昆明理工大学机电工程学院，昆明650500)

摘要：为对比分析DP590双相钢激光胶接点焊接头和激光点焊接头的疲劳强度，针对1.5 mm厚的DP590钢板，以焊接功率、焊接时间、离焦量为变量，进行三因素三水平的激光点焊和激光胶接点焊正交实验，通过拉剪实验获得两种接头的失效载荷；应用 方差分析方法辨析焊接工艺参数对两种接头焊接质量的影响程度；开展疲劳实验，建立接头的载荷-寿命曲线，并对胶接点焊接头 进行疲劳断口分析。结果表明，胶接点焊接头的拉剪失效载荷和疲劳强度均大于点焊接头;对胶接点焊接头和点焊接头的力学性 能影响最大的工艺参数分别是焊接功率、焊接时间；胶接点焊接头的疲劳裂纹主要起源于热影响区，疲劳裂纹扩展区存在明显的 疲劳条带，瞬断区出现典型韧窝形貌。

关键词：激光点焊;激光胶接点焊;拉剪实验;疲劳实验;断口分析

中图分类号：TG142 文献标志码：A文章编号：2095-1744(2019)07-0015-06

Fatigue Strength Analysis of Laser Spot Weld-bonded

Joints for DP590 Dual-phase Steel

Z H A I Tingting，Z E N G K a i，S U N X i n y u，Y I Jinquan，F E N G Y u y a n g

(Faculty of Mechanical and Electrical Engineering, Kunming University of Science and

Technology, Kunming 650500,China)

Abstract：For comparative fatigue strength analysis of laser spot weld bonding joints and laser spot welding joints for DP590 dual-phase steel, the orthogonal experiment of laser spot welding and laser spot weld bonding was designed for 1. 5 mm thick DP590 using welding power, welding time and defocusing amount as variables. The failure load of the two joints was obtained by the shearing test；the variance analysis of the mechanical properties was carried out to acquire the impact of various factors on the welding quality of the two joints. In order to achieve the load-life curves, the fatigue test was practiced and the fatigue fracture of weld-bonded joints was analyzed. The results show that the failure load and fatigue strength of the weld-bonded joints are higher than those of the spot welded joints. The maximum process parameters for the mechanical properties of the weld-bonded joint and the spot welding joints are the welding power and the welding time respectively. The fatigue cracks of weld-bonded joints mainly originate from the heat-affected zone, and there is obvious fatigue striation in the fatigue crack extension area, and the typical dimples appear in the instantaneous fracture zone.

Key words：laser spot welding；laser spot weld-bonded；tensile shear test；fatigue test；fracture analysis

胶接点焊是一种将胶接和点焊技术相结合的复 合型连接技术，其连接节点具有胶接和点焊的结构 特征[M]。胶接点焊的热源供给包括电阻、激光以及搅拌摩擦等。通常，非导电胶的应用对电阻胶接的 控制产生较大的影响，这也限制了胶焊工艺的推广 应用M。激光胶接点焊不仅避免了胶层导电性对焊

收稿日期：2018-06-22

基金项目：国家自然科学基金资助项目（51565022,51565023)

Fund ：Supported by National Natural Science Foundation of China(51565022,51565023)

作者简介：翟停停（1994一），女，研究生，主要从事板材连接方面的研究。

通信作者：曾凯（1976 —），男，博士，副教授，主要从事板材连接技术、结构可靠性设计分析等方面的研究。

引用格式：翟停停，曾凯，孙鑫宇，等.DP590双相钢激光胶接点焊接头的疲劳强度分析[J].有色金属工程，2019, 9(7): 15 —20. ZHAI Tingting,ZENG Kai,SUN Xinyu,et al.Fatigue Strength Analysis of Laser Spot Weld—bonded Joints for DP590 Dual—phase Steel[J]. Nonferrous Metals Engineering, 2019, 9(7)： 15 —20.