摘要本课题研究了 6005A 铝合金薄板焊接接头纵向残余应力的分析。采用超声 波法和小孔法测量其纵向残余应力。测量之前先使用 TIG 焊和进口 ER5356 焊丝 对铝合金进行焊接。测量结束后，对试样铝合金焊材进行切割、镶嵌以及表面处 理等工序，准备好试样后，采用蔡司显微镜观察 6005A 铝合金金相试样焊缝组 织中的微结构和测试拉伸试样时使用 WEW−1000B 型万能材料试验机。结果表 明：从焊缝区域到热影响区纵向残余应力表现为拉应力，拉应力逐渐增大，最大 值在焊缝熔合线处。随着相对于焊缝位置距离逐渐增大，残余应力随之减小，残 余应力也变为压应力。6005A 铝合金焊接接头不同区域具有不同的组织形貌和晶 粒粗化程度，焊接接头的力学性能下降。83556

掌握了 6005A 铝合金的焊接接头的残余应力分布，以及焊接过后残余应力 对材料各种性能的影响。为解决高速列车车体上服役期间残余应力存在的危害， 为此做出防范工作。

毕业论文关键词：6005A 铝合金；纵向残余应力；超声波法；小孔法

Abstract In this paper,the analysis of longitudinal residual stress in welded joint of 6005A aluminum alloy sheet was studied。The longitudinal residual stress was measured by the ultrasonic method and the small hole method。Before mearsuring residualstress,the aluminum alloy was welded by TIG welding and ER5356 welding wire。After the end of the measurement,there are some welding processes for Aluminum Alloysamples,cutting, inlay and surface treatment。After preparing samples  ,using Zeiss microscope observed 6005A aluminum alloy metallographic specimen in the weld metal microstructure。And the material was tested the main mechanical tensile specimen properties in WEW - 1000B type universal material testing machine。The results show that the residual stress of the weld zone to the heat affected zone is tensile stress, and the residual stress in the weld fusion line is the maximum。With the increase of the distance from the position of the weld, the residual stress gradually decreases, and the residual stress is gradually changed into the compressive stress。6005A aluminum alloy welded joints with different regions have different microstructure , grain coarsening degree and the decrease of mechanical properties of welded joint。

The residual stress distribution of the welded joint of 6005A aluminum alloy, and the effect of residual stress on the properties of the material after welding are mastered。In order to solve the harm of the residual stress in the high speed train body during service, the preventive work is made。

Keywords: 6005A aluminium alloy; longitudinal residual stress; ultrasonic method; little hole method

目 录

第一章 绪 论 1

1。1 研究背景 1

1。2 铝合金的研究现状与发展 2

1。3 焊接接头残余应力的分析的研究现状与发展 2

1。3。1 铝合金焊接方式的发展趋势 2

1。3。2 焊接残余应力存在的危害性 4

1。3。3 残余应力测量方法的发展趋势 6

1。4 本文的主要内容 9

第二章 实验材料及研究方法 11

2。1 实验材料 11

2。2 实验方法 11

2。2。1 试样制备 11

2。2。2 超声波法测量残余应力 12

2。2。3 小孔法测量残余应力