摘要本文针对某汽车配件厂生产的某车型门铰链的焊接问题进行研究，该门铰链为4mm镀锌钢板（上有螺孔）与2mm的镀锌钢板进行搭接的角焊缝连接。采用非熔化钨极氩弧焊（TIG焊）焊接工艺方法，研究工艺参数对焊接质量的影响。通过正交试验获得了最佳工艺规范为：焊接电流120A，焊接速度为11cm/min，保护气体流量为15L/min，填丝速度1。5m/min。87868

对各组试验焊缝的表面成型情况进行对比。通过宏观截面分析，对焊缝的焊接质量进行评估，分析焊缝缺陷产生的原因

利用金相显微镜观察焊接接头的微观组织变化。观察表明：焊接接头组织主要为铁素体与珠光体，热影响区因受热晶粒较粗大，焊缝无气孔、夹渣和未焊透等缺陷。

力学性能检测焊接接头的硬度：母材的硬度在125~135HV之间，焊缝的硬度在290~305HV之间。

毕业论文关键字：  镀锌钢板  TIG焊  角/对接填丝  焊缝成型  金相分析  力学性能

毕业设计说明书外文摘要

Title      Experimental study on TIG welding process of   galvanized steel sheet for automobile door hinge                                             

Abstract The for a auto parts factory production of a car door hinge welding were studied, the door hinge for 4mm galvanized steel plate with holes and 2mm galvanised steel were lap of the fillet weld connection。 The influence of process parameters on the welding quality was studied by the method of non melting tungsten electrode argon arc welding (TIG welding)。 Through orthogonal test, the best technological standard is as follows: the welding current is 120A, the welding speed is 18cm/min, the gas flow rate is 15L/min, and the filling rate is 1。5m/min。

 The surface molding of the test welds in each group was compared。 The welding quality of the welding seam is evaluated by the macro section analysis, and the reason of the weld defect is analyzed。

 Microstructure changes of welded joints were observed by optical microscope。 The observation shows that the microstructure of the welded joint is mainly ferrite and pearlite, and the heat affected zone is larger than that of the heat affected zone。 The hardness of welded joints is detected by mechanical properties。

 The hardness of the base metal is between 125~135HV, and the hardness of the welded joint is between 290~305HV。

Keywords  Galvanized steel sheet  gtaw Angle / butt joint  Weld formation  Metallographic analysis  mechanical property

目   次

1绪论 1

1。1  选题背景与选题意义 1

1。2  钢板的镀锌化研究 2

     1。2。1镀锌层的保护作用 2

 1。2。2钢板镀锌方法 3

 1。2。3镀锌层表面的防腐蚀处理 3

1。3  镀锌钢板的焊接性 3

1。4  镀锌钢板的焊接工艺 4

1。5  课题研究内容 6

2  试验准备 7

2。1  试验材料 7

2。2  试验设备 8

2。3  焊接试验流程 9

2。3。1  焊前处理 汽车门铰链镀锌钢板TIG焊工艺试验研究:http://www.youerw.com/cailiao/lunwen_149309.html