摘要本文采用等离子穿熔焊接工艺对板厚为6mm的Q235碳钢板材进行焊接，分析了不同工艺参数条件对焊接接头成形及微观组织的影响，并测定焊接接头的显微硬度及抗拉强度。研究结果表明：当热输入较大，等离子气流量较小时，等离子弧焊焊缝成形效果较好。热输入大小对焊接接头组织影响很大。热输入大时，焊接接头焊缝区和热影响区晶粒长大明显，细晶区与母材的分界线更为清晰。热输入小时，热影响区残存大量粒状珠光体，晶粒细小。焊缝区显微硬度值最高，母材硬度最低。拉伸试验中，焊接接头的抗拉强度大于Q235的抗拉强度400MPa。用选出的焊接工艺参数对Q235板材进行对接，能得到成形良好的焊缝。67498

毕业论文关键词   Q235板材  等离子弧焊  微观组织 显微硬度 抗拉强度 

毕业设计说明书（论文）外文摘要

Title Study on robot technology plasma arc welding of sheet component                     

Abstract This paper adopts the keyhole plasma arc welding process on the plate thickness of 6mm Q235 sheet for welding. Analysis of the different para-

meters of welded joint forming and characteristics of the organization, and determination of micro Vickers hardness of welded joint and Tensile strength .The results show that: when the heat input is larger, plasma gas flow is smaller, plasma arc welding seam forming effect is better. Heat input size has a great impact on the structure of welded joint. When the heat input is larger, the grains in weld zone and heat affected zone of the welded joints grow significantly, fine grained zone and base material boundaries more clearly. When the heat input is smaller, there exist a lot of granular pearlite, the grain is smaller. The weld zone average hardness is the highest, and the parent material hardness is the lowest. In the tensile test, the welded joint tensile strength is greater than the tensile strength of Q235 of 400MPa. With the selected welding parameters for Q235 sheet for docking, we can get good weld forming.

Keywords  Q235 sheet   plasma welding  microstructure   microhardness Tensile strength

目    录

1 引言 1

1.1  课题的意义 1

1.2  Q235的性能及其应用 2

1.3  Q235的焊接性 2

1.4  Q235常见的焊接方法 3

1.5  等离子弧焊接的国内外研究现状 5

1.6  Q235采用等离子穿熔焊接的优点 6

1.7  论文研究的内容 6

2  试验材料及试验方法 7

2.1  试验材料 7

2.2  试验设备 7

2.3  试验方案设计 9

3  小孔型等离子焊接焊缝成形及微观组织分析 10

3.1  焊缝成形分析 11

3.2  接头宏观金相分析 13

3.3  接头微观金相分析 14

3.4  本章小结 17

4  小孔型等离子弧焊接力学性能分析及对接试验 19

4.1  接头硬度分析 19

4.2  等离子对接试验