【作者】 袁玉兰；

【导师】 王惜宝；

【作者基本信息】 天津大学 ， 材料加工工程， 2006， 硕士

【摘要】 CO₂气体保护焊作为一种高效焊接技术,因其具有生产率高、焊接成本低、焊接变形小、能耗低、适用范围广、抗锈能力强以及焊后不需清渣等优点,大量应用在低碳钢、低合金钢等黑色金属的焊接,便于实现自动化生产,可以进行不同厚度工件的各种位置的焊接。但是由于CO₂气体保护焊的自身性质特点,使此焊接方法有2个主要不足:一是飞溅大;二是成形差。本论文提出了一种气-粉混合CO₂保护焊的新技术,在这种工艺中由于加入的特种活性材料参与电弧燃烧、焊丝熔化和焊缝成型过程,通过调整药粉特性而获得多种焊接工艺性能,包括极低的飞溅率和良好的焊缝表面成型性能;而通过调整药粉成分,很容易获得适宜的熔敷金属合金系统。本论文研制一套工艺设备,包括焊丝表面轧丝轮、焊丝校直系统、焊丝压丝轮、送粉器等实现气粉混合焊接过程。设计了带齿的两对不同位置的轮,把焊丝轧制成表面有凹痕的能携带药粉的焊丝;采用压轧轮把焊丝表面毛刺去除;让焊丝滚过送粉器而实现带粉进入焊接区。本文所研制的工艺设备可以比较容易地实现焊丝与药粉搭配的多样性、多用途、多品种。通过对普通CO₂气体保护焊设备的改造,可以由焊丝在焊接过程中直接带药粉进入焊接区,从而实现气-粉混合CO₂气体保护焊焊接过程。通过采用普通H08Mn2SiA焊丝带粉的气-粉混合CO₂气体保护焊焊接,与采用普通H08Mn2SiA焊丝的CO₂气体保护焊焊接的对比试验,研究气-粉混CO₂气体保护焊焊接工艺性能。实验证明,采用气-粉混合CO₂气体保护焊接,焊接飞溅率降低。熔滴过渡过程中,大颗粒飞溅物明显减少。气-粉混合CO₂气体保护焊接,焊缝熔宽、熔深都增大,而余高降低,焊缝成形得到改善,焊缝表面光滑美观。此外,采用气-粉混合CO₂气体保护焊接,使用中等规范参数,可以实现细颗粒熔滴过渡。更多还原

【Abstract】 CO₂ arc welding which is a high efficient weld technique is widely used in the weld of mild steel, low alloy steel and other black metals or the weld in different thickness and position because of its merits of high productivity and wide use in manufacturing production. On the other hand, this technique has two shortages of large quantity of spatter and formation of weld.The gas-powder-mixed CO₂ arc welding technique was developed in this dissertation. By adding active fluxes in the course of arc burning, weld melt and formation, many good qualities,such as low spatter and formation of weld will be obtained. And in the same time, conformable alloy will also formed.A new apparatus was designed in the thesis, which is consist of a rolling wheel, a revising device,a carved wheel and a delver powder device.Through two rolling wheels in different position, weld was rolled to be dented one which can be filled with powder, and the surface burr on weld can be wiped off by rolling wheels. All active fluxes can be brought to weld section by a delver powder device. Combination of weld and active powder was very alterable and multi-using by all above devices.The technics performance of gas-powder-mixed CO₂ arc welding was studied via the contrast experiment of ordinary H08Mn2SiA weld with active fluxes and ordinary H08Mn2SiA weld. Experimental results show that rate of spatter will descend by gas-powder-mixed CO₂ arc welding technics, but the penetration, width, and ratio of width/depth will increase.. Weld shapes will change as the result. So, the surface of weld slot was shaped well. .Melting drops are transferred by fine granule with gas-powder-mixed CO₂ arc welding technics according to middling standard parameters.更多还原