At present, an increasing number of factories are engaged in the re-equipment and modernization of their workshops, and the improvement of technological equipment. And, of course, there is a widespread replacement of manual arc welding machines with machines that perform automatic welding. This re-equipment allows to increase productivity, and also provides ample opportunities for the restoration of parts by the industrial method in industrial volumes. Automatic submerged arc welding is most often used. This allows for hardfacing of parts, which is considered a cost-effective solution that increases productivity and improves the quality of the weld.
If automatic welding of parts is carried out in the open air, however, in this case, flux is deposited on the resulting seam, then they say that the arc is burning in an enclosed space. This phenomenon is explained by the fact that the flux layer is a kind of electrode coating, which means it serves to protect the welding site from the harmful effects of ambient air. In addition, flux surfacing is used to prevent possible spattermolten metal.
Automatic submerged arc welding traditionally takes place with uncoated electrode wire. This method eliminates a significant number of shortcomings inherent in electric arc welding. At the same time, the metal of the parts to be welded becomes more uniform, which improves the quality and density of the weld.
If you carefully consider the process of passage of the welding current through the parts to be welded, you will notice that the arc burns in a small gap between the electrode wire and the part to be welded. Of course, it should be noted that this wire is fed from a spool, which unwinds automatically and is fed into the welding zone as the welding end melts. For these events, a special mechanism built into the welding machine is used. Thus, the flow of flux comes from a small container - a bunker. A small fraction of it is melted under the influence of an electric arc. However, once the weld has cooled and solidified, the previously melted flux can be easily removed. Unused goes back into the hopper cavity and is used in subsequent welding processes.
Automatic welding involves many ways that improve its performance.
1. Increase in welding current. It is used to increase the depth of welding, the so-called penetration depth of the metal. In this case, it is important that the width of the weld practically does not change.
2. Enlargement of the cross section of the electrode. This, on the contrary, leads to an increase in the width and a decrease in the depth of the weld. In turn, reverse transformations, i.e. reduction of the wire section, entail deeper welding and reduce the width of the weld.
3. Studies have shown that even with a slight increase in the arc advance rate, the height of the deposited metal bead increases significantly, while the penetration depth and weld width decrease.
Thus, it can rightly be said that automatic welding is vastly superior to manual electric welding.
