Today, electrical welding is most often used to connect metal pipes. However, how to weld with electric welding, because not everyone can do it, although they easily cook corners, channels and the like? In this article, this process will be described as detailed and understandable as possible.
The method for the connection, which is produced by electric welding and electrodes, the most common. The latter melt due to the influence of electric current and fill the seams between the pipes, transforming into liquid metal. The resulting compound is quite strong and does not deform due to any loads.
First, some information about the properties of the electrodes. The electrode is a thin metal rod coated with a coating for welding. Electrodes are of different thickness, it all depends on the type and thickness of the material. The coating on the electrode is involved in the metallurgical processing of the joint and its protection from the effects of the atmosphere, while providing a more stable arc burning.
Before you buy electrodes on the market or in a store, ask the professionals or the neighbors who brew at home, which manufacturers should they buy electrodes. You will also ask them how to avoid acquiring fakes, otherwise you will not be able to properly connect the seam due to poor-quality electrodes, thinking that this is a result of little experience or a bad welding machine. One can say for sure - a good electrode will not be cheap.
During such work, slag builds up on top, creating a protective film that prevents nitrogen and oxygen from being absorbed by the metal. These components adversely affect the seam in the metal, in the place where it is melted, as a result of which it does not acquire the necessary strength and becomes brittle.
What do experienced workers do in this case? After the metal hardens, the slag cools and becomes quite light and brittle. It is removed by applying small but precise strikes on it with a hammer or an electrode. If, however, to ignore it and leave the slag inside the seam - this can lead to sad consequences - to the formation of a fistula or a weak joint that can flow. The pipe is not brewed like other metal shapes. It is important to get a tighter seam so that it is not only durable, but also as tight as possible. To do this, there are special techniques - a seam in the form of a figure of eight or a horseshoe is made, and the slag is gradually replaced with each new seam. When the slag is removed, the seam will be not only durable, but also beautiful - in the form of scales.
It is important to use high-quality electrodes so that the seam is strong. Only a high-quality electrode will provide a good arc and will not stick.
How to determine the desired diameter of the electrode?
It all depends on the thickness of the joint where the welding will be performed. For small pipes, electrodes with a diameter of three millimeters can be used. They are suitable for metal from 2 to 5 mm. The connection by electrical welding of metal pipes with a greater thickness (from 2 to 10 mm) will already require the use of electrodes of a correspondingly larger diameter.
For the device of multilayer seams, as a rule, first of all, electrodes with a diameter of four millimeters are used to create a greater depth of joint connection.
Making the right stitch
Electric arc welding is used to create certain types of connections. Here are some of them: joining them among themselves, placing the products opposite each other; perpendicular arrangement of pipes; corner; overlap. Types of seams that are obtained as a result of such a connection are as follows: vertical, horizontal, lower and ceiling. The most common and most common is the bottom seam. In it, welding by electrodes is done from above. The heaviest seam is the ceiling seam. It is extremely inconvenient to connect it, since the molten metal flows down, and the location of the pipe itself somewhere under the ceiling and at the height causes a lot of trouble. Another drawback is the poor visibility of the seam, which makes it necessary to perform work with the help of a mirror, which you will agree that not everyone can do it. Sometimes it is simply impossible to get an electrode, which is why in some situations it is necessary to bend it slightly in order to connect well. To cope with such a stitch a layman, as a rule, not under force. If possible, it is better to cook the pipe when you can rotate it. In view of the above difficulties, you can practice on something else before undertaking such work.
The use of these tips will help beginners in this matter to better perform their work, so that the combined products will last for many years.
For an example, we suggest watching a video on electric arc welding of pipes: