Quite often, it is necessary to connect metal parts or fragments of parts. There are several ways to get the desired result. Most often, the method of electric welding is used to connect iron and steel parts.
What is it based on?
How to cook with electric welding? In order to understand the principle, you need to remember physics from the school curriculum. One of the
wires of the welding machine is connected to the workpiece. When the electrode touches this surface, an
electric arc arises
. A groove is formed at the point of contact, which is filled with molten metal as the electrode moves. The edges of the metal parts melt under the influence of tremendous temperature and turn into a single whole.
Arc ignition methods
Learning how to weld metal by electric welding, it is worth learning something about the method itself. The distance and the electrical high-temperature pulse between the part and the electrode are called the arc. There are two ways to create such conditions:
- In the first case, the electrode (quickly touching) “strike” on the iron, as if with a match. The arising arc must be maintained by leading an additive several mm from the working surface of the metal.
- In the second case, the tip of the electrode must be tapped sharply on the workpiece.
The resulting arc should not go out. If this nevertheless happened, before the welding continues, the joints must be cleaned of scale. Neglecting this rule leads to the formation of a hole.
The Importance of Welding Current
The calculation of the current strength corresponding to the thickness of the electrode will show in practice how to learn how to cook by electric welding. With insufficient current, the electrode will stick, and the arc will go out. At high currents, the metal will spray and burn. If you use a welding transformer, a current of 30-35 A corresponds to an electrode of 1 mm. When using a welding inverter, a current of 80 A corresponds to a 3 mm electrode. If you increase the current, iron can be cut.
The electrodes are selected taking into account the chemical composition of the metal. There are several types of this filler material:
- steel;
- bimetallic;
- cast iron;
- copper;
- brass.
All of them are marked with an index and numbers indicating what kind of hardness and thickness each type is intended for.
Learning how to cook with electric welding, you need to remember that to obtain high-quality seams, the electrodes must correspond to the thickness of the metal.
Welding flat metal sheets
Thin metal (from 1 to 3 mm) is joined end-to-end without gaps and additives, achieving good coincidence of aligned edges.
For a better fit of the joints of thicker sheets (from 3 to 8 mm), the edges should be cut at right angles. Between the sheets leave a gap of up to 2 mm. Material 8 mm thick is joined by double-sided welding. To connect thicker planes, the edges are cut with a bevel.
Where to start learning how to cook iron
Learning how to cook properly with electric welding starts with the simplest processes.
- Cooked parts are fixed on a horizontal surface (on a table for welding).
- Tacks hold them together at the edges and in the center.
- It is necessary to insert a new additive into the holder and attach the mass clip to the part.
- First work out the correct inclination of the electrode (about 75 degrees) in the direction of the arc. In this case, it is necessary to make movements that sort of rake the molten metal at the junction.
- The end of the electrode should be at the center of the seam. Due to the observance of the angle of inclination, the droplets flow more evenly from the hot electrode and form a weld seam with an even high-quality roller .
- After cooling the workpiece, you need to beat off the slag from the surface of the part.
Time after time, as you gain experience, the seams will turn out more evenly and accurately.
How to make a vertical seam
How to cook a vertical seam by electric welding? The main thing is to start by following all the recommendations. Welding vertical joints is like working horizontally, only a little more complicated. Billets are seized in two or three places. Then welding is carried out only from the bottom up, sticking drop by drop. Gradually, the entire gap is poured with hot metal. How to learn how to cook electric welding? The task is to merge both edges, melting them with a welding arc, while simultaneously directing metal drops from the end of the electrode heated to a liquid state.
You can brew a seam not in drops, but in the so-called “eight”, but only an experienced specialist can handle this. So, if it is interesting to know how to learn how to cook a vertical seam by electric welding, it is recommended first to look at the work of an experienced welder, to listen to the advice of masters. And only then independently start the process.
How to make a beautiful and strong corner seam
Correctly making the so-called "tee" seam is not as easy as learning how to cook with electric welding. This seam is used if you want to fasten parts at different angles. Metal parts are installed so that the welding flows down to the very corner. The parts to be welded fixed by the boat are seized from opposite sides. In addition, one edge of the workpiece rises slightly higher. The welding process must begin from the bottom edge. In this case, carefully following the instructions on how to cook with electric welding, the quality of the weld can be significantly improved.
Which welding machine is better to use
- Antique welding machines having an adjustable magnetic gap that allows you to adjust the current strength are transformer ones. There are many options and models that have rheostats and auxiliary chokes on the primary or secondary sides of transformers.
- Inverter machines are more modern welding devices. Operating from an increased frequency, the transformer of such units has smaller dimensions and light weight. In such devices, you can smoothly adjust the welding modes. The settings of the latter must be carried out carefully, otherwise the device can quickly fail.
Pipe welding methods
In the absence of experience, learning how to weld a pipe with electric welding is better on thick metal. Several passes are made depending on the wall thickness of the pipe. Multilayer welding improves the mechanical properties of the resulting weld, the connection becomes stronger.
First, a half ring is welded in one direction, then in the second. When the method of conducting the seam "from top to bottom" use 4-mm electrodes having organic spraying. In a short arc, relying on the formed "peak", the consoles are small transverse vibrations.
When working according to the "bottom up" method, the speed is sharply reduced. The transverse vibrations of the electrode are made in 3-5 mm.
When welding structures from pipes, you must first prepare and decompose all the material on the welding table or stand. Then they are centered and pulled together to obtain the necessary gap for welding. The assembled joints are seized together.
Pipes with a small diameter are connected by continuous welding, with a large diameter - intermittently. After completion of all welding processes, the working surface of the metal is cleaned of scale, solidified spray, and slag. A checkup is carried out to detect cracks or burns, escaping craters or pores. In the presence of poorly welded places, the restoration of the seam is performed.
For your own safety, you need to work during welding in suede gloves and mittens, in the mask of a welder, in tarpaulin or thick leather boots and in a cotton robe. Be sure to have a fire extinguisher or a container of water nearby.