How to weld metal with electric welding or inverter? Technology of proper welding

Welding of metals is the most common way of combining them in various branches of the economy (construction, mechanical engineering, laying of pipelines, etc.). In everyday life (at home, at the dacha, in the garage), we also meet with the need for welding work on metal. To the non-specialist this work seems incomprehensible, difficult and mysterious. Moreover, it involves a certain risk for life.

Let's see if this is so. How to weld metal with electric welding?

In the modern trade network there is a wide variety of welding machines, inverters, protection equipment for welding operations. They are available to anyone, therefore, having bought the appropriate equipment, you can independently perform these welding works. It is only necessary to understand what is the technology of welding metals, what are the safety requirements. In addition, you need to get the necessary practice of welding.

Types of welding metals

Nowadays, there are many different technologies developed for how to weld metal. For example, you can use electronic and laser radiation, connect products with a gas flame and cook with ultrasound. But the most widely used is a source of energy, such as an electric arc.

How to weld metal properly? Welding of metals by means of electric welding machines or inverters refers to electric arc welding, whereby obtaining a high temperature in the welding zone necessary for melting the metal and obtaining a strong joint is achieved by the arc of electric current (up to 7000 degrees Celsius), capable of melting any metal.

Safety requirements

The first thing you need to worry about before properly welding the metal is about your own safety when carrying out the work. It is necessary to prepare and put on protective clothing (tight pants, jacket, safety shoes, suede or leather gloves). It will protect you from burns with possible splashing of molten metal. Also, you need to prepare a special protective mask or welding shield - this will protect your eyes from damage by light from arc welding.

Also it is necessary to worry about fire safety - remove all flammable materials and liquids from the place of welding, prepare fire-extinguishing means for use (if there are no special tools, even a bucket of water will fit), ensure ventilation of the room where the work will be done, especially from the front and back sides Welding machine.

Be sure to read the instructions for using the welding machine and follow all the recommendations there.

electrical safety

Before trying to master in practice how to weld metal, it is necessary to make sure that the parameters of the electrical network from which the welding machine is powered correspond to its requirements. Otherwise, other electrical appliances connected to the network may be damaged, not only from you, but also from neighbors. This is especially true for transformer welding machines, which significantly affect the power supply network by the presence of voltage surges during the beginning of welding and increased consumption of electric current when the electrode is sticking at the welding location. In addition, the welding machine should be positioned so that it can not fall, damage itself, or cause damage to surrounding people and objects during work. The wires connected to the device must be in good condition and be straightened. The possibility of damaging them must be avoided.

The order of preparation for work

How to weld metal properly? The place to be welded must be cleaned to the metal, be dry. It is forbidden to carry out welding work in wet weather, in rain and at negative air temperatures. Do not allow the welding machine and electrodes to get wet.

How to weld metal with electric welding?

Welding is carried out at constant voltage or with alternating voltage. Transformer welding machines provide variable voltage welding.

When welding DC, there are two options for connecting the welding machine. When you connect the plus to the mass, and the minus to the electrode (this is called direct polarity), the metal is heated more, the melting zone is created deep and narrow. Such inclusion is used in welding of thick metal and leads to economical consumption of electrodes. With the opposite inclusion (reverse polarity), the electrode is heated more rapidly and the electrode is consumed faster, the melting zone is wide and shallow. Therefore, the reverse polarity is used only when welding thin metal sheets.

Distinctive features of inverters

How to properly weld metal inverter? Inverter welding machines convert the alternating voltage of the industrial network into a pulse train of a higher frequency and then form a DC voltage current. Due to the electronic circuitry that realizes these transformations, the inverter has a small effect on the power supply network during operation, has a smoother adjustment of the output voltage, is characterized by a small weight and dimensions. The quality of the welding seam obtained by the inverter is not inferior to other similar equipment. Therefore, welding inverters have received recently, when the prices for such devices have decreased, is very widespread. The advantage of this device is its relatively simple use in welding.

How to choose an inverter

An important parameter of the inverter is the load period (DC) of the current source. This value, characterizing the efficiency of the inverter, shows the ratio of the welding time to the idling time. Household appliances do not work continuously. They should cool down periodically. So, the value of PV 30% of the inverter means that after every 3 minutes of welding you will have to wait 7 minutes until the source cools down. When trying to continue working without interruption, the unit may burn. Or the protection will work, and it will turn off. Therefore, it is necessary to choose an inverter with a voltage of at least 60% and a maximum current of at least 140 - 160 A.

Getting Started with the Inverter

To gain experience in how to properly weld metal inverter, it is first recommended to work with metal at least 2-3 mm thick and use electrodes 3 mm. Electrodes are better to buy new ones. Old, stale, borrowed from others, with a high probability will be damp and unfit for work.

How to weld metal properly? If this is your first experience, first try to make a seam on the surface of one piece of metal, not welding it with another piece.

Consider the sequence of the work.

First, it is necessary to connect the electrode to its holder, and the ground wire to the welded workpiece by means of a terminal. The other ends of the wires must be connected to the outputs of the inverter in direct polarity.

Secondly, it is necessary to turn on the device and set its output parameters in accordance with the recommendations, depending on the thickness of the material being welded and the chosen electrode size.

The technology of metal welding provides that for heating the metal to the temperature necessary for obtaining a high-quality weld, it is necessary to take the electrode corresponding to the thickness of the material. The thicker the latter, the more a layer of metal it can heat up and the more current must be installed on the inverter to form an electric arc. At the same time, the more current, the faster the metal melts and the faster the electrode is consumed. For a thin layer of metal at a high current and a thick electrode, holes are often formed, the material is burnt through. If the current is too low, either there is no electric arc, or, if it occurs, a low-quality seam is obtained, the so-called non-groove.

The third thing to note is the formation of an electric arc. To do this, it is necessary to strike the end of the electrode in place, which must be welded, like a match on the box, without removing the end of the electrode from the metal. When an arc arises on the metal, a red spot forms. But this is not yet molten metal, but only the flux that forms when the powder coating of the electrode melts. It is necessary to wait, while holding the end of the electrode at a distance of 1-4 mm from the surface of the metal, until the metal in the arc is heated to the formation of a so-called weld pool - a drop of molten metal, which is characterized by a bright orange color and shaking from the current flow.

Fourth, we must shift the end of the electrode one or two millimeters to the side of the joint to be performed, again holding it at the specified distance from the metal. Again wait for the formation of a drop, and so on, moving along the welding seam. When the electrode touches the surface of the metal, a short circuit is created, the arc disappears, and the inverter turns off the current. Therefore, when making a seam, we must try to maintain a constant distance between the end of the electrode and the surface of the metal, gradually bringing the electrode closer to it as it burns. Rather, the electrode does not burn, but melts, the metal in the weld pool is formed mainly from the metal core of the electrode. Powder coating of the surface of the electrode, melting forms a flux and gases, preventing the flow of oxygen from the ambient air to the place of welding and oxidation of the metal, as well as helping the formation of a high-quality welding seam.

In the welding process, it is recommended to hold the electrode at an angle of approximately 30 degrees from the perpendicular to the work piece so that a compact welding bath is formed and the welding location is clearly visible to you. The more the electrode is inclined to the part during welding, the more elongated in the opposite direction will be the spot of the heated metal surface and the more time the welding bath is formed for the same current strength. The narrowest spot of a melting metal is reached when the electrode is perpendicular to the surface of the metal. But in this case it is difficult for the welder to observe the welding process. Therefore, this position is only used when welding in hard-to-reach places.

How to weld metal inverter correctly?

After training in the execution of the weld on a simple surface, you can proceed to join the metal parts. The process is similar, the difference is that the welded part must first be fixed in the right place with a clamp or in another way, and when the welding bath appears, move the electrode end not directly along the seam, but zigzag movements from the seam center to one side first, then the other Details, gradually moving along the seam, connecting them in this way.

The main thing is that success comes with experience. By purchasing it, you will be able to learn how to perform welding work with your own hands instead of using the services of outside specialists (for quite a lot of money). Successful training and work!