Electric arc welding for beginners. How to learn to work with electric welding: the learning process at home

Today, the industry has learned to create very strong permanent connections using various techniques welding This process was invented at the beginning of the last century, and for quite some time short term he not only firmly established himself in industrial production, but also found great application in all areas of our lives.

IN this material the basics of welding work are discussed in an accessible form using the example of one of the types of welding - manual electric arc, since it is the most popular method of welding in the household. Naturally, this is the most affordable way for mastering by the majority of those interested.

What is welding?

The classic definition of the welding process is: “The process of creating inextricable connections through the establishment of interatomic relationships between parts that are connected during the process of heating and/or plastic deformation”. Keeping in mind the phenomenon of diffusion, it is known that in hot water the process of interpenetration accelerates. Welding is very similar to diffusion, only the two parts are heated using a high-temperature electric arc generated by the welding machine. Under its influence, melting and interpenetration of the materials of the parts occurs. A weld appears, which consists of materials from both parts and other chemical substances, which were introduced by the consumable electrode (element of the welding machine). There are many versions about the strength of this seam, some believe that 1 cm of the weld seam can withstand 100 kg, others claim that it is more, but everyone agrees on one thing: the strength of the weld seam is not inferior to the strength of the base metals of the parts. In addition to defining the main concept, theoretical basis welding operations also include physical and chemical processes occurring during welding.

What happens during welding from the point of view of chemistry and physics?

Let's consider a diagram of the welding process using electric arc welding as an example.

Electrical voltage is supplied to the electrode and to the part, but only with different polarities. As soon as the electrode is brought to the part, an electric arc immediately ignites, melting everything in its field of action. At this time, the electrode material is transferred dropwise into the weld pool. In order for the process not to stop, and this will happen when the electrode is stationary, it is necessary to move the electrode in three directions at once: transverse, translational and stably vertical (Fig. 2).

After all the manipulations, the welder removes the welding machine and the weld pool, solidifying, forms the same welding seam. This is the chemistry and physics that happens during electric arc welding. Naturally, with other types of welding, the mechanisms will be different. For example, in the form mentioned, the main thing is the melting mechanism, and when pressure welding, the welded surfaces are not only heated, but also compressed using sedimentary pressure. Let's take a closer look at the classification of welding types.

Types of welding.

There are three main classes of welding work, each of which has many subtypes.

The first class is heat welding. These include:

beam welding;
electro-beam;
plasma;
electroslag;
gas-flame;
electric arc.

The second class is thermomechanical welding. It contains the following varieties:

welding with high frequency current;
blacksmith's;
diffusion;
contact

Third class - mechanical welding. These include:

cold welding;
ultrasonic;
explosion welding;
friction welding.

Each type is applicable to different metals and parts, for example, friction welding is used to weld drills, cutters and dissimilar metals, and cold welding (forging) is used to weld ductile metals: copper, tin, aluminum, etc. Each of the three classes of welding also has its own specifics, for example, for each type of electric welding different electrodes are needed. They are:

melting (rods made of copper, nickel, aluminum alloys, steel);
non-consumable (tungsten, graphite and carbon rods).

They also differ in the types of coating: rutile, cellulose, basic and acidic. All of them are relevant for welding various materials and for working in different spatial positions of the welder himself.

Carrying out manual welding using an inverter is gaining increasing popularity among home craftsmen, due to the wide offer of various models with different price ranges. To connect iron products using inverter welding, a minimum of equipment is required, characterized by its versatility along with low energy consumption and compact dimensions, which further attracts the attention of inexperienced craftsmen. Learning inverter welding technology for beginners will not be the slightest difficulty.

Operating principle of a welding inverter

A welding inverter is a powerful power supply, which in terms of energy conversion is similar to a switching power supply.

The main stages of energy conversion in the inverter:

Reception and rectification of network current with a voltage of 220 V and a frequency of 50 Hz.
Converting the resulting rectified current into alternating current with high frequency from 20 to 50 kHz.
Reduction and rectification of high-frequency alternating current into a current whose strength is in the range of 100 ... 200 A, and a voltage from 70 to 90 V.

Converting high-frequency electric current to a current of the required value allows you to get away from inconvenient dimensions and heavy weight inverters, which have conventional transformer devices in which the current value is achieved by converting the EMF in an induction coil. Also when turned on welding inverter there will be no sudden surges in the network electrical energy, and moreover, the device contains in its circuit special storage capacitors that protect the device when welding during an unexpected power outage and allow the inverter arc to be ignited more gently.

Obtaining a high-quality weld when welding depends on many factors, therefore, before starting work, the master must familiarize himself with how to properly use the inverter according to the attached instructions, as well as the basic rules and nuances of performing welding work, which will be described in detail below.

Particular attention should be paid to the diameter of the welding electrodes. It is important to know that the amount of energy consumed directly depends on the thickness of the welding rods, and, accordingly, the larger their diameter, the higher the energy consumption. This information will help to correctly calculate the maximum electrical energy consumption of the inverter, which will prevent adverse consequences from its operation as reflected on household appliances. There is also a dependence of the diameter of the electrode on the current selected for the work, a decrease in which will lead to deterioration in the quality of the seam, and an increase - to an excessive combustion rate of the welded rod.

Inverter design for welding

In order to understand how to properly use a welding machine, a novice master should familiarize himself with the design of the inverter.

The welding inverter is a metal box with internal components, a total weight of about 7 kg, which is equipped with a handle and a shoulder strap for ease of carrying. The housing of the welding inverter may contain ventilation holes that promote better air outflow when cooling the unit. The front panel has buttons for switching the operating state, knobs for selecting the required voltage and current, outputs for connecting work cables, as well as indicators indicating the presence of power and overheating of the inverter during welding. The cable for connecting the device to the power supply is usually connected to the connector located on the back of the inverter.

When the electrode comes into contact with the metal plates being welded during welding, a high-temperature arc is formed, as a result of which both the elements of the welded rod and the metal of the welded joint melt. The bath formed in the arc area by the molten metals of the plates and electrode is protected from oxidation by a liquefied coating of the electrode. After complete cooling of the metal, the upper surface of the seam, protected by electrode coating during welding, will turn into hardened slag, which can be easily removed by light mechanical action (for example, tapping). It is important to maintain the same distance-gap between the metal of the welded joint and the electrode (arc length), which will prevent its extinction. To do this, the supply of the electrode to the fusion area must be carried out at a constant speed, and the guidance of the welding rod along the weld joint must be smooth.

Safety precautions

Before starting home welding, the electric welder needs to take care of safety precautions:

wear a protective suit made of durable, high-density natural fabric that is not subject to fire and melting when sparks hit it. The suit should cover the neck area and have sleeves that fasten tightly at the wrist.
protect your hands with mittens made of rough fabric;
wear comfortable leather shoes with thick soles;
Protect your eyes with a welder's mask with a light filter that depends on the current strength during welding.

The place where welding will be carried out must also be carefully prepared:

a wooden flooring has been laid, which performs a protective function against possible electric shock;
the welding site is cleared of anything unnecessary (to prevent welding splashes);
lighting must be of high quality;
The welder's movements should not be constrained.

Basics of welding with an inverter

Learning to weld with a welding inverter is not difficult. The very first stage of mastering welding techniques will be preparing the metal plates to be welded:

cleaning the edges of the plates from traces of corrosion with a wire brush;
degreasing the edge with a solvent.

Relying on the diameter of the electrodes, the choice of which is based on the grade of the metal being welded, it is necessary to select the current value for welding. The value of the welding current will also be determined by the cross-section of the elements being welded. To ensure that the quality of the seam is not affected when welding with an inverter, the pre-welded rods should be dried in an oven with a heating temperature of 200 º for 2-3 hours.

In order to weld metal, the ground terminal must be connected to the plane of the element being welded. Next you need to ignite the arc. You can do this in two ways:

striking the metal surface of the plate, similar to igniting a match head;
tapping the electrode on the surface to be welded.

Working with a welding inverter will be more convenient if, when welding, the holder cable is pressed to the body, having first wrapped it around the forearm of the working hand. In this position, the cable will not pull towards the holders and adjusting its position will be more convenient. Therefore, when choosing an inverter Special attention it is necessary to pay attention to the length and flexibility of the cables, because the convenience of the welder will depend on these indicators.

After igniting the arc, the electrode must be moved away from the plane of the metal plate to a distance equal to the length of the arc (approximately 2-3 mm) and welding can begin. To make high-quality welding, you must constantly monitor the length of the electric arc. A short arc (about 1 mm) can cause a welding defect called “undercut.” This welding defect is characterized by the appearance of a shallow groove parallel to the weld, leading to a decrease in the strength of the weld. Long arc is unstable, provides more low temperature in the welding zone, and, as a result, such a seam has too shallow a depth and is “smeared”. A welder who knows how to properly adjust the arc length will receive a high-quality weld.

After welding is completed, you should carefully beat off the scale that has frozen on top of the seam with a hammer.

Polarity when welding with an inverter

Melting of the metal is caused by exposure to the high temperature of the welding arc, which occurs as a result of connecting the opposite terminals of the inverter to the metal plate and to the welding rod. Depending on the order of connecting the welding inverter terminals, a distinction is made between direct and reverse polarity.

Polarity is the setting of the direction of electron movement. Both direct and reverse polarity are used when welding with an inverter, so it is important for a novice welder to know the differences between these types of connections.

Straight polarity is the polarity that occurs after connecting the electrode to the minus terminal and the metal plate to the plus terminal. With this connection, the current flows from the electrode to the metal, as a result of which the metal heats up more intensely, and the melting zone becomes sharply limited and deep. The direct polarity of connecting the welding inverter is selected when welding thick-walled elements and when inverter cutting.

Reverse polarity is characterized by connecting the “minus” to the metal plate, and the “plus” to the electrode. The fusion zone with this connection is wider and has a shallow depth. The direction of current is directed from the metal workpiece to the electrode, resulting in more intense heating of the electrode. This procedure reduces the risk of burn-through and is used when welding thin-walled metal products.

Working with thin metal

Welding of thin-walled metal products with an inverter is carried out by connecting the terminals according to a circuit corresponding to reverse polarity and placing the electrode at an angle forward. This welding technique provides a smaller heating zone with sufficient seam width.

Ignition of the electrode should be done extremely carefully, because the beginning of the pool when welding thin metal is often accompanied by a burn-through. Welding thin metal with an inverter must be carried out gradually, welding small areas with a short-term removal of the electrode from the bath. At this moment, you need to make sure that the yellow glow of the electrode tip does not go out.

The quality of the weld directly depends on the quality of the electrodes, which will help avoid excessive formation of slag in a small-section weld. Also, the use of small-diameter electrodes avoids burning through the metal.

When completing a weld, you should not abruptly tear off the electrode to extinguish the arc, because in this case a noticeable crater will form at the end of the seam, which will worsen the strength of the metal of the welded joint and the result of the welding equipment will be unsatisfactory.

Another defect that often occurs when welding thin metal is deformation of the product. To prevent its occurrence, it is necessary to carefully secure the parts being welded before welding.

A welder with little experience often wonders how to properly weld metal using electric welding. General tips for working with an inverter and rules for welding metal with an electrode will be given in the section below.

When welding metal with an inverter, you must carefully monitor that the weld is flush with the metal. An electric arc penetrating the metal with intense speed and sufficient depth causes the pool to move backward and creates a weld that can become defective if the speed of the electrode is too high. An ideal seam will be obtained if the electrode performs zigzag and circular vibrations.

When changing the direction of movement of the electrode, remember that the bath follows the heat. The formation of an undercut occurs against the background of insufficient metal of the electrode, so it is worth strictly monitoring and controlling the boundaries of the bath.

By positioning the electrode at a certain angle, you can control the direction of movement of the bath, while the vertical position of the electrode will contribute to sufficient penetration. In this position, the bathtub will be pressed down and have good boundaries, and the seam will have less convexity. Too much tilt of the electrode will not allow you to control the bath.

Inverter welding is also applicable when performing pipe welding work. Welding takes place under rather difficult conditions, so it is necessary to pay great attention to the quality of penetration at rotary joints. An angle of 30º is the standard angle of inclination of the electrode to the pipe surface. On pipes made of low-alloy steels with a wall cross-section up to 12 mm, the seam will be single-layer. For pipes with a larger wall thickness, a second weld should be applied, which will increase the overall strength of the weld. After each new weld, it is imperative to clean the hardened slag. Pipes with a diameter of up to 0.5 m must be boiled continuously.

An inverter is a simple welding machine that is ideal for a novice welder to carry out welding work at home. When choosing an inverter, you must rely on your own needs and the compliance of the selected device with them, thus meeting your needs.

Almost every person has encountered a situation where it was necessary to weld some metal part. Most often this happens during construction work. It’s great if a man knows this process, but sometimes you have to turn to professionals in your field. But you can learn welding on your own. Beginners usually start by learning seams. Complex work should begin only when the home craftsman learns how to weld using electrodes correctly.

Basic Concepts

Welding today is the most reliable metal connection, because it fuses materials into one whole. The procedure takes place under the influence of high temperatures. Most welding machines use an electric arc to operate.

The principle of its operation is as follows: It heats the metal in a certain small zone to the melting point. This type of welding is called electric arc welding.

When forming an electric arc, both direct and alternating current can be used. For alternating voltage, transformers are used, for constant voltage, inverters are used.

The work is easier with inverters, since they operate on a 220 V network. They are small in size and weight, about 4-8 kg. They make almost no noise and do not affect voltage.

It is much more difficult to work with transformers, since the current is alternating, it affects voltage surges, which neighbors and household appliances are usually not very happy about. The device is large and heavy.

Thus it becomes obvious that For beginners, a welding inverter is more suitable.

Required Tools

For welding work you need a set of tools and special protection. This is the welding machine itself, electrodes, hammer and brush. The diameter of the electrodes depends on the material to be worked on.

Don't forget about protection. To protect your eyes, a welding mask is a must, and you should also wear thick clothing, suede gloves, and durable shoes. Devices that convert alternating current into direct current are also useful - this is a rectifier, inverter or transformer.

Work technology

For an electric arc to occur, conductive elements are needed: in this case, it is metal and an electrode. When metal and electrode come into contact, an electric arc appears. In the same place, the metal immediately begins to melt, and at the same time the electrode melts and is transferred to the weld pool.

Also in the process, the protective surface of the electrode burns, partially evaporating and releasing a certain amount of gases. These gases create a curtain and protect the metal from oxidation. The metal is also coated with slag, which helps the metal by maintaining its temperature.

The formation of a seam occurs when the electrode moves, which is the whole secret of welding. More it is necessary to monitor the angle of inclination and current parameters. After the metal cools, a slag crust remains on it, which protects the metal from oxidation. The slag is then beaten off using a hammer.

How to learn to cook

At first, welding work must be carried out under the supervision of an experienced welder; he will show you how to learn how to weld, give advice and help in case of problems. You can practice on a piece of metal.

For beginner welders 3 mm electrode is most suitable. It costs a little more, but is easier to work with. Later, as experience is gained, you can move on to other options. You can fix it in a special holder, which can be spring or screw and is attached to one of the cables. After fixing the electrode, you can begin connecting the cables.

On welding machine there are two outputs: positive and negative. There are also two cables, one of them ends with a holder into which the electrode is inserted, the other with a special clamp.

At usual types When welding, straight polarity is connected: minus goes to the electrode, plus to the part. But in some work, reverse polarity is used.

Electric welding process

After preparing all the parts and devices, you can start working. First of all, attach the cable with the clamp. Then you need to check the other cable for insulation and reliable fixation of the electrode. Then the current power is set on the welding machine depending on the diameter of the selected electrode.

An electric arc is ignited. To do this you need to slightly touch the metal with an electrode, sparks should fly out. After the first contact, the electrode touches the metal and rises to a height of 5 mm.

The height of 5 mm must be maintained throughout the entire operation. As the process progresses, the electrode should burn out and it will need to be changed. It can also periodically stick to the metal, in which case you need to shake it slightly.

After igniting the arc, you can proceed to fusing the bead. This is done with light oscillatory movements, smoothly moving the electrode. The result of the operation should be a seam with a slight deposit of metal.

Electrode movement can occur in three directions:

Progressive.
Transverse.
Longitudinal.

As you work, you can superimpose one option onto another. Each master prefers to work in his own direction. After all, the main task is to reliably connect metals, and how this happens is not so important.

Some nuances

It is not enough to simply move an electrode across metal. You need to know some of the nuances of welding and how to properly weld a certain metal. One of them is that the seam “pulls” the part, which can cause them to lead. And in the end the result will be completely different from what the master expected. Most often, this problem can be avoided by grabbing the part in several places, approximately every 10 cm. This is done on both sides, after which the main work begins.

How to choose the right current

In addition to bonding the metal before welding, you need to know what current value to set in certain situations. It all depends on the thickness of the metal being worked on and the diameter of the electrode.

But sometimes the voltage may suddenly drop, the inverter itself will not be able to react to this situation. In this case, you just need to slow down the movement of the electrode to warm it up. Repeatedly running the electrode along the seams may also help. If this doesn't help, you can install a smaller diameter electrode.

Pipeline welding

Using electric arc welding, you can make a horizontal seam that runs around the circumference of the pipe and a vertical seam that runs from the side, as well as top and bottom seams. The most convenient option is the bottom seam.

Steel pipes must be butt welded, welding all the edges along the height of the walls. During operation, the electrode must be installed at an angle of 45 degrees - this is done in order to reduce sagging inside the products. The seam width should be 2−3 mm, height - 6−8 mm. If welding is overlapped, then the required width is 6-8 mm, and the height is 3 mm.

Immediately before starting work preparatory procedures need to be carried out:

The part needs to be cleaned.
If the edges of the pipe are deformed, then straighten them or cut them off with an angle grinder, or simply with a grinder.
The edges where the seam will go must be cleaned to a shine.

After preparation, you can start working. Necessary weld all joints continuously, completely welding. Pipe joints with a width of up to 6 mm are welded in 2 layers, with a width of 6-12 mm in 3 layers and with a wall width of more than 19 mm in 4 layers. main feature consists of constantly cleaning the pipes from slag, i.e. after each completed layer it is necessary to clean it of slag and only then weld a new one. Particular care must be taken when working on the first seam, it is necessary to fuse all blunts and edges. The first layer is carefully checked for the presence of cracks; if they are present, then they must be melted or cut out and welded again.

All subsequent layers are welded while slowly turning the pipe. The last layer is welded with an even transition to the base metal.

Mistakes of novice welders

To find out how to properly cook with electric welding, you need to consider the main mistakes that beginners make:

All of the above mistakes are just the most serious ones. There are many more nuances that can only be understood with experience.

When welding thin-walled metal or profile requires a careful approach to work. Thin parts can be welded by applying a cleaned electrode and welding directly on top of it.

Welding on non-ferrous metals is strikingly different, as it requires different electrodes. A special protective environment is also required. Now you can buy universal machines that cook almost any metal.

There are also semi-automatic devices for working with thin-walled metals. Its essence lies in fusing a special wire.

Electric welding for beginners is not an easy task. But if you have enough desire, you can master it. You just need to follow the basic rules and listen to the advice of more experienced masters. As a result, you will be able to move on to complex tasks, honing your skills.

Profession: “Electric welder of manual arc welding” Electric welder

Welding is used in almost all industries. It is difficult to name any segment of production that does not require the work of a welder. As a profession for beginners, it provides the opportunity to obtain promising work. Welders work on construction sites creating systems various communications and structures, in industry, using their skills and experience, in shipbuilding, mechanical engineering, energy, agriculture, oil refining industry.

First of all, the welder must be fluent in welding equipment. At the same time, he, as a specialist, is required to have a thorough knowledge of the principles of its operation, preparing the equipment for operation and identifying possible malfunctions. The welder must master the technology of carrying out welding work from preparing the surfaces to be joined to cleaning the weld and detecting.

A specialist performing welding work must know how to properly weld with electric welding, determine optimal mode for welding various materials, set the current value. The complexity of the work of a gas-electric welder also lies in the fact that during the welding process, changing the welding mode can negatively affect their quality, therefore it is extremely important to correctly determine the welding speed from the very beginning. Qualified welders perform manual arc welding and can create quite complex metal structures and pipelines. The welder must know how to handle different types metals: alloys, steels (including those with limited weldability).

How to learn to cook with electric welding

Welding professions are taught in colleges, vocational schools, and courses. Training is carried out for three years on the basis of ninth grades and two years on the basis of eleventh grades.

If you are not going to work as a welder, but want to learn how to learn how to work with electric welding so that, if necessary, you can weld something yourself, you can use the advice in this article, or the literature from the “Electric welding tutorial” series. Of course, in this case you will not become a top-class welder, but this is not required. The main thing is to understand how to use electric welding correctly, learn the basics of electric welding, and learn basic work techniques.

Basics of electric welding

First of all, you need to purchase a welding machine and electrodes, which you need to stock up on in decent quantities, since during the learning process, you will have to ruin a lot of them before you achieve the first positive result. Choose electrodes for welding with your own hands with a diameter of 3 mm. They are the most suitable for training at home, since the thinner ones are suitable for very thin metal, which only experienced welders can weld, while the thicker ones place a heavy load on the electrical network.

DIY electric welding

For beginners, this is not an easy task, but it is quite doable, although it requires a lot of perseverance. You just need to practice more. And the learning process is best carried out under the supervision of professionals who can help with advice and correct mistakes.

To understand how to weld metal correctly, use some unnecessary piece of metal. Place a bucket of water nearby in advance. Never do work on a wooden workbench. Be careful as even small remnants of an already used electrode can cause a fire.

Securely attach the "ground" clamp to the part. The cable must be well insulated and tucked into the holder. After this, you can set the current power value on the welding machine. It must match the diameter of the electrode.

Spatial positions of the weld

Now you can try to light the arc. To do this, install the electrode at an angle of about 60 degrees relative to the workpiece. Run the electrode very slowly across the surface. After sparks appear, touch the workpiece with the electrode and lift it so that the gap does not exceed 5 millimeters. If everything is done correctly, the arc will light. This gap must be maintained throughout the entire operation. Please note that the electrode will burn out. It must be moved slowly. If the electrode gets stuck, swing it to the side. If an arc 2 - 3 millimeters long does not ignite, then it is necessary to increase the current strength by . Try to get a stable arc 3 - 5 millimeters long between the part and the end of the electrode.

If you succeeded in igniting and maintaining the arc, then you can try fusing the bead. To do this, you need to light the arc and smoothly move the electrode horizontally, while performing oscillatory movements(see below for details). “Rake” the molten metal towards the center of the arc. The result should be a beautiful seam with small waves of deposited metal.

To form and hold an electric arc, the product being welded and the electrode are supplied from the power source. welding current(constant or variable).

Electrode movement diagram

When connecting the positive pole of the power source (anode) to the product, manual arc welding of straight polarity is performed. If the negative pole is connected to the product, then reverse polarity welding is performed. Under the action of an arc, the metal rod of the electrode (the so-called electrode metal), its coating and the material of the product (base metal) are melted. The electrode metal, now in the form of individual droplets coated with slag, enters the weld pool, in which it is mixed with the base metal, with the molten slag coming to the surface.

The size of the weld pool depends on the spatial position and welding modes, the design of the welded joint, the speed of movement of the arc on the surface of the product, the size and shape of the cutting of the edges being joined, etc. It usually varies within the following limits: width 8 - 15 mm, depth up to 6 mm , length 10 - 30 mm.

The arc length is the distance from one active spot on the surface of the weld pool to another on the molten surface of the electrode. When the electrode coating melts above the weld pool and near the arc, gas atmosphere, displacing air from the welding zone and preventing its interaction with the molten metal. It also contains pairs of alloying elements of the electrode and base metals.

Covering the surface of the weld pool and drops of molten electrode metal, the slag prevents their interaction with atmospheric air and helps clean the molten metal from impurities.

With the gradual removal of the arc, the metal in the weld pool crystallizes, forming a seam connecting the parts being welded. A layer of frozen slag forms on its surface.

Manual arc welding technique

The key to quality welding is the correct maintenance and movement of the electric arc. If the arc is too long, oxidation and nitriding of the molten metal occurs, splashing its droplets and creating a porous structure of the weld.

An even, beautiful and high-quality seam is obtained only with the correct size of the arc and its uniform movement. It can occur in three main directions.

Welding with electrode support

As a result, all three movements, overlapping each other, create a rather complex trajectory of the electrode. In practice, each experienced craftsman has his own skills in choosing the trajectory of the electrode. The classic trajectories of electrode movement performed during manual arc welding are presented in the figures below. But in any case, the trajectory of the arc must be chosen so that the edges of the parts to be joined are fused, forming the required amount of deposited metal and the specified weld shape.

Bottom layered seams

During the process of electric arc welding of metals, the electrode can burn out almost completely - only a small piece of the rod remains in the clamp of the holder. If the seam cannot be completed by this point, welding should be temporarily stopped. After replacing the electrode, it is necessary to remove the slag and resume welding again.

Electrode movement pattern when making vertical seams

To complete a broken seam, the arc is struck at a distance of 12 millimeters from the depression that has formed at the end of the seam, called a crater. To do this, the electrode is returned to the crater in order to form an alloy of the new and old electrodes, and then they begin to move it again along the originally chosen trajectory.

Horizontal seam on a vertical plane

Advantages of manual arc welding:

the ability to perform work in places with limited access;
welding capability various types steels due to a very wide selection of manufactured electrode types;
the possibility of a relatively quick transition from one joined material to another;

possibility of welding from any spatial position;
simplicity and fairly easy transportability of welding equipment.

The disadvantages of electric arc welding of metals include:

harmful conditions of the welding process;
low productivity and efficiency compared to others

Thanks to the reliability and durability of welding joints, there is not a single industry that does not use this technology. In the household, it is also sometimes impossible to do without welding work. Having the skills to work with an electric welding machine will allow you to create any metal structures, from a simple fence in a summer cottage to an openwork garden swing or a multifunctional barbecue. We will talk about how to properly weld and reveal all the tricks and secrets of this craft so that your first seam is not only strong, but also neat.

Learning to cook with electric welding. Video tutorial

In order to learn how to weld using electric welding, it is not enough to study the theoretical fundamentals and learn the secrets of the craft. Only the experience that is gained with every centimeter of the weld can bring you closer to the ability to weld metals.

A video on how to weld using electric welding will help you understand all the nuances of this craft and tell you what other materials and tools, in addition to a welding machine, will be needed when carrying out the work.

Made in the form step by step lessons The video of the welding process begins with a story about preparing surfaces before welding. Next, you will learn how to make simple seams and only after that you can start joining parts.

Thanks to the recommendations from the video, welding your first structure will not be difficult, and quality control of the seams will show how well you have mastered the welding technique. Watch a video on how to weld with electric welding, prepare yourself theoretically, and then pick up an electrode and start creating.

Welding process technology

In order to learn how to cook by welding, you need to know that electric arc welding is a process of joining metals using an electric arc between the surface of the part being welded and the electrode . The resulting high temperature promotes simultaneous melting of the electrode and the metal base. In this case, the so-called weld pool, in which the base metal is mixed with the molten electrode.

Bath size directly depends on the welding welding mode, edge shapes connected surfaces, electrode movement speed, position of parts in space etc. and ranges from 7 to 15 mm wide, 10-30 mm long and up to 6 mm deep.

High temperature prevents metal from burning gas layer, formed when the electrode coating melts, which displaces all oxygen from the melting zone. After the electric arc is removed, the metal crystallizes and forms common seam for welded surfaces, covered with a protective layer of slag, which is removed after cooling.

The advantages of electric arc welding are :

high performance;
the ability to weld various materials without the need to readjust equipment;
good quality weld;
inexpensive consumables;
availability.

IN disadvantages of this method welding, you can write down the mandatory presence of power supply and the need for preliminary preparation of the edges to be welded.

Getting ready for welding. Selection of materials and equipment

Before you start welding, you need to understand that this process is accompanied by the formation of sparks and splashes of molten metal, the release of toxic gases and danger to the eyes.

Therefore, in order to safely weld metal, you need to stock up not only with good equipment, but also with the appropriate equipment.To start electric welding you will need:

welding machine;
set of coated rod electrodes;
welder's hammer;
metal brush;
welding mask;
overalls, suede gloves.

You can arc welding without a factory set of overalls. It is important that the protective suit is made of thick fabric with long sleeves, and it is better to tuck the trousers into the boots.

Choosing a welding machine

A good welding machine with the ability to adjust the current from 10 to 200A will help you learn how to weld properly. Of course, you can assemble a simple welding transformer with your own hands, but then you don’t even have to think about how to weld thin metal, because such work requires minimum power values. Factory-made devices are divided into:

Welding transformers . Designed to reduce the network voltage while simultaneously increasing the current. Being inexpensive and productive devices, they can weld metal quite well, but they have disadvantages such as an unstable arc, a strong “drawdown” of the supply voltage and a large mass.

Welding rectifiers . Such devices are the same welding transformers, equipped with a diode rectifier, thanks to which the alternating voltage of the network is converted into constant pressure, necessary for the appearance of an electric arc. Welding metal with straighteners is a little easier due to the higher arc stability. Otherwise, this type of welding machine has the same disadvantages as transformers.

Welding inverters . True electronic welding is possible thanks to the modern technological filling of such devices. They provide a lot of opportunities to cook with electrodes with the most optimal parameters. The electronic components of the circuit of modern inverters make it possible to regulate not only the current strength, but also the ignition speed, arc forcing, etc., which ensures excellent weldability of parts. In addition, inverters are compact and lightweight.

The debate among welders continues unabated about which welding method is best. Some people like the simplicity and reliability of the transformer, while others are satisfied with manual welding with a rectifier. However, the best way to learn how to weld is with a welding inverter. The ability to precisely adjust the parameters will allow you to weld metal correctly literally from the very first steps.

Selecting electrodes for welding

Used for manual arc welding rod electrodes with protective coating . The metal of the rod must match the type of metal being welded, so different electrodes are used for welding steel, bronze or magnesium alloys.

During the welding process, the coating of the rod melts and turns into slag, which, floating to the surface of the weld pool, protects the melt from the influence of oxygen and nitrogen in the air. Some coatings contain gas-forming additives, which during the welding process emit gas that limits the access of air to the melting zone.

Most often, the question of which electrodes to weld with is not an issue for novice welders, since they usually begin to learn the craft by welding simple low-carbon structural steels.

The use of welding rectifiers makes it possible to use for such, as well as stainless alloys, electrodes brand UONII , designed for direct current operation.

Electrodes of a different brand - ANO , can be used for welding with both rectifiers and transformers; they allow you to weld with both direct and reverse current, so amateurs use them much more often than UONII.

Meanwhile, professionals in the question of which electrodes are better give preference to UONII. They cite as an argument the fact that this type of rod leaves behind significantly less slag, therefore, cleaning the seam is required much less frequently, which significantly increases the speed of work.

Depending on the thickness of the parts being welded, electrodes with a diameter of 1.6 to 5 mm are used. In addition, 4-5mm rods are used for cutting metals, setting the maximum current strength.

The required electrode diameter can be determined using tables of the dependence of this parameter on the thickness of the parts, as well as using mathematical formulas. Novice welders rarely use thick rods more than 4mm.

Type of welding work(horizontal, overhanging, butt welding, etc.) practically does not depend on the diameter of the electrodes, which cannot be said about weld pool depth And seam width.

Since the specific welding current depends on the cross-section of the electrode, the current concentration is higher at the end of a thin rod, so the penetration depth will be greater than when using a thick electrode. In turn, the use of rods with a diameter of 4-5 mm melts the metal less, forming a wider seam.

As you can see, it is impossible to answer exactly which electrodes to cook with, since right choice must take into account a lot of factors, ranging from the type of welding machine to the required width of the weld. In addition, it should be borne in mind that the quality of electrodes, even of the same brand, can differ significantly among products from different factories, so before you start welding, ask for advice from specialists.

Selecting the current strength and its polarity for electrode welding

After watching a video about how to cook by welding, you probably noticed the need current adjustment depending on the thickness of the parts and the diameter of the electrode. As a rule, it is not difficult for experienced welders to set the required value. For beginners it is better to contact special tables. Electrode manufacturers often indicate the required parameters on their packaging.

To properly weld metal, the required current is determined by calculation or from tables, and then this parameter is set on the inverter control panel. The higher the current, the higher the arc power and the deeper the weld pool. . However, you should not exceed optimal value- the metal will begin to burn out and the seam will be of poor quality.

When setting the current value for electric welding, be sure to take into account the location of the place of work. Maximum current is set for horizontal surfaces. When welding vertical stitches it reduced by 15%, A ceiling will require reduce current by 20% and more.

If you weld using inverter welding or a rectifier, then the quality of work is influenced not only by the strength of the current, but also by its polarity , that is, the direction of electron flow.

From physics courses, everyone knows that electrons move from the region of negative charge to the region of positive charge. To cook with an electrode correctly, the polarity is changed, setting both forward current (the electrode is connected to the minus of the inverter, and the part to the plus) and reverse. Most often, a direct connection is used, since the part in this case heats up more, however, for welding thin products, the polarity is changed by switching the inverter terminals. Reverse polarity is also used for welding alloy alloys that are prone to burning out of low-melting alloys.

The good news for those who want to know how to weld with electrodes is that reverse connection makes it easier to ignite the arc . In addition, it is characterized by higher stability, which is an invaluable advantage when welding thin parts with an electrode, for example, sheet steel.

Safety precautions when carrying out welding work

Every novice welder wants to be reminded of safety rules. Remember that welding is one of the most dangerous ways installation of metal structures, so do not neglect the following rules:

It is prohibited to carry out welding work in high humidity or in cold weather.
The use of a welder's mask and protective shield is mandatory. This will avoid burns to the cornea of the eyes.
Clothing should prevent metal splashes from coming into contact with exposed skin. It is better to wear suede gloves on your hands, and the best material for a welder’s suit is a thick tarpaulin.
Welding work is associated with high temperature and the risk of fire, therefore, a container of water and a fire extinguisher must be present at the welder’s workplace.

Also, be aware of the risk of injury electric shock, therefore, exclude the possibility of moisture getting on the welding machine, make sure that the cables do not touch hot surfaces.

Manual arc welding technique. How to cook by welding

Before starting practical exercises, I would like to remind you once again about safety precautions. No wooden workbenches or flammable materials near the work area. Be sure to place a container of water at your workplace. Be aware of the risk of fire.

In order to figure out how to properly weld, we present to your attention detailed instructions and video of the welding process.

First try lighting the arc and holding it for the required time. To do this, follow our tips:

Using a metal brush, you need to clean the surfaces of the parts to be welded from dirt and rust. If necessary, their edges are adjusted to each other.
It is best to learn how to weld with electric welding using direct current, so connect the “positive” terminal to the part, install the electrode in the clamp, and set the required current value on the welding machine.
Tilt the electrode relative to the workpiece at an angle of about 60° and slowly move it along the surface of the metal. When sparks appear, lift the edge of the rod 5 mm to ignite an electric arc. You may not have been able to get sparks due to a layer of coating or slag on the edge of the electrode. In this case, tap the tip of the electrode on the part, as suggested in the video on how to properly weld with electric welding. The resulting arc is maintained with a 5 mm welding gap throughout the entire welding process.
If the arc lights up very reluctantly, and the electrode constantly sticks to the metal surface, increase the current strength by 10-20 A. If the electrode sticks, shake the holder from side to side, possibly even using force.
Remember that the rod will burn out all the time, so only maintaining a gap of 3-5 mm will allow you to maintain a stable arc.

Learning to strike an arc , try to slowly move the electrode towards you, while making movements with an amplitude of 3-5mm from side to side.Try to direct the melt from the periphery to the center of the weld pool. After welding a seam about 5 cm long, remove the electrode and let the part cool, then tap the joint with a hammer to knock off the slag. The correct seam has a monolithic wavy structure without craters or irregularities.

The cleanliness of the seam directly depends on the size of the arc and correct movement of the electrode during welding. Watch a video about how to weld, filmed using protective filters. In such videos you can clearly see how to maintain the arc and move the electrode to obtain a high-quality seam. We can give the following recommendations:

Translational movement of the rod maintain the required arc length along the axis. During melting, the length of the electrode decreases, so it is necessary to constantly bring the holder with the rod closer to the part, maintaining the required gap. This is precisely what is emphasized in numerous videos on how to learn to cook.
Longitudinal movement of the electrode they create a fusing of the so-called thread roller, the width of which is usually 2-3 mm greater than the diameter of the rod, and the thickness depends on the speed of movement and current strength. A thread bead is a real narrow weld.
To increase seam width the electrode is moved across its line, performing oscillatory back-and-forth movements. The magnitude of their amplitude will determine how wide the welding seam will be, so the magnitude of the amplitude is determined based on specific conditions.

The welding process uses a combination of these three movements to form a complex path.

After watching the video on how to weld using electric welding and studying the diagrams of such trajectories, you will be able to figure out which of them can be used for overlap or butt welding, with vertical or ceiling arrangement of parts, etc.

During operation, the electrode will sooner or later melt completely. In this case, stop welding and replace the rod in the holder. To continue working knock down slag at a distance of 12mm an arc is ignited from the crater formed at the end of the weld. Then the end of the old seam is fused with a new electrode and work continues.

Features of electric welding of metal pipes

It is best to learn to weld profile pipes on thick-walled products using a welding rectifier or inverter. Depending on the diameter of the pipes, their wall thickness can reach more than 16mm, but you will most likely need to weld structural steel products with a wall thickness of up to 12mm. To weld a pipe, single-layer welding is often used, but to increase the strength of the connection it is better to perform two or more passes.

When welding pipes, the seams are made two half rings top down or bottom up.

If the direction of movement of the electrode corresponds to the first option, then 4 mm rods with low slag formation and organic coating are used. This coating burns out more slowly, forming a visor at the end of the electrode, on which they rest, performing transverse vibrations of small amplitude.

When welding from bottom to top, the amplitude is increased to 3-5 mm, and the speed of the rod is reduced.

Pipe connections are made:

Butt (exact orientation of the ends of one pipe relative to another);
Overlapping (by placing pipes or parts on top of each other);
Angle;
T-joint (one pipe is perpendicular to the other).

In order to weld one pipe to another, first clean and prepare their ends and place the products at the workplace. Next, the elements are centered relative to each other and secured in several places with spot welds. After checking the alignment of the pipes, they can be welded using one of the specified methods.

If it is impossible to rotate the pipes, they joints are made in multilayers. The first, root layer, serves to initially connect the parts. The following, filling layers, are designed to create the actual durable, monolithic seam. And, if necessary, they perform a finishing, facing seam, which covers all defects and irregularities. A video on how to weld a pipe will help you better understand the features of such work.

After cleaning the seams from slag, the surface is carefully inspected to identify lack of fusion, pores, cracks and burns. If necessary, defects are eliminated by welding. If the seam meets all the requirements, then it is cleaned using an angle grinder.

Protection of metal from corrosion after welding

Remember, at the very beginning of the article it was said that in order to weld correctly with electric welding, it is not enough to watch the video, but you also need to prepare theoretically? Agree that the text allows you to better understand the theory. In addition, the videos somehow miss the need to protect parts later. We will try to eliminate this shortcoming.

Everyone knows that metal quickly begins to rust when exposed to oxygen in the air. Believe me welds corrode even faster.

In order to protect metal surfaces from corrosion, painting is most often used. To avoid repeating this work every year, do it according to all the rules.

First of all, old paint and rust must be removed . To do this, it is best to use metal brush attachments for a drill or grinder, but you can also work with a regular metal brush. Do not forget to protect your eyes with glasses or a shield.

After cleaning the surface treat it with a rust converter and then coat it with a coat of primer . Choose a primer composition specifically designed for working on metal. After this layer has dried, you can begin painting. Acrylic and pentaphthalic enamels intended for outdoor use give good results.

It is best to use a spray bottle rather than a brush or roller for painting purposes. With its help, you can apply a uniform, thin layer of paint that will not crack or peel over time.