Welding work lessons in Russian. Step-by-step process for creating a welding joint

A welding seam is one of the most reliable ways to connect parts. It is used in industry and in general Everyday life. Every home master uses welding from time to time. It’s good if he knows how to cook himself, but often you have to turn to specialists. But welding can be learned. You should start with the simplest: electric welding for beginners is, first of all, learning how to make various seams. More complex work can be done only with experience. Let's look at the basics of technology and some tricks of the welding process, as well as the equipment and materials used.

Types of welding machines

To choose the right welding machine, it is necessary to take into account all the pros and cons of various types and models of welders.

transformers- the simplest and most traditional devices, rather heavy in weight, made on the basis of a step-down transformer, which brings the voltage to the required value for operation. The peculiarity of transformers is to work on alternating current, which creates an unstable arc. In combination with an increased amount of slag and gas impurities, such an arc contributes to metal spatter and spoils the appearance of the seam. A high-quality seam with such an apparatus can be made by an experienced welder with skills in working on a transformer.

A simple apparatus that runs on alternating current

Rectifiers- welders who can convert alternating current to direct current and lower the mains voltage using semiconductor diodes. Direct current gives a stable arc and allows you to make the welding seam uniform and tight, strong and beautiful. The rectifier is universal, all types of electrodes are suitable for it, all types of metals can be welded with such an apparatus: stainless steel, aluminum, copper, titanium, various alloys.

Universal welding machine, suitable for all types of electrodes

inverters are very popular because they have light weight, excellent functionality, automated settings. Such technical characteristics allow beginners to work on it. The design of the device includes a number of blocks that convert the alternating current of the network into D.C. high power. The advantage of this type of welder is:

the possibility of precise settings;
performance of a wide range of tasks;
stable arc;
resistance to power surges;
high quality welding, smooth seam;
work with all types of electrodes;
connection of all types of metals of any thickness and position in space.
has additional functions that prevent sticking of the electrode and separation drops;
the possibility of ignition of the electrode at maximum current supply;

Of the minuses can be noted:

the need for frequent cleaning from dust;
limited cable length of 2.5 m;
inability to work at air temperatures below -15 degrees.

The inverter is suitable for novice welders

Semiautomatic - are of two types. The former increase the productivity of welding work due to continuous wire feed. In this case, it is not necessary to constantly change the electrodes. The seam is smooth, continuous and without defects. The latter work in a gaseous environment, for this they use oxygen, nitrogen and carbon dioxide as well as argon and helium. Gas welding has the following advantages:

one apparatus designed to work with both gas and wire;
excellent quality and aesthetics of the seam;
stable smooth arc;
high functionality;
the ability to weld complex joints.

With this device, you can make a high-quality weld

What does a beginner welder need to work

First of all, you need to prepare equipment and overalls.

Tools and means of protection

You will definitely need a welding machine, a set of electrodes, a hammer and a chisel for knocking down slag, a metal brush for cleaning the seams. The electric holder is used to clamp, hold the electrode and supply current to it. You also need a set of templates to check the dimensions of the seam. The electrode diameter is selected depending on the thickness of the metal sheet. Don't forget about protection. We are preparing a welding mask with a special light filter that does not transmit infrared rays and protects the eyes. Screens and shields perform the same function. Canvas suit, consisting of a jacket with long sleeves and smooth trousers without cuffs, leather or felted shoes to protect against metal splashes and gloves or mittens, canvas or suede with slouched sleeves. Such tight, closed clothing prevents the welder from getting molten metal on the body.

There are special protective equipment that are used to work at heights and inside metal objects, when working in a prone position. In such cases, you will need dielectric boots, a helmet, gloves, a mat, knee pads, armrests, and for high-altitude welding you need a safety belt with straps.

Which electrodes to choose

Electrodes come in a variety of types and brands. This is due to the need to select the metal of the parts to be joined and the same metal of the electrode.

Each electrode has a marking that gives the welder all the necessary information. Learning to read labels is easy.

Special markings on the electrodes

Often, they are covered with various coatings on top, which give the electrodes the properties necessary for welding different metals and working conditions. Here is a table of classification of electrodes by types of coatings and application features.

Special coating gives the electrodes special properties necessary for welding different metals

The classification of electrodes by type and purpose is reflected in the product labeling.

Electrodes differ in types and purpose

Types of welds

Connecting welds are subdivided according to location, strength, technology, design features. Types of seam arrangement:

Lower. The simplest and most convenient, due to gravity, the metal fills the gap between the parts. This is the most durable and economical seam.
Horizontal. The workpieces are perpendicular to the electrode and the seam runs horizontally. Part of the metal leaves the welding zone and the electrode is consumed faster.
Vertical. In this case, the workpieces are also perpendicular to the electrode, but the seam is formed vertically. The molten metal tends to go down, the consumption of the electrode is significant.
Inclined. The movement of the welder's hand is inclined. Used for corner and tee joints.
Ceiling seam is located above the master.

Structural division:

Butt. The butt joint is quite strong and economical, it does not distort the joint surface. This is a universal connection.
Overlap weld parts when there is not enough space for a butt weld. The thickness of the blanks should not be more than 8-10 mm.
It is recommended to weld the fillet weld on both sides, while the workpieces are located at an angle to each other. This seam is not easy to perform due to the increase in the heat-affected zone and the high consumption of the electrode.
A tee weld is a fillet weld where the planes of the parts are welded perpendicularly. The seam is formed on both sides, it is quite complicated.
The seam for electric rivets is used when there is no need for a sealed seam, it is the most economical and inconspicuous.

Welding can be carried out both in one layer and in several layers for thick workpieces.

How to learn to cook by welding - a guide for beginners

Welding is a high temperature process. For its implementation, an electric arc is formed and held from the electrode to the workpiece to be welded. Under its influence, the base material and the metal rod of the electrode are melted. As experts say, a weld pool is formed, the base and electrode metal are mixed in it. The size of the resulting pool directly depends on the selected welding mode, spatial position, arc speed, shape and size of the edge, etc. On average, its width is 8-15 mm, length 10-30 mm and depth - about 6 mm.

The coating of the electrode, the so-called coating, during melting forms a special gas zone in the region of the arc and above the bath. It displaces all air from the welding area and prevents the molten metal from interacting with oxygen. In addition, it contains pairs of both base and electrode metals. Slag is formed over the seam, which also prevents the interaction of the melt with air, which adversely affects the quality of welding. After the gradual removal of the electric arc, the metal begins to crystallize and a seam is formed that unites the parts to be welded. On top of it is a protective layer of slag, which is subsequently removed.

During the welding process, the electrode coating melts, forming a special gas zone. Inside it, the base metal and electrode are mixed.

It is best for novice welders to get their first experience under the guidance of a specialist who can correct possible mistakes and give useful advice. Get to work should be securely fastening the part. In order to fire safety you need to put a bucket of water near you. For the same reason, you should not perform welding work on a wooden base and carelessly treat even very small remnants of the used electrode.

Connecting the welding machine

For welding to work safely, you need to connect the machine to the network, observing the following rules:

First you need to check the voltage and frequency of the current. This data must be the same on the network and on the device.
We set the calculated value of the current power on the welding machine, which should correspond to the selected electrode diameter. If the welder's settings block allows you to select the voltage, you need to set it immediately. The connection is made through a special plug and a grounding lug.
We securely fasten the "grounding" clamp. We check that the cable is insulated and neatly tucked into a special holder.
Be sure to check all connections, cables, plugs.
You can use a special extension cord that connects without intermediate connections.
In older houses with weak wiring, voltage drops are possible. It stops the work process and can damage the welding equipment. In this case, you need an electric generator that will provide voltage at the operating level.

The welding machine is simple

How to choose the right current

Welding current is an important indicator of welding and determines the type and nature of the seam and performance. The higher the current, the more stable the arc and the greater the depth of penetration. The current strength depends on the location of the blanks in space and on the size of the electrode. The highest value is set for welding horizontal workpieces. For vertical joints, the current value is applied less by 15%, and for ceiling joints - by 20%.

The current strength depends on the location of the workpieces and on the size of the electrode

How to light an arc

The first way is touch. To do this, we set the electrode at an angle of about 60 ° relative to the product. Slowly draw them across the surface. Sparks should appear, now we touch the metal with the electrode and raise it to a height of no more than 5 mm.

If the operation was performed correctly, the arc will ignite. A five-millimeter gap must be maintained throughout the welding. It should be borne in mind that with proper welding of metal by electric welding, the electrode will gradually burn out, so we constantly bring it slightly closer to the metal. Move the electrode slowly, if it suddenly sticks, you will have to slightly swing it to the side. If the arc does not ignite, it may be necessary to increase the current.

The second way is scratching. You need to bring the electrode to the surface of the workpiece and strike it over the part, as if lighting a match. It is possible to facilitate the ignition of the electrode by tapping the coating from its edge.

Tilt and movement of the electrode

After it turns out to ignite and maintain the arc without any problems, it's time to move on to welding the bead. We ignite the arc, slowly and smoothly move the electrode horizontally, performing light oscillatory movements with it. At the same time, the molten metal seems to be “raked up” to the very center of the arc. The result should be a strong weld with small waves formed by the deposited metal.

The angle of inclination of the electrode for a novice welder is better to keep about 70 degrees, that is, with a slight deviation from the vertical. Below is a diagram of arc welding.

The angle of the electrode is about 70 degrees

If during the process of welding parts the electrode burned out almost completely, and the seam is not yet completed, we temporarily stop the work. We change the used element to a new one, remove the slag and continue to work. At a distance of about 12 mm from the recess formed at the end of the seam, which is also called a crater, we ignite the arc. We bring the electrode to the recess so that an alloy is formed from the metal of the old and newly installed electrode, after which the welding of the seam continues.

During welding, the electrode makes certain movements, mainly translational, longitudinal and transverse. Various types of seams are made up of their combinations, the most common are shown in the diagram.

The trajectory of the arc movement in the process of welding parts can be carried out in three directions:

Translational. Assumes the movement of the arc along the axis of the electrode. Thus, it is quite easy to maintain a stable arc length.
Longitudinal. Forms a thread welding roller, the height of which depends on the speed at which the electrode moves and its thickness. This is a regular seam, but very thin. To fix it, in the process of moving the electrode along the welded seam, transverse movements are also performed.
Transverse. Allows you to get the desired width of the seam. It is carried out by oscillatory movements. Their width is selected based on the size and position of the seam, the shape of its cutting, etc.

In practice, all three basic movements are used, which overlap one another and form a certain trajectory. There are classic options, but each master usually has his own handwriting. The main thing is that in the course of work the edges of the elements to be joined are well melted, and a seam of a given shape is obtained.

As a rule, all three directions are applied, they can overlap each other and form a trajectory

Making welds

Ceiling weld

This seam is considered the most difficult, as the weld pool is turned upside down and located above the welder. The electrode is chosen no more than 4 mm and taken a little to the side so that the metal does not spread. Use a short arc and completely dry electrodes, the seam for overhead welding should be thin. The movement takes place on itself, so it is easier for the welder to control the quality of the seam. There are several ways to do it:

ladder;
crescent;
backwards.

Ceiling seam is considered the most difficult

Video: ceiling seam

Vertical

When making such a seam, you can lead the electrode from top to bottom or from bottom to top. To prevent the metal from dripping, the electrode should be tilted 45-50 degrees down from the perpendicular position. Experienced welders recommend doing this seam in one pass.

When performing a vertical seam, the electrode is located at an angle of 45-50 degrees

Video: vertical seam

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Making a horizontal seam

When making such a seam, the main difficulty lies in the flow of metal down. To solve this problem, the welder must adjust the electrode angle and travel speed. Welding is carried out from left to right or right to left.

When performing a horizontal seam, you need to choose the right angle of inclination of the electrode and the speed of passage

Angular

When forming fillet or tee welds, the parts are placed at different angles in a boat so that the molten metal flows into the corner. Then they are welded on both sides, one edge of the structure should be slightly higher than the other. The movement of the electrode starts from the bottom point.

In fillet welding, the movement of the electrode starts from the bottom point

Features of pipeline welding

Electric arc welding can make a vertical seam, which is located on the side of the pipe, horizontal - along its circumference. As well as the ceiling and bottom, located, respectively, above and below. Moreover, the latter is considered the most convenient to perform. Steel pipes are usually butt-welded with mandatory penetration of all edges along the height of the walls. To reduce the influx inside the pipe, the angle of inclination of the electrode is chosen not more than 45 ° relative to the horizontal. Seam height - 2-3 mm, width - 6-8 mm. When welding with an overlap, the height of the seam is about 3 mm, and the width is 6-8 mm.

Before starting to weld a pipe by electric welding, we carry out preparatory work:

thoroughly clean the part;
if the ends of the pipe are deformed, cut or straighten them;
clean up the edges. We clean at least 10 mm of the outer and inner plane adjacent to the edges of the pipe to a metallic sheen.

Now you can start welding. All joints are processed continuously, up to complete welding. Rotary, as well as non-rotatable joints of pipes with a wall width of up to 6 mm, are made in at least 2 layers. With a wall width of 6-12 mm - three layers are performed, more than 19 mm - four. The peculiarity of pipe welding is that each seam that is applied to the joint must be cleaned of slag, after which the next one is performed. The first seam is the most responsible. It should completely melt all edges and dullness. It is especially closely examined for the detection of cracks. If they are present, they are smelted or cut down and the fragment is brewed again.

The final layer is made as even as possible with a smooth transition to the base metal

The second and all subsequent layers are performed while slowly turning the pipe. The end and beginning of all layers must be shifted relative to the previous layer by 15-30 mm. The final layer is made with a smooth transition to the base metal and with a flat surface. To improve the quality of pipe welding by electric welding, each subsequent layer is carried out in reverse side relative to the previous one, and their closing points must be spaced apart.

Self-welding is a rather complicated undertaking. However, if you wish, you can still master it. You need to learn the basic rules of the process and gradually learn to carry out the most simple exercises. No need to spare time and effort to master the basics, which will become the basis of mastery. Subsequently, it will be possible to safely move on to more complex techniques, honing your skills.

To understand how to learn, you must first find out what exactly these devices are. The welding inverter has a fairly compact design, it is much easier to move it from one place to another compared to an ordinary transformer-based welding machine. In addition, working with a modern device is much more convenient.

It is possible to weld metal elements with the help of an inverter reliably enough only if you know at least its approximate structure. First of all, the design of this equipment does not take up too much space: all the necessary parts are placed in a small metal box, which does not exceed half a meter in length, usually no more than 20 cm in width, and about 30 cm in height. The total weight of the structure is about 10 kg.

The principle of its operation is to issue an electric current with a suitable strength and voltage. The inverter produces a direct current in the area of the welded surface, which is formed from the alternating voltage located in the household network - 220 V.

The devices always have two terminals - the cathode, or negatively charged conductor, and the anode - positive. One of them is used to connect the electrode, and the other is connected to the metal that will be welded. After the voltage begins to be applied, a single electrical circuit is formed. If you make a slight gap in it, the size of which will be only a few millimeters (as a rule, no more than 8), then in this place the air is ionized and a corresponding electric arc occurs.

To be correct, it should be understood that the bulk of the heat is released precisely in the electric arc, which burns at a temperature of about 7000 degrees. This allows you to qualitatively melt the edges of the welded metal blanks.

When the arc sparks, not only the edges of the metal, but also the electrode itself melt, as a result, all these materials mix with each other. If welding work is carried out poorly, then the slag, which, as a rule, is much less dense than the metal, will remain in the thickness of the metal. This significantly reduces the quality of the resulting welded joint.

Typically, slag comes to the surface and prevents the welded elements from being oxidized by oxygen contained in the air, or from beginning to absorb nitrogen from the environment. After the molten metal begins to solidify, a welded joint is formed.

The main parameters of welding work

To learn from the experience of experienced welders, you need to understand such a thing as current polarity, because it can be direct and reverse. The first is formed if the current flows from the cathode to the anode. Reverse polarity is obtained in the opposite situation.

If a person knows how to cook correctly, then he will understand that the highest temperature will be formed at the terminal from which the electric current begins to flow. When using straight polarity, the temperature will be higher directly on the workpieces. As a rule, welders who are just starting to learn the basics of this craft use this technology.

With reverse polarity, a higher temperature is formed at the electrode. This technology is useful when working with sheets of metal of insignificant thickness, as well as when working with metals that do not respond well to overheating, which can lead to damage to the workpiece.

An important role is played by the thickness of the electrode or welded wire. This indicator directly depends on how thick the parts to be welded will be. In principle, this indicator should be repelled when choosing the current strength. It turns out that the higher the thickness of the electrode, the great strength electric current must be applied to it.

It should also be borne in mind that the current strength indicator is directly affected by the location of the seam - horizontal, vertical, ceiling, and so on. For the gradual development of inverter welding, you should carefully study the table, which shows the corresponding current strengths, electrode diameters and other important indicators related to welding.

What are the main positive qualities of the inverter?

The inverter machine is much more convenient for welding. Even most professional welders say that this technology is much better and simpler than a primitive transformer. Thanks to the use of this product, you can not only easily form an arc, but also get it ultimately as stable as possible.

This effect helps to prevent excessively strong spatter of the metal. The inverter is also good because it provides a number of different kinds of additional characteristics. In particular, one of the most useful functions is the so-called "Hot start", which allows you to make the welding current at the very beginning of the work as strong as possible. This makes it much easier and faster to form an arc.

Another feature is "Strong Arc". This element is activated only if the electrode is too close to the elements to be welded. With such a development of events, the device will increase the current in automatic mode. This allows the metal to be melted as quickly as possible so that the electrode does not stick to the workpieces.

The third useful quality is the Anti-Zalip option. If necessary, it makes the electric current as low as possible so that the electrode can be torn off the metal surface very quickly and the work can continue. The function is very useful for those who have not yet fully figured out how to properly tear off the electrode from the workpiece.

The inverter is a fairly economical device. If we consider electrodes with a diameter of 3 mm, then for their high-quality use it is quite enough to set a voltage with a power of 4 kW - this fully corresponds to the normal parallel connection of two electric kettles.

The cost-effectiveness of the design in terms of electric current consumption allows literally within one season to justify the rather high cost of an inverter welding machine.

What safety precautions must be observed?

To figure out how to cook with inverter welding, you first need to understand the basic safety standards. The fact is that welding work is particularly dangerous for human health and life, so they should be approached with caution.

Before starting work, you need to clean the adjacent space from wooden objects and other things that can quickly ignite. This moment is very important for those people who are just starting to master welding. Electrodes, slag, molten metal are very hot, which can cause a quick fire.
You should wear tight clothing that, if possible, covers the whole body: long tight trousers, a jacket or sweater with long sleeves. This is done so that drops of molten metal cannot get on the skin and cause severe thermal burns.
Eyes and face must be protected with a special mask with built-in dark glass or light filter. It won't skip sunlight, but the arc burning will be perfectly visible, and this filter will also allow you to carefully consider how the metal is melted and the weld is filled.
If the arc burns, but metal welding does not occur, then this may indicate a malfunction of the apparatus or insufficient current. You can add it on the working panel of the equipment. If this does not help, then the tool should be immediately de-energized, since some kind of breakdown must have occurred inside it. It may cause electric shock.
It is strictly forbidden to work in wet weather, when too low temperatures and other adverse atmospheric phenomena, because this also often causes electric shock.
You should not observe the conduct or performance of welding work without a protective glass - this causes a severe burn of the cornea, from which you will have to recover within a few days. Burns of this plan are different: a weak degree is characterized by the appearance of bright spots before the eyes; the middle degree begins with a feeling of sand in the eyes; severe can cause partial or complete loss of vision.

How to light an arc correctly?

People seeking to figure out how to learn how to cook with an inverter welder should first practice how to properly strike the arc and keep it burning throughout the entire period of work.

At the first stage, you should connect the terminals, depending on what polarity you plan to work with - direct or reverse. If there is no experience in welding at the moment, then only direct connection should be used. It is better for a beginner welder to take universal electrodes suitable for most metals: their diameter is 3 mm.

The use of thicker electrodes is undesirable, as they can cause serious arc fluctuation and unstable arc burning. Working with such consumables requires better skills.

Initially, you need to set the current to 100 A. Using the mask out of habit can cause some discomfort, but it can be sacrificed to preserve vision. Before direct ignition of the arc, you need to lightly tap the electrode on the metal to knock the coating off its edge.

You can set fire to the arc in one of the following ways:

strike;
light touch.

If you take into account all the points considered, then figuring out how to cook with a welding inverter will not be too difficult. Moreover, it can be used for various materials.

Holding manual welding with the help of an inverter is gaining more and more 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 even more attracts the attention of inexperienced craftsmen. Learning inverter welding technology for beginners will not be the slightest difficulty.

The principle of operation of the welding inverter

The welding inverter is the most powerful power supply, which is similar to the switching power supply in terms of energy conversion.

The main stages of energy conversion in the inverter:

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

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

Obtaining a high-quality seam during welding depends on many factors, therefore, before starting work, the master must be familiar with how to properly use the inverter according to the attached instructions, as well as the basic rules and nuances of welding, 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 consumption of electrical energy by the inverter, which will prevent adverse effects from its operation in reflection on household appliances. There is also a dependence of the electrode diameter on the current strength chosen for operation, a decrease in which will lead to a deterioration in the quality of the weld, and an increase in it will lead to an excessive combustion rate of the welded rod.

The design of the inverter for welding

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

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

When the electrode contacts 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 are melted. The pool formed in the area of the arc by the molten metals of the plates and the electrode is protected from oxidation by a liquefied coating of the electrode. After the metal is completely cooled, the upper surface of the weld, protected by the electrode coating during welding, will turn into a hardened slag, which can be easily removed by light mechanical action (for example, by tapping). It is important to observe 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 electrode should be fed into the fusion area at a constant speed, and the welded rod should be guided along the weld joint evenly.

Safety

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

put on a protective suit made of durable high-density natural fabric, which 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 hands with mittens made of coarse linen;
put on comfortable leather shoes with thick soles;
protect your eyes with a welder's mask with a light filter, which depends on the strength of the welding current.

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

a wooden flooring was laid, which performs a protective function against possible electric shock;
the place of welding is freed from everything superfluous (to prevent the ingress of welding spatter);
lighting must be of high quality;
the welder's movements should not be constrained.

The basics of inverter welding

Learning how to cook with a welding inverter is easy. The very first step in mastering the welding technique will be the preparation of the metal plates to be welded:

cleaning the edges of the plates from traces of corrosion with a metal 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 choose the amount of current for welding. The value of the welding current will also be determined by the cross section of the elements to be welded. So that the quality of the seam does not suffer 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 to be welded. Next, you need to ignite the arc. You can do this in two ways:

striking on the metal surface of the plate, by analogy with the ignition of a match head;
by 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 against the body, after wrapping it around the forearm of the working hand. In this position, the cable will not pull to the side of the holder and adjustment of its position will be more convenient. Therefore, when choosing an inverter, special attention must be paid to the length and flexibility of the cables, because the convenience of the welder will depend on these indicators.

After ignition of the arc, the electrode must be removed from the plane of the metal plate to a distance equal to the length of the arc (approximately 2-3 mm) and you can start welding. To make high-quality welding, you must constantly monitor the length of the 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, and leading to a decrease in the strength of the weld. A long arc is unstable, provides a lower temperature in the welding zone, and, as a result, such a seam has too little depth and “smearing”. A welder who knows how to correctly adjust the length of the arc will get a high quality seam.

After welding is completed, the scale that has solidified over the seam should be carefully beaten off with a hammer.

Polarity when welding with an inverter

The melting of a metal is caused by the impact on it high temperature welding arc that occurs as a result of connecting opposite terminals of the inverter to metal plate and to the welded rod. Depending on the connection order of the terminals of the welding inverter, there are direct and reverse polarity.

Polarity is the direction in which electrons move. 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.

Direct polarity is the polarity that occurs after connecting the electrode to the minus terminal, and the metal plates 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 intensively, and the melting zone becomes sharply limited and deep. The direct polarity of the connection of the welding inverter is selected when welding thick-walled elements and during 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 the current is directed from the metal workpiece to the electrode, resulting in a stronger 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 the scheme corresponding to the reverse polarity, and placing the electrode at an angle forward. This welding technique provides a smaller hot zone with a sufficient weld width.

The ignition of the electrode should be done with extreme care, because the beginning of the bath when welding thin metal is often accompanied by a burn. Welding of thin metal with an inverter must be carried out gradually, welding small areas with a short-term removal of the electrode from the pool. At this point, 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 to avoid excessive slag formation in a small cross-section weld. Also, the use of small diameter electrodes avoids burning through the metal.

At the end of the seam, the electrode should not be abruptly torn off 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 operation of the welding machine equipment will be unsatisfactory.

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

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

When welding metal with an inverter, it is necessary to carefully control that the weld is flush with the metal. An electric arc penetrating the metal at an intense speed and sufficient depth causes the puddle to move backwards and creates a weld that can become defective if the speed of the electrode movement is too high. An ideal seam will be obtained if the electrode makes zigzag and circular vibrations.

When changing the direction of the electrode movement, remember that the bath follows the heat. The formation of the undercut occurs against the background of insufficient metal of the electrode, so it is worthwhile to strictly monitor the boundaries of the bath and control them.

By positioning the electrode at a certain angle, it is possible to control the direction of movement of the pool, while the vertical position of the electrode will contribute to sufficient penetration. The bath in this position will be pressed down and have good borders, and the seam will have less bulge. 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 in rather difficult conditions, so it is necessary to pay great attention to the quality of penetration at the rotary joints. An angle equal to 30º is the standard angle of inclination of the electrode to the pipe surface. On pipes made of low-alloy steels with a wall section of up to 12 mm, the seam will be single-layer. For pipes with thicker walls, a second seam should be applied, thereby increasing the overall strength of the weld. After each new suture, it is imperative to clean the hardened slag. Pipes with a diameter of up to 0.5 m must be welded continuously.

The 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 suitability of the selected device, thus meeting your needs.

Very often in everyday life there is a need to use a welded joint, especially in the private sector. If there is a lot of work, then you can use the services of a welder, but if it is a couple of small jobs, then it is better to resort to using an inverter welding machine. Why inverter? In fact, this is one of the simplest, most affordable and convenient types of welding. Inverter welding, for beginners to delve into the topic of welded joints, will help you sort out the basics by spending a little money without stuffing a lot of cones.

To make it easier, let's look at the advantages of this type of welding:

availability (almost household appliance, each welding equipment store provides a wide selection of inverters);
cheapness (some welds cost less than you pay for the services of a welder);
light weight, mobility (devices weigh 3-10 kg and can be easily moved from place to place);
universality (practically any metal can be welded with such a device);
efficiency (the efficiency of the inverter is about 90%, which means that electricity bills will not be huge);
low voltage requirements (with a 3 mm electrode it is possible to carry out welding work at low currents at 180 - 170 V in the network)
ease of learning (after reading this material, you will already have enough knowledge to start welding yourself).

Before you figure out how to cook with inverter welding, you need to make preliminary preparations. It consists of a number of safety requirements, and this is clothing, properly arranged workplace, individual funds protection and so on. On the other hand, this is the use of suitable electrodes, as well as setting up a welding inverter. Without this knowledge, it is quite difficult to get an even, high-quality seam, but it is even more difficult to ensure your own safety.

Remedies

We will start with how to learn how to weld safely or how to protect yourself while welding metal with an inverter. We will need:

Gloves made of thick fabric (not rubber).
Welding mask. Each welding current must have its own mask, otherwise you will catch "bunnies" or simply not be able to control the weld. You can also buy a mask "Chameleon" - this is a special mask for a welder, which independently adjusts to the intensity of the arc. For a chameleon, there is one remark - at low temperatures, the reaction rate decreases.
Clothing that does not catch fire from sparks. The requirements for pants, tops and shoes are universal - they must withstand the ingress of scale and not catch fire at the same time.

Workplace preparation

The next step is to create a comfortable working platform to learn how to cook with a welding inverter. Experienced welders prefer to use a special welding table, for beginners, any metal table is suitable to conveniently position and, if necessary, fix the parts to be welded. Of course, adequate lighting must be provided. Since sparks and large scales may occur while working with the inverter, the table and the area around it must be cleared of flammable and flammable liquids and materials. The welder himself must stand on a surface that protects against possible electric shock, such as a wooden deck.

How to choose an electrode

To select an electrode when welding with an inverter, we need to know: the type of metal and its thickness. More experienced welders also take into account the position for welding, the depth of penetration and other nuances, but only two points will be enough for us. For each type of metal there is a type of electrode, they are produced for a specific brand of metal. Stainless alloy, cast iron or ordinary steel cannot be welded with the same grade. The thickness of the electrode is selected based on the thickness of the metal and the desired depth of penetration. For beginners, we advise you to take steel parts and weld them with selected electrodes, for example, ANO-21 or UONI 13/55, the cross section of which is 3 - 5 mm.

Electrodes UONI

Inverter wiring diagram, polarity

The general scheme looks something like this - socket welding inverter, earth cable and cable with electrode. Here we are more interested in connecting the welding inverter wire. Two cables come from the device, the first one is a mass, has a clothespin or clip at the end, the second cable is made in the form of a handle with a clamp for the electrode. We hook the mass cable directly to the workpiece to be welded or to the welding table in contact with the workpiece. We insert and attract the electrode into the wire with the clamp.

There are two options for connecting the ground and the handle: direct (ground +, handle -) and reverse (ground - handle +). With direct polarity, the amount of heat acting on the metal is reduced, the penetration is deeper. Direct connection of the welding inverter allows you to weld thick metal.

Reverse polarity when welding with an inverter concentrates heat on the product and allows you to lay a wider seam, but with less penetration. With this connection, thin metal is brewed, which is easy to burn through.

Connecting the welding inverter to the network

Metal preparation

The parts to be welded must be carefully prepared. To do this, the edges are cleaned with a special brush, removing the oxide layer. After rough cleaning, additional degreasing is carried out with special means.

Correctly position the parts to be welded. Depending on their position, not only the types of connections are distinguished, but also the electrode movement pattern, voltage, direct or reverse slope. There are the following connections:

butt;
corner;
tee;
end;
lap.

This completes the preparatory work. The question of current strength remained unresolved. To begin with, it is worth choosing this parameter, according to the values \u200b\u200bspecified by the manufacturer of the electrodes. They can be found on the box. You should not set the value higher than the maximum, otherwise the metal will burn through, but you can also cut metal in this way. If the current is set too low, the arc will not ignite and the electrode will begin to stick.

Welding can not only connect, but also cut parts. Having learned how to use an inverter for welding, you can figure out - "How to cut metal?" It is enough to increase the current strength and you can cut off the fittings or corners. It is also worth noting that there is no question of any even cut.

Choice of current strength when welding with an electrode

How to work with a welding inverter

Inverter welding occurs when the arc formed between the metal and the electrode begins to melt the electrode rod, as well as part of the metal. In the resulting bath, the metals mix and form a seam. To protect against oxidation and splashing of molten metal in the bath, a layer of a special coating applied to the electrode helps.

Arc ignition

The story of how to properly cook with an inverter begins - by igniting the arc. This is done in one of two ways:

strike;
tapping.

Striking (like a match) with an electrode, we provoke the start of an arc to the place where welding begins. To be precise, we touch the metal with the electrode, then we lead it touching the surface and smoothly raise the electrode to the set distance. In this case, if ignition did not occur, parts of the molten electrode may remain on the metal. Therefore, you need to strike directly at the junction or near it.

In almost the same way, the electrode is ignited by tapping. The difference is that we do not run it along the metal surface, but simply touch the edge of the welding cable to the place where the weld begins and remove the electrode.

Arc ignition methods

How to move the electrode while welding

All the processes described earlier were not difficult for a beginner, but now we move on to more complex tasks. The first difficulty that a novice welder faces is the electrode movement scheme to form an even seam. If you ignite the arc, and then simply guide the electrode evenly along the junction, then the probability of getting a good penetration and an even seam is minimal. The exception is thin metals, for which this welding method is used.

The three pillars holding the beautiful seam are:

electrode tilt angle;
scheme of longitudinal and transverse movements;
electrode speed.

How to learn to weld metal evenly

Let's start in order, with the angle of inclination. Optimal, for welding forward and backward, is considered an angle of 30 to 40 degrees. For hard-to-reach places, work at a right (90 degree) angle can be used.

Angle of inclination of the electrode during welding

As we have already said, the seam is not placed in a linear motion, but in a combined longitudinal and transverse. There are special patterns with which you can train to move the electrode. You can start with simple curls in both directions, then practice more intricate and angular patterns. Each welder independently selects a convenient scheme for himself. You can train your hand at home and without welding by drawing diagrams on paper.

Ways to make welds

Speed is partly trained when drawing diagrams. Each line must be clearly drawn, so all movements occur smoothly and moderately. Over time, depending on the condition of the bath, you will be able to adjust your speed.

The faster the electrode moves, the less penetration is obtained. If you drive it slowly, then overheating of the metal and its burning can occur.

Arc gap control

The last, but not least, point is the distance from the electrode to the metal or the arc gap. A small gap, up to 2 mm, leads to the fact that a short arc is formed. It cannot warm up the junction sufficiently, so the penetration is shallow and part of the molten electrode protrudes strongly above the surface. A large gap, more than 3 millimeters, leads to the fact that the arc is very large. A large arc is unstable, constantly changing the direction of melting. Also, with such a large distance, the melting pool is not completely covered with a protective layer, which means that spatter increases.

To cook well with an inverter, you need a properly selected gap. The optimal arc gap for a beginner welder is 2-3 mm. With such a distance, the arc warms up the metal enough to get a deep and wide penetration, plus the protective layer fully works.

Depending on the model of the inverter and the presence of various functions in it that facilitate welding, maintaining the distance between the electrode and the metal is sometimes not required. It will be enough to lead the electrode along the surface of the metal.

A useful addition to the above is to watch the following video:

Do not neglect protective equipment, especially eye protection. Even a fleeting glance at welding can cause retinal burns, and a longer exposure will inevitably cause deterioration or even loss of vision.
The first time you try to weld various joints, you will get a lot of errors. Before you start finishing work, we advise you to practice for several days in various types of connections.
Even a child can start working with welding, but an even and reliable welded joint is the result of training and a thorough approach to business.
Do not forget to beat the slag, after welding, otherwise you stimulate corrosion processes.
Not sure why the electrode sticks? Pay attention to the current settings, as well as the dryness of the electrodes.
The electrodes for the inverter must be wound in a dry room. Raw electrodes can be dried in the oven.
Before turning on/off, check the position of the wire, otherwise a short circuit may be caused.
The operating instructions for the welding inverter contain information about the operating cycle. This is the optimal duration of continuous operation of the mechanism, after which the operating device will begin to overheat. The work cycle must be alternated with breaks.

We hope that this material has fully answered your questions and you can easily connect a welding inverter, the inverter welding technique has become available to you. Using this guide, you will gradually begin to improve your skills, you will be able to weld metal with an inverter without any problems. After a little practice, you can independently replace the fence, weld an arch for grapes and a number of other welding works. Good luck

Electric welding is the most common way to obtain a permanent connection. The availability and simplicity of welding equipment allow even novice electric welders to assemble simple metal structures on their own.

Those who want to learn how to learn how to weld parts should start with the basics of electric welding using electrodes.

Before starting any training, you need a home craftsman. First of all, this applies to welding machines and electrodes, and then move on to the basics.

For one-time work, you can rent a welding machine from specialized companies, but if there is a lot of work to be done, the best solution would be to buy a reliable, sufficient level unit power.

You can do gas welding, but this is a more expensive method. For various purposes, the industry produces the following types of equipment:

welding machine (transformer), designed to convert alternating currents into welding current great strength. Cheap welding machines can overheat greatly even at low loads, and they produce uneven welding current with large drops;
Rectifiers convert AC power to DC. These are the most productive devices with good characteristics, but they cost an order of magnitude more expensive;
modern inverters are capable of converting alternating current to direct current, they are characterized by high performance characteristics with small dimensions and weight. To date, this is the most affordable, reliable type of welding equipment, many welders use them. This is the best option for beginners, where you can practice the basics of working with electrodes.

Beginners need to know that electrodes are used for arc welding. Information about the electrodes refers to the basics of learning. The success of welding depends on the quality of the electrode and the composition of the core.

The product is quite simple in design. This is a steel wire made of various materials and alloys, with a special coating (coating) applied to it.

The coating prevents unwanted gases from entering the weld pool. For domestic use, electrodes with a core thickness of 3 mm are most suitable. produced by electrodes with a cross section of 2 mm.

Organization of the workplace and reliable equipment of the welder

When welding with electrodes, a strong infrared radiation. To protect the eyes and skin, a special welding helmet and protective clothing made of dense material must be used.

It is better to buy a welding helmet with chameleon glass, with the ability to adjust the degree of glass darkening. On your hands you need to wear split gloves or mittens. Protective clothing should be worn regardless of whether you are a beginner welder or a specialist.

The place of welding must be enclosed with protective screens to protect the eyes of others, especially at home. Welding shoes must not be nailed.

In such shoes, the welder will constantly dance even with slight dampness of the air. Be sure to properly ground the work area before welding.

Having completed the preparatory work, you can begin to learn welding and get the basics.

Sequencing

Step-by-step instruction includes several types of work. First you need to equip the welding inverter. It has 2 cables coming out of it. One is designed to connect the ground wire.

On another, of sufficient length, an industrial or home-made holder is connected. The process of learning electric welding is a rather complicated and time-consuming process.

Current regulation

The Welding Guide includes information about machine settings. Welding current is subject to mandatory adjustment. First you don't need to set maximum value this value.

All data are indicated in the table on the packaging of the electrodes. You need to set a lower value and start learning.

With experience, when it turns out to ignite the arc and make the simplest seam, it is necessary to set a higher value for the welding current. This will allow you to better warm up the metal and make a better seam.

welding arc

Welding lessons for beginners cannot be imagined without learning how to strike an arc. At first, the electrode will constantly stick to the metal. There are 2 ways to start the arc:

by holding the tip of the electrode along the surface of the parts;
The arc can be ignited by tapping the electrode. Sometimes, when using MP-5 electrodes, the welder has to knock often and for a long time.

In the first case, there are no significant marks on the parts, the second method is important with a large layer of coating on the tip of the electrode. Sometimes it is necessary to grind the ends of the electrodes before welding.

It's very easy to learn. You just tap, and when igniting the arc, the main thing is not to stick the electrode into the molten metal and not to carry it over a long distance. In the first case, the arc will go out. The second option will lead to the formation of strong spatter and violation of the bead of the seam.

It is better to learn on thick metal. Only after learning how to ignite the arc and keep it burning, you can proceed to the next stage of training.

We develop the correct angle of inclination

The most common electrode position is a tilt span of 30° to 60°. Very rarely there is a need to cook, holding the core at a right angle. When choosing a slope, it is necessary to monitor the behavior of the slag in the weld pool.

It should securely cover it, but without spreading the metal. You can not go much ahead of the bath. To begin with, place the holder at a right angle, and gradually making the angle sharper, achieve normal filling of the weld pool with slag.

The quality of welding depends on the development of the normal position of the electrode holder. A novice welder should work, laying seams only in the lower position, on thick metal.

Having mastered the basics, you can gradually move on to the horizontal and vertical seam. Depending on the thickness of the parts, you will also have to adjust the angle. Over time, this operation will be performed automatically.

holder movements

For this, it is necessary to hold the tip of the electrode core at least 2 mm away and see the weld pool.

The problem for beginners is the need to perform several actions at once. For better filling of the joint bead, it is necessary to lead the electrode in several ways.

For welding metal with a thickness of more than 6 mm, it is better to use a triangle motion. And less than this thickness of parts, it is better to use a broken zigzag welding line.

At first, only these methods of leading the electrode will be required. Pay attention to the constant size of the oscillatory movements. It may be necessary to guide the electrode in a straight line at first to gain skill.

Don't think that you will succeed on the first try. This is a long process, so be patient while learning the basics.

Basic rules for joining parts

After the basics of welding have been mastered, it is necessary to independently weld metal structures, proceed to perform the simplest operations of assembling and tacking nodes in living conditions. As a rule, the home master does not cook thick metal, so cutting the edges is not required. To begin with, you can practice connecting the profile pipe. To do this, it will be necessary to cut sharp corners at the ends of the parts, for a larger penetration area.

The parts are inserted into the corner clamp and fixed with a clamping bar. Now you need to pre-grab from several sides. To do this, light an arc and put a small dot.

It is not required to withstand a large leg, you just need to fix the parts. After checking the diagonals, tacks are performed from all available sides. Now they remove the structure and scald it with a reliable and high-quality seam.

If the lessons on the angle of inclination, laying the metal in a molten weld pool are well learned, then the assembly operations of metal structures will not cause difficulties even for dummies in the welding business.

Having studied the basics of welding and gained theoretical knowledge, you need to practice as often as possible, put on welding equipment, turn on the welding machine and hone your skills for a long time. Only practice will allow you to become a high-class welder.