What types of welding electrodes are currently used? How are brands of electrodes deciphered.

Today, welding work is carried out quite often. This is due to the relative simplicity of the process and low financial costs with an acceptable level of quality of the resulting seam. For welding, special equipment is used and Consumables. An example is electrodes for manual arc welding, without which it is almost impossible to carry out the work under consideration. Manual arc welding with coated electrodes is carried out quite often today, which has determined the emergence of a large number of varieties of consumables. An example is the structure of the electrode, which corresponds to the features of the work being done. Consider all the most important points more.

Classification of electrodes for manual arc welding

When considering various types of electrodes for manual arc welding, attention should be paid to the fact that various coatings can stabilize the resulting arc during combustion. All types of rod coating have their own characteristics, which should be considered when considering the types of electrodes for manual arc welding. The same brands can be produced by different manufacturers. It should be borne in mind that the quality of consumables can vary significantly.

The purpose of the electrodes can be very different. According to this criterion, the following classification of electrodes for manual arc welding is carried out:

Alloyed metals have become quite widespread, since by adding various chemicals they significantly improve performance characteristics. Some chemical substances can significantly increase the thermal stability of the metal. For such alloys, electrodes are used, which have the letter "T" in the marking.
For welding steels that have a low concentration of impurities, design options are used, the marking of which uses the letter "U". In addition, such electrodes for manual arc welding are suitable for metal compounds with an average carbon concentration. The tensile strength achieved is 600 MPa.
Structural steels are also very widespread. They also contain alloying elements. The tensile strength in this case is 600 MPa.
In some cases, metal can be soldered onto the surface. Metal can have exceptional performance. For this case, a design option is suitable, in the designation of which the letter "H" is used.
On sale there are electrodes designed for steels with a high concentration of alloying elements.
Steels that have high ductility properties are assigned to a separate group. It is quite difficult to work with such a material, so they began to produce electrodes for aluminum or other similar alloys. The marking indicates the letter "A".

The diameters of electrodes for manual arc welding can vary significantly, due to the peculiarities of the work being done. Classification is also carried out according to the thickness of the coating being created. There are the following types of electrodes:

With a thin coating. The designation uses the letter "M". As a rule, in this case, the surface layer is about 20% (the indicator is taken from general meaning diameter).
Medium coverage. The designation is indicated by the letter "C". In this case, a layer is applied, the thickness of which is 45% of the diameter of the rod used in the manufacture.
The thick coating is 80% of the diameter, the letter "D" is indicated in the marking.
There are also particularly thick versions, the designation of which indicates the letter "G". In this case, the thickness is more than 80%.

Do not forget that the electrodes may have restrictions on the use and position during the work. An example is that some substances have increased fluidity, and it will be difficult to carry out work near the ceiling surface. In order to be able to quickly determine the purpose of the electrodes for manual arc welding, a certain marking scheme is used:

1 - versions that can be used in almost any position. This is due to the fact that the applied coating retains its shape and is not too fluid.
2 - can be used in almost all positions, with the exception of working with a vertical arrangement of the tool used.
3 - these electrodes are designed for horizontal and vertical use, ceiling position is excluded
4 - electrodes for manual arc welding, which can only be used in a horizontal position.

It should be noted that different countries apply various standards markings. On sale there are electrodes for manual arc welding of domestic and foreign manufacturers, the classification of which may differ significantly.

Application of electrodes

Welding electrodes for manual arc welding have a fairly large number of features in the application. The main requirements that apply to this consumable are as follows:

The electrodes used in arc welding must ensure stable burning of the resulting arc. Only under this condition it is possible to provide conditions for the formation of a high-quality seam.
Steel metal coated must have a seam with a certain chemical composition. Only in this case the resulting product will serve for a long time and reliably.
During operation, the electrode rod must melt evenly over the surface.
Consumables must provide all the conditions for high performance welding.
Minimum degree of splashing of the molten material. When working, too much spraying can damage a good coating.
High strength of the resulting connection. The easy separability of slags is another positive characteristic of the electrodes used for manual arc welding.
Do not forget that the electrodes must be stored and retain their quality over a long period. That is why the physical and chemical qualities should not change from environmental influences.
The minimum degree of toxicity during the work. During combustion, a variety of substances can be released, which, even in high concentrations, should not have a negative effect on the human body.

When connecting, pay attention to the following points:

With direct polarity, the electrode is connected to the clamp with a negative terminal, the part with a positive one.
To work with parts made from a thin sheet, the reverse polarity connection method is used. In this case, the electrode is connected to the positive terminal, the part to the negative.

When carrying out work, safety precautions must be observed. When performing work, you should use:

special gloves;
protective overalls;
boots;
the most suitable safety helmet.

In many ways, the quality of the resulting seam depends on the skills of the welder and the correct choice of the electrode according to the main criteria.

Coating Features

A variety of coatings can be used in the manufacture of electrodes. It should be borne in mind that coatings can be in pure or mixed form. Pure coated electrodes for manual arc welding are classified as follows:

sour;
rutile;
main;
cellulose;
other.

A special coating of electrodes for manual arc welding can stabilize the resulting arc and provide the most favorable working conditions. Every year, new types of electrode coatings for manual arc welding appear, which have more attractive performance.

The electrodes are used quite simply, the welding machine has an appropriate clamp. Do not forget that this consumable has the same storage and transportation conditions as the welding wire. If necessary, the electrodes for manual arc welding are pierced no later than 5 days before welding. Do not forget that storage should be carried out in closed sealed plastic bags. It is possible to significantly extend the service life by eliminating the possibility of air getting inside. It is also worth considering that it is impossible to perform piercing more than two times, as this will worsen the main performance.

Labeling principles

The brands of electrodes for manual arc welding indicate the main performance qualities of the consumables used. An example of marking is E46-LEZANO-21-F-UD E 43 1 (3) - RTs13. Decryption is carried out as follows:

E46 - designation of the type of electrodes. As previously noted, the classification is carried out according to purpose. In this case, the consumable is intended for carbon and low-carbon steels.
LEZANO-21 - brand indicated by the manufacturer. This part of the marking does not carry information about the performance of the electrodes.
Ф - a symbol designed to indicate the diameter. The absence of any number indicates that the diameter value is displayed elsewhere.
U - the symbol in the marking indicates the possibility of using consumables for working with carbon and low-carbon steels to obtain a seam with a power limit of up to 588 MPa.
D - symbol used to determine the thickness of the applied coating. In the case under consideration, the coating is thick.
E is a symbol associated with the international classification system for materials used as a coating.
43 - part of the marking is used to indicate the tensile strength (430 MPa).
1 - relative elongation, which is 20%.
(3) - part of the marking, which is used to indicate the temperature required to achieve a specific viscosity of at least 34 Dm / cm2. In this case, the indicator is 20 degrees Celsius.
RC - symbols indicating the type of coating (rutile-cellulose).
1 - a symbol that determines the permissible spatial position.
3 - a group of consumables for welding, which is characterized by a certain current and voltage at idle.

In order to decipher the marking, you should use the reference literature, which contains all the necessary tables.

When choosing electrodes for manual arc welding, one should take into account the fact that the manufacturer recommends a certain type of electrodes for each welding machine. It should be borne in mind that welding can take place using several methods:

contact;
roller;
gas press;
electrostepping.

To date, the most widely used two methods: contact and gas pressure. If it is necessary to achieve high productivity, as a rule, the gas-pressing method is chosen. It is used when laying a pipeline over a long distance.

The quality of welding largely depends on the quality of the wire used as the base. The next defining indicator can be called the type of material used as a coating.

The choice of electrodes should be based on the parameters of the coating to be welded. In this case, one should take into account the fact that each brand of electrodes used has its own specific qualities. If you choose the wrong consumable material, the resulting seam will not have the required performance.

When choosing electrodes for arc welding, the following classification should be considered:

Coating type and thickness. In the manufacture of parts, various steels can be used. Examples include carbon and alloy steels. The choice is also made depending on the thickness of the metal.
Appointment. The choice is also made depending on which seam should be obtained. For example, the required width and length, as well as the quality.
Coating composition and mechanical properties. There are quite a few requirements for seams. An example is strength and tensile strength.

Other features of the choice include the following points:

With a metal thickness of not more than 8 mm, electrodes with a diameter of 8-12 mm should be used, and the current strength is 450A. The length of the seam reaches 45 cm. The elements to be welded can be made using various metals.
A consumable with a diameter of 6 mm can be used at a current strength of 370A, the thickness of the metal can be 4-15 m. The welding seam also reaches a length of 45 cm.
On sale there are versions with a diameter of 5 mm. They are suitable for the case when the current strength is 280A. The thickness of the metal used is from 4 to 15 mm.
With a diameter of 4 mm, welding should take place at a current of 100-220A. By reducing the current strength, the thickness of the metal is reduced to 10 mm.
With a current strength of 50-70A, the diameter of the consumable used is 2 mm. The thickness of the metal is only 1-2 mm.

Electrodes with a thickness of less than 3 mm are used when welding parts that are made using alloy steel.

In conclusion, we note that the characteristics of the resulting seam largely depend on the quality of the consumable material used. That is why his choice should be given attention. If we consider the products of domestic and foreign manufacturers, we note that the workmanship does not differ much. But the cost can vary in a fairly large range.

To form a high-quality weld, it is necessary to choose the right brand of electrodes. This is possible only after familiarization with the main regulatory documents - GOSTs. They describe in detail the characteristics of the electrodes, their operational and technical parameters.

Marking

The electrodes are designed to supply current to the workpiece to form a connecting or repair seam. They differ in the material of manufacture, scope and specifics of work.

First, you should first deal with the features of the classification and. With the ability to correctly recognize characters, you can pick up optimal brand.

Marking consists of several sections:

Strength characteristic, MPa.
A unique brand is a numerical and letter designation.
Diameter, mm.
Scope - an indication of the content types of steels or other metals.
Coating thickness.
A special index by which the characteristics of metals can be determined. This is indicated in GOST 10051-75, 10052-75 and 9467-75.
Operating parameters. Type of coating, spatial position during welding and the mode of operation of the apparatus - current (direct or alternating), its polarity.

Each of these characteristics indicates the scope of the electrode, its performance. Therefore, we need to consider them in more detail.

Purpose

The most important characteristic is the scope of the electrodes in relation to the materials to be welded. Some models can successfully form connecting and repair seams in metals various kinds. But most often there are restrictions on a certain type.

The main criterion is the brand of metal and the types of work with it. According to this parameter, there are 5 classes of electrodes, each of which has several types:

"U" - work with carbon and low-carbon steel grades, which are characterized by a tensile strength of more than 600 MPa.
"L" - welding work with high-alloyed metals and tensile strength over 600 MPa.
"T" - for heat-resistant steel grades.
"B" - work with metals with special properties.
"H" - for surfacing surface layers.

The table shows some brands of electrodes by destination.

The exact purpose is indicated by the manufacturer on the packaging. But besides it, it is necessary to choose the right model depending on the type of work performed.

Thus, you can choose the optimal brand of consumables for welding.

Coating characteristics

The electrode coating determines the parameters of the future weld. It is applied during the production process and in most cases it is necessary to form an optimal gas environment in the bath.

There are 5 types of coverage:

Rutile.
Sour.
Main.
Pulp.
Mixed type.

Each of them is designed to perform a specific job. They also directly affect the possible directions of welding.

In addition, you should pay attention to the thickness of the coating. The volume of the gaseous medium will depend on this. The main characteristic is the ratio of the diameters of the steel rod and the coating.

Important - when choosing, one should be guided not only by the overall diameter of the electrode, but also by the thickness of its coating and composition.

Electrode position

Before welding, it is necessary to correctly select the location of the electrode relative to the workpiece. Not all models can work in the down or upright position. This is especially important when welding hard-to-reach places steel structures.

You can find out the possible positions from the marking data. They can be either numerical or in the form graphic image. The latter is convenient, since you can clearly see the recommended position of the electrode relative to the plane of the part.

It should be noted that the complexity of the work depends on the position of welding. How fewer options for a specific brand of electrodes - the more difficult it will be to make a weld.

Operating modes of the welding machine

It is important to consider the permissible operating modes of the welding machine. These include the value idle move and polarity. It is also necessary to know tolerances these characteristics.

Knowing the above parameters, you can choose the optimal brand of electrodes, thereby ensuring a high-quality weld. But we must remember that this largely depends on the qualifications and experience of the worker.

There are quite a lot of technologies for obtaining high-quality permanent joints, however, the most popular method today is manual arc welding, which is performed using stick electrodes. Depending on the selected brands of electrodes for manual arc welding, you can use the same equipment, slightly adjusting the settings of the device, to get high-quality seams different types and destinations. Moreover, you can get reliable seam at any position in space, even in the most inaccessible areas.

To make welded joints as good as possible for each metal, they produce their own varieties of electrodes for welding.

The electrodes used to obtain reliable welds are made in the form of rods made from calibrated welding wire. In this case, cold-drawn technology is used, which implies that a special protective layer will be applied during the crimping process.

This coating of welding electrodes is intended to ensure that during the work the metallurgical processing of the weld pool is carried out, it is not affected by the environment.

This coating also makes it possible to achieve the most stable arc burning, which is also very important in consumable electrode arc welding. With an uneven arc, it will be very problematic to get the same seam along its entire length. The protective coating contains the following substances:

Stabilizing substances, thanks to which the arc burning becomes the most uniform. These include various kinds of alkali and alkaline earth metals, which are characterized by a low ionization potential. These elements include potassium, magnesium, sodium, calcium and a number of other substances;
The compounds that form slag in the seams are made from titanium and manganese ores or various kinds of minerals. Due to these substances in the region of the weld pool begins to form protective film from slag, which does not allow the occurrence of various kinds of oxidative processes;
Substances that allow gas formation. They include inorganic compounds such as marble, magnesite and others, but can also be used organic matter- starch, wood, ground into flour and so on. The main purpose of these compounds is the release of certain gases into the area of the electrode on the metal, which will form another protective shell;
Deoxidizers or alloying substances, which include manganese, titanium, silicon and some other elements. Alloys of these substances with metal can act as alloying elements. Thanks to them, the metal acquires the necessary composition;
Special binding components to make the protective coating monolithic;
Various kinds of molding additives contribute to giving the coating a protective property of good plastic characteristics.

Marks of electrodes for manual arc welding can be formed depending on the coating, its quality and a number of other indicators.

What are welding electrodes?

In the welding process, consumable and non-consumable electrodes can be used - this depends on the technology of manual arc welding, and various kinds can be used for this. additional elements and materials.

When using non-consumable electrodes in the course of work, it should be remembered that they are made from electrotechnical coal, tungsten or artificially obtained graphite. It must be remembered that the electrical conductivity of graphite is much higher compared to other materials, besides, they do not oxidize so quickly - it is quite economical and profitable to use them in manual arc welding with a non-consumable electrode.

Their diameter ranges from 4 to 18 mm, they are up to 70 cm long. For welding using semi-automatic or automatic technology, a special calibrated wire is used, which can be from 0.2 to 12 mm in diameter. It replaces the electrodes themselves with protective coating. The wire is produced in coils, which can weigh up to 80 kg. Today there is a technology for the production of flux-cored wire, wire, which incorporates special alloyed elements, and produces electrode tape and plates.

Consumable electrodes for manual arc welding are made from a special welding wire, which can be simply carbon, with alloyed elements, or with big amount these substances.

Types of electrodes and their scope

The types of electrodes used for welding or surfacing can be classified according to the application (for example, for joining elements made of steel, cast iron, non-ferrous metals, surfacing), various technological features- for argon welding, for roller work, for the most complete penetration of the material. In addition, manual arc welding with coated electrodes can be classified according to the mechanical characteristics of the weld, according to the method of applying metal to the workpiece, according to physical properties slag and so on.

The main requirements for electrodes during welding are as follows:

They must necessarily ensure reliable arc burning and the formation of a high-quality seam;
A metal of a certain composition must appear in a welded joint;
They melt evenly, distributing along both edges of the metal being welded;
The weld metal should not spatter much, which allows for high productivity;
Ideally, the slag leaves as easily as possible;
The covering metal must be fairly strong;
Over time, the electrode metal should retain its original characteristics;
In the process of welding with electrodes of any brand in environment the minimum amount of toxic substances should be released.

Manual arc welding with coated electrodes can be carried out using special products with additional cellulose coatings, rutile coatings, and so on. As a rule, such electrodes are used for work with stainless steel.

The difference between electrodes from each other, marking

According to their key functions, the electrodes may have certain differences depending on their brand and the technique of the work being carried out:

Welding electrodes marked "U" are connected to each other by steel blanks, which contain a minimum amount of alloying elements and a low amount of carbon. The tensile strength in this case is approximately 600 MPa
For heat-resistant steels with a high content of alloyed elements, electrodes marked "T" are used. They also have a tensile strength of about 600 MPa;
In order to fuse the surface layer on the surface of the metal, electrodes with special technical specifications. Marking in this case - "H";
The high plastic characteristics of metals imply the use of electrodes marked "A".

The modes of manual arc welding with coated electrodes are also selected depending on the type of coating. Information about it is also available on the label:

The thinnest coating in thickness does not exceed 20% of the diameter of the welded material;
The average thickness is about 45% of the diameter. This coating is most common, as it is universal;
Thick coating - approximately 80% of the diameter;
The thickest - over 80%;

Useful Tips and Safety for Welding

First of all, professional welders recommend learning to cook on the very machine that is planned to work in the future. This allows you to study all the characteristics of this equipment as quickly as possible, to select the optimal current strength for each type of electrode.

It is also desirable to approach the selection of a welding mask most responsibly. Protective filters have certain numbers, and these filters must also be selected optimally, taking into account the features of vision - eye sensitivity, diopters, and so on. When choosing a filter, there is a main criterion - the weld pool must be perfectly visible.

Welding elements must be at a certain distance from each other - in this case, the connection will be of the highest quality. If the gap is made too small, then the weld will be too convex - this is due to insufficient heating of the metal. Too big gap will not allow uniform application of molten metal, as the welding arc will begin to strongly deviate from the welding line.

When carrying out welding work by hand arc technology it is strictly forbidden to lay a ground electrode on a damp base, for example, in puddles, snow, and so on. All work must be done in special protective gloves and shoes with thick rubber soles. Before starting work, you should carefully check how intact all the protective elements are.

Gloves may only be used if they are completely dry. If you do not take into account this moment, when changing the electrode, you can get a lesion electric shock that will happen in the circuit: rheostat, electrode holder, welder himself and ground.

The face is always protected with a special mask: it helps protect against hot metal splashes, from bright light that will occur during the work. The fact is that the brightness of the emitted light rays can be several thousand times higher than the permissible values for human vision. Viewing welding with unprotected eyes can eventually lead to temporary visual impairment. Welding is also a source of infrared radiation, which causes certain visual defects, in particular, cataracts may begin to develop, however, this does not happen too often.

When welding, the greatest danger to vision is ultraviolet radiation, which causes photophobia, which can manifest itself as pain in the eyes, redness, profuse lacrimation and temporary weakening of vision. This can be cured with ordinary eye drops.

Outcome

If you choose the right apparatus, electrodes and mask, then all welding work will be absolutely safe, and the weld will turn out to be very reliable, high-quality and durable.

When working with manual arc welding, you are constantly working with electrodes. This element of the welding process is not as simple as it seems and has its own extensive classification. Today, you can choose products for any need, based on the metals to be welded, the type of equipment, the required properties of the seam and many auxiliary parameters. Below you will get acquainted with the classification of coated electrodes and their designation.

The electrodes applicable for work with manual arc welding are divided into consumable and non-consumable. Weldable rods are made from cast iron, steel, copper, or other metal, depending on the material. They play the role of an anode or cathode, and also serve as a filler material. They are either covered or uncovered.

The coating in consumable rods performs many functions from arc retention to the formation of a gas cloud that prevents the weld from oxidizing.
Non-consumable electrodes for welding are made from various refractory materials - graphite, tungsten or coal. They serve to ignite and hold the arc, and the filling of the seam with additives is carried out using the manual supply of fusible material.

What is a consumable electrode

The consumable electrodes for manual arc welding consist of an inner core and an outer layer. According to the requirements of the State Standard, when creating consumable welding electrodes, a variety of steels are used: carbon steels, with a large or small number of impurities, copper, aluminum, nickel and other non-ferrous alloys are also used. The composition of the rod is determined by the material to be welded, since both metals must fit together. The exception is cast iron, which can be welded with both steel and copper and iron electrodes.

Like the rod, the outer layer is made taking into account the metal to be welded, which is why its composition may vary somewhat. But despite this, it invariably performs the following functions:

contributes to the retention of the arc;
produces slag enveloping the weld pool, melting the mineral components of the coating;
produces a protective gas that appears as a result of the combustion of the organic components of the coating.
performs deoxidation or alloying of metal.

Classification of coated electrodes

Considering a long list of possible variations from coating, alloy and other parameters of coated electrodes, for a more convenient search desired type rods they received an extensive classification. Kinds welding electrodes divided based on the following features:

By appointment:

alloys with a small proportion of impurities and carbon alloys;
material with a large number ligatures;
alloys of reinforced strength and with unique properties;
welding electrodes with unique properties.

Type - the value of the final seam, characterized by tensile strength, temporary or point mechanical impact.

Brands of welding electrodes - a unique value assigned by the manufacturer for the internal classification of products. That is why the marking of electrodes for welding with the same parameters, but from different manufacturers, can be different.

The thickness of the outer layer - based on their thickness ratios, to the size of the central bar, the outer layer is classified into thin, medium thickness, thick and thickest.

Type of current - electrodes of direct current, alternating current with direct or reverse connection.

The composition of the coating - there is a division into a welding electrode with an acid, basic, cellulose, rutile, layer with an increased concentration of iron, a spray consisting of various layers.

According to the permissible positions, the rods are divided into products suitable for work in:
any provisions;
All except for the vertical, directed downward;
bottom and vertical directed upwards;
bottom.

According to the quality or condition of the seam, after working with the rods, the electrodes are divided into three groups. Products best quality belong to the first group.
Thickness - a parameter indicating the diameter of the steel base, can be in the range from 1.6 to 12 mm.

Marking of welding electrodes and their interpretation

To figure out which electrodes are presented in front of you, you should study their markings. Each package contains information about 9 main characteristics according to GOST 9466-75.

Types coated electrodes for welding.
High-strength steels, with a large proportion of carbon, high or low percentages of ligatures, are welded with electrodes marked with the symbol E - electrode, then there are numbers indicating the maximum allowable tensile loads (kgf_mm2), at the end there is an index A - indicating increased stability seam to plastic and impact loads. For example: E 42, E 50, E46 A, E 60, etc.
Heat-resistant and high-alloy steels: the symbol E, numbers after the dash, indicating the amount of carbon, followed by letters and numbers - indicating a specific chemical element(A - nitrogen, M-molybdenum, F - vanadium, etc.) and its amount in hundredths. Chemical components are arranged in descending order of their quantity in the product. For example: E-09M; E-10KhZM1BF; E-30G2KhM, etc.
Stamps electrodes for welding
Brands are an individual parameter and depend solely on the manufacturer.
Diameter
The thickness of the inner part of the coated electrode ranges from 1.6 to 12 mm; in everyday life, thicknesses of 3-5 mm are most often used.
Purpose
Made to work with carbon steels and with a low number of impurities, as well as strength up to 60 kgf / m2, the electrodes are marked with the letter - U;
Alloyed structural steels with a tensile strength above 60 kgf / m2 are welded with products marked - L;
Products for steels with a low thermal conductivity are marked with the letter - T;
Metals with a large proportion of impurities and unique properties can be welded with products marked - B;
Surfacing layers with unique characteristics are produced by products marked with - H.
Coating thickness
Value indicating the ratio of the coating thickness to the inner core. If this ratio is less than 1.2, then the product is marked with the symbol M and referred to as thinly coated; the middle layer ranging from 1.2 to 1.45 is marked with the symbol C; thick ones - from 1.45 to 1.8 are marked with the symbol D and finally the thickest, the ratio of which is more than 1.8, is marked with the mark G.
Basic properties of the seam
The exact properties of the alloys, for each type, these values \u200b\u200bare their own and indicate strength, the percentage of impurities, operating temperature seam and a number of other indicators. These values can be found in the corresponding tables with transcripts.
Type of electrode coating
A - acid coating.
B - calcium fluoride.
C - cellulose.
R - rutile.
G - high iron content.
There are also mixed species electrode coatings, which are marked with several letters based on the composition.
Attitude marking
1 - all
2 - everything except vertical, directed downwards;
3 - lower, plus vertical (movement from bottom to top);
4 - exclusively lower.
Genus welding current and connection
- Index 0 electrodes for direct current and reverse connection;
- index 1,4, 7 - indicates products for any kind of voltage and any connections;
- pointers - 2,5,8 - any current, but the connection must be direct;
- indices - 3,6,9 for any currents and reverse connection.

Welding electrode manufacturers

Below are three the best manufacturers welding, coated electrodes Russia:

NPP "Welding of Eurasia". For more than 70 years of history, the company has managed to master the full cycle of electrode production and currently produces all types of electrodes - melting, welding, for alloy steels and many others.
CJSC Electrode Plant. The manufacturer is famous for its products supplied to the largest engineering plants countries, the company also manufactures products for the average consumer. Professional welders note the convenience of work and the quality of the products of this company.
LLC NPO Spetselectrod. The products of this company are more than 50 different brands of consumer rods up to 6mm thick. The production also accepts individual orders.

Do not forget about the world leaders, the top three:

Esab is a company with a century of history and products recognized as the best in the world. These Swedish electrodes are known on all continents as the highest quality.
Kobe Steel is a Japanese company that gained popularity by supplying their products to oil companies.
Klöckner & Co SE is a German company producing steel and welding consumables. Electrodes for welding of this company are very popular and widely used in Russia.

» Electrode coatings

The electrode for manual arc welding is a metal rod with a protective coating-coating. The components of the coating provide protection of the welding zone from oxidation by air, contribute to the enhancement of ionization. Coated rods are used for both ferrous and non-ferrous metals, as well as alloys.

Purpose of electrode coating

The main task that manufacturers assign to the coating of electrodes for manual arc welding is melting metal protection. They protect the melting metal from interaction with air, preventing oxidation, and make the finished seam of high quality and strength.

When working with welding machine protective coating creates a shell of slag on droplets of electrode metal moving along the arc gap, as well as on the melting surface of parts welded to each other.

Slag protective layer reduces the rate at which the metal cools and the rate at which it solidifies, due to which gas and other inclusions have time to get out of it, which adversely affect the strength of the structure. As a rule, protective spraying consists of a whole complex of slag-forming elements, such as kaolin or titanium concentrate.

What features does high-quality coverage provide?

The coating covering the metal rods performs whole line primary and secondary tasks. Among the primary ones are:

Secondary, but no less important tasks:

ensuring uninterrupted arcing in a wide range of operating modes, simplifying the ignition process. The stability of the arc is realized due to the presence in the surface layer of the rod of components that are not prone to ionization in a large volume. This contributes to an increase in the number of ions that stabilize combustion in the arc space;
removal of oxygen dissolved in the metal of the weld pool. To do this, ferroalloys are added to the composition of the coating, which react with oxygen more easily and faster than the metal itself;
cleaning of weld metal from impurities (refining).

Coating diameter

On sale you can find many brands of electrodes designed for different types of metal and the strength of the expected loads on the future design. Coated rods have two diameters: the diameter of the electrode itself and the total diameter of the rod and coating. When choosing suitable option diameter is one of the determining factors: the larger it is, the greater the thickness of the metal can be connected using a rod.

Important! The operating mode of the welding machine is set based on the thickness of the parts to be joined and the diameter of the rods. It is important to correctly calculate the current strength, since if the current is too strong, the metal can simply be burned through, and if it is too weak, it will not be possible to form an arc.

The diameter of the coated rod affects not only the ease of working with the material during welding, but also provides the desired characteristics of the connection made, affects the strength of the resulting structure.

Letter "E" in the marking means a stick electrode, commonly used for manual arc welding at home.

The number following the letter, - the minimum value of the guaranteed temporary resistance to rupture of the seam. The larger this number, the greater the load the welded part will withstand.

For example, products of the E42 type provide a resistance of at least 42 kgf / mm2, and rods marked E46 - at least 46 kgf / mm2. E42A electrodes are used for metal with similar tensile strength, but in conditions where higher parameters of impact strength and relative elongation of the resulting weld are required. The improved performance is indicated by the letter "A" in the marking, which indicates the acidic type of coating on the rod.

Coating thickness

Blue coating of the electrode brand

In addition to the characteristics of the coating applied to the electrode rod and the diameter of the electrode itself, when selecting materials for welding, they also focus on the thickness of the protective coating.

The thickness of the coating of the electrode rod is the ratio overall diameter (D) and inner rod diameter (d). That is, a thicker electrode may have a smaller coating thickness if it has a smaller D/d ratio.

For each diameter of the inner rod, there is a different coating thickness. In total, there are 4 categories of electrodes, differing in coating thickness:

thin or stabilizing electrodes (the letter M is used for their designation) with a ratio of 1.2 or more;
medium electrodes (denoted by the letter C) with a ratio of 1.45 or more;
thick having a ratio less than or equal to 1.8, which are also called high-quality (marked with the letter D);
extra thick electrodes are also included in the quality category and have a diameter ratio of more than 1.8 (you can recognize it by the letter G in the marking).

The coating thickness of high-quality electrodes ranges from 0.5 to 2.5 mm, which is 20-40% of the mass of the inner rod. If iron powder is taken into account, then the diameter will be 3.5 mm, and mass fraction- fifty%. Such electrodes are used when a seam is needed High Quality capable of withstanding heavy loads.

Thin or stabilizing electrodes, the coating thickness of which is approximately 0.1-0.3 mm, make the arc burning even and continuous, but in no way affect the quality indicators of the deposited steel.

Types of electrode coating for manual welding

Consider what electrode coatings are, their components and how which of them is indicated. There are four major types of coatings used in the production of electrodes for welding:

coating sour type, denoted by the letter A;
basic(B) coating;
cellulose coating (C);
rutile(R).

The coating of welding electrodes is selected based on what type of steel is planned to be welded, the load force on the structure and other factors.

Sour

The main advantage of acid type coating is when welding work the probability of pore formation in the weld area tends to zero, even if the places where the elements are welded to each other. The acidic coating contributes to the uniform burning of the arc and its easy ignition. This type of electrode is used when the requirements for finished construction minimal.

Acid-protected rods work well both constant and variable current. The most tangible disadvantages are spatter during welding, toxic fumes, the risk of hot cracks during welding.

CAREFULLY! Acid coating is toxic when heated!

Main

Due to the weak oxidation of such a coating, it contributes to the easy disposal of oxygen from the melting metal. A seam made using an electrode with a basic coating, protected from hot cracking. This type of electrode need to be ignited before work to eliminate the possibility of pores in the seam. Due to the difficulty of maintaining the arc burning, it is necessary to weld with basic coated electrodes only using a reverse polarity DC source (applies not to all, but to most brands).

Electrodes with a basic type of coating are used for welding metal parts made of hardenable steels that are at risk of cold cracking, as well as for welding metal elements with a large percentage sulfur and phosphorus content. "Basic" electrodes show high efficiency when welding in several layers of structures that need high rigidity.

Cellulosic

The use of products with cellulose coating (they are marked “C” on the package) in work with the welding machine gives good quality arc burning predominantly at DC . This variety is used when welding root welds on main pipelines made of low-carbon steel.

Also cellulose coated rods excellent for single-sided welding with good penetration in the area of the root seam. The use of rods gives a good result when welding is carried out in a vertical position.

It is not recommended to use for welding steel with a high percentage of carbon and other alloying components in the composition. Another disadvantage - high degree susceptibility to high temperatures and the likelihood of splashes of molten metal during operation.

Rutile

This type of coating is indicated by the letter "P". Rods coated with rutile composition show good results even or traces of scale on the surface at the welding points, hot cracks do not form during the joining of parts.