Manual arc welding is performed using electrodes. It is this metal rod with a special coating (or without it) that provides a melting arc and forms a weld with certain parameters.

To obtain a high-quality, durable, and aesthetically beautiful connection, it is necessary to choose the right consumables. Criteria for the selection of electrodes for welding:

1. By the type of material to be welded. Steel with varying degrees of alloying, cast iron, aluminum, copper, etc.
2. According to the welder used. Alternating current, direct current of the selected polarity;
3. Type of welding works- connection, fusion;
4. Welding method, seam position;
5. Welding conditions are in the atmosphere, in a certain gas environment, in water.

All electrodes are divided into two main types. Non-metallic (carbon, graphite) and made of wire. Accordingly, metal electrodes are non-melting or melting. The latter can be uncovered or with it.

Single piece uncoated electrodes were used at the dawn of the development of welding. They are hardly used today. This type has evolved into a welding wire that is continuously fed to the arcing zone in semi-automatic welding machines. Due to the work carried out in an inert gas environment, the electrode does not stick.

The coating (coating) of stick electrodes is designed to form the correct arc, create the necessary chemical environment at the welding point, and give the seam the required characteristics.
Various types and brands are offered by manufacturers.

The assortment is hundreds of varieties. Experienced master can immediately tell which consumable is needed for a certain type of work. Nevertheless, you need to know exactly what kind of electrodes are, and be able to decipher the designation on the package.

Marking of stick electrodes for manual arc welding

Symbols, labeling and even short instruction for storage, preparation and use is usually applied to packaging or offered as an insert on a separate sheet of paper.

Such information can be done in any form, even with comic-style pictures. However, the official (according to which, among other things, claims can be made to Rospotrebnadzor) is the marking in accordance with GOST.

The production of products is regulated by standards. The most common segment is covered by GOST 9466-75, which determines the procedure for production, testing, labeling of packaging for stick electrodes.

According to this standard, information in the following form must be applied to each package.

And so let's talk about how you can decipher the brands of electrodes different types.

First of all, you need to pay attention to his guest in abbreviated form of the word " State standard". For an example, take one of the brands of electrodes and consider it in more detail. Next, I will write everything down as expected. Our experimental electrode will be called" blue "in the common people, but in fact what it is called.

Electrodes are manufactured for different types of welding and metals respectively and are marked differently. And how to choose electrodes and brands to determine exactly what we need. To begin with, a little theory. Brands can be divided into several categories. For cutting, surfacing, welding of non-ferrous metals, etc. But we can talk about this for a long time. Further, the electrodes can be subdivided by GOST, by type, and so on. Well, all in order. And so there is a brand, let's decipher it.

• The type of electrode is marked in orange.
• In yellow we have this brand of electrode.
• Green is the diameter of the electrode (if several are produced with a diameter of one brand, they are written in another place).
• In the red square we have the purpose and thickness of the electrode coating.
• In black the sign is that it is an index.
• The index itself is in graphite color. (you can write about indices separately)
• In blue, this is the type of coverage.
• In a pink square, two different meanings these are the welding positions and the recommended current.

And now we will put on the shelves what we wrote above.

Electrode type.

• E - Electrode.
• 46 - The ultimate tensile strength kgf / mm 2, in other words, what kind of load can withstand after welding with this electrode, namely, this is 46 kilograms per square millimeter. kgf is a kilogram of force. mm2 - square 1mm -1mm - 1mm. I think everything is clear here. Move on.

• The brand we have contains the short name of the manufacturer's plant - the Losinoostrovsk electrode plant and the brand MR-3C itself.

Electrode diameter.

• If the diameter is not indicated, but only the icon, then it is written on the seal. There is also a table of what other diameters are available for electrodes.

Purpose and thickness of the coating.

• U - Designated as - Electrode for welding carbon and low alloy steel.
• D - It says that we have an electrode with a thick coating. I will describe all the notation below.

Electrode index.

• He tells us the characteristics of the metal to be welded with these electrodes. All this can be viewed in accordance with GOST 9467-75. Tear resistance, impact strength and a few more parameters are all in accordance with GOST.

• This brand of electrodes has two letters RC and means this - R scrap and C cellulose. Of course, I will write in more detail about the types of coverage.

• And so the number one tells us that we can cook with these electrodes in all spatial positions. And from bottom to top and top to bottom, ceiling, vertical, etc.

Now let's take a closer look at everything. I think there are no problems with the type and brands. After all, we are interested in what all these letters and numbers mean.

Designation of electrodes by coating thickness.

• M - Thin coating
• C - Medium coverage
• D - Thick coating
• D - With an extra thick coating.

Welding position designations.

When working with manual electric arc welding, you constantly work 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 needs, based on the metals being welded, the type of equipment, required properties seam and many auxiliary parameters. Below you will learn about the classification of coated electrodes and their designation.

Electrodes suitable for manual arc welding are divided into consumable and non-consumable. The rods melted during welding are made from cast iron, steel, copper or other metal, depending on the material. They act as an anode or cathode and also act as a filler material. They can be covered or uncovered.

The coating in the melt rods performs many functions from holding the arc to forming a cloud of gas to prevent oxidation of the weld.
Non-consumable welding electrodes are made of 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 manual feed of fusible material.

What does a consumable electrode consist of?

Consumable electrodes for manual arc welding consist of an inner core and an outer layer. According to the requirements of the State Standard, in the creation of consumable welding electrodes, a variety of steels are used: carbon, 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 match each other. 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:

• helps to keep the arc;
• produces slag enveloping the weld pool, melting the mineral components of the coating;
• produces a protective gas resulting from the combustion of organic components of the coating.
• performs deoxidation or alloying of metal.

Classification of coated electrodes

Considering the long list of all possible variations from coating, alloy and other parameters of coated electrodes, for a more convenient search for the desired type of rods, they received an extensive classification. Views welding electrodes divided on the basis of such signs:

By appointment:

• low-impurity alloys and carbon alloys;
• material with a large number ligatures;
• reinforced alloys and with unique properties;
• surfacing electrodes with unique properties.

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

Welding electrode grades are a unique value assigned by the manufacturer for internal product classification. That is why the marking of electrodes for welding of the same parameters, but from different manufacturers, may be different.

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

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

Coating composition - there is a division into a welding electrode with an acidic, basic, cellulose, rutile, a layer with an increased concentration of iron, a spraying consisting of various layers.

According to the permissible positions, the rods are divided into products admissible for work in:
· Any provisions;
· All except for the vertical, directed downward;
· Bottom and vertical upward;
· 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 decoding

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

1. Types coated electrodes for welding.
   High-strength steels, with a large proportion of carbon, high or low percentages of ligatures, are welded with electrodes with a marking starting with the symbol E - electrode, then there are numbers indicating the maximum permissible loads when stretched (kgf_mm2), at the end there is an index A - denoting the increased resistance of the seam to plastic and shock loads. For example: E 42, E 50, E46 A, E 60, etc.
   Heat-resistant and high-alloy steels: the E symbol, 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 constituents are arranged in decreasing order of their quantity in the product. For example: E-09M; E-10HZM1BF; E-30G2XM, etc.
2. Stamps welding electrodes
   Brands are an individual parameter and depend solely on the manufacturer.
3. 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.
4. Appointment
   Manufactured for work with carbon steels and with a low number of impurities, as well as strength up to 60 kgf / m2, electrodes are marked with the letter - U;
   Alloyed structural steels with a tensile strength above 60 kgf / m2, welded with products marked - L;
   Products for steels with a low coefficient of 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 manufactured by products with the marking - N.
5. Coating thickness
   A value indicating the ratio of the coating thickness to the inner bar. If this ratio is less than 1.2, then the product is marked with the symbol M and is referred to as thinly coated; the middle layer in the range 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.
6. Basic properties of the seam
   The exact properties of alloys, for each type, these values ​​are their own and indicate the strength, the percentage of impurities, working temperature seam and a number of other indicators. These values ​​can be found in the corresponding tables with explanations.
7. Type of electrode coating
   A - acid coating.
   B - calcium fluoride.
   C - cellulose.
   P - rutile.
   F - increased iron content.
   There are also mixed types of electrode coating, which are marked with several letters based on the composition.
8. Location marking
   1 - everything
   2 - everything except the vertical downward one;
   3 - bottom, plus vertical (bottom-up movement);
   4 - exclusively bottom.
9. 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 is a triple the best manufacturers welding, coated electrodes in Russia:

1. NPP "Welding Eurasia". For more than 70 years of history, the company managed to master full cycle production of electrodes and this moment produces all types of electrodes - consumable, welding, for alloy steels and many others.
2. ZAO Electrode Plant. The manufacturer is famous for its products supplied to the largest machine-building plants in the country; the company also manufactures products for ordinary consumers. Professional welders note the convenience of work and the quality of the products of this company.
3. OOO NPO Spetselektrod. The products of this company are more than 50 different brands consumer rods up to 6mm thick. The production also accepts individual orders.

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

1. 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.
2. Kobe Steel is a Japanese company that has gained popularity due to the supply of their products to oil companies.
3. Klöckner & Co SE - German company, which produces steel and consumables for welding. Welding electrodes of this company are very popular and are widely used in Russia.

Before starting welding work, you need to carefully select the materials required for this. The quality of the weld and the success of the work in general depend on them to a large extent. One of the main materials are electrodes, which are rods of a certain size, metallic and non-metallic. Metal products, in turn, are subdivided into different kinds and types. In addition, they are melting and non-melting. Non-metallic rods can only be non-consumable. There are no universal electrodes for welding; each one is only suitable for specific materials, weld parameters and working conditions.

Electrodes are not universal, each of them is suitable only for a specific material and parameter of the weld.

What are the criteria for the classification?

The bar marking has alphanumeric designation and is carried out in accordance with the parameters to which they correspond. The classification of products is made according to the following criteria:

• metal that you have to work with;
• seam technology;
• thickness and type of coating;
• chemical composition;
• the kind of current (direct, alternating) and its polarity;
• mechanical indicators of the metal from which the seam is made;
• the condition of the coating and the presence of harmful impurities.

In manual arc welding, the designation of coated metal welding electrodes is used, which is defined by GOST 9467-75. It reflects characteristics such as:

• brand;
• appointment;
• diameter;
• type of coverage;
• coating thickness;
• purpose (for which metals and alloys it is allowed to use);
• the location of the seam in space;
• kind of current.

Table of electrode types and its color designation in different countries.

In accordance with GOST 9467-75, the type of product is chosen for certain types of steels that the electrode will weld. So, the first type is used for materials with ultimate strength up to 490 J / cm 2. The second type is used with the same resistance, but for a metal from which higher elongation and toughness values ​​are required. For steels with a ultimate tensile strength of more than 490 J / cm2, the third type is intended. It is designed for the possibility of growth of the indicator up to 590 J / cm 2.

According to the same state standard, the grades of electrodes for such steels are determined:

• carbon, structural low-alloy;
• alloyed structural, increased and high strength;
• heat resistant;
• heat-resistant, heat-resistant;
• specialized.

And also for alloys and other metals:

• corrosion-resistant steels and alloys;
• dissimilar alloys and steels;
• cast iron;
• non-ferrous metals.

The symbol for all characteristics of the electrode has the following structure:

1. Brand.
2. Product diameter (in mm).
3. Destination encoding.
4. Coating thickness coding.
5. Indices of weld metal and weld metal characteristics.
6. Coating type coding.
7. Welding position coding.
8. Current characterization coding.

Non-consumable electrodes and their marking

Products made only of tungsten or with additives from tungsten, yttrium, thorium, lanthanum, zirconium oxides have a melting point that is significantly higher than the welding temperature. They give a stable arc with any kind of current and polarity. The electrodes are highly wear-resistant and allow welding various metals... Welding work, as a rule, is carried out in an inert gas environment.

Tungsten bar size chart.

Non-consumable welding electrodes that contain tungsten start with the letter "W". In addition, the color in which the end of the product is painted will help to navigate. In particular, green WP (pure tungsten) is used when welding magnesium, aluminum and alloys. The work is done with alternating current. Red WT-20 (with thorium dioxide) is a direct current welding of such steels: low alloy, carbon, stainless. The dark blue WY-20 (with yttrium dioxide) is also suitable for copper and titanium. Welding with alternating current will help with WZ-8 white... It can withstand high current loads and is used for magnesium, aluminum and their alloys.

Products of subsequent brands can be used for welding with both direct and alternating current. The gray electrode WC-20 (with cerium dioxide) can be used for all types of steels. The gold electrode WL-15 can weld alloyed, the blue WL-20 can weld laminated steel, and both are suitable for stainless steel. Lanthanum dioxide is used as an alloying additive for them, and the number indicates its amount.

All non-metallic electrodes are non-consumable: carbon, graphite, copper-plated carbon, copper-plated graphite. The copper layer mainly serves as a surface protection during transportation. They are used for gouging, fast cutting, including very thick sheet metal, elimination of casting and welding defects. Products made of graphite have a higher efficiency and have better characteristics in comparison with carbon electrodes.

Marking by thickness and type of coating

The structure of the symbolic designation of electrodes according to GOST.

Nowadays, uncoated electrodes are rarely used. To indicate the thickness in GOST 9467-75, letter marking is used. So, a thin coating is marked with the letter "A", its value does not exceed 1.2. Letter "C" - this is a coating of average thickness, the indicator is in the range of 1.45. Letter "D" - thick coating, up to 1.80. Letter "G" means extra thick coating, over 1.80. This indicator is not indicated in absolute numbers, but is calculated by dividing the diameter of the coated electrode by its diameter without coating.

The type of coating for welding electrodes has its own marking. The letter "A" stands for acidic coating. It contains oxides of silicon, manganese and iron. This class includes the most commonly used brands of welding electrodes OMM-5, SM-5, TsM-7, MEZ-4. They can only be used for unalloyed and low-alloyed steels, since excess oxygen is released during melting, and this, in turn, entails the loss of alloying elements.

The base coat, "B", is called calcium fluoride. It is formed by such natural minerals as marble, dolomite, magnesite, fluorspar. During melting, a protective atmosphere of gases is formed, which practically does not contain hydrogen. Used for high alloy steels and products large thickness... Hardfacing prevents hot cracking. Since the arc can be unstable during cooking, to increase it, welding is performed at direct current reverse or alternating polarity. It can be carried out in any spatial position.

Table of types of electrodes.

The rutile “P” coating is based on the mineral of the same name, which consists mainly of titanium dioxide. In addition, it includes aluminosilicates and carbonates. Coating helps create seams High Quality virtually crack-free, minimizes metal spatter. Ceiling and vertical joint results are superior to all other coatings.

Cellulosic coating "C" also creates gas protection, but at the same time increases the hydrogen content in the weld metal. The coating includes organic matter containing cellulose, including regular flour. It makes it possible to carry out work in a top-down position and suspended. The general designation of a mixed coating is the letter "P". It includes a mixture of rutile with another type of coating: "AR" - acidic, "RB" - basic, "RC" - cellulose. Rutile coating with iron powder is designated by the letters "RZh".

Electrode type: how to determine the purpose of the marking

Although many types of electrodes are rather difficult to classify, GOST 9467-75 defines the types that should be used when welding certain steels. The alphanumeric designation is deciphered as follows: the letter "E" means "electrode", the number indicates the ultimate tensile strength, the minimum value of which is guaranteed by the manufacturer. Letter "A" indicates increased viscosity and ductility of the weld metal. The designations are as follows: E38, E42A, E50A.

In addition, the electrode is marked with a letter, from which you can determine the type of steel for which it is intended. For example, products for welding carbon steel are marked with the letter "U", alloyed heat-resistant - with the letter "T", and surfacing on the surface with the letter "H". The document indicates which letters represent one or another chemical element that is part of the surfacing. An example of marking products with hardfacing: Э-09М, Э-09Х1МФ, Э-10Х3М1БФ. Molybdenum is marked with letter "M" in the marking, letter "X" - chrome, letter "F" - vanadium, and letter "B" - niobium.

Modern market welding consumables very diverse. The same class may correspond to a large number of brands, both domestic and foreign.

When choosing a product necessary for welding, one should first of all focus not on the brand under which it is sold, but on the characteristics determined by the standard.

The electrodes are made from carbon, alloyed and high-alloy steel alloys.

This is a classification (melting or non-melting), type of electrode, type of coating, kind and polarity of current, location of seams in space. In addition, you need to choose the right diameter of the rod.

The diameter is determined based on the thickness of the material to be welded. For the thinnest electrodes, it is only 1 mm, which allows welding sheets of metal no more than 1.5 mm thick, while using a current strength in the range of 20-25 A. Of course, when choosing, factors such as the brand of metal, current parameters , the shape of the edge of the sheet. The most common electrode diameter is 3-4 mm. It makes it possible to weld metal up to 10 mm thick at a current strength not exceeding 220 A. An increase in diameter - and its maximum size is 12 mm - requires more and more powerful welding equipment.

What are the rods made of?

In accordance with the requirements of the State Standard, for the manufacture of a rod of consumable welding electrodes, various types of steels are used: carbon, alloyed and high-alloyed. The wire from which they are made is marked in a certain way. First, there are the letters "Sv" (welding), the following number indicates the presence of carbon in the metal (in hundredths of a percent), then the letter coding of the alloying elements is indicated, and after that the percentage of these elements. The marking indicating the content of carbon (0.10%), chromium (1%), manganese (2%) and silicon (1%) in the rod material looks like this: Sv-10HG2S. The composition of the rod and the steel welded with it must match.

For welding non-ferrous metals, the electrode rod can be made of similar material, that is, from copper, aluminum, nickel and some alloys - bronze, brass. However, cast iron products can be welded not only with steel, but also with copper-iron electrodes. The material from which they are made is obtained by mechanical mixing of copper and an iron-carbon alloy. In the process of building up the weld, carbon is released from the melt, which increases its strength. This view The electrodes consist of 5-10% iron and 90-95% copper.

Today, welding works are 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. Special equipment and consumables are used for welding. As an example, electrodes for manual arc welding can be cited, without which it is almost impossible to carry out the work under consideration. Manual arc welding with covered electrodes is carried out quite often today, which determined the appearance of a large number of varieties consumable... An example is the structure of an electrode, which corresponds to the characteristics of the work being carried out. Consider all the most important points in more detail.

Classification of electrodes for manual arc welding

Considering different types of electrodes for manual arc welding, attention should be paid to the fact that different coatings can stabilize the resulting arc during combustion. All types of rod coating have their own characteristics that should be considered when considering 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 manual arc welding electrodes is carried out:

1. Alloy metals have become quite widespread, since due to the addition of various chemicals, they significantly improve performance characteristics... Some chemical substances can significantly increase the heat resistance of the metal. For such alloys, electrodes are used, which have the letter "T" in the marking.
2. For welding of steels that have a low concentration of impurities, versions are used, when marking which the letter "U" is used. In addition, such electrodes for manual arc welding are suitable for compounds of metals with a medium concentration of carbon. The achieved tensile strength is 600 MPa.
3. Structural steels are also very widespread. Alloying elements are also found in their composition. The tensile strength in this case is 600 MPa.
4. In some cases, metal can be soldered onto the surface. The metal can be of exceptional performance. For this case, a version is suitable, in the designation of which the letter "H" is used.
5. On sale there are electrodes designed for steels with a high concentration of alloying elements.
6. A separate group includes steels that have high plastic properties. It is quite difficult to work with such a material, therefore, they began to produce electrodes for aluminum or other similar alloys. The letter "A" is indicated in the marking.

The diameters of electrodes for manual arc welding can differ significantly, which is associated with the peculiarities of the work being carried out. Classification is also carried out by thickness created coverage... There are the following types of electrodes:

1. With a thin coating. The letter "M" is used in the designation. As a rule, in this case, the surface layer is about 20% (the indicator is taken from overall value diameter).
2. With an average coating thickness. When designating, the letter "C" is indicated. In this case, a layer is applied, the thickness of which is 45% of the diameter of the rod used during manufacture.
3. The thick coating is 80% of the diameter, the letter "D" is indicated in the marking.
4. There are also especially thick versions, with the designation of which the letter "G" is indicated. In this case, the thickness is more than 80%.

Do not forget that electrodes may have limitations in their use and position during work. An example is the fact that some substances have increased fluidity, and work at ceiling surface it will be hard. In order to be able to quickly determine the purpose of 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, except for work with a vertical position of the tool used.
• 3 - these electrodes are designed for horizontal and vertical use, overhead position is excluded
• 4 - electrodes for manual arc welding, which can only be used in a horizontal position.

It should be borne in mind that different countries apply different labeling standards. On sale there are electrodes for manual arc welding of domestic and foreign manufacturers, the classification of which may differ materially.

Application of electrodes

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

1. The electrodes used in arc welding must ensure a stable burning of the resulting arc. Only under this condition it is possible to provide conditions for the formation of a high-quality seam.
2. Steel coated metal must have a seam with a certain chemical composition... Only in this case the resulting product will serve for a long time and reliably.
3. During operation, the electrode rod should melt evenly over the surface.
4. The consumable must provide all the conditions for high-performance welding.
5. Minimal splashing of molten material. Excessive spraying during operation can damage the good coating.
6. High strength of the resulting compound. Easy separability of slags is another positive characteristic of the used electrodes for manual arc welding.
7. Do not forget that the electrodes must be stored and retain their qualities for a long period. That is why the physicochemical properties should not change due to environmental influences.
8. The minimum degree of toxicity during work. When burning, the most various substances, which, even in high concentration, should not provide negative impact on the human body.

When connecting, you should pay attention to the following points:

1. With straight polarity, the electrode is connected to the clamp with the negative terminal, the part with the positive.
2. For working with parts made from thin sheet, the reverse polarity connection method is applied. In this case, the electrode is connected to the positive terminal, the part to the negative.

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

1. special gloves;
2. protective robe;
3. boots;
4. 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

In the manufacture of electrodes, the most various coatings... It should be borne in mind that coatings can be in pure or mixed form. The clean coating of MMA electrodes is classified as follows:

1. sour;
2. rutile;
3. basic;
4. cellulose;
5. other.

Special coating of electrodes for manual arc welding can stabilize the resulting arc and provide the most favorable conditions for work. Every year there are new types of electrode coating for manual arc welding, which have more attractive performance.

The electrodes are used quite simply, in welding machine there is a corresponding clamp. Do not forget that this consumable has the same storage and transportation conditions as welding wire... If necessary, the electrodes for manual electric 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... The service life can be significantly extended by eliminating the possibility of air ingress. It should also be borne in mind that piercing should not be performed more than twice, as this will worsen the basic performance.

Principles of labeling

The brands of electrodes for manual arc welding indicate the main performance characteristics of the consumables used. An example of marking is E46-LEZANO-21-F-UD E 43 1 (3) - RC13. Decryption is carried out as follows:

1. E46 - designation of the type of electrodes. As previously noted, the classification is by purpose. In this case, the consumable is intended for carbon and low carbon steels.
2. LEZANO-21 is the brand indicated by the manufacturer. This part of the marking does not provide information on the performance of the electrodes.
3. Ф - a symbol intended to indicate the diameter. The absence of a number indicates that the diameter value is displayed elsewhere.
4. Y - the symbol in the marking indicates the possibility of using consumables for working with carbon and low-carbon steels to obtain a weld with a power limit of up to 588 MPa.
5. D - a symbol used to determine the thickness of the applied coating. In the case under consideration, the coating is thick.
6. E is a symbol associated with the international system classification of the materials used as a coating.
7. 43 - part of the marking is used to indicate the ultimate strength (430 MPa).
8. 1 - relative elongation, which is 20%.
9. (3) - part of the marking that is used to indicate the temperature indicator required to achieve a specific viscosity of at least 34 Dm / cm2. In this case, the indicator is 20 degrees Celsius.
10. RC - symbols indicating the type of coating (rutile-cellulose).
11. 1 - a symbol that determines the permissible spatial position.
12. 3 - a group of consumables for welding, which is characterized by a certain current and voltage at no-load.

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, you should take into account the point that the manufacturer recommends for each welding machine certain type electrodes. It should be borne in mind that welding can take place using several methods:

1. contact;
2. roller;
3. gas press;
4. electrostepping.

Today most widespread received two methods: contact and gas press. When it is necessary to achieve high productivity, as a rule, the gas-press 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 in the form of a 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, it should be borne in mind that each brand of used electrodes has its own specific qualities. If you choose the wrong consumable, then the resulting seam will not have the required performance.

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

1. The type of coating and its thickness. Various steels can be used in the manufacture of parts. Examples include carbon and alloy steels. The choice is also made depending on the thickness of the metal.
2. 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.
3. Coating composition and mechanical properties. Quite more requirements are imposed on the seams. Examples include strength and tensile strength.

Other features of the choice include the following points:

1. With a metal thickness of no more than 8 mm, electrodes with a diameter of 8-12 mm should be used, and the current strength is 450A. The seam length reaches 45 cm. The elements to be welded can be manufactured using various metals.
2. Consumable material with a diameter of 6 mm can be used at a current of 370A, the thickness of the metal can be 4-15 m. The welding seam also reaches a length of 45 cm.
3. 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 used metal is from 4 to 15 mm.
4. With a diameter of 4 mm, welding should take place at a current of 100-220A. By reducing the current strength, the metal thickness is reduced to 10 mm.
5. 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 used. That is why attention should be paid to his choice. If we consider the products of domestic and foreign manufacturers, then we note that the workmanship does not differ much. But the cost can vary in a fairly wide range.