Appointment and marking of welding electrodes. We study the marking of electrodes for welding

The popularity of welding is due to the relative simplicity of the process, as well as low financial costs at a high level of quality. There are various brands of electrodes for handheld arc welding... They are selected according to what kind of metal will have to be welded, as specialists try to achieve identity between the metal of the rod and the workpiece. In addition, there are a number of factors that affect the external conditions that accompany the joining process. It is these conditions that create the situation, due to which there are various types of electrodes for manual arc welding.

They often have a coating that maintains a stable arc burning and provides protection against negative effects. external factors... they can also have many differences that make them suitable for certain conditions, but often they also depend on what kind of metal the products are intended for. The same brands can be made by different manufacturers, the main thing is that the production standards are observed, which will give a guarantee of obtaining the declared technical characteristics.

Types of electrodes for manual arc welding

Manual arc welding electrodes can differ in several ways. First of all, they differ in purpose:

• For welding steels with low alloying elements and also with medium carbon content. As a rule, their tensile strength is about 600 MPa. In the Marking, they are designated by the letter "U".
• For welding alloy steels with a high degree of thermal stability. In the marking, they are indicated by the letter "T".
• For welding structural steels containing alloying elements. Their tensile strength is also about 600 MPa.
• For deposition of surface layers on metals with special properties... They are designated by the letter "H".
• For welding steels with a high alloy content and with special properties.
• For welding metals with high ductility. Contains the letter "A" in the designation in the marking.

Appearance of electrodes for manual arc welding

Classification welding electrodes for manual arc welding, it can also occur along the thickness of the coating. They depend on the diameter of the metal rod, but the varieties relate to this ratio, and not to the absolute size. There are four main types:

• Thin coating "M". Its thickness is about 20% of the diameter of the rod;
• Average "C". The thickness is about 45% of the diameter of the rod (the most common variant);
• Tolstoy "D". The thickness is about 80% of the diameter of the bar;
• Extra thick "G". Thickness over 80% of the diameter of the bar.

They are also distinguished depending on the availability of the coating and its variety. It should be noted right away that they are found not only in their pure form, but also in various combinations, where the composition includes the main components of at least two types. Electrode coatings for manual arc welding are designed for protective function, which in gas welding is performed by an inert gas. Pure types include such as:

• "A" - Sour;
• "B" - Basic;
• "C" - Cellulose;
• "R" - Rutile;
• "P" - other (this does not include double types, such as RC, BC and others, which are distinguished separately).

Electrodes for can have limited use in spatial position. The fact is that some of them turn out to be too fluid, therefore, when they are overhead, they simply cannot melt into the desired place, but will flow down. To make it clear which brand is intended for what, the designation of manual arc welding electrodes contains a point on the spatial position:

• "1" - can be used in all possible positions;
• "2" - all positions are available except for the vertical one, which is brought from top to bottom;
• "3" - for horizontal and vertical, excluding overhead position;
• "4" - only horizontal varieties are acceptable.

Table of electrode grades and fields of application for manual arc welding and surfacing of alloy steel

Some types of electrodes are initially created for working with certain technical metals. Alloyed steels are often used in production, so consumables are produced specifically for their properties. They contain the same alloying elements as in the base metal to compensate for their deficiency after exposure to temperature.

Table of electrode grades and fields of application for manual arc welding and cladding of cast iron

The choice of electrodes for manual arc welding of cast iron depends on the carbon content in the given metal. In any case, it is quite high and therefore consumables also contain this element, which distinguishes their properties relative to other electrodes.

Table of electrode grades and fields of application for manual arc welding and surfacing of non-ferrous metals

Non-ferrous metals are more rare than steel. The electrodes for them are intended for both pure metals and alloys. Here, the presence of a large amount of the main element in the composition is mandatory, since many of the parts are difficult to weld.

Table of grades of electrodes and fields of application for metal cutting

These types of materials are unique, since the heating and melting of the electrode during arc welding usually occurs at medium conditions, while these must be used at maximum current. They have increased heat resistance, but they still belong to fusible options.

Designation and marking of electrodes for manual arc welding

On the example of the electrode E-46 LEZANO21 UD E 43 1 (3) RC13

• E-46 - type for low-alloy and carbon steels;
• LEZANO21 - brand;
• U - purpose, for low-alloy and carbon steels;
• D - thick coating;
• E - consumable electrode;
• 43 - tensile strength - 430 MPa;
• 1 - relative elongation about 20%;
• (3) - 20 degrees Celsius to maintain toughness;
• RC - rutile-cellulose coating;
• 1 - spatial positions, all are allowed;
• 3 - current for welding, can be welded with direct current of reverse polarity and alternating current at no load of 50 V.

Appearance of the electrode E-46 LEZ ANO-21

Choice

The primary factor in the selection is the metal in the rod. It should be similar to the one from which the workpiece is made. for manual arc welding go to the next item, since they should not exceed the thickness of the part itself. The coverage is selected according to the conditions in which you have to work. Before the final choice, it is worthwhile to study the marking in detail to make sure it is correct.

"Important! Before using the electrodes, they must be dried and calcined."

To form a high-quality weld, it is necessary to select the correct 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 material of manufacture, field of application and specifics of work.

First, you should first understand the features of the classification and. With the ability to correctly recognize characters, you can choose optimal brand.

The marking consists of several sections:

• Strength characteristic, MPa.
• Unique brand - numerical and letter designation.
• Diameter, mm.
• Scope - indication of 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.
• Operational parameters. The type of coating, the spatial position during welding and the operating mode of the apparatus - current (direct or alternating), its polarity.

Each of these characteristics indicates the field of application of the electrode, its performance... Therefore, you need to consider them in more detail.

Appointment

The most important characteristic is the field of application of the electrodes in relation to the welding materials. Some models can successfully form connection and repair joints on various types of metals. But most often there are restrictions on a certain type.

The main criterion is the grade of the 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 with high-alloy metals and rupture strength over 600 MPa.
• "T" - for heat-resistant steel grades.
• "B" - work with metals with special properties.
• "N" - for surfacing the surface layers.

The table shows some brands of electrodes by area of ​​application.

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

Thus, you can choose the optimal brand Supplies for welding.

Coating characteristics

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

There are 5 types of coverage:

1. Rutile.
2. Sour.
3. Basic.
4. Cellulosic.
5. Mixed type.

Each of them is designed to do 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 bar to the coating.

It is 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 carrying out welding work, it is necessary to select the correct location of the electrode relative to the workpiece. Not all models can be operated in a down or upright position. This is especially important when welding in hard-to-reach places steel structures.

You can find out the possible positions from the marking data. They can be both digital and 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 labor intensity of the work depends on the welding position. How fewer options for a particular brand of electrodes, the more difficult it will be to make a weld.

Operating modes of the welding machine

It is important to take into account the permissible operating modes of the welding machine. These include the value idle move and polarity. You also need to know tolerances these characteristics.

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

For a high-quality, durable connection metal structures and alloys are used for welding. In this case, it is important to choose the correct brand of electrode. To do this, you need to know the classification of electrodes, their marking methods, the areas in which they are recommended to be used.

Two large groups of electrodes are consumable and non-consumable, while consumable electrodes are divided into some subspecies, such as coated or uncoated (wire).

Consumable electrodes

There are several types of electrodes according to the type of steels to be welded or deposited:

for welding carbon steels (marking - "U"). These are electrodes E38, E42, E46, E50.

alloyed (marking - "L"). These are electrodes E70, E85, E100, E125, E150.

heat-resistant (marking - "T"). Welding of such steels is carried out with preheating and final heat treatment seams. Usually, electrodes are used that are not described in GOST (for example, ANZhR-2).

for steels with special properties, such as corrosion-resistant, heat-resistant, heat-resistant (marking - "B"). The list of types of electrodes is regulated by GOST 10052-75.

for surfacing of surface layers of metal (marking - "H"). These are the electrodes E-09M, E-09MH, E-09H1M, E-05H2M, E-09H2M1, E-09H1MF, E-10H1M1NFB, E-10HZM1BF, E-10H5MF.

Melting coated (coated) electrodes

Welding electrodes are coated or coated in order to ensure good ignition and stable arc burning, protection of the weld pool from environment, to obtain the required properties of the weld, to reduce losses during spraying, to increase the speed of welding, to reduce the toxicity of gases emitted during welding, to eliminate the loss of coating properties during storage.

According to the thickness of the coating (coating), by calculating the ratio of the diameters D (coated electrode) and d (rod), the electrodes are divided into:

• thinly coated, with a D / d ratio of up to 1.2, are designated by the letter "M";
• electrodes with a coating of medium thickness, D / d up to 1.45, are designated by the letter "C";
• thick-coated (otherwise, high-quality), D / d from 1.45 to 1.8, marked with the letter "D";
• with a particularly thick layer of coating, D / d greater than 1.8, marked with the letter "G".

By the type of chemical composition, there are several types of electrode coating:

• Acid-coated electrodes (contains iron or manganese oxide). This type of coating is characterized by high temperature arc, respectively, high welding speed, however, manganese oxide is very toxic and hazardous if inhaled. Designated with the letter "A" (DIN - A).
• Rutile-coated electrodes containing titanium dioxide have a quiet weld pool, low spatter, allowing fine seams to be applied to workpieces. They are designated by the letter "P" (DIN - R). There are also widespread electrodes with mixed coatings, which include rutile-cellulose (RC), rutile-basic (RB), rutile-acid (RA) and rutile with iron powder (RF). (DIN - RC, RB, RA and RR respectively).
• Electrodes with basic coatings (designated by the letter "B", DIN - B) contain calcite, magnesium carbonate and fluorite in small amounts. Such coatings are sensitive to moisture, therefore, it is necessary to take responsibility for their storage conditions. However, the weld obtained using these electrodes has excellent mechanical properties, is free from cracking and aging, and is practically free of nitrogen and oxygen. These electrodes are used to weld the most loaded and critical structures.
• Cellulose-coated electrodes (designated by the "C" index) contain organic matter, which, when burned, envelop the weld pool with shielding gases. They are used when working mainly with high-strength structures, pipelines. They are used more often for welding vertically located seams, however, they form a large amount of spatter during operation.
• Iron powder coated electrodes are used for butt welding with large gaps. When using such electrodes, a stable burning of the arc is observed, there are practically no splashes, the weld cools faster, and the appearance of slag, which is easily separated from the metal, is minimized.

In the marking of the electrode, there is always a pointer (in the form of a number from 1 to 4), or an international designation (diagram) for the spatial position of the weld:

1 - any position;

2 - any, except for vertical top-down;

3 - bottom position, horizontal and vertical from bottom to top;

4 - bottom or corner joints bottom "boat".

If the position of the weld is indicated by the diagram, then the arrows indicate its direction in space.

When selecting electrodes for different welding modes, it is necessary to take into account the polarity of the direct current source and the nominal (base) voltage (Uxx) of the open circuit of the power source (alternating current). These parameters on the electrodes are indicated by a number from "0" to "9":

Index:	Polarity used		U xx
	Straight	Feedback
	Not	Yes	n / and
	Yes	Yes	50 V
	Yes	Not	50 V
	Not	Yes	50V
	Yes	Yes	70V
	Yes	Not	70V
	Not	Yes	70V
	Yes	Yes	90V
	Yes	Not	90V
	Not	Yes	90 V

GOST 9466-75, which regulates the manufacture and marking of consumable electrodes, requires that the packaging contains all the necessary information:

- - -

E - -

Position "1" indicates the type of electrode.

Then, in position "2" its brand is indicated.

In position "3" either the diameter (in mm) is clearly written, or the sign Ø is put, which means that the diameter is indicated separately.

Positions "4" and "5" are intended to indicate the purpose and thickness of the coating.

In position "6" the index is indicated.

Coverage type by chemical composition specified in position "7".

Positions "8" and "9" indicate the position of the seam in space and the number denoting the genus, respectively. welding current.

For instance:

The marking shows: electrode type - E46, grade - "LESMR-3S", diameters are indicated in the table, the electrode itself with a thick coating (otherwise called high-quality) is used for welding in any position of carbon steels. At the bottom of the marking, it is indicated that the electrode is rutile-cellulose coated, welding with both alternating current and constant reverse polarity is possible.

Tables of various indices (position "6") for the characteristics of the weld metal or the deposition of various types of steels are indicated below:

These indices reflect various characteristics and weld or weld deposit properties (immediately after welding, no heat treatment), such as toughness, elongation, or tensile strength, by the specified electrode type. Information is taken from GOST 9467-75.

Uncoated consumable electrodes

Nowadays, uncoated electrodes (or welding wire) are widely used. Specifications and GOST (2246-70) identified about 80 of its types. However, in household needs, units are used for welding metal structures from ordinary rolled metal or stainless steel. The wire is subdivided into alloyed (represented in GOST 30 by grades, contains up to 10% alloying elements), low- (6 types, with alloying additives up to 2.5%) and high-alloyed (41 grades in GOST, alloying impurity content exceeds 10%) , depending on the percentage of the alloying substance.

The welding wire is identified with the letters "CB" at the beginning of the marking. Then comes the designation of hundredths of a percent of carbon, followed by the name and percentage of alloying elements. If the percentage is not explicitly stated, then it is in the range from 0.5 to 1%.

Alloying impurities in the wire are designated as follows:

Letter	Designation in the periodic table (number)	Element
"A"	N (7)	Nitrogen
"B"	Nb (41)	Niobium
"V"	W (74)	Tungsten
"G"	Mn (25)	Manganese
"D"	Cu (29)	Copper
"M"	Mo (42)	Molybdenum
"WITH"	Si (14)	Silicon
"T"	Ti (22)	Titanium
"X"	Cr (24)	Chromium*
"N"	Ni (28)	Nickel*
"YU"	Al (13)	Aluminum
"F"	V (23)	Vanadium
"C"	Zr (40)	Zirconium

Also, at the very end of the marking, one or two letters "A" may be present, which means a high and very high degree of purification of the steel used.

Thus, the marking "Wire 3 SV04X19N9" means a 3 mm consumable electrode with a carbon content of 0.04%, chromium - 19% and nickel - 9%. Wire with chromium and nickel in the composition (indicated by an asterisk in the table) is used for welding corrosion-resistant alloy steels (stainless steel).

Non-consumable electrodes

Tungsten

Tungsten electrodes are designed for welding, cutting, mainly in an environment of protective gases, such as argon, helium, nitrogen or their mixtures. In addition to tungsten, the electrode can contain various impurities that increase its wear resistance. This type of electrodes provides high stability of the welding arc and allows you to work with any metals and alloys.

Designation	Welding mode		Metal	Color
	D.C	Alternating current
	Not	Yes	Magnesium, aluminum, alloys	Green
WT-20	Yes	Not	Low alloy steel, stainless steel, carbon steel	Red
WC-20	Yes	Yes	Universal. All types of steel	Grey
WL-15	Yes	Yes	Stainless steel, alloy steel	Gold
WL-20	Yes	Yes	Stainless steel and laminated steel	Blue
WY-20	Yes	Not	Titanium, low alloy steel, stainless steel, carbon steel, copper	Navy blue
WZ-8	Not	Yes	Aluminum and magnesium	White

Coal

There are also other types of non-consumable electrodes on the market, including carbon and graphite. Considering that coal is soft material, to improve the quality and safety of the coating, copper plating is used in them. They are mainly used for working with thin metals, as well as for surface cutting, edging, gouging, etc.

Several types of graphite or carbon electrodes are made, including round, connectable (endless, with a nipple), flat and semicircular. Round and endless electrodes contain in the marking the diameter of the electrode from 3 mm to 25 mm, flat ones can be presented as square or rectangular, with different sections. In semicircular (the most universal) indicate the dimensions of the flat side, the radius of the circle and the length of the electrode.

There are also hollow electrodes used exclusively for gouging, they are produced mainly by foreign companies.

Connection of several parts in monolithic structure often occurs with the use of welding equipment. To obtain required quality connection, it is necessary not only to rationally select the welding method, but the corresponding welding electrodes.

Welding

Basic requirements for electrodes

The variety of materials and welding methods to be welded suggests a wide range of electrodes used.

But they all must meet general requirements:

• ensure the stability of arc burning, small radius of spatter of the rod, coatings, high productivity of welding;
• create conditions for the formation of a high-quality weld;
• to make the flow of the welding process even;
• maintain physical, chemical, technological properties during a specific welding.

A special place in the requirements is toxicity. The electrodes should release a minimum amount of toxic substances during work.

Classification of welding fittings

Electrodes are used as the main element for manual arc welding. There are two types of electrodes:

• melting, which correspond to the composition of the substances to be welded;
• non-consumable of three types: coal, graphite, tungsten.

Several methods are used to classify electrodes. By appointment, there are electrodes for connecting stainless steel, non-ferrous metals, various types of steel, cast iron.

Note! Electrodes for manual arc welding are marked in this way: B - high-alloy steel, L - alloy steel in structures with ultimate tensile strength, T - heat-resistant steel, U - carbon and low-alloy steel, H - surface layers with special properties.

The type of construction involves obtaining various types of seams. It can be a vertical, overhead or bottom seam. For each type of seam, a special electrode is selected:

• for any position;
• not used for welding vertically from top to bottom;
• for the bottom, vertical from bottom to top and for horizontal, located in the vertical plane;
• for the bottom.

The variety of coating material, its thickness also classifies the electrodes. Top electrodes are covered protective layer from a composite composition, it includes the following substances:

• arc burning process stabilizers;
• granite, silica, titanium and manganese ores, components for the formation of slags, from which a film is formed. This slag film prevents oxidation processes;
• marble, magnesite, starch, wood flour, forming a gas film to protect the weld pool. Can be inorganic and organic;
• silicon, magnesium, titanium as deoxidizers and alloying elements;
• ferromanganese, ferrosicilium, ferrotitanium for the reduction of metals from oxides;
• bentonite, kaolin, dextrin to improve plastic properties.

Note! To classify the types of coating, the following designations are used: A - acidic, B - basic, - C cellulose, P - rutile, P - others. Sometimes a combination of letters is used if the coating mixed species.

The electrodes are covered with a thin protective layer, medium, thick and even extra thick. Marking of the thickness of the coating, which is defined as the ratio of two diameters - with the coating and the rod itself:

• M - ratio up to 1.2;
• C - ratio up to 1.45;
• D - ratio up to 1.8;
• G - the ratio is more than 1.8.

An important technical indicator is the type used electric current... There are electrodes that are connected to DC or AC sources, as well as with different kinds polarity.

Basic labeling standards

All designations can correspond to two marking systems for welding electrodes: according to GOST and the international ISO standard. They also use the European EN standards and the American AWS standard.

Electrode marking

Domestic manufacturers are guided by GOST 9466-75, 9467-75, 10051-75, 10052-75 and the brands of electrodes for welding are applied in two groups of signs. The marking includes both numbers and letters. The first group is only internal, and the second is adapted to the international standard.

The first group of marking symbols consists of five positions:

1. type of electrode. This designation will help you figure out what kind of steel it can weld. Manual welding is designated by the letter E. Further numbers indicate compliance with the tensile strength of steel. This group can end with the letter A, if it has a purpose for the formation of a plastic seam. Can also use a hyphen to indicate that the number after it indicates the percentage of carbon;
2. electrode grade according to the composition of the coating;
3. the diameter of the wire, indicated by numbers with a dimension of mm;
4. the type of steel for which this electrode is used;
5. coating thickness.

The second group of marking symbols has six positions and more corresponds to international requirements:

• a figure showing the value of the tensile strength of steel with a dimension of 10-7 Pa;
• a figure indicating the magnitude of the relative elongation;
• an index number defining the minimum temperature at which the impact strength meets the standard;
• type of coating, indicated by one or two letters. Two letters are used in cases where a mixed coating is used;
• a figure that will help determine whether a given electrode is suitable for performing the required welding position;
• welding current parameter in index form. Each index from 0 to 9 corresponds to a pair of parameters: polarity and permissible no-load voltage in V.

The choice of electrode depends on many components. This is the type of metal and its thickness, the method of welding. To be able to carry out various welding works, several electrodes are selected at once or with more universal indicators, which can be learned from the applied markings.

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Marking of electrodes for manual arc welding

Home »Welding work in the country.

Manufacturing of critical metal structures is carried out using electric arc welding. There are many ways to obtain permanent joints - MIG / MAG (mechanized method in protective gases), TIG (argon-arc method). But in everyday life it is most often used manual welding stick electrode (MMA).

How to decipher the marking of the electrodes?

Regulatory documentation a certain marking of coated electrodes is regulated, which indicates their main characteristics. To choose the right welding material, you need to know and be able to decipher all the designations.

For instance:

E46 - ANO-21 - 3.0 - UD E - 430 (3) - R11

Symbols designation:

• E46 - type of electrode;
• ANO-21 - name;
• 3.0 - section;
• U - designed for welding structural carbon steels with a tensile strength of up to 600 MPa;
• D is the thickness of the powder coating (thick);
• E - electrode;
• 430 (3) - indicates technical characteristics deposited metal (determined according to GOST 9467, as well as 10051 and 10052);
• P - type of powder coating (rutile);
• 1 - recommended positions of the electrode rod during welding (all);
• 1 - requirements for the arc power source.

Description and varieties of alphabetic and numeric positions in the marking

By type, electrodes are - E38, 42, 42A, 46, 50, 50A, 55, 60, 70, 85, 100, 125 and 150. According to this brand, mechanical properties welded joint.

Marking the purpose of the electrodes:

• U - structural steel;
• L - alloyed steel grades with a strength of more than 600 MPa;
• T - heat-resistant metal;
• B - for metals with a high percentage of alloying elements;
• H - for surfacing.

Thickness and type protective coating:

Possible spatial position of the stick electrode during welding:

1. Can be cooked in any position.
2. An exception is vertical welding guidance when the electrode is moved down from the top of the workpiece.
3. Welding is possible in the lower position, horizontal (with the location of the workpiece being welded in a vertical plane) and vertical, when the electrode is from top to bottom.
4. Welding can only be carried out in the lower position.

• What is a soldering flux for?
• Cast iron electrodes: marking

samanka.ru

We study the marking of electrodes for welding

All welding electrodes are marked and assigned. It contains all the information about the electrode itself, for example, about its composition, and sometimes even about the manufacturer. Understanding all these designations, you can always independently select the required materials for the connection.

First of all, it is always worth checking whether the selected electrode matches state standards... To do this, the packaging must have the inscription "GOST" and a few numbers after it.

If all this is present, you can safely continue the selection of welding electrodes, selecting them according to other indicators, without fear of fakes and low-quality goods.

The composition and purpose of the electrode

The electrode is made in the form of a rod, it can be either metal or made of other materials, depending on its purpose. And just in general, its purpose is to supply current to the place of welding. Therefore, an experienced welder will always pay attention to the conductivity of the material. For the production of electrodes, it is customary to use wire, which includes alloys with varying degrees of alloying. It is worth paying attention to the outer coating as well. It is applied to provide protection against external irritants such as nitrogen or oxygen. Other advantages of the coating include maintaining the stability of the welding arc and removing possible impurities - they can be in the molten metal.

Consider several components that ensure the quality of the electrode coating:

1. Manganese ore.
2. Titanium concentrate.
3. Quartz sand.
4. Kaolin.
5. Marble.

Dextrin and flour are the components that create a gas-forming environment. The goal of any welding is to ensure a quality weld, corrosion resistance and high strength. For this, the following alloying impurities must be included in the composition of the electrode:

• vanadium;
• manganese;
• nickel;
• chromium;
• titanium.

There can be much more of them, these are only the main ones and are more common.

Marking

All electrodes are globally divided into two types: consumable and non-consumable. The former include copper, bronze, steel and copper materials... Sometimes uncoated products are found, it is customary to use them as wire for connections with the use of shielding gas. And non-consumables are lanthanum tungsten or thoriated electrodes.

By type of coverage

If the product is marked with the letter "A" - this indicates that its coating is acidic, it should be used for steel structures if there is high level carbon and sulfur.

The letter "B" will indicate that it is prohibited to work with such products in an upright position - by the way, as in the case of the letters "A" and "P". The letter "C" means that there is no prohibition on any non-standard positions and these electrodes can produce quality work in any position. But one drawback was noticed - in the form of excessive splashing and constant control over the temperature of the product.

Fine marking details

Naturally, this is not all designation. There are many nuances. The first numbers and letters usually indicate the maximum load limit. If there is such a marking: "E41" - this means that the parts that have been welded will be able to withstand a load of 41 kilograms per 1 square mm. There are also other options for characterizing the weldment:

1. "U" - shows that you can safely work with low alloy and carbon steels;
2. "T" and "B" - it is possible to connect high-alloy and heat-resistant steel;
3. "L" - work with alloyed structural alloys;
4. "H" - useful in the case of overlaying a layer with any properties.

Coating layer thickness designation:

• "M" - thin;
• "D" - thick;
• "C" - average;
• "G" is the maximum.

The numbers at the end of the marking are written to understand the spatial position of the products and the current value that is recommended to be used in this case.

More details:

• "1" - parts can be welded in any position;
• "2" - except for the position from top to bottom;
• "3" - restrictions on the ceiling orientation are added to the second option;
• "4" - only for the bottom seams.

In addition, the box with products can be marked with fragile goods inside that should not be tested with moisture. All these markings are easy to decipher, even on an intuitive level, having general knowledge of welding. This will greatly facilitate the search for the required material for welding.

Sergey Odintsov

electrod.biz

Electrode marking

Home page»Marking of electrodes

For welding carbon and low-alloy steels, as well as alloyed with increased and high strength, the designation of the type of electrodes consists of:

• - index E - electrode for manual arc welding and surfacing:
• - the numbers following the index, denoting the value of the ultimate tensile strength σв;
• - index A, indicating that the weld metal has increased properties in terms of ductility and impact strength.

For welding heat-resistant, high-alloy steels and for surfacing, the type designation of the electrodes consists of:

• - index E - electrode for manual arc welding and surfacing;
• -dephisa (dash);
• - the numbers following the index indicating the average carbon content in hundredths of a percent:
• - letters and numbers indicating the percentage of chemical elements.

The order of the letter designations of chemical elements is determined by the decrease in the average content of the corresponding elements in the deposited metal. With an average content of the main chemical element less than 1.5% figure after letter designation chemical element is not specified. With an average content of silicon up to 0.8% and manganese up to 1.0% in the deposited metal, the letters C and G are not put down.

For welding carbon and low-alloy steels with σu up to 490 MPa (50 kgf / mm2), 7 types of electrodes are used: E 38; E 42; E 46; E 50; E 42A; E 46A; E 50A.

For welding carbon and low-alloy steels with σw from 490 MPa (50 kgf / mm2) to 588 MPa (60 kgf / mm2), 2 types of electrodes are used: E 55; E 60.

For welding alloy steels of increased and high strength with σv over 588 MPa (60 kgf / mm2), 5 types of electrodes are used: E 70; E 85; E 100; E 125; E150.

For welding heat-resistant steels - 9 types: E-09M; E-09MH; 3-09X1 M; E-05X2M; E-09X2M1; E-09H1MF; E-10X1MNBF; E-YUHZSHBF; E-10H5MF.

For welding high-alloy steels with special properties - 49 types: E-12X13; E-06X13N; E-10X17T; E-12X11NMF; E-12X11NVMF and others.

For surfacing the surfaces of layers with special properties - 44 types: E-1 OG2; E-1 OGZ; E-12G4; E-15G5; E-16G2XM; E-ZOG2XM and others.

For welding carbon and low-alloy steels with σu up to 588 MPa (60 kgf / mm2) - marked with the letter U: For welding alloyed structural steels with σu over 588 MPa (60 kgf / mm2) - marked with the letter L: For welding heat-resistant steels - marked with a letter T: For welding high-alloy steels with special properties - marked with the letter B; For surfacing the surfaces of layers with special properties - the letter H;

Depending on the ratio of the diameter of the electrode coating D to the diameter of the electrode rod d, the electrodes are divided into the following groups:

• with a thin coating (D / d ≤ 1.2) - marked with the letter M;
• with medium coverage (1.2
• with a thick coating (1.45
• with an extra thick coating (D / d> 1.8) - G.

6.1 For electrodes used for welding carbon and low-alloy steels with σv up to 588 MPa (60 kgf / mm2)

» Electrode coatings

An electrode for manual arc welding is a metal rod with a protective coating-coating. The constituent coatings provide protection of the weld zone from air oxidation and enhance ionization. The 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 consumable metal protection... They protect the melting metal from interacting with air, preventing oxidation, make the finished seam high-quality and durable.

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 speed of its solidification, due to which gas and other inclusions have time to leave it, which negatively 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 functions does high-quality coverage provide?

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

Minor, but no less important tasks:

• ensuring uninterrupted burning of the arc 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 stabilizing combustion in the arc space;
• removal of oxygen dissolved in it from the metal of the weld pool. For this, ferroalloys are added to the composition of the mixture, which react lighter and faster than the metal itself;
• cleaning the weld metal from impurities (refining).

Coating diameter

On sale you can find many brands of electrodes designed for different types metal and the strength of the expected loads on the future structure. The coated rods have two diameters: the diameter of the electrode itself and the total diameter of the rod and spraying. 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 work 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 necessary 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.

Number following a letter, Is the minimum value of the guaranteed ultimate tensile strength of the seam. The higher this number, the more loads the welded part will withstand.

For example, products of the E42 type provide a resistance of at least 42 kgf / mm2, and rods with the E46 marking - at least 46 kgf / mm2. E42A electrodes are used for metal with similar quality tensile indicators, but under conditions when higher parameters of impact strength and relative elongation of the resulting weld are required. Improved performance is indicated by the letter "A" in the marking, which denotes the acidic type of core coating.

Coating thickness

Blue coating of the brand electrode

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 are also guided by the thickness of the protective coating.

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

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

1. thin or stabilizing electrodes (the letter M is used for their designation) with a ratio of 1.2 or more;
2. average electrodes (designated by the letter C) with a ratio of 1.45 or more;
3. thick having a ratio less than or equal to 1.8, which are also called quality (marked with the letter D);
4. extra thick electrodes, also included in the category of quality and have a ratio of diameters over 1.8 (can be recognized 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 we take into account the iron powder, then the diameter will be 3.5 mm, and mass fraction- 50%. Such electrodes are used when a seam is needed. High Quality capable of withstanding heavy loads.

Thin or stabilizing electrodes, the thickness of the coating of which is approximately 0.1-0.3 mm, make the arc burning even and continuous, but do not in any way affect the quality indicators of the weld 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 type of coatings used in the production of welding electrodes:

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

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

Sour

The main advantage of acid-type coating is when welding works the probability of pore formation in the weld area tends to zero, even if the elements are welded to each other. The acidic coating promotes uniform arc burning and easy ignition. This type of electrodes is used when the requirements for finished structure minimal.

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

CAREFULLY! Acidic coating is toxic when heated!

The main

Due to the weak oxidation of such a coating, it facilitates easy disposal of oxygen from the melting metal. A seam made using an electrode with basic coating, protected from hot cracks... This type of electrode need to ignite before work to eliminate the likelihood of pores in the seam. Due to the difficulty of maintaining arc burning, welding with electrodes with a basic coating is necessary only using a direct current source of reverse polarity (this does not apply to all, but to most brands).

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

Cellulose

The use of products with cellulose coating (marked "C" on the packaging) in work with a welding machine gives a good high-quality arc burning mainly with direct current ... This type is used when welding root welds on main pipelines made of low carbon steel.

Also rods coated with cellulose excellent for one-sided welding with good penetration in the area of ​​the root seam. The use of rods gives good results when welding in an upright 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 molten metal splashing during operation.

Rutile

This type of coating is designated by the letter "P". Rutile-coated rods show good results even or traces of scale on the surface at the weld points; hot cracks do not form during the joining process.