Home Roses Interpretation of electrodes for welding table. Brands of electrodes for manual arc welding

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Interpretation of electrodes for welding table. Brands of electrodes for manual arc welding

Welding is technological process obtaining reliable connections by heating the edges of parts to the melting point. Manual arc is its most common type. This method is highly productive, universal, technologically simple and available at home.

The essence of RDS

The edges of the parts being connected melt due to the heat generated by the ionized flow of particles between the cathode and anode - an electric arc. Ionization occurs due to the presence of current and short circuit between two poles with constant or variable characteristics.

The tool used to create and burn an arc is an electrode - a rod of metallic or non-metallic origin. The work can be performed with one or several rods with the possibility of creating an additional arc between them (three-phase arc welding). The ionized flow of electrons is surrounded by vapors from the tool and its coating, the melting metal of the parts being connected, and the results of their interaction with air. Types of electrodes for welding are determined taking into account all the characteristics inherent in a particular material.

Classification of rods by material of manufacture

At their core, all welding tools for welding joints are divided into consumable and non-consumable.

Consumable: metal tools made of cast iron, steel, aluminum, copper (depending on the type of metal being welded). The rod acts as a cathode or anode, and also functions as a filler material to fill the weld pool and form a seam.
Non-consumable: carbon, graphite, tungsten rods; perform only a primary function; additionally, filler metal wire is used; tungsten ones are needed for argon arc welding.

Among the first group there are electrodes:

Without cover. This type of instrument is not used for RDS.
Covered. An appropriate coating is used to maintain arc stability, protect the metal from burnout, from the influence of gases, and increase the mechanical characteristics of the weld through natural alloying (the penetration of alloying elements from the melting rod into the weld pool).

Application by type of work

The types of electrodes listed above have individual applications depending on the method of work.

Uncoated carbon electrodes - the primary welding invention, which belongs to N. N. Benardos and dates back to 1882 - are still used in modern times. Features: direct current, straight polarity, additional supply of filler wire, stable arc, the rod burns slowly, no carburization occurs. The use of reverse polarity reduces the characteristics of the arc and the weld (it becomes carburized).

Metal electrodes are the next invention in the field of welding technology, which belongs to N. G. Slavyanov (1888). Together with them, the prototypes of modern welding machines were born. Welding using consumable rods has found wider application in industry and has received active development. Today it is used in manual arc, automatic and semi-automatic (submerged arc) welding.

Due to the high melting point of 3422˚C, it is used as a non-consumable material in argon arc welding. Thus, specific types of electrodes correspond to different welding technologies.

Distribution by purpose

Purpose is the characteristic according to which absolutely all known electrodes are distributed. The types and use of rods are indicated by one letter (GOST 9466-75):

structural steels, including low-alloy steels with a strength of 60 kgf/mm 2 (600 MPa) are marked in the markings with the letter “U” - carbon;
alloyed structural steels having a strength of 600 MPa - “L”;
high-alloy structural steels - “B”;
heat-resistant alloy steels - “T”;
alloys with special properties, which are characterized by surfacing - “N”.

The purpose is indicated on the unfolded stamp.

Rod coatings

Coatings of various compositions and origins are used in individual cases For various materials. The following types of electrode coating are used:

Sour "A". Contains ferromanganese and ferrosilicon. Used for direct or direct current. Characterized by high melting rates. Best used for bottom seams.
Rutile "R". Contains rutile (titanium dioxide), carbonates, aluminosilicates, ferromanganese, liquid glass. any position and type with direct or direct current. As a result of successive chemical reactions A protective slag is formed, which prevents the elements from burning out. Good quality, low toxicity.
Cellulose "C". The composition includes cellulose, manganese ore, talc, rutile, ferromanganese. Shielding gases are formed around the arc and weld pool. For all seams; high speed of work; good quality; overheating must not be allowed; large losses due to splashing. Used for permanent connections of pipelines.

Basic B's. Contains calcium carbonates and fluorides. A protective layer is formed carbon dioxide due to the reaction of carbon from carbonates with arc combustion oxygen. It is advisable to perform work under direct current with reverse polarity. During alternating welding, a low-quality seam is obtained; additional technologies are required to improve its mechanical characteristics.
Other "P". Contain alloying elements. The quality of the weld is improved by introducing into it a certain amount of alloying elements from the melting electrode.
Special. Contains liquid glass with resin-containing substances. Protects against moisture penetration. Applicable for

All coated electrodes have specific purposes. The main type of coating is rutile due to its versatility. Coatings perform protective functions by deoxidizing the alloy in the weld pool, adding alloying elements to it, and forming a halo of protective gases or slag. This makes it possible to avoid a lower quality of seam than that of the materials of the edges of the parts, and to ensure the formation of high-quality welded joints.

Requirements for tools established by GOST 9466-75

Electrodes must be made of high quality material.
The coating must be solid and free from significant defects (small dents and cracks without swelling or porosity are allowed).
High mechanical resistance to random shock loads.
Different types of electrode coatings must melt evenly, not crumble, not form uneven islands, and not splash beyond the permissible characteristics.
The rod must ensure the formation of a high-quality weld: without cracks, pores, or local excess of deposited metal.
A rational choice, taking into account all the necessary parameters and adherence to technology, is the key to the formation of a reliable, durable connection.

Choosing a rod depending on the size

A novice welder is more familiar with the types of electrodes determined by size. The diameter of the tool with which the work will be carried out is selected strictly in accordance with the thickness of the part to be welded. It is not encrypted, but is clearly indicated on the instrument labeling. The length of the electrode is also fixed according to its diameter. It is important to have an idea of the length of the stripped bare end of the tool.

Thickness of prepared edges, mm	Electrode diameter, d, mm	Electrode length, mm	Length of stripped uncoated end, mm
			20
			25
			25
			30
			30

For home welding work the most commonly used types of electrodes for arc welding with a diameter of 2-4 mm. Thick rods are suitable for repair shops and production.

Coating thickness

It has its own designation in the instrument marking. It is determined by the coefficient of its ratio D (mm) to the thickness of the rod itself d (mm). Distributed into 4 groups:

thin “M” (coefficient up to 1.2);
average “C” (the coefficient has values ranging from 1.2 to 1.45);
thick “D” (coefficient - within 1.45-1.8);
especially thick “G” (coefficient value over 1.8).

The results of the work are influenced not only by the types of coatings of manual arc welding electrodes, but also by the thickness of the coating layer itself, as well as the dimensions of the rod. Correct selection of electrode size ensures good speed work, quality parameters of the arc and the formed connection.

Selection of rods depending on the type of seam and its spatial position

Seams have several classifications:

Depending on the action of the main forces: flank, frontal, oblique, end.
In accordance with the position of the parts being welded: butt, corner, T-joints, overlay joints.
Depending on the presence of bevel of the edges: with bevel, without bevel.
In accordance with the position in space: lower, upper, horizontal, vertical.

The choice is influenced by the spatial position of the seam. Its type is indicated by the rod marking.

1 - for welding in all positions;
2 - exceptions apply only to vertical seams from top to bottom;
3 - for lower seams, horizontal near the vertical plane, vertical from bottom to top;
4 - for the bottom seams.

The type of weld relative to the spatial position is taken into account when determining the current values.

The influence of arc electrical parameters on the choice of welding tools

Welding can be carried out under direct or direct current, direct (“minus” on the electrode, “plus” on the product) or reverse polarity. The choice depends on the material being welded and its properties. The type of current is determined by the power source.

The main equipment that generates and (or) converts current can be used: transformers and oscillators (reduce the network voltage to the required values), converters and rectifiers (convert the alternating current of the network into direct current of the welding process).

The parameters required to ignite the arc differ significantly from those observed during its maintenance. The voltage required to quickly form an arc is called open circuit voltage. Let us consider the voltage values required to ignite the arc and to maintain its combustion.

Kinds welding electrodes vary depending on network characteristics and are designated by numbers from 0 to 9:

0 - only for direct current of reverse polarity;
1-9 - for any currents;
1, 4, 7 - any polarity;
2, 5, 8 - straight;
3, 6, 9 - reverse;
1-3 - open circuit voltage 50 V;
4-6 - 70 V;
7-9 - 90 V.

The choice affects the features of the technology and the quality characteristics of the seams. So, minimum depth boiling is ensured by working with variable network parameters. Used for unpretentious materials and simple structures. When welding with an arc constant characteristics and reverse polarity, the depth of the weld pool and mechanical properties the seams are 50% higher than even with direct polarity. Used for stubborn materials and critical structures.

Determination of current strength

For manual arc welding, it can be different - from 30 to 600 A. The required value is selected depending on the diameter of the working electrode and the type of seam relative to the spatial position. Calculated as follows:

For bottom seams: I=d*k.
For the top ones - I=k*d*0.8.
For horizontal ones - I=k*d*0.85.
For vertical seams - I=k*d*0.9.

where I is the current strength, A;

d - diameter, mm;

k - coefficient, A/mm.

The coefficient depends on the diameter of the rod:

for electrodes with a thickness of 1-2 mm - k=25-30 A/mm;
3-4 mm - k=30-45 A/mm;
5-6 mm - k=45-60 A/mm.

Increasing the force speeds up the welding process. Exceeding the permissible values can lead to overheating of the edges, excessive burnout of components, and deterioration in quality weld.

Marking

In order to consider all the nuances of marking, it is important to give a standard example in accordance with GOST 9466-75 and 9467-75: (E42A-UONI-13/45-3,0-UD)/(E432(5)-B10).

Brand: UONI-13/45.
Type: E42A - electrode for RDS, provides a weld strength of 420 MPa with increased ductility (A).
3.0 - diameter 3 mm.
U - for welding carbon steels and low-alloy structures.
D - thick coating.
E432 (5) - indices in which the characteristics of the connection and deposited metal are encrypted.
43 - tensile strength not less than 430 MPa;
2 - relative elongation not less than 24%;
5 - welding is possible at temperatures down to -40˚С; this ensures the minimum permissible metal value of 34 J/cm 2 .
B - main coating.
1 - spatial position of the seam: any.
0 - welding only with an arc with constant characteristics and straight polarity.

Using different types and brands of welding tools

Everything discussed above relates more to the marking of electrodes for RDS steel. It is important to provide examples of rods used for a variety of ferrous and non-ferrous metals. Below are the most common types.

The types of electrodes are distributed depending on the metal being welded and the specified typical mechanical characteristics of the seam.

Carbon low-alloy steels are welded with rods of the following types:

E42: grades ANO-6, ANO-17, VSC-4M.
E42: UONI-13/45, UONI-13/45A.
E46: ANO-4, ANO-34, OZS-6.
E46A: UONI-13/55K, ANO-8.
E50: VSC-4A, 550-U.
E50A: ANO-27, ANO-TM, ITS-4S.
E55: UONI-13/55U.
E60: ANO-TM60, UONI-13/65.

High strength alloy steels:

E70: ANP-1, ANP-2.
E85: UONI-13/85, UONI-13/85U.
E100: AN-KhN7, OZSh-1.

High-strength alloy steels: E125: NII-3M, E150: NIAT-3.

Metal surfacing: OZN-400M/15G4S, EN-60M/E-70Kh3SMT, OZN-6/90Kh4G2S3R, UONI-13/N1-BK/E-09Kh31N8AM2, TsN-6L/E-08Kh17N8S6G, OZSh-8/11Kh31N11GSM3YuF.

Cast iron: OZCh-2/Cu, OZCh-3/Ni, OZCh-4/Ni.

Aluminum and alloys based on it: OZA-1/Al, OZANA-1/Al.

Copper and alloys based on it: ANTs/OZM-2/Cu, OZB-2M/CuSn.

Nickel and its alloys: OZL-32.

From the above list we can conclude that the marking system is very complex, and is based on approximately the same principles for encoding the characteristics of the rod, its coating, diameter, and the presence of alloying elements.

The quality of the welding joint depends on a rational technological scheme. The following factors influence which types of electrodes to choose:

The material to be welded and its properties, presence and degree of alloying.
Product thickness.
Seam type and position.
Specified mechanical properties of a joint or weld metal.

It is important for a novice welder to understand the basic principles of selecting and marking tools for welding, as well as to operate with the distribution of rod grades according to their intended purpose, to know the main types of electrodes and to use them rationally during welding work.

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

First of all, you need to pay attention to its GOST, which is short for the word “State Standard”. As an example, let’s take one of the brands of electrodes and consider it in more detail. Next I will write everything down as it should be. Our experimental electrode will be popularly called “blue”, but in reality this is what it is called. .

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

The type of electrode is marked in orange.
Yellow For us this is the brand of electrode.
Green is the diameter of the electrode (if several diameters of the same brand are produced, it is written in a different place).
In the red square we have the purpose and thickness of the electrode coating.
The black sign means that this is an index.
The index itself is in graphite color. (you can write about indexes separately)
In blue this is a type of coating.
There are two in the pink square different meanings These are the welding positions and recommended current.

Now let’s break down what we wrote above.

Electrode type.

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

Our stamp contains short name The manufacturer's plant is the Losinoostrovsky Electrode Plant and the MR-3S brand itself.

Electrode diameter.

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

Purpose and thickness of the coating.

U - Designated as - Electrode for welding carbon and low-alloy steel.
D - This indicates that our electrode has a thick coating. I will describe all the notations below.

Electrode index.

He shows us the characteristics of the metal for welding with these electrodes. All this can be viewed according to GOST 9467-75. Tensile strength, impact strength and several other parameters are all according to GOST.

This brand of electrodes has two letters RC and this means - R salvage and C cellulose. Of course, I will write more about the types of coating.

And so 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. I think there are no problems with the type and brands. We are interested in what all these letters and numbers mean.

Designations of electrodes by coating thickness.

M - Thin coating
C - Medium coverage
D - Thick coating
G - With a particularly thick coating.

Welding position symbols.

The connection of several parts into a monolithic structure often occurs using welding equipment. To obtain required quality connections, it is necessary not only to rationally select the welding method, but also the corresponding welding electrodes.

Welding work

Basic requirements for electrodes

The variety of weldable substances and welding methods requires a wide range of electrodes used.

But they all have to answer general requirements:

ensure stability of the arc, a small radius of spattering of the rod, coating, high productivity of welding work;
create conditions for the formation of a high-quality weld;
make the welding process uniform;
preserve physical, chemical, technological properties during a particular weld.

A special place in the requirements is toxicity. The electrodes must emit minimal amount toxic substances while working.

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 being welded;
non-melting of three types: coal, graphite, tungsten.

Several methods are used to classify electrodes. According to their purpose, electrodes are distinguished for connecting stainless steel, non-ferrous metals, various types of steel, and cast iron.

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

The type of construction involves obtaining different types of seams. This can be a vertical, ceiling 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 lower, vertical from bottom to top and for horizontal, located in the vertical plane;
for the bottom.

The variety of coating material and its thickness are also classified by electrodes. On top, the electrodes are covered with a protective layer of a composite composition, which includes the following substances:

stabilizers for the arc combustion process;
granite, silica, titanium and manganese ores, components for the formation of slag from which the film is created. 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, ferrosilicon, ferrotitanium for the recovery of metals from oxides;
bentonite, kaolin, dextrin to improve plastic properties.

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

The electrodes are covered with a thin protective layer, medium, thick and even especially 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 - ratio more than 1.8.

An important technical indicator is the type of electric current used. There are electrodes connected to direct or alternating current sources, as well as with different types of polarity.

Basic labeling standards

All designations can comply with two systems for marking electrodes for welding: according to GOST and the international ISO standard. The European standards EN and the American standard AWS are also used.

Electrode marking

Domestic manufacturers are guided by GOST 9466-75, 9467-75, 10051-75, 10052-75 and brands of welding electrodes are applied in two groups of marks. The markings include 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:

electrode type. This designation will help you figure out what type 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 may end with the letter A if it is intended to form a plastic seam. May also include a hyphen indicating that the number after it indicates the carbon content as a percentage;
brand of electrode according to the composition of the coating;
wire diameter, indicated by numbers with the dimension mm;
the type of steel for which this electrode is used;
coating thickness.

The second group of marking symbols has six positions and is more consistent with international requirements:

a figure showing the value of the tensile strength of steel with a dimension of 10-7 Pa;
a number indicating the relative elongation;
index number defining the minimum temperature at which impact strength meets the standard;
type of coating, indicated by one or two letters. Two letters are placed in cases where a mixed coating is used;
a figure that will help determine whether a given electrode is suitable for performing necessary position welding;
welding current parameter in index form. Each index from 0 to 9 corresponds to a pair of parameters: polarity and permissible open-circuit voltage in V.

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

stroitel5.ru

Marking of electrodes for manual arc welding

Home » Welding work at the dacha.

The production of critical metal structures is carried out using electric arc welding. There are many ways to get permanent connections– MIG/MAG (mechanized method in protective gases), TIG (argon arc method). But in everyday life, manual stick welding (MMA) is most often used.

How to decipher electrode markings?

Regulatory documentation regulates certain markings of coated electrodes, which indicate their main characteristics. To choose the right welding material, you need to know and be able to decipher all the symbols.

For example:

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

Symbols:

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

Description and types of letter and number positions in markings

The types of electrodes are E38, 42, 42A, 46, 50, 50A, 55, 60, 70, 85, 100, 125 and 150. According to this brand, the mechanical properties of the welded joint are determined.

Marking of electrode purpose:

U – structural steels;
L – alloy steel grades with a strength of more than 600 MPa;
T – heat-resistant metal;
B – for metals with a high percentage of alloying elements;
N – for surfacing works.

Thickness and type of protective coating:

Possible spatial position of the piece electrode during the welding process:

Can be cooked in any position.
An exception is vertical welding, when the electrode moves from top to bottom of the part.
Welding is possible in the lower position, horizontal (with the position of the part being welded in a vertical plane) and vertical, when the electrode is from top to bottom.
Welding can only be done in the lower position.

What is soldering flux used for?
Electrodes for cast iron: marking

samanka.ru

We study the marking of electrodes for welding

All welding electrodes are marked and intended for use. 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 meets state standards. To do this, the packaging must have the inscription “GOST” and several numbers after it.

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

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. But in general its purpose is to supply current to the welding site. Therefore, an experienced welder will always pay attention to the electrical conductivity of the material. For the production of electrodes, it is customary to use wire containing alloys with to varying degrees doping. It is worth paying attention to the external coating. 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 may be in the molten metal.

Let's consider several components that ensure the quality of the electrode coating:

Manganese ore.
Titanium concentrate.
Quartz sand.
Kaolin.
Marble.

Components that create a gas-forming environment include dextrin and flour. The goal of any welding is to ensure a high-quality weld, with corrosion resistance and high strength. To do this, the electrode must contain the following alloying impurities:

vanadium;
manganese;
nickel;
chromium;
titanium.

There can be many more of them, these are just the main ones and the most common ones.

Marking

All electrodes are globally divided into two types: melting and non-melting. The first include copper, bronze, steel and copper materials. Sometimes uncoated products are found; they are usually used as wire for connections using protective gas. And non-consumable ones 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 working with such products in a vertical position is prohibited - by the way, as is the case with the letters “A” and “P”. The letter “C” means that there is no prohibition on any non-standard positions and these electrodes can produce high-quality work in any position. But one drawback was noticed - in the form of excessive spattering and constant monitoring of the temperature of the product.

Fine marking details

Naturally, this is not all the designations. There are a lot of nuances. The first numbers and letters usually indicate the maximum load limit. If the following marking is present: “E41”, this means that the parts that were welded can withstand a load of 41 kilograms per 1 square mm. There are also other options that allow you to characterize the welding product:

“U” - shows that you can safely work with low-alloy and carbon steels;
“T” and “B” - you can connect high-alloy and heat-resistant steel;
“L” - work with alloyed structural alloys;
“N” - useful in the case of surfacing a layer with any properties.

Coating layer thickness designation:

"M" - thin;
"D" - thick;
"C" - average;
"G" - 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 in this case.

More details:

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

Additionally, the box containing the products may be marked with marks indicating that the product inside is fragile and should not be exposed to moisture. All these markings are easy to decipher even on an intuitive level, with general knowledge of welding. This will greatly facilitate the search for the required material for welding.

Sergey Odintsov

electrod.biz

Electrode marking

Home page» Electrode marking

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

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

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

- index E - electrode for manual arc welding and surfacing;
-hyphen (dash);
- the number 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 arrangement of letter designations of chemical elements is determined by a decrease in the average content of the corresponding elements in the deposited metal. If the average content of the main chemical element is less than 1.5%, the number after the letter designation of the chemical element is not indicated. If the average content of silicon in the deposited metal is up to 0.8% and manganese up to 1.0%, the letters C and G are not affixed.

For welding carbon and low-alloy steels with σв 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 σ in excess of 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-09Х1МФ; E-10Х1МНБФ; E-YUHZSHBF; E-10Х5МФ.

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

For surfacing surfaces of layers with special properties - 44 types: E-1 OG2; E-1 OGZ; E-12G4; E-15G5; E-16G2ХМ; E-ZOG2ХМ and others.

For welding carbon and low-alloy steels with σв up to 588 MPa (60 kgf/mm2) - marked with the letter U: For welding alloy structural steels with σв over 588 MPa (60 kgf/mm2) - marked with the letter L: For welding heat-resistant steels - marked with the letter T: For welding high-alloy steels with special properties - marked with the letter B; For surfacing 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, 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 thick coating (1.45
with particularly thick coating (D/d > 1.8) - G.

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

There are quite a lot of technologies for producing high-quality permanent connections, however, the most popular method today is manual arc welding, which is produced through the use of stick electrodes. Depending on the selected brands of electrodes for manual arc welding, you can use the same equipment, slightly adjusting the machine settings, to obtain high-quality seams different types and purposes. Moreover, you can get a reliable seam in any position in space, even in the most difficult to reach areas.

To ensure that the welded joints are as good as possible, each metal produces its own types of welding electrodes.

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

This coating of welding electrodes is intended to ensure that during the work, metallurgical processing of the weld pool is carried out, and 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 when arc welding with a consumable electrode. With an uneven arc, it will be very difficult to obtain an identical seam along its entire length. The protective coating contains the following substances:

Stabilizing substances, thanks to which the arc burning becomes more uniform. These include various kinds alkali and alkaline earth metals characterized by low ionization potential. These elements include potassium, magnesium, sodium, calcium and a number of other substances;
The compounds that form slag in welds are made from titanium and manganese ores or various types of minerals. Due to these substances, a protective film of slag begins to form in the area of the weld pool, which prevents the occurrence of various types of oxidation processes;
Substances that allow gas formation. These 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 connections is to release certain gases into the area where the electrode passes through 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 that make the protective coating monolithic;
Various types of molding additives help give the coating protective properties good plastic characteristics.

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

What types of electrodes are there for welding?

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

When using non-consumable electrodes in the process of work, it should be remembered that they are made from electrical coal, tungsten or graphite obtained by artificial means.

It must be remembered that the electrical conductivity of graphite is much higher than that of other materials; moreover, they do not oxidize so quickly - using them in manual arc welding with a non-consumable electrode is quite economical and profitable.

Their diameter ranges from 4 to 18 mm, their length is up to 70 cm. For welding work using semi-automatic or automatic technology, a special calibrated wire is used, which can have a diameter from 0.2 to 12 mm. It replaces the electrodes themselves with a protective coating. The wire is produced in spools that can weigh up to 80 kg. Today there is a technology for the production of flux-cored wire, wire that contains special alloyed elements; electrode strip and plates are produced. Consumable electrodes for manual arc welding are made from special welding wire, which can be simply carbon, with added alloy elements, or with big amount

of these substances.

Types of electrodes and their scope of use The types of electrodes used for welding or surfacing can be classified according to the scope of application (for example, for joining elements made of steel, cast iron, non-ferrous metals, surfacing), various technological features – for argon welding, for bead 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 seam, the method of applying metal to the workpiece, and physical properties

slag and so on.

The main requirements for electrodes when carrying out welding work are the following:
They must ensure reliable arc burning and the formation of a high-quality seam;
They melt evenly, distributed along both edges of the metal being welded;
The deposited metal should not splash much, which allows for high productivity;
Ideally, the slag comes off as easily as possible;
The covering metal should be quite strong;
Over time, the electrode metal must retain its original characteristics;
In the process of welding work using electrodes of any brand in environment a minimum amount of toxic substances should be released.

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

Difference between electrodes and markings

According to their own key functions electrodes may have certain differences depending on their brand and the technique of work performed:

Welding electrodes marked “U” are used to connect steel workpieces that 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 alloy elements, electrodes marked “T” are used. They also have a tensile strength of about 600 MPa;
To fuse onto a metal surface surface layer, take electrodes with special technical characteristics. The marking in this case is “H”;
The high ductility characteristics of metals imply the use of electrodes marked “A”.

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

The thinnest coating 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 because it is universal;
Thick coating – approximately 80% of the diameter;
The thickest – over 80%;

Useful tips and safety precautions when carrying out welding work

First of all, professional welders recommend learning to weld on exactly the machine you plan to use in the future. This allows you to study all the characteristics of this equipment as quickly as possible and select the optimal current strength for each type of electrode.

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

The 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, the weld will be too convex - this is due to insufficient heating of the metal. An excessively large gap will not allow the molten metal to be applied evenly, as the welding arc will begin to deviate greatly from the welding line.

When carrying out welding work using manual arc technology, it is strictly forbidden to lay the ground electrode over a damp base, for example, through puddles, snow, and so on. All work must be carried out wearing 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 don't take into account this moment, when changing the electrode, you can get injured electric shock, which will occur in the circuit: rheostat, electrode holder, the welder himself and grounding.

The face is always protected with a special mask: it helps protect against hot metal splashes and bright light that will arise during the work. The fact is that the brightness of the emitted light rays can be several thousand times higher compared to the permissible values for human vision. Looking at welding with unprotected eyes can ultimately lead to temporary visual impairment. Welding is also a source of infrared radiation, which causes certain vision 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 blurred vision. This can be cured with ordinary eye drops.

Bottom line

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

Before starting welding work, you need to carefully select the materials necessary for this. The quality of the weld and the success of the work as a whole largely depend on them. One of the main materials are electrodes, which are rods of a certain size, metallic and non-metallic. Metal products, in turn, are divided into various types and types. In addition, they come in melting and non-melting types. Non-metallic rods can only be non-melting. There are no universal electrodes for welding; each of them is suitable only for specific materials, weld parameters and operating conditions.

Electrodes are not universal; each of them is suitable only for a certain material and weld parameter.

What are the criteria for classification?

The rods are marked with an alphanumeric designation and are carried out in accordance with the parameters to which they correspond. Products are classified according to the following criteria:

the metal with which you will have to work;
seam technology;
thickness and type of coating;
chemical composition;
the type of current (direct, alternating) and its polarity;
mechanical characteristics 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 determined by GOST 9467-75. It reflects characteristics such as:

brand;
appointment;
diameter;
type of coating;
coating thickness;
purpose (for which metals and alloys are allowed to be used);
location of the seam in space;
type of current.

Table of electrode types and their color designations in different countries.

In accordance with GOST 9467-75, the type of product is selected for certain types of steel that the electrode will weld. Thus, the first type is used for materials with a temporary resistance of up to 490 J/sq.cm. The second type is used for the same resistance, but for a metal from which higher elongation and toughness values are required. For steels with a tensile strength of more than 490 J/sq.cm, the third type is intended. It is designed to allow the rate to increase to 590 J/sq.cm.

The same state standard determines the grades of electrodes for the following steels:

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:

Brand.
Product diameter (in mm).
Destination encoding.
Coating thickness coding.
Indices of weld deposit and weld metal characteristics.
Coating type coding.
Welding position coding.
Current characteristics coding.

Non-consumable electrodes and their markings

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

Tungsten Rod Size Chart.

The marking of non-consumable welding electrodes, which contain tungsten, begins with the letter “W”. In addition, the color in which the end of the product is painted will also help you get your bearings. In particular, green colored WP (pure tungsten) is used in welding magnesium, aluminum and alloys. The work is carried out using alternating current. Red WT-20 (with thorium dioxide) is DC welding of the following 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 be helped by WZ-8 white. It can withstand high current loads and is used for magnesium, aluminum and their alloys.

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

All non-metallic electrodes are non-consumable: carbon, graphite, copper-bonded carbon, copper-bonded graphite. The copper layer mainly serves as surface protection during transportation. They are used for gouging, fast cutting, including very thick sheets of metal, eliminating casting defects and welding work. Products made from graphite have a higher efficiency and have better characteristics compared to carbon electrodes.

Marking by thickness and type of coating

Structure symbol electrodes according to GOST.

Nowadays, uncoated electrodes are rarely used. To indicate thickness, GOST 9467-75 uses letter markings. Thus, a thin coating is marked with the letter “A”; its value does not exceed 1.2. The letter “C” is a coating of medium thickness, the indicator is within 1.45. Letter "D" - thick coating, up to 1.80. The letter “G” means a particularly 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 uncoated diameter.

The type of coating of electrodes for welding 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-alloy steels, since during melting excess oxygen is released, and this, in turn, entails the loss of alloying elements.

The main coating, “B”, is called calcium fluoride. It is formed by such natural minerals, like marble, dolomite, magnesite, fluorspar. When melting, a protective gas environment is formed, which practically does not contain hydrogen. Used for high-alloy steels and thick products. Surfacing prevents the occurrence of hot cracks. Since arc instability may occur during welding, to increase it, welding is performed with a direct current of reverse or alternating polarity. It can be carried out in any spatial position.

Table of electrode types.

The basis of the rutile coating “R” is formed by a mineral of the same name, which consists mainly of titanium dioxide. In addition, it includes aluminosilicates and carbonates. The coating helps create seams High Quality, practically without cracks, minimizes metal spattering. Results for ceiling and vertical position seams are superior to all other types of coating.

Cellulose coating “C” also creates gas protection, but at the same time it increases the hydrogen content in the deposited metal. The coating contains organic substances containing cellulose, including ordinary flour. It makes it possible to carry out work in a top-down position and in weight. The general designation of 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 its purpose by marking

Although many types of electrodes are quite 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 temporary tensile strength, the minimum value of which is guaranteed by the manufacturer. The letter “A” indicates the increased viscosity and ductility of the deposited metal. The designations are as follows: E38, E42A, E50A.

In addition, the electrode is marked with a letter, which can be used to determine the type of steel for which it is intended. For example, products for welding carbon steel are marked with the letter “U”, heat-resistant alloyed steel with the letter “T”, and surfacing on the surface with the letter “H”. The document indicates which letters indicate this or that chemical element, which is part of the surfacing. Example of marking of products with surfacing: E-09M, E-09Kh1MF, E-10Kh3M1BF. The letter “M” in the marking is marked with molybdenum, the letter “X” with chromium, the letter “F” with vanadium, and the letter “B” with niobium.

The modern market for welding materials is very diverse. The same class can correspond a large number of brands, both domestic and foreign.

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

Electrodes are made of carbon, alloy and high-alloy steel alloys.

This is the classification (consumable or non-consumable), type of electrode, type of coating, type and polarity of the current, location of the 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 being welded. For the thinnest electrodes, it is only 1 mm, which allows you to weld metal sheets no more than 1.5 mm thick, using a current in the range of 20-25 A. Of course, when choosing, factors such as the grade of metal, current parameters must be taken into account , leaf edge shape. The most common electrode diameter is 3-4 mm. It makes it possible to weld metal up to 10 mm thick at a current not exceeding 220 A. Increasing the diameter - and its maximum size is 12 mm - requires increasingly powerful welding equipment.

What are the rods made of?

In accordance with the requirements of Gosstandart, various types of steels are used to manufacture the core of consumable welding electrodes: carbon, alloyed and high-alloyed. The wire from which they are made is marked in a certain way. First come the letters “Св” (welding), the number following them indicates the presence of carbon in the metal (in hundredths of a percent), then the letter coding of alloying elements is indicated, and after it the percentage presence of these elements. Marking indicating the content of carbon (0.10%), chromium (1%), manganese (2%) and silicon (1%) in the material of the rod looks like this: Sv-10ХГ2С. The compositions of the rod and the steel welded with it must match each other.

For welding non-ferrous metals, the electrode rod can be made of a similar material, that is, 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 mechanically mixing copper and an iron-carbon alloy. In the process of building up the weld seam, carbon is released from the melt, which increases its strength. This type of electrode consists of 5-10% iron and 90-95% copper.