Most professional and home welders sooner or later face the need. Not surprising! This is one of the most common types of welding. But pipe welding is characterized by increased requirements for the quality and tightness of seams, especially for gas and water supply units. For these purposes, special electrodes are used.

Electrodes for welding pipelines are designed taking into account all the features of the future operation of pipes. They are strong and durable, they can withstand maximum temperature loads. Such electrodes have a special composition, due to which they provide good quality welded joints. Novice welders usually have a lot of questions on this topic. How to choose the right electrodes? What rods should be used to weld the tubing pipe? Which electrodes are best for welding pipes? We will try to answer these and many other questions in this article.

How to weld a pipe if you plan to supply main gas through it? We recommend OK-46, LB-52 or UONI-13/55 electrodes (the same electrodes can be used to weld tubing pipes). All of the listed brands have a suitable composition; they can be made using manganese, phosphorus, sulfur or silicon. And OK-46 s electrodes are considered universal. In our experience, they are especially convenient for welding parts with a wide gap.

There is also a brand LB 52U on the market with a basic coating. Let's take a closer look at it. Such electrodes contain a small amount of hydrogen, so the seam is of very high quality. At the same time, it is stable, ignites easily, and completely cooks the metal.

If you have to weld particularly critical components (for example, rotary ones), and the pipe is made of carbon or low-alloy steel, then we recommend electrodes for welding pipes of the MTG-01K brand. The arc burns stably, slag is removed easily and quickly, and metal spattering is insignificant.

Electrodes for heating pipes

If you need to weld heating pipes with high quality, we recommend the following brands of electrodes: E42A, UONI 13/45 (diameter 3 mm). These rods have a thick coating that allows you to weld carbon steel comfortably. Also suitable for welding heating pipes are the E-09X1MF and TsL-20 grades. They are designed to form a strong seam when welding heat-resistant steel. These rods also have a fairly thick coating. If you need to weld stainless, carbon or alloy steel, then use TsL-9 with a base coating. There is little hydrogen in such rods, and we already know that this guarantees excellent weld quality.

If you plan to weld pipes in which there will be a continuous supply hot water and maybe high blood pressure, then use electrodes for MP-3 pipes. These same rods can be used to weld a tubing pipe. Electrodes of this brand have and are made of special wire. Manufacturers offer diameters from 3 to 5 mm. When working with this brand, tilt the electrode towards the deposition and use a short arc. Then it will be as airtight as possible.

It is very important to set the current correctly. The smaller the thickness of the metal and the diameter of the electrode, the lower the voltage value. If you set the voltage too low, the metal may not be welded. And vice versa: if you set too great importance current, the part may become deformed. Therefore, pay attention to the thickness of the metal and the dimensions of the electrode.

Electrodes for water supply

For welding water pipes, we recommend the following brands: MN-5, MNZh5 (for), NZh-13 (for pipes from) and MNCh-2 (for welding pipes). If you have to weld at home with an inverter, and the pipes are made of ferrous metal, then you can use the MP-3s brand. They can qualitatively weld even a pipe with a diameter of 32 by 2.8 mm at low current.

If you need to do this, then use MNCh-2 electrodes. TsCh-4 is suitable for cold and hot welding, but note that it can only be used in the lower position. By the way, when choosing electrodes, pay attention to the presence of coating. Be sure to buy rods with coating, as it will protect the welding area from negative influence oxygen. We recommend electrodes for welding thick coated pipelines.

If you have a specific type of work to do, consult with the salesperson in the store. Read the information on the packages carefully. For most work, pipe electrodes from such manufacturers as UONI, OZS, ANO, KOBELKO, ESAB are suitable. Among domestic producers We also recommend electrodes from the Ural and Kamensk plants.

Using welding equipment to connect elements requires certain skills and abilities. To perform this procedure, it is important to take into account various nuances and parameters. Particular attention is paid to the choice of material for each individual case. It is the electrodes that influence the welding mode, the size of the seam and its properties. However, they have the most important effect on the strength of the joint.

When making any connection, you should take into account the characteristics of the material, since each type of electrode for welding pipes has its own individual characteristics. This means that each specific connection is made by specific electrodes. This means that all varieties need to be studied to determine their suitability for a specific process.

Welding parameters of electrodes for pipes

The main advantage of rutile acid electrodes for welding pipelines is the removal of slag during narrow joints of elements.

• Rutile coating forms a seam with an attractive appearance, removes slag well, and ignites quickly when reused. Application - creation corner connections and potholders.
• Rutile + basic coating makes it possible to obtain root joints. Mainly used on pipelines whose elements have medium and small diameters.
• Electrodes with rutile-cellulose coating are considered universal solution for welding elements with thick coating.
• The cellulose coating makes it possible to perform circumferential seams when connecting pipes with a high diametrical index. This best electrodes for welding pipes.
• The main electrodes are used for any joining, regardless of the position of the seam. Despite the fact that the seam from such welding has a less attractive appearance, the risk of cracks in the weld is reduced. The greatest effect from the use of such electrodes can be obtained when connecting elements with thick walls and poor welding properties. It is also effective to use basic electrodes when joining strong steel.

Material properties

The weld metal must have similar toughness and strength as the base metal. Therefore, it is necessary to study the brand of electrodes for pipe welding, which must comply with the DIN EN 499 standard. This document regulates the tensile strength, yield strength and toughness of the weld metal.

For example, electrodes with the designation E 46 3 B 4 2 H5 have the following parameters:

• The letter E denotes electrodes intended for manual welding. These electrodes can be used for welding water pipes.
• Next comes the yield strength indicator, 460 N/mm2 is considered the minimum limit.
• The next designation is the temperature conducive to crack development, -300C.
• B - means the type of coating, in this case - the main one.
• The next number is the applied current. 4 – welding using direct current.
• Next comes the designation of the direction of the seam. 2 – any, excluding vertical.
• The last designation is the amount of hydrogen that the deposited metal may contain. H5 means 5 ml/100 g.

Diametral section

The diameter of the electrodes for pipelines is of great importance. This value affects the consumption of filler material and the properties of the seams.

The nominal diameter is the thickness of the rod without coating. The coating thickness is different for each type of electrode and is regulated by GOST 9466-75.

The coating can be determined by the ratio of the total diameter of the electrode to the diameter of the rod:

• A coating is considered thin if the ratio is equal or less than 1.2.
• Average coverage is defined as equal to or less than 1.45.
• If the diameter ratio is equal or less than 1.8, the coating is thick.
• If the diameter ratio is more than 1.8. That coating will be especially thick.

It is worth noting that imported products must also meet these rules. However, it is rarely possible to note the correspondence of their diameters Russian standards.

Calculated power of electrodes

Depending on the diameter, the main capabilities of the electrodes are determined:

• When working with electrodes with a diameter of 8-12 mm, the current should not exceed 450 A, the thickness of the material being welded can be higher than 8 mm. The length of such electrodes is 35-45 cm. The main application is equipment industrial purposes with high performance.
• Electrodes with a diameter of 6 mm allow you to work with any type of steel at a current of 230-370 A, the thickness of the material being welded is from 4 to 15 mm. Used for professional purposes.
• For welding products made of alloy and low-carbon steel, electrodes with a diameter of 1.5 to 3 mm are suitable. In this case, the materials being joined can have a thickness in the range of 1-5 mm. Using a material with a diameter of 2-5 mm, you can solve the problem of which electrodes are best for welding heating pipes.

It is worth noting that each type of electrode has its own current strength.

Before starting work, you should decide which electrodes to weld pipes with. The correctly selected material for welding allows you to make a high-quality and durable seam.

trubaspec.com

Electrodes for welding joints of pipes and pipelines

The quality of the resulting weld seam significantly depends on how correctly the electrodes for welding pipes are selected. Unfortunately, many welders underestimate the importance of their selection.

Welding electrodes are rods that supply current to the place where the seam should be made.

Types of electrodes used for pipe welding

Now there are many types of electrodes, which differ in purpose, coating and production method.

The most important difference is that the electrode can be melting or non-melting.

This parameter depends on the material from which the electrode was made and the method of further processing. For the manufacture of non-consumable electrodes, tungsten, graphite and electrical coal are used. Consumable electrodes for pipeline welding are made from welding wire, which is coated with a coating to protect, stabilize and impart the desired magnetic properties.

The coatings prevent air from getting onto the metal of the electrode, which gives the welding arc combustion stability, and this, in turn, helps to obtain a better and more uniform seam. The electrode is coated by pressing or dipping into molten material.

Advantages and disadvantages of consumable electrodes

Consumable electrodes have the following advantages:

• Ability to work from almost any position.
• Oxidation has little effect on the process.
• Higher performance.
• Good protection worker during welding.

Of course, these electrodes also have certain disadvantages, which include:

• Large radiation electric arc.
• Limitations on current parameters.
• Significant metal spattering.

When working, these shortcomings should be taken into account. Electrode manufacturers are striving to improve their products to minimize the impact of these negative factors.

Decoding the letter markings of the electrodes

According to GOST 9466-75, consumable electrodes have a number of letter designations, indicating their parameters. The first shows the purpose - for which groups of steels the electrode can be used.

Electrodes intended for welding low-alloy and carbon steels are designated by the letter U, alloyed steels by L, and high-alloy steels by V. Also, when choosing an electrode, the tensile strength of the steel is important. It is indicated in kgf/mm².

The thickness of the electrode coating is also indicated by letters. Thin layer coatings are marked M, medium - C, even thicker - D and G.

The type of coverage is indicated as follows:

• A – sour.
• B – basic.
• C – cellulose.
• R – rutile.
• P – other.

The coating can be marked with two letters at once.

Features of welding joints of pipes and pipelines

A fairly important parameter of electrodes is the diameter. Electrodes for welding pipe joints are selected depending on the wall thickness of the pipe itself.

Accordingly, the thicker-walled pipe needs to be welded, the larger the electrode diameter required.

To ensure a good seam, the surface of the pipe being welded must be thoroughly cleaned of rust, dirt or soil. The presence of dents or other types of deformation can significantly complicate the welding work or make them completely impossible.

Welding of joints must be carried out continuously, without downtime or interruption. To make the seam strong, welding must be performed in at least two layers. The next layer can be applied only when the previous one has been cleaned and completely prepared.

After analyzing all the material presented, you can come to the conclusion which electrodes to use to weld pipes. Only if you select them correctly and comply with all the requirements for the technical process, you can most likely obtain a high-quality result from welding work.

steelguide.ru

Choosing electrodes for pipe welding

The selection of electrodes for welding pipes is a fundamental process on which the quality of the seam and its reliability will ultimately depend. It is necessary to take into account absolutely all the nuances, even the most insignificant ones, but, unfortunately, many welders, including professionals, do not always pay due attention to this.

If we're talking about about laying profile or standard pipes, sooner or later you will have to use welding machine. When choosing an electrode, you should know about the first and most important difference between them: they can be melting or non-melting.

Features of consumable electrodes

For the production of this type of electrodes, welding wire is used, it has protective covering, which is necessary to stabilize the work and required magnetic characteristics. And the non-melting one is made from graphite, tungsten and electric coal.

The coating for the consumable electrode is also necessary to be able to obtain a high-quality and reliable seam; it is applied by immersion in molten metal and pressing.

What are the advantages of consumable electrodes:

1. They allow welding from any position.
2. Increased productivity.
3. Minimal influence of oxidation on the joining process.
4. Safe for the welder while working.

Flaws:

• high radiation of the welding arc;
• spattering during welding;
• Current limits have been set.

These are the main parameters that should be taken into account before selecting the required electrodes.

How to choose the right electrode

The rods may differ in their thickness and amount of coating. For welding galvanized pipes or any other, electrodes with a diameter of 2-5 mm are used. And the coating itself will amount to from 5% to 20% of the total mass of the product.

Most often, specialists use thicker rods. This happens because they are able to provide the necessary atmosphere to the welding process, which prevents air from entering the joint area. But it is also worth considering that they are distinguished by a large amount of waste released. And they, in turn, can affect the reliability of the docking. Therefore, it is necessary to learn to find golden mean for optimal performance with pipeline welding.

How to choose an electrode, taking into account the thickness of the pipe?

1. If the thickness, for example, stainless pipes, is 5 mm, then the electrode should have a diameter of no more than 3 mm.
2. When the pipe is larger than 5mm, 4mm rods will be required.
3. Also, a diameter of 4 mm is used for multi-layer formation of a welded joint.

It is also worth taking into account the maximum current that the rod can pass through, and the consumption of electrodes when welding pipes, which will help reduce financial investments.

Pipeline welding process

Once the choice is made, you can proceed to the welding process. To begin with, it is worth understanding how to move the arc along the connection; several help with this simple tips from the experts:

• the arc is drawn transversely, using oscillatory movements to obtain the required seam thickness;
• if you move the arc longitudinally, this will allow you to make a thin seam with a height that completely depends on the speed of movement of the selected rod along the surface to be joined;
• To maintain the stability of the electric arc, it must be carried out gradually throughout the welding process.

Note!

Safety regulations

Safety is a component of the welding process that should be approached with great responsibility. After all, if you ignore the rules, you can get serious injuries, such as burns from molten metal, eye burns from an arc flash, or become a victim of electric shock. To avoid similar situations it is possible by adhering to simple recommendations, namely:

• the welder should not wear wet clothes while working;
• It is imperative to use a protective face mask;
• All wires through which current flows must be insulated with any in an accessible way;
• before starting welding, you must not forget about grounding the unit and additional devices, if any;
• V small rooms It is necessary to use rubber shoes or lay a rubber mat, it will act as an insulator.

Conclusion

To make the choice of electrode more prepared, it is worth taking into account the consumption rate of the rods and taking into account the connection of a certain type of pipe to the material from which the rods are made. And for more better understanding selection procedure, it is best to seek advice from experienced specialists who have extensive experience in carrying out this type of work.

Sergey Odintsov

electrod.biz

What electrodes are needed for welding pipes, profiles and other metal structures

There is a misconception that the quality of the weld depends only on the performer, but this is far from true, and any good welder understands this - electrodes for welding heating and water pipes play an important role in such work.

First of all, it should be noted that such conductive rods can be either metallic or non-metallic, that is, carbon or graphite, but in this case, we are not interested in the second type.

A good welder always knows which electrodes to weld pipes with.

Let's look at what characteristics can be used to distinguish consumables of this type, how best to select them, and the video in this article will demonstrate visual information on our topic.

How are they distinguished?

The photo shows the wire for welding

Electrodes made of metal can be consumable or non-consumable. The first type can be coated, with a steel, cast iron, bronze, copper or aluminum rod, but uncoated ones are currently used only in the form of wire (see photo above) when welding work is carried out in a gas protective environment.

The non-melting type includes intruded, thoriated, lanthanum, and tungsten, therefore, it is quite natural that their price is much higher.

In addition, electrodes are classified according to their purpose, that is, according to the type of material to be processed. For high-carbon steel according to GOST 9467-75, the material is marked with the letter U, for alloy and heat-resistant steels - with the letter T, but for deposition of the surface layer - with the letter T.

Tungsten - TIGWIG

In most cases, there is a coating on the rods, but it also varies and has its own marking according to GOST 9466-75.

For example:

• thin coating is marked with the letter A (international format - A);
• middle - letter C (international format - B);
• thick - letter D (international format - R);
• and especially thick - the letter G (international format - C).

In addition to the thickness of the coating layer, it is classified according to its type:

• A - sour;
• B - basic;
• C - cellulose;
• R - rutile;
• P - mixed.

In addition, the mixed layer can be:

• AR - acid-rutile;
• RB - rutile-basic;
• RP - rutile-cellulose;
• RZh - rutile, with an admixture of iron powder.

Note. Due to the fact that welding work can be carried out in different positions, electrodes here are classified into different types. So, they can be for the lower position, vertical from bottom to top, horizontal and lower in a boat.

The instructions also include rods for any position.

By appointment. Types of materials

Welding gas pipe high pressure

• Carbon and low-alloy structural steels. In this case, the temporary tensile strength can be up to 60 kgf/mm or 600 MPa.
• High-alloy types of steel that are endowed with special properties.
• Structural steels where arc welding is used. Here the temporary tensile strength will already be more than 60 kgf/mm or 600 MPa.
• Surfacing of a surface layer of metal having special properties.
• Cast iron.
• Non-ferrous metals. (See also the article Sewerage in a cottage: features.)

More about coverage

Various coatings

• A - acid or sour coating. It contains oxides of iron, manganese and silicon.
• B - basic. It contains calcium fluoride and calcium carbonate. Welding work using such electrodes is carried out with direct current of alternating polarity.
• C - cellulose. It contains flour and other organic components, which are intended to create a gas protective shell during welding work.
• R - rutile. It contains rutile as the main component, as well as other mineral and organic components. In addition to gas protection, such components can significantly reduce spatter during weld production.

Note. IN household use(heating, frames) everything is somewhat simpler, since for all cases they usually use electrodes with a main (B) coating, the diameter of which depends on the thickness of the metal. For example, if you are interested in what electrodes to weld a profile pipe with, then given the thin profile wall (1.0-1.5 mm), you are better off using a rod with a cross-section of 2 mm.

Depending on the welding (transformer or inverter), you will select the consumables itself (for alternating or direct current).

Consumption rates

Vertical connection without bevel of edges

For heating installation, the consumption rates of electrodes when welding pipes may be different, depending on the joining of the heating pipes being welded and the type of seam, but we will consider only a vertical connection without beveled edges, as the most commonly used.

Consumption of electrodes when welding pipes per meter of seam

Consumption of electrodes when welding pipes per joint

Note. By by and large electrodes of any type are classified as one of the groups welding materials. In addition to them, this includes filler rods, wire, shielding gases and filler fluxes.

Conclusion

As you noticed, there are quite a few brands of electrodes, but if you want to heat your home with your own hands, then you immediately need to select materials for high-alloy and non-ferrous steels, as well as cast iron.

In addition, the thickness of the walls of heating pipes is usually at least 2 mm, then a 3 mm rod is needed. In addition, you will need an electrode for all positions, with a medium coating (C) type, acid (A) or basic (B), for carbon and low-carbon steels.

How to weld pipes, select electrodes and make seams?

When connecting pipes, welding is most often used. You can find it on sale today big choice welding machines, both domestic and industrial, so many homeowners undertake welding work themselves.

At the same time, beginners naturally have questions: how to weld pipes correctly, how to select electrodes, how to prepare surfaces for welding and check the quality of seams. Let's try to understand these problems.

Today in construction there are many various methods welding

Thus, according to the method of joining metal, welding is divided into:

• Thermal, which includes all fusion welding methods.
• Thermomechanical, which includes the butt contact welding, as well as a welding process using a magnetically controlled arc.
• Mechanical, which includes friction and explosion welding methods.

At enterprises and during the construction of pipe lines, in most cases, automatic and semi-automatic welding methods are used. In private construction, the manual arc welding method is widely used.

Preparatory work

Before you begin making welded joints, you need to prepare the surfaces of the pipes and select the right materials for the job.

Selecting Electrodes

For performing manual arc welding as consumables electrodes are used. This material is available in a huge range, so the question of which electrodes to use to weld pipes is extremely important.

The entire variety of electrodes produced can be divided into two groups:

• Electrodes with a consumable base;
• Non-consumable electrodes.

This classification is made by evaluating the material that is used to make the electrode core. Thus, consumable electrodes are made from welding wire of various thicknesses and compositions. The core of non-consumable electrodes is made of tungsten, graphite or electrical carbon.

In addition, the classification of electrodes is carried out by assessing their coating.

Each type of coating is designed to solve certain tasks, therefore it is extremely important to take this circumstance into account when choosing.

• Cellulose coated electrodes (grade C) used for making circumferential and vertical seams on pipes large diameter.
• Electrodes coated with rutile acid type (RA grade) They are distinguished by the special structure of the slag formed during welding, which can be easily removed at the end of the work.
• Electrodes with rutile coating (grades R, RR) are distinguished by easy re-ignition, a good degree of slag impact and allow you to create seams with commercial grade outer surface. They are used for setting tacks, as well as for creating corner seams and welding the outer layers of seams, which should have a beautiful appearance.
• Electrodes with rutile-cellulose coating (RC grade) recommended for making seams in any direction, including in the most difficult case - when forming a vertical seam from top to bottom.
• Basic coated electrodes (grade B) allow you to create seams with excellent toughness characteristics and the lowest likelihood of cracking.
  These electrodes are recommended for welding pipes with large wall thicknesses, as well as in cases where it is necessary to maintain high weld toughness, for example, to create pipelines that will be operated at low temperatures.

Pipe surface preparation

Before welding pipes, it is necessary to prepare their edges, that is, the surfaces that will be involved in the welding process.

• Pipes should be checked for compliance with the requirements laid down in the pipeline design. Basic conditions: conformity of dimensions, availability of a certificate, absence of deformation (ellipseness), no difference in the thickness of the pipes, compliance of the chemical composition of the metal of the pipes and their mechanical properties with the requirements of GOST.
• When preparing the joints, they are cleaned of dirt, oil and traces of rust, the perpendicularity of the plane of the end of the pipe axis is checked, the angle of opening of the edge and the amount of bluntness are measured.

Edge opening angle to create good seam should be equal to 60-70 degrees. The amount of dullness is usually 2-2.5 mm.

• If the shape of the bevel of the pipe edges does not match, they are mechanically processed using chamferers, end-cutters or grinders.
  For preparing large diameter pipes use milling machines or use thermal preparation methods, for example, gas-acid or air-plasma cutting.

Performing welding

Let's look at how to properly weld pipes.

Installation of potholders

• Potholders are integral part weld, they are performed using the same type of electrodes that will be used for the main welding.
• When performing welding with a diameter of up to 300 mm, four tacks are made, placing them evenly around the circumference. Each tack should have a height of 3-4 mm and a length of 50 mm.
• When welding pipes of larger diameter, tacks are placed every 250-300 mm.

When assembling pipelines, you should strive to ensure that the maximum number of joints is made in a rotating position. Pipes with a wall thickness of up to 12 mm are connected by welding in three layers. Let's look at how to properly weld a pipe in a rotating position.

Rotary welding

The first welding layer is made with a height of 3-4 mm; for this, electrodes with a diameter of 2 to 4 mm are used. The second layer is created using electrodes of larger diameter.

They do the job like this:

• The joint is divided into four sectors.
• First, the first and second sectors located in the upper hemisphere of the pipe are welded.
• After which the pipe is turned and the remaining two sectors are welded.
• Next, the pipe is turned again and a second layer of seam is made on the first two sectors.
• The work is completed by making a second layer of seam in the third and fourth sectors, after first turning the pipe over again.

The third layer of seam is applied in one direction while rotating the pipe.

When welding pipes with a diameter of up to 200 mm, you can avoid dividing into sectors, performing all layers of the seam in one direction while rotating the pipe.

Welding plastic pipes

In private construction, metal pipes are rarely used today, preferring to work with plastic.

Therefore, the question of how to cook plastic pipes interests many home craftsmen.

• Special butt welding machines are used for this.

When designing a pipeline from polypropylene pipes, it should be taken into account that when heated, such pipes may stretch somewhat.

• Heating nozzles are fixed in the device.

A temperature of 250-270 degrees is required.

• Next, pipe sections of the size specified by the project are measured and cut. It is recommended to sharpen the edges of the parts at a slight angle.
• A marker on the pipe marks the length of the connection with the fitting so that the end of the pipe does not rest against it.
• The surfaces of pipes that will be welded should be degreased.
• The fitting takes a little longer to heat up than the pipe, so it is treated first. Then the pipe is put on the heated nozzle.
  After warming up (the time depends on the characteristics of the device used), the parts are removed from the nozzle and secured with a smooth movement without turning. The seam should be fixed until it cools down.

Thus, you can obtain reliable connections using plastic pipes - how to weld such parts is described above, however, when performing the work, the following should be taken into account:

• To get a truly reliable pipeline, you need to carefully consider the choice of raw materials, namely, purchase high-quality pipes and connecting parts.
• We must not forget about the need machining joined edges, since otherwise it is impossible to obtain quality connection. After cutting, the end of the pipe must be cleaned using trimmers, shaver or finely cut files.

conclusions

Making pipe joints during pipeline construction is a responsible job, the quality of which determines the reliability of the networks being constructed. Therefore, regardless of the material of the pipes used, welding work must be carried out in strict accordance with the requirements of SNiP.

In order for electric welding using an inverter to give the desired result, and for the resulting weld to have high reliability and strength, it is necessary to correctly select electrodes for inverter welding. It is very easy to get confused in the huge variety of similar products presented on the modern market.

They differ in the material of manufacture, their type, diameter, coating composition, as well as a number of others. significant characteristics. What electrodes can be used for welding with an inverter, as well as how to choose them correctly, we want to talk about in this article.

Electrode selection criteria

First of all, it should be borne in mind that electrodes can be of consumable and non-consumable type. The first ones are made of a metal rod, onto the surface of which a special coating is applied, which helps protect the welding zone and increases the stability of the arc. They are used to perform manual arc welding. Products of the second category - non-consumable - are used to perform welding work in a shielding gas (argon), their varieties and features of use will be discussed in a separate article.

When choosing electrodes for welding using an inverter, you should take into account that the material of the parts being connected will also affect quality characteristics the seam being formed. Accordingly, in order to cook different materials, are used different types. So, for example:

• to connect products made from, carbon electrodes are chosen;
• to connect products made of alloy steel, electrodes of the corresponding brands are used: OZS-4, MR-3 (GOST 9466-75), MR-3, ANO-21, UONI 13/45 (GOST 9467-75);
• if it is necessary to carry out welding work with surfacing or other types of steel, then choose electrodes with a core made of high-alloy metal - TsL-11 (GOST 9466-75);
• in order to cook cast iron, it is also necessary to select electrodes of the appropriate brand - OZCH-2 (GOST 9466-75).

To date, the following rating of electrodes used for welding using an inverter has been formed.

• ANO. Welding electrodes of this brand are highly flammable and do not require additional calcination. Both novice welders and professionals can work with them equally successfully.
• MP-3 - universal type, they can even be used to join uncleaned surfaces.
• MR-3S. Electrodes of this brand should be chosen if increased demands are placed on the characteristics of the seam.
• UONI 13/55 is used for installation of critical structures that require high quality welds. It will be difficult for a novice welder to work with them: their use requires certain experience and high qualifications.

Advantages of popular brands of electrodes

Many modern views electrodes for welding using an inverter have the following advantages.

• Easy to weld. Difficulties when welding with such electrodes can arise if you incorrectly select them according to the composition of the core material.
• High quality seam. This parameter is the most important during welding work, and the electrodes of the indicated brands make it possible to ensure it. Using such electrodes for the inverter, you can obtain high-quality internal and external connections, welds of convex and concave shapes.
• Easy slag separation. The slag obtained when welding using such electrodes is easily separated, which makes it possible to immediately see what quality of weld they provide.
• Corroded parts can be welded. Of course, products covered with a layer of rust are cooked very rarely, but these electrodes make it possible to obtain a high-quality and reliable seam even in this case.
• The welding process is safe for the welder in terms of sanitary and hygienic standards.

Differences in electrodes by brand and diameter

There is an opinion among experienced welders that when using an inverter, you can weld with any electrodes. As a rule, such an opinion is based only on personal experience such specialists engaged in performing work certain type(welding of structures from profile pipes or corners). When performing work using an inverter, no serious requirements are placed on the connection regarding its tightness, so electrodes with a diameter of 0.5–2 mm can be used without problems.

The choice of diameter and brand of electrode should be based on the thickness of the metal that needs to be connected with them. Details large thickness require long-term welding, and accordingly, the electrode for welding them must be selected with a larger diameter. You still need to learn how to work with small-diameter welding electrodes; they burn out very quickly. Typically, such products are used for tack work.

Which electrodes are best to choose is also influenced by the type of work for which they are planned to be used. Thus, to perform complex route work, it is necessary to select electrodes of large diameter, and installation of structures from profile elements can be made with products with a diameter of up to 2 mm. These electrodes are used, in particular, during installation sectional doors and production of various enclosing structures from profile pipes and corrugated sheets.

Classification of welding electrodes

First of all welding electrodes divided into individual types for their main purpose. Thus, it is customary to distinguish the following types:

• those used to cook carbon and low-alloy steels;
• for connecting structures made of high-strength heat-resistant steels;
• to work with (they are often called);
• those with the help of which they perform, as well as its alloys;
• intended for welding copper and its alloys;
• for connecting cast iron parts;
• those with the help of which surfacing is carried out and various repair work is carried out;
• intended for joining parts made of steels of indefinite composition and difficult-to-weld steels.

Welding electrodes can be applied various coatings. According to the type of coating, they are divided into 4 categories. The most common are electrodes with two types of coatings.

Products with a basic coating, which are called basic. The most popular products are UONI 13/55. It is worth choosing them if you need to obtain welds of high quality, characterized by exceptional impact strength, ductility and mechanical strength. In addition, welds obtained when working with such electrodes are highly resistant to the occurrence of crystallization cracks. They are also not prone to natural aging. Their choice is worth making if you need to install critical structures that are planned to be used in harsh conditions.

They also have a drawback: if their coating is moistened or there is rust, traces of oil or scale on the edges of the parts that are connected, then pores form in the weld. Pores in the seam can also form when welding is performed with a long arc. The disadvantage of using such electrodes is that they can only be used for DC and reverse polarity.

The second type is electrodes with rutile type coating. Products with such a coating, the most popular brand of which is MP-3, are successfully used to connect parts made of low-carbon steel. Welding electrodes of this brand are distinguished by the following technological advantages:

• stable arc burning when operating on both direct and alternating current;
• minimal spattering of material during welding with an inverter;
• the ability to obtain high-quality welds of any spatial position;
• easy slag separation;
• the welds are excellent decorative characteristics;
• Suitable for welding surfaces covered with rust or dirt.

Selection of products according to other parameters

The type of current, as well as the polarity of its connection, are the most important parameters welding operations. They predominantly generate direct current, which can be connected to the workpiece and the electrode in two circuits.

• Straight polarity. With this scheme, the plus is connected to ground, and the minus to the welding electrode.
• Reverse polarity. This scheme involves connecting the minus to ground, and the plus, respectively, to the holder with the electrode.

When deciding which electrodes to choose for welding structures of a certain thickness, you can be guided by the following criteria:

• for parts whose thickness is 2 mm, electrodes Ø 2.5 mm are best suited;
• when connecting parts with a thickness of 3 mm, you should choose electrodes Ø 2.5–3 mm;
• if the thickness of the parts to be welded is 4–5 mm, then electrodes Ø 3.2–4 mm are suitable;
• parts with a thickness of 6–12 mm are best welded with electrodes Ø 4–5 mm;
• when the thickness exceeds 13 mm, then the optimal choice is electrodes Ø 5 mm.

It is very important to choose the correct diameter of the electrodes, since if this parameter is exceeded, the density decreases welding current. This will lead to the welding arc becoming unstable, the penetration of parts will deteriorate, and the width of the weld will increase. Many manufacturers indicate on the packaging information about the best current values ​​to use.

If such information is not contained on the packaging, then you can follow the following recommendations:

• for welding with electrodes Ø 2 mm, the welding current should be set to 55–65A;
• for products Ø 2.5 mm, a current of 65–80A is used;
• electrodes Ø 3 mm - current 70–130A;
• for electrodes Ø 4 mm, choose a welding current of 130–160 A;
• products Ø 5 mm - current 180–210 A;
• It is better to cook with 6 mm electrodes at a current of 210–240 A.

As it becomes clear from all of the above, for high-quality welding with an inverter it is important right choice electrodes according to their diameter. You should also set the optimal welding current. If, for example, you plan to weld thin metal with an inverter, using large-diameter electrodes, or the welding current exceeds the permissible values, then pores may form in the finished weld, which will significantly reduce its quality characteristics.

Electrodes from foreign manufacturers

Electrodes have gained great popularity in the domestic market trademark ESAB. Characteristic feature electrodes from the Swedish manufacturer is that their marking begins with the designation “OK”, followed by 4 digits. Among the wide variety of electrode models of this brand greatest distribution received the following ones.

• OK 46.00. In terms of characteristics, they are very similar to domestic MP-3 products. Using an inverter, they can cook carbon and low-alloy steels using direct as well as alternating current. When used, it is ensured high quality the resulting connection.
• OK 48.00. They can operate exclusively on direct current; they are used for the installation of particularly critical structures.
• OK 53.70. They are a specialized type; they are used to weld root passages and connect pipe joints.
• OK 61.30 and 63.20. They are used for welding stainless steel parts with an inverter, but before purchasing them, it is important to clarify whether they are suitable for working with the grade of metal you are interested in.
• OK 68.81. Using products of this brand, inverter welding is carried out on parts made of unspecified steel grades, as well as from difficult-to-weld grades.
• OK 96.20. They work on cast iron, and also connect cast iron parts to steel ones.
• OK 92.60. Designed for welding products made of aluminum and its alloys using an inverter.

By the way, the range of electrodes of this brand also includes products that can be used to weld copper and its alloys.

What to consider when choosing electrodes

Summarizing all of the above, we can identify a number of basic parameters on the basis of which electrodes for inverter welding should be selected. The first thing you need to consider is the type of materials you are going to cook. If installation of a critical structure is required, then it is better to choose electrodes from a well-established manufacturer. For example, ESAB brand products produced by a well-known Swedish manufacturer are well suited for such purposes.

If the surface of carbon steel parts that you are going to weld with an inverter is covered with rust or wet, then it is better to choose electrodes with a rutile type coating.

Products with a basic coating are used in cases where it is necessary to weld particularly critical structures with an inverter. The quality of welding with such electrodes also depends on how carefully you prepare the surfaces to be joined. To understand how such preparation is performed, you can watch a training video that is easy to find on the Internet.

During construction country house proper planning is important engineering communications. At the project stage, heating, water supply and drainage schemes are laid out. Today there is a large number of technological solutions to these issues. There are tap water and heating pipes PVC and classic metal pipes.

The choice of pipe type is influenced by a large number of factors. But, despite the increased popularity of polymer products, metal pipes remain popular and are quite often used in the creation of utility networks.

In order to finished design was strong and durable, it is necessary to connect all the joints correctly. The main connection method metal pipes is welding. And the quality of welding is influenced not only by the skill of the master, but also by the correctly selected brand of electrode suitable for connecting such products. If you have basic skills and necessary equipment welding heating pipes can be done by yourself.

Welding heating pipes can be divided into several stages.

1. Preparation of equipment and tools.
2. Preparation of the surface to be welded.
3. Welding process.

To perform welding work you will need a welding machine, an angle grinder, a hammer, a protective mask and gloves, as well as welding electrodes. The surface of the pipes that is planned to be welded must be clear out from rust, dirt and paint, as well as degrease. Cleaning must be done inside And outside to a depth of at least 1 cm. After this, you can begin the welding process.

For beginners, rutile electrodes of the OK46, ANO-21, MR-3 and OZS-4 brands are recommended for welding heating and water pipes. These electrodes are of the same type and have similar characteristics. Professionals can use electrodes of the UONI-13/45 brand. The choice of electrode diameter depends on the thickness of the pipe walls. For metal thickness up to 5 mm, electrodes with a diameter of 3 mm are suitable. To weld pipes with a wall thickness of up to 10 mm, you need to use electrodes with a diameter of 4 mm. In this case, surfacing is performed in several layers.

The welding current strength for each diameter and brand is set individually. Experienced welders rely on their feelings. Beginners are recommended to choose the welding modes indicated on the packaging with electrodes. The pack also indicates the calcination modes. And if electrodes with rutile coating at proper storage you don't have to ignite it, then main brands Necessarily subject to calcination. This is necessary to remove from the coating excess moisture, to ensure a high-quality and durable seam.

When performing welding work, remember safety precautions. Use special protection and ground the welding machine. Do not use shoes with metal inserts.

After completion of the work it is necessary check for leaks designs. Run water or gas through the pipes. There should be no leaks at the welding site. If everything was done correctly, the pipe connection was successful.

You can select welding electrodes and learn more about welding on the manufacturer’s website: https://goodel.ru/

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