Selection of electrodes for manual arc welding. Which electrodes are best for a welding inverter

» Which electrodes are better - tips and ratings

Each welder, whether he is a novice specialist or an experienced craftsman, will answer the question posed differently. This is due to the extreme subjectivity of this approach. In this article, we will try to reveal the answer to the question in more detail by analyzing various brands and types of electrodes.

Which electrodes are better

First of all, it is necessary to list the criteria according to which the choice of electrical conductors occurs:

it is recommended for novice welders to use consumables in their work; for experienced specialists, the coating of the rod does not play an important role;
electrodes can be melting and;
it is necessary to determine what type of structure, product or equipment is to be welded;
the choice also depends on the grade of the processed steel (see);
product thickness;
the type of work also has a significant impact: complex and massive structures are welded with electrodes large diameter, welding profile elements carried out with materials up to 2 mm in diameter .;
the kind of its connection;
and plays an important role quality welding electrodes.

Do not use materials with chipped coating!

For newbies

Most often, the question is about which are better, which ones are worse for beginners, so let's start with what are good electrodes for beginners. As stated earlier, preferred option electrodes for beginners are rods with. This is due to the fact that this type of conductor is characterized by ease of use.

Most popular brands with:

(on the picture).

For household welding

Household welding is characterized by a low level of complexity, as well as the absence of special requirements for the reliability and quality of the weld. At the same time, ease of operation is expected. Therefore, we will separately consider good electrodes for household welding.

Household welding includes work on the manufacture of small structures (for example, welding of protective systems (fences), greenhouse frames, etc.), small work in the garage or at the construction site of a private house.

ANO electrodes (in the picture on the right) are most often chosen for welding at home. This brand is suitable for work with almost all types of welding inverters. Therefore, I received wide distribution among beginners and home craftsmen.

Conductors of the MP-3 brand are distinguished by their versatility and unpretentiousness. These consumables allow the surface.

For welding cast iron

OZZHN-1 electrodes

What good electrodes for welding cast iron would you recommend? Cast iron is one of the most popular materials used in a wide variety of fields and fields. There are several types of cast iron: malleable, gray, ductile, etc.

As a rule, almost all of the electrodes listed below are suitable for cast iron, but not of any kind (the electrode must correspond to the metal grade, but this is already a topic for another conversation):

The entire list of electrodes intended for welding cast iron is presented in the section.

For pipes

It should be noted that electrodes are the most popular among professional welders. This brand is excellent for welding critical tanks; gas pipelines, inside which high pressure is maintained.

Amateurs and novice welders for household purposes are recommended to purchase brands with:, and others.

For inverter

Again, beginners ask the question: "Which welding electrodes are best for an inverter?" In the modern market of materials for welding, there are a great variety of electrodes for the inverter.

Majority(and almost all) brands are suitable for equipment of this type, since such units produce direct current. And if the electrode is cooked with a “change”, then it will cook with a “constant”.

If the welder has a question about the types of conductor suitable for the inverter, most likely this is a novice specialist. Accordingly, it is recommended to use consumables with.

The best electrodes for welding - baked and dry

The main component of convenient and comfortable welding, as well as a high-quality result, are dry electrodes without damage. and drying is extremely important. The implementation of these procedures will help to avoid many problems during the welding works: adhesion of the conductor, shedding of the coating, etc.

What kind of coverage is needed

There are four main types, each of which has its own distinctive properties.

1.Consists mainly of iron, manganese, silicon and other chemical elements. Electrodes with this type of coating are marked with the letter "A". Advantages consumables with an acidic coating: high resistance to the appearance of air channels in the welded joint; the possibility of processing rusty products and parts with scale. The main disadvantage- danger of hot cracks on the weld metal.

2. Electrical conductors from the coating are designated by the letter "Ц". The peculiarity is a high content of organic substances (the mass fraction can reach 50%): cellulose, organic resins, ferrospalves, etc. When burned in an arc, such coatings emit a large amount of protective gases and a small amount of slag. This is guarantees convenience vertical welding. Flaws: high hydrogen content when working with steel can adversely affect the characteristics of the weld metal; significant amount of spray.

3. The electrodes are marked with the letter "P". The basis of the coating is rutile, as well as some silicon and oxygen content. This view It is characterized by quiet melting, a small amount of splashes, easy slag separation, the seam has a fine pattern. Important feature — ease of re-ignition arcs. Welding work should be carried out in conditions of normal humidity and after the materials have been calcined, otherwise the quality of the joint deteriorates and signs of oxidation appear.

4. The electrodes are designated by the letter "B", consists of magnesium and calcium carbonates. Conductors with this type of coating are designed for direct current operation, as well as for connecting and. The weld metal has elevated level plasticity, does not exhibit a tendency to oxidation. The main thing dignity- weak saturation of this type of coating with hydrogen makes it possible to exclude the deterioration of the characteristics of steel and other metals. Basic flaw- the formation of a large amount of slag.

Many novice welders are wondering which electrodes for an inverter are best to choose. After all, it is this equipment that is most often used by home craftsmen. In general, transformer units, which were used earlier, have been replaced quite a long time ago. This is due to the fact that the inverter is easy to operate, it is inexpensive, in addition, it can be used to weld quite quickly metal parts and designs.

Such equipment is commonly used in fusion arc welding. Inverters are characterized by constant stability and indicators of the welding current, which provides an ultra-strong connection due to the high quality of the seam. The role of one of the main components of the described welding is metal rods, which are necessary to supply current to the welding zone. In this case, it should be borne in mind that welding units are represented by different types. Therefore, they require different electrodes.

Which electrodes to choose

If you, too, were among those who asked about the question of which electrodes are best for the inverter, then you should familiarize yourself with the information provided below. Used in inverter and in general in arc welding, consumable electrodes are made from welding wire, in the process of which the state standards of 1970 are used.

According to GOST 2246, electrodes for inverter welding are classified into:

alloyed;
carbonaceous;
highly alloyed.

The former are made of the following types of wire:

Sv-08H3G2SM.
Sv-08ХН2ГМТА.
SV-08HGSMFA.

When deciding which electrodes are better for inverter welding, you should familiarize yourself more closely with carbon rods, which are made of wire Sv-08 and Sv-08AA, etc. High-alloyed electrodes are based on Sv-30X25N16G7 and Sv-01X23N28M3D3T wires. However, none of these lists are complete. The core is coated by pressing. It protects the weld pool from atmospheric influences and allows the arc to burn more steadily.

Beginners should be aware that electrodes can be classified into two subgroups. The first provides for products intended for making a seam when connecting critical metal structures. The second subgroup is designed to work with conventional connections.

For critical products, it is best to prefer SSSI or ANO electrodes. If you are faced with the question of which electrodes are better for the inverter, then you should also pay attention to products marked MP-3, which are intended for conventional welded joints. The brand of SSSI electrodes is rather capricious. This is due to the fact that not every novice master will be able to work with such rods. If you do not have experience in such events, then it is better to refuse such electrodes.

Popular types of electrodes

If you cannot make a choice, then you should pay attention to the most popular brands, they look as follows:

UONI-13/55.
MP-3C; MP-3.

The former are popular among experienced craftsmen. These rods allow you to achieve a high-quality seam, which is true when low temperatures outside air. At the same time, the density indicators remain optimal.

When deciding which electrodes are best for the inverter, it is worth turning Special attention for rods МР-3С, which are used when it is necessary to perform a seam with high quality requirements. These electrodes are used to connect elements with direct and alternating current of reverse polarity.

The most universal brand is MP-3, with its help you can connect metal blanks with a dirty surface, rusty and damp structures. The most bought among Russians are ANOs. They do not require preliminary calcination, and they can be ignited without special efforts... In the end, you are guaranteed to receive excellent result, even when welding is done by an inexperienced technician.

Choice of electrodes for different materials

Before starting work, you need to remember that products from different materials require specific electrodes. If you plan to work with high-alloy or stainless steel, then it is best to use TsL-11 rods, which are made according to state standards 9466-75. But if you plan to weld workpieces from carbon steels, then OZS-4 electrodes are best suited.

If you are still deciding which welding electrodes are best for the inverter to choose, then you should pay attention to ANO-6. They are designed for mild steel products. In this case, we are talking about rods with an ilmenite coating.

ANO-4, which have a rutile coating, are also welded. Different grades of cast iron can be connected using OZCH-2. When purchasing electrodes, you should inquire whether they have epidemiological certificates that guarantee high-quality welding. The use of material made according to state standards also speaks of the safety of work.

For reference

The inverter is a modern piece of equipment that can be used to weld different surfaces using almost all existing types of electrodes. This is the popularity of the device. However, when choosing the best welding electrodes, you should remember that not all rods provide a high-quality result and an excellent presentation of the seam.

In addition, safety issues when using rods that are not recommended for this type of welding will be lame. This suggests that when choosing rods, it is necessary to be guided by the recommendations of specialists.

The choice of electrodes for the apparatus "Resanta"

Regardless of which brand of apparatus will be used for welding, the electrodes are selected according to the above scheme. If you are faced with the question of which electrodes are better for the Resant 190 inverter to choose, then you should be guided by the settings of the current strength and the diameter of the rods. The last parameter is selected depending on the thickness of the workpiece. If it is 1.5 mm or less, then it is better to use argon-arc or semi-automatic welding.

What electrodes are better for the Resant inverter, many are interested. Answering this question, it can be argued that the diameter of the electrode is selected, as mentioned above, according to the thickness of the steel. If it is 2 mm, then the diameter of the rod can vary from 2 to 2.5 mm. With a steel thickness of 12 mm, it is best to prefer an electrode with a diameter of 5 mm.

When choosing the best electrodes for welding, you may be faced with the need to purchase a rod for a 13mm workpiece. In this case, the electrode diameter is 5 mm. It is this parameter that will be relevant for workpieces of more impressive thickness. But as for the current, it is set depending on the diameter of the electrode. Thus, based on 1 mm of diameter, it is necessary to set 30 A. For a 3-mm rod, the current can be 80-110 A. The final value will depend on the spatial position, the number of passes and the thickness of the metal.

Finally

If you have already decided for yourself which electrodes are better for the Resanta 220PN inverter, taking into account the above recommendations, then you should remember that there are no identical and accurate settings today. The master sets the current parameters independently by the method of errors and trial. At high currents, you should be prepared for the weld pool to be less controllable and more fluid.

Quickly and efficiently weld any, even the most complex structures made of metal, you can use inverters. These units quickly entered modern operating processes because they are easy to operate, while the weld seam is of high quality, even and neat. Of course, the main component of the welding process is the electrodes for welding with an inverter. Basically, it is a metal rod that is coated with a special material called plaster.

Welding electrodes are made from different steel wires corresponding to GOST 2246-70. Therefore, the electrodes for inverter welding are divided into several groups according to the raw material.

Made from alloy wire. For example, from Sv-08H3G2SM.
High-alloyed - Sv-30X15N35V3B3T.
Carbon - Sv-10G2.

Welding wire grades are listed one at a time, but the list is quite extensive.

As for the protective coating (coating), it is specially applied to the rod in order to protect the weld pool from oxygen exposure to the molten metal. This particular chemical element negatively affects the quality of the material, creating oxide films on its surface. This is the first. The second is arc stabilization.

The protective coating is applied to the welding rod by pressing, so the bond between the two materials is very high. The coating itself is divided into four types.

The main one.
Sour.
Cellulose.

The first and last type are only used for DC welding. The rest are both for direct current and for alternating current.

What electrodes are best for cooking with an inverter

The electrodes for the inverter are divided into two groups.

Common, which are used everywhere for any design. These include brands ANO and MR.
Consumables for critical structures. These include the UONI brand.

All welders believe that the SUNI brand is very capricious. Not everyone can cook with these electrodes; experience and qualifications are needed here. Therefore, welding with an inverter for novice craftsmen is best done with conventional types.

Electrode brands

To answer the question of how to choose electrodes, you need to understand the brands indicated above.

SSSI

Their main purpose is welding products from carbon and low-alloy steels. As mentioned above, they are used to assemble structures that are subject to increased requirements. Particularly stringent requirements for welds, which must have increased toughness and ductility.

Welding can be done at low temperatures. The coating is basic, the current is constant, the polarity is reversed. Stem diameter: 2-5 mm. The weld is of high quality, high density. The structures welded with these electrodes cope perfectly with temperature changes, bending loads and impacts.

MR

MP-3. They are used for joining carbon blanks, the joint of which can withstand resistance (temporary) up to 490 MPa. The coating is rutile, the current is alternating or constant, the polarity is any. You can cook with an electrode in any position with a reservation. So, in the lower position, welding is carried out with electrodes up to 6 mm in diameter, in the vertical position up to 5 mm, in the ceiling (upper) position up to 4 mm. With the help of MP-3, you can weld workpieces with a rusty coating, contaminated. With them, welding is carried out with increased productivity.
MP-3C. This is a model that is used for the same purposes as the previous one. The joint welded by it can withstand resistance up to 450 MPa. The coating is rutile-cellulose, the current is alternating and constant, the polarity is any. Welding position - any. They can even cook wet metals.

The brand of MR consumables for beginners can be called as the best electrodes. They are not capricious, they easily tolerate the process itself, a slight spatter of metal, plus an excellent seam.

ANO

We must pay tribute to this brand, which all experts consider universal. It is ANO that is the most popular brand today. If we have to choose from all the types offered by manufacturers, then this one.

With the help of these electrodes (welding electrodes for the inverter), workpieces up to 5 mm thick can be welded in different positions, even in vertical position from top to bottom. In this case, the joining of two metals can be: docking, overlapping, angular. There are not great requirements for the cleanliness of the edges to be welded; it is possible to weld oxidized surfaces. They also perform root welding of thick workpieces. The coating is rutile-cellulose. Current - alternating or direct. Any polarity.

Is in lineup of this type, grade ANO-4 with rutile-carbonate coating, which is used for welding critical structures.

OK 63.34

If it becomes necessary to weld two stainless steel workpieces, then this can be done using an inverter using an electrode from the Swedish manufacturer ESAB. By the way, this electrode can be used to connect structural steel products.

The seam from such a consumable turns out to be equal with a smooth transition from the base metal. In this case, the slag is formed in small quantities, it is easy to beat it off. You can weld any position of joints in metals with a thickness of 6-8 mm in root welding. Although the electrode itself was designed for welding thin stainless steel products. You can connect them to butt joints and overlap. It is also used for multilayer welding not only in horizontal plane but also in vertical.

Carbon and graphite electrodes

An important component of the welding process is tightly pressing the edges of the workpieces together. This can be done with tack welds, spot welds, or mechanical fixtures (clamps, clamps, etc.). By the way, this technology can only be used in the lower position.

Welding process

The work of the welder depends not only on the correct brand of electrodes. You will have to correctly select their diameter, precisely set the welding parameters on the inverter itself. This mainly concerns the current strength. In addition, it will be important to know which output (plus or minus) to connect your chosen consumable.

The diameter of the welding rod must be equal to the thickness of the workpiece to be welded. For example, the thickness of the parts to be welded is 3 mm. This means that it is better to cook them with an electrode with a diameter of 3 mm. If a thick metal is being welded, for example, 10 mm, then any of the diameters can be used, because welding in this case will be carried out in layers. But even here it is better to use a thick consumable.

As for the polarity, it depends on which output the electrode is connected to: to minus or to plus. If to minus, and plus, respectively, is connected to the workpiece being welded, then this is direct polarity. If the opposite is true, then it is the opposite.

In what. Everyone knows that the flow of electrons (which is also an electric current) moves from minus to plus. And that element of the welding process, which is connected to the plus, heats up more. That is, if you change the location of the electrode relative to the connection position, you can change the intensity of its heating.

Attention! With an electrode with a diameter of 3 mm, it is better to weld metal with a thickness of 2 mm on reverse polarity. And with the same consumable, it is better to cook metal with a thickness of 6 mm on straight polarity.

Now, with regard to the current strength when welding with an inverter. It is usually indicated on the packaging. But you can use a simple ratio: for one millimeter of the diameter of the rod, 20-30 amperes of current. Let's face it, the range is quite wide. But it will be necessary to take into account the mode of laying the weld. That is, it will be stacked continuously without a break, or with a break. In the first case, when calculating, an indicator of 20 amperes is taken, in the second 30. Although all these are only recommendations, because you need to take into account a fairly wide list of criteria for the welding mode.

The fluidity of the base metal, its grade.
The speed of the welder's hand.
The position of the electrode during welding. For example, in the overhead position, the current is reduced.

The optimal regimen will come with time and experience. Therefore, the welder must pay attention to the weld pool. It is she who is an indicator of the quality of the selected mode. The correct seam must be uniform. If a lot of metal has formed in the bathtub, then either the arc is too short or the welding speed was insufficient. If a saddle turned out in the bathroom, then the seam was welded too quickly, or the arc refused to be long. The displacement of the metal in the bathroom to one of the sides indicates that the electrode movement, even strictly along the axis, was not sustained. In addition, the current strength was high.

Choosing a good option that suits the mode and the metal is not always easy. This is beyond the power of a beginner, so manufacturers give recommendations on the packaging. More or less they coincide with the actual ones. But, as mentioned above, everything will come with experience. We suggest that you familiarize yourself with the video - which electrodes are better to choose for welding with an inverter.

A strong and reliable connection of metals depends on many factors, the main of which is the correspondence of the electrode and the workpieces to be welded. Before choosing electrodes for welding, it is necessary to determine the chemical composition of the parts, as this will help to select the optimal combination of coated product and workpieces. It is also very important to choose the right coating, which is applied to the electrode and is at the same time a flux with alloying additives. This coating significantly affects the welding process and its correct choice in relation to specific materials provides the best indicators of strength and durability of the welded joint.

Welding machines and selection of consumable electrodes

With a qualified selection of the welding mode, it is imperative to take into account the parameters of the welding unit, which make it possible to use the best electrodes and the most preferable conditions for fusion of parts. There are several types of welding, using melted coated products, non-consumable tungsten or semi-automatic feeding methods using wires with special properties. Welding equipment is divided into the following types:

step-down transformer of alternating current or with rectifying circuit of direct current;
DC inverter apparatus;
apparatus with the use of an inverter, with a refractory tungsten electrode and manual feeding of the welding wire into the melt zone;
semi-automatic unit with wire feed to the weld zone.

Each of the devices has technical properties in terms of current and voltage, which dictate the selection of products of the appropriate diameter and coating composition. It should be noted that the wire, which is an electrode when semi-automatic and manual feeding into the melting zone, also serves the purpose of best matching the composition of the parts to be welded. The choice of electrodes depends on the method of welding with direct or reverse voltage connection, since the welding depth is related to polarity and the selection of the diameter directly depends on this.

The coating of the rod, as well as the composition of the wire, serves to realize specific tasks:

the use of carbon oxides protects the weld pool from atmospheric oxygen;
facilitates ignition and stabilizes the arc discharge;
helps to remove oxygen from the melt zone, deoxidizing the seam;
with the help of impurities, it has an alloying effect on the seam.

It is these requirements that determine the selection of good coated electrodes for specific applications. Russian industry produces a wide range of products for welding various metals and alloys. For domestic purposes, it is necessary to select priority welding materials. As a rule, this is the welding of ferrous metals, cast iron, stainless steels and alloys of aluminum and copper. Sometimes, they resort to welding workpieces of dissimilar composition, and here, you should choose an electrode with the closest parameters to the main composition of the parts.

Popular types of electrodes

Various types of welding products are produced, which are selected taking into account the characteristics of the materials to be joined and the welding methods. In the case of argon-arc welding, a refractory tungsten rod is used, and a wire is manually fed into the melt zone. When working with the use of semi-automatic machines, the electrode for inverter welding is a wire of different composition fed through a variable speed torch. The most common method is the use of piece consumable electrodes, the thickness of the coating of which is especially thick (D), thin (M), medium (C) and thick (D).

The choice of the thickness of the coating by the welder creates conditions for changing the degree of impact on the seam to protect it from the influence of air oxygen, traces of contamination and an oxide layer. According to the composition of the coating, the electrodes are subdivided as follows:

the main type for direct current welding and obtaining a plastic seam;
type with an acidic coating to ensure ductility of the metal in the zone of the weld pool;
impact resistance is given by a cellulose coating, these products are also used on a vertical seam;
rutile coating contributes to stable ignition of the arc;
special electrodes for welding copper and aluminum, as well as their alloys.

When choosing a product, it is necessary to take into account the thickness and composition of the workpieces, the welding current and the diameter of the electrode; these parameters must be linked to the characteristics of the apparatus. For welding steel with a thickness of 1 mm, electrodes with a diameter of 1.2 to 2 mm are selected, while a current of 45-55 A is required. For workpieces with a thickness of 2 mm, a diameter of 2.5 mm and a current of 60-80 A are required, parts from 3 up to 5 mm require the use of a diameter of 3 to 4 mm and a current of 70 to 130 A. Thicker workpieces are welded with an electrode of 5 mm and a current of 210 A and higher. The most popular products, especially among beginners, are rods with rutile and basic coatings, although the choice largely depends on the composition of the material to be welded.

The main coating of the UONI brand electrodes allows inverter welding, both in direct and reverse polarity, and the rutile MP-3 brand makes it possible to use alternating and direct currents and is characterized by light arc ignition.

Weldable metals and electrode selection

For high-quality welding, certain experience is required, as well as knowledge chemical composition blanks. Therefore, before choosing welding electrodes, you need to find out which metal or alloy you are going to join. For different types of metals, appropriate products have been developed with different kind coatings and many of them are analogues. Various reference books, advice from sales professionals or experienced professionals can help here. In most cases, they work with carbon steels, stainless steels, cast iron and copper and aluminum alloys. Welding of galvanized steel, dissimilar workpieces and nickel-plated parts is quite popular. High strength and durability of the weld is achieved by precise selection of the consumable electrode material and its coating to the metal or alloy being joined and consists in the following recommendations:

structural low-alloy carbon steels weld very well using grades MR-3M, UONI-13/55, OMA-2, OZS-30, VI-10-6, ANO-21 and VSF-65U;
high-strength alloy steels are welded using EA-981/5, EA-395/9, NIAT-5, OSHZ-1 and NIAT-3M;
heat-resistant alloys and heat-resistant steel are connected by grades TsL-39, ANZhR-2, TML-3U, OZL-35, IMET-10 and KTI-7A;
for corrosion-resistant and stainless materials, electrodes IZH-15S, NIAT-1, UONI-13NZH, TsT-15 and EA-400 / 10T are suitable;
parts made of materials of dissimilar composition are welded with grades ANZhR-2, EA-391/15, VI-IM-1, TsT-28, OZL-32, NII-48G, IMET-10, V-56U and;
for special steels, brands OZL-44, ANV-20, EA-112/15 and NII-48G are used;
for cast iron blanks, TsCH-4, OZZHN-1, OZCH-2 and MNCH-2 are used;
aluminum alloys are welded using OZA-1, OZA-2, OZANA-1, OZANA-2;
copper and its compounds are cooked using ANTs / OZM-2, OZB-3, Komsomolets-100; OZB-2M is suitable for bronze;
OZL-32 and V-56U are suitable for nickel alloys;
for metal cutting, the brands ANR-2M, OZR-2 and OZR-1 are used.

When welding thin-walled sheets, it is sometimes necessary to reverse the polarity in order to lower the penetration depth and get rid of the risk of burning through the workpieces. In this case, resort to inverter welding high-frequency, pulsed alternating current.

Outcome

We talked about the basic principles of choosing coated electrodes for welding using various machines. It is necessary to take into account when selecting a brand, the type of coating and the diameter of the rods, the current strength and the composition of the parts. With the acquisition of some experience and skills, effective work will not be difficult.

Sergey Odintsov

electrod.biz

How to choose electrodes for welding

When the task is to buy electrodes, of course, it is better to understand this issue thoroughly: what types of metal are, how they differ, for which metals they are intended, and also what types and brands of electrodes are.

Now, in order to start practicing sewing as quickly as possible, a simpler path of choice will be considered.

As for choosing a store, it is preferable to buy in a specialized store that sells welding equipment and expendable materials, and not in an ordinary hardware store, because in a specialized store, most likely, the sellers understand this topic and will be able to suggest something.

In the same place where everything is sold in a row, most likely, the sellers do not have the proper competence in the selection of welding electrodes. In addition, it often happens that the prices are higher in ordinary hardware stores. Perhaps it is implied that a person who buys such materials in a non-specialized one does not understand the issue enough to have a good idea of how much they cost.

Arriving at a specialty store, suffice it to say that you need electrodes for welding ordinary quality carbon steel, or ordinary carbon steel. Each type of electrode can have several brands. For example, Table 5 is shown with electrodes of the E46 type.

A type	Brand
E46	MP3S; ANO-21, ANO-4; OZS-4, OZS-6, OZS-12, etc.

Sometimes the letter "A" is put in the marking - for example, E46A. This means increased ductility of the weld. Since type E46 is taken as an example, further explanation of the selection principles will take place using the example of the same type of electrodes. There is a wide range of electrodes of the ANO brand (21, 36, 4, etc.), OZS, MR-3.

It is unlikely that the entire "line" of certain markings will be in the store. There will likely be one or two options. It makes sense to buy the smallest portion that they can offer and try which electrodes will produce the best quality seams in this particular situation.

It also makes sense to try to cook with UONI 13/55 electrodes, this is the E50 type. It differs from type E46, in some situations with their help it will be possible to obtain a better quality weld.

In any case, first you need to try: buy a small batch, and then, if you get a high-quality result, you can take required amount for the entire scope of welding.

The principle of operation of the electrode

The figure shows a diagram of the manual arc welding (MMA) process.

The electrode is a metal rod on which a coating or coating is applied.

As a result of the burning of the arc 3 and under the influence of its temperature, the metal rod 5 melts, and the metal from this rod is transferred to the weld pool 2. Also, the coating melts from the high temperature. As a result of its melting, it forms protective gases that protect the arc and the weld pool from the effects of oxygen, nitrogen and other gases contained in the air. In addition, the resulting gases contribute to the stabilization of the arc burning.

In the process of melting the mixture, liquid slag is formed, which spreads over the surface of the weld pool. At the same time, liquid slag deoxidizes the metal, ridding the weld pool of oxygen, and, conversely, adds alloying additives to improve the quality of the weld metal and the welded joint as a whole. As the seam cools, the liquid slag turns into a slag crust 10, which must subsequently be removed.

What electrode diameter is suitable for a particular metal thickness;
What welding current to set to obtain a high-quality seam.
The difference between welding modes on straight polarity and reverse

Electrode diameters

Measured in millimeters, these values are standard and according to Russian GOST are: 1.6; 2; 2.5; 3; 4; five; 6, etc. Imported ones have other diameters, for example 2.6 instead of 2.5; 3.2 instead of 3. Diameters over 4 mm are not of interest for household welding, because the household electrical network does not produce such power that would allow the use of electrodes with a diameter of 5-6 mm or more.

Even with a diameter of 4 mm, it is often impossible to use, since welding machines, as a rule, do not produce the required welding current, and some Electricity of the net, especially outside the city, do not allow cooking with such electrodes.

The diameter of the electrode, indicated in millimeters, means the diameter of the metal rod, that is, without taking into account the thickness of the coating. Usually, the larger it is, the longer it is.

Defects

The coating should be applied to the electrode evenly along the entire length and around the entire circumference. If the coating is uneven in thickness, that is, somewhere thicker, and somewhere thinner, this is a marriage. When the coating is applied evenly along the length, but thicker on one side and thinner on the other, this is also a marriage. In such cases, it is more difficult to obtain a quality seam.

The coating should not crumble and fall off. If the coating has fallen off at the end of the electrode, it will be much more difficult to ignite the arc. Except in cases of manufacturing defects, the coating can also crumble when the electrode is old or it was not stored properly. One way or another, it will be very difficult, if not impossible, to work with such a rod.

Ending electrodes

IN this option the metal rod is covered with slag, and when trying to ignite the arc, there will be no electrical contact between the metal rod and the metal of the part, and the arc will not burn. It is necessary to hit hard enough on a solid dielectric surface to beat off the slag.

The coating of the electrode is covered with slag

Important: you can hit any solid dielectric surface with the electrode. It is permissible to knock on the part to be welded, but in this case, make sure that there is no operating voltage on it!

If metal is visible at the end of the electrode, then arc striking will not cause problems. In the photo below, the situation is the opposite. The coating fell off. In this case, it will be difficult to ignite the electrode for another reason.

The coating performs the function of protecting the arc, stabilizes the burning of the arc - roughly speaking, "helps the arc burn." If there is no coating, the arc will either not burn at all, or it will burn very unstably, and a good welding will not work. The problem is solved by biting off this part of the electrode.

Electrode coating fell off

There is another option for more experienced welders - "scratch" with the electrode, barely touching the metal and preventing the electrode from sticking to the part. To do this, you need to apply a minimum force in the vertical direction and sufficient force - in the direction of movement of the electrode parallel to the workpiece, without holding the electrode in one place. In this way, carry out the required number of movements until the metal rod is burned.

Remaining electrode

When performing a weld, the electrode burns out and the question arises as to what is the minimum length to use it. In other words, how long should the cinder remain.

In principle, the optimal length is 3 cm, but this figure may vary. For example, if 4 cm remains and you need to lead the next relatively long seam, then there is no point in burning this centimeter. Better to take a new one right away.

It is undesirable to burn the rod to the holder, since in this case the electrode holder itself is damaged. In addition, during the execution of the weld with a small length of the electrode, the weld pool is obscured by the holder, and it becomes impossible to visually control the execution of the seam.

Welding thin metal

When welding thin metal, that is, 0.5-1 mm thick, the depth of the weld pool is greater than the thickness of the metal. Therefore, if you just weld such a metal without preparing the edges, it will burn through. To prevent this from happening, flanges are made when welding two parts end-to-end.

When the flanged edge is melted by the heat of the arc, the folded parts melt inward, close the entire gap between the workpieces and, together with the metal that comes from the electrode, form a seam. Thus, there is no penetration of the metal through, but a completely filled seam is obtained. (Experienced and highly skilled welders can weld such thin metal without flanges, but amateur welders usually cannot.)

Cast iron welding electrodes

For decorative welding of surface defects, steel electrodes Sv-08 are used.

For welding the defects of the processed non-working surfaces during the repair of irresponsible cast iron products of small size with small deposition volumes, which do not require mechanical treatment after welding, TsCh-4 electrodes are used.

Also, when welding cast irons, UONI-13/45 electrodes are used. They are welded with direct current of reverse polarity.

Copper electrodes, for example OZCH-2 and OZCH-6, are used for welding small-sized products with small defects, working with minor static loads and requiring tight seams made of gray or ductile iron. These electrodes provide a sufficiently strong welded joint that can be processed well. Unheated cast iron can also be welded with filler materials in the form of nickel-based cast iron alloys with a nickel content of more than 20%. The resulting weld is characterized by high ductility and low hardness.

For welding products made of high-strength, gray cast iron, as well as for making dissimilar joints of cast iron with steel, electrodes of the TsCh-4A grades are used. Hot welding is carried out as follows: machining the workpiece; forming of parts to be welded; heat; welding and cooling of welded parts. Parts can be heated with a gas burner.

Electrodes for this type of welding are made of rods that are homogeneous to the base metal. For example, ECH-1, ECH-2, PCh-1, PChS-1, PChS-2 are used. The heating temperature, depending on the grade of cast iron and the volume of the part being welded, is 300-700 ° C, followed by 100% cooling. Cast iron welding is performed on a reverse polarity current. Recommended welding modes are presented in the table.

Welding should be carried out in small sections 30-60 mm long with layer-by-layer air cooling up to 60 ° C. Immediately after welding, the seam is forged with light hammer blows.

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Welding electrodes, electrode marking, which electrodes to choose

One of the main conditions for obtaining a high-quality and correct welding seam is high-quality, correctly selected electrodes for welding with an inverter machine. The modern market has a very large assortment for electric welding. They all differ in type, coating material and other characteristics. Below we suggest that you familiarize yourself with the available options and choose the most suitable one.

Types of electrodes for welding with an inverter machine

All existing electrodes for electric welding are divided into consumable and non-consumable. At the heart of the consumable electrode is a wire rod made of metal wire, coated on the outside with a special coating. Thanks to the coating, the welding arc can burn stably, and the coating also provides good protection of the seam from gas and slag.

Electrodes, the purpose of which is to weld steel of undetermined composition, as well as copper, stainless steel, cast iron and other metals, are made from a specific alloy. Non-consumable types of electrodes are used most often when working with argon welding.

Working welding elements are available in different lengths and diameters. The length of the electrode depends on the alloying characteristics of the wire steel rod of the product, and can be from 30 to 45 centimeters. Regardless of the diameter, all types of electrodes are widely used. The only exception is the 1.6 mm diameter. This type of electrodes is available on request only. They are practically not used by Russian welders.

The most commonly used classification of all existing electrodes is according to their purpose. Based on this parameter, the electrodes are divided into:

Designed to work with elements made of carbon and low alloy steels. For working with high-strength heat-resistant steels. "Stainless steel electrodes" - for working with high-alloy steel. "Electrodes for aluminum". Electrodes for welding copper parts and products based on it. Cast iron electrodes. For repairs and surfacing. For welding work on metals, the composition of which is not defined.

Classification by the type of electrode coating is also quite often used. There are four main types of coatings, but only two are in widespread use.

Basic type electrodes.

They got their name due to the fact that the electrode rod has a so-called basic coating. The most popular among the main electrodes is the SONI 13/55 model. The use of this product makes it possible to obtain high quality seams with high impact resistance, strength and ductility. In addition, crystal cracks rarely appear on such seams, they are poorly prone to "aging". SSSI electrodes are typically used for heavy duty welding and products that will work in harsh conditions. The disadvantages of this type of electrodes include the elongation of the arc, the instability of the coating to moisture and rust, the appearance of scale or oil in the area of the weld. Taken together, all this can lead to the appearance of micropores. In addition, the main electrodes can only be operated with reverse DC current.

The second type of electrodes is rutile coated.

These products are used for welding parts made of metal with a low carbon content. The most commonly used grade is MP-3. These electrodes are distinguished by good technological qualities, namely:

The electric arc burns steadily on both direct and alternating current. The hot metal practically does not spray.

High quality seams in any position of the welded parts.

Slag separates very well. The electrodes can be used on dirty and rusty surfaces. Finished welds have a very good view, without pores and cavities.

Well suited for welding parts made of steel with a low carbon content.

Choosing an electrode taking into account the material and mode of operation

Right choice of the electrode for work, of course, plays a large role, however, in addition, you still need to know with what polarity and current you need to work in each specific case. Almost all inverters use direct current in their operation. Working with direct current, the electrode part can be connected in several ways, namely:

If the polarity is straight, the electrode is connected to "minus" and the part to "plus".

When working on reverse polarity, on the contrary, the electrode is connected to "plus", and the workpiece to "minus".

Operating on straight polarity produces a higher temperature when compared to the same values when operating on reverse polarity. Therefore, operation with reverse polarity makes sense in the following cases:

If it is necessary to weld thin sheet metal... Since the temperature on the reverse polarity is lower, the workpiece will not burn out.

When working with high-alloy steel grades. "Return" in this case significantly reduces the likelihood of overheating of the part.

It is better to work on straight polarity with massive workpieces that need to be heated well for high-quality welding.

In the welding business, there are three main characteristics, on which the quality of work directly depends:

Welding current. Workpiece diameter.

Working material thickness.

First, you need to decide on the dependence of the diameter of the working element and the thickness of the part with which to work. For example, steel up to 1.5 mm thick. it is almost always cooked using a semiautomatic device or argon welding.

Electric arc welding is practically not used for this. Steel 2mm thick is welded with 2.5mm diameter electrodes. To weld steel with a thickness of 3 mm with high quality, you will need electrodes with a diameter of 2.5-3 mm.

For steel with a thickness of 5 mm - electrode 3.2-4 mm. In work with products with a thickness of 6 to 12 mm. working elements with a diameter of 4-5 mm are used.

For steel thicker than 13 mm. an electrode of 5 mm is used.

An important point: the larger the electrode diameter, the lower the working current density. As a result, the arc begins to oscillate, "wander", change its length and behave unstably. Because of this, the depth of the seam decreases, and the width, on the contrary, increases. In most cases, manufacturers of such electrodes indicate on the packaging the required values of the welding current. If the manufacturer did not provide the necessary information, you must focus on the following indicators:

For an electrode with a diameter of 2 mm, a current of 55-65 A is needed. For an electrode with a width of 2.5 mm - 65-80 A. For a 3 mm - 70-130A. For 4 mm - 130-160 A. For 5 mm - 180-210 A.

For 6 mm - 210-240 A.

Based on the foregoing, when choosing a working element of a certain diameter for welding, you must first of all pay attention to how thick the workpiece is. If you work on a thin metal with a large-diameter electrode, or exceed the welding current, then pores will necessarily remain in the seam.

Welding electrode marking

The most common brand among foreign manufacturers of electrodes is ESAB.

The name of each type of electrode of this brand begins with OK, followed by a 4-digit designation. There are many variations on the market, but the most common are the following:

OK 46.00 - the electrode is practically similar to the properties of the MR-3 brand. Excellent for low alloy and carbon steel applications Suitable for AC and DC applications. Provides a high quality seam.

OK 48.00. Designed to work on critical structures. They work only on direct current.

OK 61.30 and OK 63.20. Used for welding "stainless steel" of almost all brands. Before buying, be sure to ask the sales assistant if these electrodes are suitable for working with a particular grade of stainless steel.

OK 68.81. Great model. Excellent for welding of undefined steels and difficult-to-weld parts.

OK 92.60. Electrodes for cast iron and the connection of cast iron parts with different types steels.

OK 96.20. Aluminum electrodes.

Criteria for selecting suitable electrodes

After analyzing all of the above, you can determine several main points that you must pay attention to when choosing electrodes for electric welding. First, you need to determine exactly what kind of metal you have to work with and choose an electrode according to the type of metal. If you have to work with a responsible design, it is better not to save money and buy products from a well-known manufacturer. For example, the Swedish products we mentioned above have proven themselves very well. When welding carbon steel parts, be sure to keep the surface clean. If it is oiled, damp or rusty, rutile-coated electrodes should be purchased. If you have to work on critical structures, it is recommended to use work items with a basic coating.

However, in any situation, it must be remembered that all products require preliminary surface preparation. In addition, it is necessary to accurately determine the thickness of the workpiece, on the basis of which, to select the optimal welding current. The selection process must be approached as responsibly as possible. If the electrodes are chosen correctly, then even the cheapest inverter can weld almost any metal at the highest level.

svouimirukami.ru

How to choose electrodes for inverter welding

In the welding craft, the ability to choose the right electrodes depending on the type of joints and steel grade is a very important professional skill. In this article, we will walk you through the main types of MMA coating electrodes and explain how to use them for their intended purpose.

How they work and how they differ

The electrode is a simple metal rod that melts in an ignited electric arc and fills the seam between two parts, simultaneously heating their edges. The coating of the electrode, when burned, ionizes the medium and maintains a continuous burning of the arc. In addition, during combustion, the composition releases gases that displace oxygen from the weld pool, and forms a slag that floats to the surface of the molten metal and covers it, protecting it from corrosion, cracking and other negative effects at the time of cooling.

Understanding the essence of the work of electrodes is very important to explain such a huge number of their varieties. They differ not only in the strength characteristics of the seam, but also in its position and the type of welding current used.

The difference between the electrodes in the location of the seam

Let us briefly recall how the orientation of the weld pool in space can change and how this affects the welding technique. The most convenient is the lower position of the horizontal seam, which can be flat and fillet. In this case, the melt effectively fills the seam and chamfer, and a uniform slag crust forms on top, which is easily separated. Almost all brands of electrodes, with the exception of special ones, can be cooked in the lower horizontal position.

Vertical seams are more difficult to cook. Typically, a pull-up welding technique is used. Accordingly, the coating of the electrode should be capable of fast and short-term ignition of the arc and efficiently guide the molten metal. Also, vertical seams can be welded without tearing, but for this the coating must have a thickness greater than usual, so that a semicircular hole is formed at the contact point on the electrode.

The upper (overhead) location of the horizontal seam is considered the most difficult in MMA welding. It is almost impossible to weld such seams without tearing, more often they are deposited by the point method with an overlap of 3/4 of the previous weld. The coating of electrodes for ceiling seams contributes to the rapid melting of small portions of metal and the same rapid cooling. Slag from electrodes also behaves differently. For the most part, it flies off to the side (the electrode is held at an angle) and covers the previous sticking point. Ceiling welding electrodes are most sensitive to current and polarity compliance.

Welding current type and polarity

As you know, inverters have alternating or direct current at the output, the latter having direct and reverse polarity of connection. Most electrode welding tasks are solved by reverse polarity, in which the electrode is connected to the positive "+" contact, and the part to the negative "-". The peculiarity of reverse polarity is that electrons, continuously moving from the negative to the positive pole, heat the electrode and its coating, and the metal of the part is heated only by indirect radiation.

With straight polarity, the flow of the electrodes is directed from the electrode to the workpiece and heats it directly. The electrode burns more slowly, adding small portions of molten metal to the bath. It is unreasonable to expect such a weld to efficiently fill a wide gap joint; straight polarity is used to join well-fitted parts with uniform weld thickness. For example, in this way it is good to weld metal sheets, the seam is minimally noticeable. Due to the higher temperature of the weld pool with straight polarity, it is optimal to weld massive parts for which the maximum heating depth is required.

AC welding is usually characterized by strong spatter of molten metal. The coating of electrodes for AC welding has additives to stabilize the arc and special alloying impurities that make the melt more viscous. The quality of the weld when working with electrodes on alternating current is considered the highest for RDS.

Explanation of symbols

There are two main specifications according to which electrodes are marked: domestic GOST 9466 and European standard ISO 2560. Each of them uses its own system of symbols.

Top line - T11-XXX-Y-ZN:

· T - type of electrodes, "E" for MMA welding;

· 11 - the yield point of the metal in MPA;

· XXX - brand of electrodes;

· Y is the diameter of the electrode;

· Z - the purpose of the electrode (U - low-alloyed and carbonaceous up to 60 kgf / mm, L - alloyed over 60 kgf / mm);

· N - coating thickness.

Bottom line - E-AAA-B-C-D:

E-AAA is the type and regulatory index defining strength characteristics seam;

· B - type of coverage;

· C - the position of the seam;

· D - current characteristics.

· T - designation of the type of electrodes, "E" - for MMA welding;

· XX - metal yield point in MPA;

· Y - index of resistance to impact destruction in MPA;

· SS - type of electrode coating;

Types of coatings

The acidic coating (A) strongly melts the weld pool, which makes the metal susceptible to cracking when solidified. At the moment, it has been superseded by rutile acid.

The main (B, C) coating provides a high toughness of the metal in the bath and uniform heating of the part. Such electrodes are intended for welding loaded structures, however, they should be calcined before use in order to avoid the formation of pores in the metal.

The cellulose (C, C) coating burns out in the arc almost completely, almost without forming a slag. This type of electrodes is one of the few that can weld vertical seams from top to bottom.

The basis of the rutile (P, R) coating is titanium dioxide. The electrodes are optimal for pull-off welding: they ignite well and hold the arc, they evenly weld the metal. The rutile coating provides complete control over the welding process and allows a wide range of arc lengths.

Rutile-cellulose (RC, RC) coatings inherit positive traits both types. It is these electrodes that are used for installation in cramped conditions; they leave an aesthetic facial seam that does not require further processing.

Types of electrodes for welding and steel

Considering the types and brands of electrodes for welding, to begin with, let's dwell on the first. Coated electrodes (namely, they are presented in the IES product catalog) are divided into 4 main types - depending on the coating that is applied to them.

Basic coverage ("B")

This is one of the most common types of coating, which contains calcium and magnesium carbonates. In the marking are indicated by the letter "B". The key advantage is the low hydrogen content in the coating composition. This and other properties make it possible to obtain a mechanically very strong, highly plastic weld with excellent impact strength. The electrodes are used in welding of especially critical structures, as well as structures that will be operated in conditions with variable temperature and severe northern conditions. The most widely known brand is UONI 13/55, UONII 13/55, UONI 13/45. Among the disadvantages: the formation of a relatively large amount of slag during welding, the risk of pores in the weld when welding on a long arc, with a wet or oxidized surface.

Rutile coating ("P")

It is also one of the most widely used. The basis of the composition is rutile (titanium dioxide), in addition to it, oxygen and silicon are present. Products provide easy initial, re-ignition, stable arc burning, small amount of splashes, easy separation of the slag crust, even seam of the marketable appearance. Ideal for welding low carbon steels. The most popular brands are MR-3 LUX, MR-3, OZS-12, ANO-21. Among the disadvantages: the need for low humidity and mandatory preliminary calcination in order to avoid the risks of oxidation of the weld metal.

Acidic coating ("A")

Contains iron, silicon, manganese, and other elements. Electrodes with acidic coating can be used to weld on surfaces with scale or rust, they provide high resistance to the formation of air channels in the weld metal. Of the minuses - the threat of the appearance of hot cracks in the latter.

Cellulosic coating ("C")

Consists of cellulose, organic resins, ferroalloys and other elements. The electrodes are well suited for vertical welding due to the low slag content and the release of shielding gases. Among the cons - high level metal spatter and high hydrogen content, which can degrade the quality of the weld metal.

Selection of electrodes for welding metal structures

The choice of the types of electrodes listed above depends on what kind of work is performed (welding or surfacing, welding of casting defects), as well as on what metals and alloys are used. Therefore, pick up the best option electrodes for metal structures should be, taking into account their main purpose:


Welding of carbon and low alloy structural steels
Welding of heat-resistant, heat-resistant steels and alloys
Welding "stainless steel", corrosion-resistant steels and alloys
Welding of elements from different materials and steels of different classes	OZL-32, TsT-28, EA-391/15, ANZHR-2, VI-IM-1, IMET-10, NII-48G, V-56U
Welding of products from nickel alloys	B-56U, OZL-32
Cast iron welding
Surfacing of parts operating under intense shock loads with abrasive wear	12AN / LIVT, TK3-N, VSN-6
Surfacing of parts operating under severe wear conditions with shock loads	TsS-1, TsN-11,
Surfacing of parts operating under intense shock loads	0ZN-250U, 0ZN-400U
Surfacing of worn parts made of high manganese steels
Surfacing of metal cutting tools	TsI-2U, OZI-5

How to choose the diameter of the electrode depending on the thickness of the metal

When choosing, one should take into account the dependence of the electrode diameter on the thickness of the welded metal of products and elements. The thicker the latter, the correspondingly greater the thickness of the electrode rod. So,

with a thickness of the welded elements of 1.5-2.5 mm, the electrode thickness will be 2-2.5 mm;
with a thickness of 3 mm - respectively 2.5-3 mm;
at 4-5 mm - 3-4 mm;
at 6-10 mm - 4-5 mm.

Allowable welding current values also vary depending on the diameter of the consumable (more on this below). At increased current values (always indicated on the packaging) and exceeding the recommended diameter values, there are risks of pore formation in the weld metal. It should also be said that if the thickness of the products is not more than 1.5 mm, manual arc welding is usually not used.

The choice of the strength of the welding current for the electrodes

Electrode consumables can operate on direct and / or alternating current. So, rutile-coated electrodes are used in welding both on permanent and on alternating currents, while products with a basic type of coating (such as SONI 13/55 →) - only on direct current of reverse polarity.

The choice of the strength of the welding current directly affects the quality of welding and the result obtained. If it is selected incorrectly, the workpiece may simply burn through during welding, or, on the contrary, the metal will not melt to the required depth. For correct selection there are guests and recommended settings, proven over years of practice. One of the key rules is the dependence of the current strength on the electrode diameter; an important role is also played by:

workpiece thickness;
spatial position of welding;
arc length;
number of seam layers.

For novice welders, it will be useful to know one of the basic unspoken rules: an average of 20-30 Amperes of current falls on 1 mm of the electrode diameter. The averaged values look like this:

Selection of electrodes for pipes

Which electrodes are best for welding pipe butt joints is determined by two key factors. The first is the way they are connected, in which welding is carried out. It can be an overlap, butt, corner or T-joint. The second and most important is the thickness of the pipe wall: the larger it is, the larger the diameter of the electrode rod should be. When installing gas and oil pipelines, reservoirs designed for high pressure, electrodes of the following brands are widely used: (for stainless steel)

Among the above, experts most often recommend rutile-coated electrodes, such as MP-3 →. Even in the absence of experience, at the initial stage of mastering welding, they allow you to get good quality seam due to easy ignition, simple control of the position of the weld pool and its good protection from oxygen. Consumables allow you to cook metal on direct (inverters, rectifiers) or alternating (transformers) current. Connection to inverters is carried out on reverse polarity (at electrode +).

Rutile coating makes it possible to weld in any spatial position, except for vertical from top to bottom, while - even on dirty, wet or oxidized surfaces. In case of difficult ignition, it is recommended to bake the electrode for 30-40 minutes at a temperature of 150-180 ° C.

Buying electrodes: how to determine quality

When buying this product, you should immediately pay attention to several points:

expiration date (indicated on the package) - it must not be exceeded;
the quality of the coating - its crumbling from the core should not be observed, otherwise it was either stored for a very long time, or is a product with an original factory defect;
in addition, the coating should be applied to the core evenly, with the same layer thickness.

In addition, you should immediately eliminate the risks of dampness by placing the electrodes in special cases. If, nevertheless, the latter happened, drying or calcining of the products is possible at t +400 ° C.