For example, with a part thickness of 10 mm, it is preferable to use a rod with a diameter of 5 mm. The Resanta company produces electrodes itself; they have a diameter from 2.5 to 5 mm. But they have one drawback - reduced plasticity.

How to cut metal with a welding inverter

Many novice craftsmen ask: “Which welding electrodes are best for an inverter when cutting?” But there is already a mistake in this question.

To understand which electrodes to choose for cutting metal with an inverter, keep in mind important feature: There are now special electrodes for cutting and there is no longer a need to use standard welding rods for this.

Yes, craftsmen used to use welding rods for cutting, but they did this only due to lack of best option. Specialized cutting electrodes provide a stable arc and easily oxidize the liquid metal, removing it from the cutting site. The work is done faster and with better quality. The diameter of such electrodes varies from 3 mm to 6 mm.

Instead of a conclusion

So which electrodes are best for welding? Briefly summarizing all of the above, we have highlighted several points that you should pay attention to in order to understand which electrodes to choose for welding with an inverter:

• If you have a particularly important job to do (for example, you are making a product to order), then it is recommended to use components from trusted foreign manufacturers. Also choose one with a base coat. But if you are just an amateur, and this is not work for you, then use budget components from domestic manufacturers.
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Connection of different metal products most often performed by welding. For this purpose, special equipment is used, which includes both transformer and inverter units. But even the simplest of them cannot work without electrodes. After all, in order to obtain a high-quality seam, it is necessary to melt the steel rod. But for each material, the electrodes for the inverter must be made of a specific alloy. Only then can you achieve a good result.

Inverters and components for them

Modern welding units are very different from their predecessors. They have compact dimensions, light weight, and are easy to use and transport. But in order for the seam made using them to be of high quality, it is necessary to use correctly selected electrodes. The success of the welding depends 90% on this.

Design features and technical characteristics

What is an element that is so necessary when performing welding work? This is a piece of coated steel wire. It is necessary to maintain a stable arc, and also provides:

• Metal protection;
• Seam alloying.

However, the functional features of an element depend on its purpose.

Let's watch the video, types and their main purposes, as well as selection criteria:

Main technical characteristics welding electrodes for inverter are:

1. Diameter and length of the rod;
2. The material or alloy from which it is made.

The length of the product can be from 300 to 450 mm and depends on the nature of the alloying of the electrode. As for the diameter, there is a whole line of rods, where the thinnest rod measures 1.6 mm, and the thickest reaches 5 mm. But welding electrodes with a diameter of 1.6 mm are usually produced to order, since they are not widely used in the domestic market.

Types of electrodes

As for the classification of these elements, they are divided into two main types:

1. Melting;
2. Non-melting.

The former can be made from either steel wire or special alloys, depending on what materials will be used for welding. Typically, when using a welding inverter with cast iron, copper, and dissimilar steels, electrodes made of alloys are used.

Non-consumable or tungsten products are used in argon welding. They may also have different performance depending on the application.

Table of types of electrodes

In addition, electrodes are divided according to purpose into the following types:

• For various steels;
• For stainless steel;
• For aluminum;
• Nickel;
• For repair;
• For difficult to weld alloys.

There are differences in the type of coatings. There are four types of electrodes on the market, the most common being: basic and rutile.

Criterias of choice

Since this consumable is necessary for any type of welding, it should be purchased taking into account the characteristics of the equipment and the specifics of the work performed.

Let's watch the video, types and their differences:

In this case, the following characteristics should be taken into account:

1. Diameter;
2. Composition of the material.

To make a quality seam, you need to choose the right Consumables. And first of all, their parameters are taken into account, including diameter. And yet, which electrodes are better for an inverter? For various steel grades it is indicated in regulatory documents. But it should be taken into account that the nominal diameter corresponds to the dimensions of the internal rod and does not include coating.

The thickness of this layer is individual for a specific type of product and is marked with the letters:

M - denotes a small diameter and a small layer of coating up to 1.2 mm, and D - over 1.8 mm. Both domestic and foreign companies adhere to this marking. However, their diameters will be different.

Watch the video on how to choose the right electrode for welding:

But not only dimensions are important when choosing electrodes. The composition of the components in it also plays an important role. Since the electrode consists of a rod and coating, the material from which they are made is also taken into account. For most products, low-carbon wire is used as the basis, and the coating composition includes various components:

• Fluorine compounds;
• Titanium dioxide;
• Rutile.

The use of electrodes of the first type makes it possible to achieve a strong and heat-resistant connection characterized by good ductility. Products with titanium dioxide create a stable arc and achieve high joint strength. Rutile electrodes are used when welding structures with high humidity. In addition, when choosing electrodes, the characteristics of the metal being welded must be taken into account.

For example, for carbon steels, UONI or MR rods are used. The former have a low level of spattering, the latter are characterized by rapid slag separation. They can be used in both professional and portable equipment.

Manufacturers – whose products are better

Since there are a large number of different brands and types of such products, we will consider only those that are intended for manual welding. Moreover, from them we will select only samples used when working with carbon and low-alloy steels.

Watch the video, test various welding electrodes:

We will be based on reviews left by users, as well as publications from specialized magazines. According to these sources the best electrodes for inverters on the domestic market are products from the following factories:

• St. Petersburg ESAB-SVEL;
• Tyumensky;
• Kamensk-Shakhtinsky;
• Orlovsky;
• Losinoostrovsky.

Among foreign manufacturers, the products of the following companies are in greatest demand:

• Kobelco;
• Ecab,

These electrodes for inverter welding are superior to domestic products in many respects, although they have a rather high price.

Watch a video about Monolith products:

As for Russian products, they are inferior in most options, although some samples are already appearing that rise to the level of the most inferior imported electrodes. But even then, only joint ventures owned by European or Asian manufacturers could achieve such results.

Now let's move on to considering the products themselves. Thus, electrodes from the St. Petersburg plant cost about 135 rubles per 1 kg and, according to welders, are the best among domestic models.

The price of electrodes for inverter welding from a Tyumen company is slightly higher, although their quality is practically no different from the previous sample.

The products of the Kamensk-Shakhtinsky plant are mainly designed for use with household inverters and have a price of about 130 rubles. for 1 kg.

Penza electrodes are considered the best in terms of price and quality. Their cost does not exceed 58 rubles.

Although the products of the Japanese company are expensive, they allow you to achieve excellent results when testing for strength. Experts say that these electrodes fully justify such a high price.

The welding process cannot be called simple, so before you start assembling a certain structure using it, you should first practice if you have never done this before.

To do this, the clamp is attached to the part, and the electrode is inserted into the holder. Then the current is set according to the diameter of the steel rod. At the same time, you should study on new electrodes - this will help you better understand the meaning of the work.

Watch the video, basic welding skills:

Creating an arc is done as follows. The electrode is installed at an angle of about 70° to the part. Then they quickly pass it over the workpiece, and a sheaf of sparks and a characteristic sound should appear.

In order for electric welding to bring good results, the seams turned out to be reliable and super-strong, you should know how to choose the right electrodes. Get confused in wide range products offered in the markets are very easy. They are distinguished by types, materials of manufacture, coating composition and other important parameters. The wrong choice will reduce the quality of the work performed.

How to choose welding electrodes

First of all, you should pay attention to the fact that products can be melting or non-melting. The former consist of metal rods with a special surface coating, which protects the welding zones and increases the stability of the arc. They are used in the process of manual arc welding. The second category is intended for work in an environment with a protective gas (argon); its features will be considered separately.

When choosing, you also need to take into account what materials the parts to be connected are made from. Different types of electrodes are selected for welding different metals. For example:

• If you need to connect low-carbon and low-alloy steels, you need to purchase carbon electrodes.
• To connect alloy steel, products are purchased (GOST 9467−75, GOST 9466–75).
• When work with surfacing or steels is planned different types, then you will need products whose core is made of high-alloy metals.
• When cooking cast iron, you also cannot do without the appropriate electrodes - OZCH-2.

Nowadays, a kind of rating of famous brands has been formed:

• ANO. They have good ignition and do not require additional calcination. Both beginners and experienced professionals can work with them.
• MP-3. Universal, can also be used for connecting uncleaned surfaces.
• MR-3S. They are used when increased demands are placed on the seams.
• SSSI 13/55. They are used when installing critical structures in which the seams must have high quality. Inexperienced welders are not recommended to work with them, as experience and certain qualifications are required.

Advantages of famous brands

1. Facilitate the welding process. Difficulties can only arise if the core material is incorrectly selected.
2. High quality seams. This parameter is very important. Allows you to obtain strong connections, both external and internal, convex and concave welds.
3. Easy slag separation. This makes it possible to see how high quality the seam is.
4. You can weld elements that have been susceptible to corrosion. Of course, such procedures are not performed too often, but they will be performed at the proper level.
5. Safety for the welder, sanitary and hygienic requirements are met.

Differences in brands and diameters

Experienced welding specialists sometimes claim that using inverter welding machines, you can buy any electrodes. These opinions are based on their personal experience when they perform certain types of work. Mostly, when inverter welding there are no serious requirements regarding the tightness of the seams, therefore products with a diameter of 0.5–2 mm can be used.

The diameter and grade should be selected based on the thickness of the metals that will need to be connected. For significant thickness, long-term welding will be required, which means the electrode must have a large diameter.

You still need to learn how to work with thin electrodes for welding, because they burn quickly. As a rule, they are used to make tacks.

Also, the choice of welding materials depends on the type of work for which they are planned to be used. Thus, when complex routing work is carried out, large electrodes will be needed, and a structure from profile components can be mounted using electrodes with a diameter not exceeding 2 mm. They are used when connecting gate sections, making fences from corrugated sheets and pipes.

Product classification

The division into individual types is made, first of all, depending on their main purpose.. In particular, the following stand out:

• For welding carbon and low-alloy steels.
• Allowing the connection of high-strength heat-resistant steels.
• For working with high-alloy steels (“electrodes for stainless steel”).
• For cooking aluminum and its alloys.
• For working with copper and its alloys.
• Allowing the connection of cast iron elements.
• Those through which surfacing is carried out and repair work is carried out.
• Connecting steel parts of uncertain compositions and difficult-to-weld steels.

Apply to electrodes for welding different coatings. Products with double coatings are most often used.

Products with a base coating, the most famous of them are UONI 13/55. They are selected to produce high quality welds with exceptional toughness, ductility and mechanical strength. In addition, such seams are resistant to crystallization cracks and are not prone to natural aging.

They have some disadvantages. So, if the components being connected are wet, there is rust or oil traces, or scale, pores will appear in the seams. Also, work is only possible on direct current and reverse polarity.

Another type is rutile coated electrodes. Such products, the most famous brand of which is MP-3, are used when connecting structural elements made of low-carbon steel. They have the following technological advantages:

• Arc stability on both direct and alternating current.
• Minor splashing of materials during work.
• Obtaining high-quality welds regardless of location in space.
• The slag is easily separated.
• Good decorative characteristics seams.
• Can weld rusty and contaminated surfaces.

The article will focus on coated electrodes used for manual arc welding. The parameters for choosing electrodes are quite numerous, let’s list the main ones:

• selection of metals, alloys (steels, alloys, types of cast iron, etc.).
• types of structure or equipment served;
• type of work, which depends on the design (massive, thick-walled, thin-walled, tee, etc.);
• type of current used for welding;
• the welder has experience;
• actually, the quality of the electrode itself.

Based on these parameters, we will consider the question of how to make the optimal choice.

Types of electrodes for welding and steel

Considering the types and brands of electrodes for welding, let’s first focus on the first ones. Coated electrodes (namely, they are presented in the MEZ product catalog) are divided into 4 main types, depending on the coating that is applied to them.

Basic coating (“B”)

This is one of the most common types of coating, which contains calcium and magnesium carbonates. In the marking they are designated 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 seam with excellent impact strength. Electrodes are used for welding particularly critical structures, as well as structures that will be operated in alternating temperature conditions and harsh northern conditions. The most widely known brands are UONI 13/55, UONII 13/55, UONI 13/45. Among the disadvantages: education during welding is relatively large quantity slag, risks of pores appearing in the weld when welding with a long arc, with a wet or oxidized surface.

Rutile coating (“R”)

It is also one of the most widely used. The basis of the composition is rutile (titanium dioxide), in addition to it there is oxygen and silicon. The products provide easy initial and re-ignition, stable arcing, low spatter, easy separation of the slag crust, and a smooth, marketable seam. Optimally suitable 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 pre-calcination to avoid the risk of oxidation of the weld metal.

Acid coating (“A”)

Contains iron, silicon, manganese and other elements. Electrodes with acid coating can be used for welding on surfaces with scale or rust; they provide high resistance to the formation of air channels in the weld metal. One of the disadvantages is the threat of hot cracks appearing in the latter.

Cellulose coating (“C”)

Consists of cellulose, organic resins, ferroalloys and other elements. The electrodes are well suited for welding in a vertical position due to the low amount of slag and the release of shielding gases. Among the disadvantages - 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 above types of electrodes depends on what kind of work is being performed (welding or surfacing, welding casting defects), as well as on what metals and alloys are used. Therefore, select best option electrodes for metal structures should be taken into account their main purpose:

Welding carbon and low-alloy structural steels
Welding of heat-resistant, heat-resistant steels and alloys
Welding of 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 made of nickel alloys	V-56U, OZL-32
Welding cast iron
Surfacing of parts operating under conditions of intense shock loads and abrasive wear	12AN/LIVT, TK3-N, VSN-6
Surfacing of parts operating under conditions of intense wear and 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	CI-2U, OZI-5

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

When choosing, you should take into account the dependence of the electrode diameter on the thickness of the metal products and elements being welded. 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 thickness of the electrode 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.

Valid values welding current 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, there is a risk of pores forming in the weld metal. It should also be said that if the thickness of the products is no more than 1.5 mm, manual arc welding is usually not used.

Selecting the welding current for the electrodes

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

The choice of welding current directly affects the quality of welding and the resulting result. If it is chosen 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 guidelines and recommended settings, proven over years of practice. One of the key rules is the dependence of the current on the diameter of the electrode; the following also play an important role:

• 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: per 1 mm of electrode diameter there is an average of 20-30 Amperes of current. The average values ​​look like this:

Selecting electrodes for pipes

Which electrodes are best for welding pipe butt joints is determined by two key factors. The first is the method of connecting them, which involves welding. It can be an overlap, butt, corner or T-joint. The second and main thing 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, tanks designed for high pressure, electrodes of the following brands are widely used: (for stainless steel)

Among those listed, experts most often recommend electrodes with rutile coating - such as MP-3 →. Even with no experience, initial stage mastering welding work, they allow you to get good quality weld due to easy ignition, simple control of the position of the weld pool and its good protection from oxygen. Consumables allow you to weld metal using direct (inverters, rectifiers) or alternating (transformers) current. Connection to inverters is carried out with reverse polarity (on the + electrode).

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

Buying electrodes: how to determine quality

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

• expiration date (indicated on the packaging) - it should not be exceeded;
• quality of the coating - it should not crumble from the core, otherwise it has either been stored for a very long time or is a product with an initial manufacturing defect;
• In addition, the coating must be applied to the core evenly, with the same layer thickness.

In addition, you should immediately eliminate the risk of it becoming damp by placing the electrodes in special cases. If the latter does happen, the products can be dried or calcined at +400 °C.

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

How they work and how they differ

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

Understanding the essence of how electrodes work 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.

Difference between electrodes according to 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 or angular. In this case, the melt effectively fills the seam and chamfer, and a uniform crust of slag is formed on top, which is easily separated. Almost all brands of electrodes, with the exception of special ones, can be welded in the lower horizontal position.

Vertical seams are more difficult to weld. Typically, the welding technique is used with a lift-off welding process from the bottom up. Accordingly, the electrode coating should allow the arc to be ignited quickly and briefly and effectively direct the molten metal. Also, vertical seams can be welded without tearing, but for this the coating must be thicker than usual so that a semicircular hole is formed at the point of contact on the electrode.

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

Type and polarity of welding current

As is known, inverters have an alternating or D.C., the latter has direct and reverse connection polarity. Most electrode welding problems are solved by reverse polarity, in which the electrode is connected to the positive “+” contact, and the workpiece is connected to the negative “-”. The peculiarity of reverse polarity is that electrons, continuously moving from the negative pole to the positive, heat the electrode and its coating, and the metal of the part is heated only by indirect radiation.

With direct polarity, the flow of electrodes is directed from the electrode to the part and heats it directly. The electrode burns more slowly by adding small portions of molten metal to the bath. It is useless to expect that such welding will effectively fill a joint with a wide gap; straight polarity is used to join well-fitted parts with uniform weld thickness. For example, this method is good for welding sheets of metal, the seam is minimally noticeable. Thanks to more high temperature weld pool with direct polarity, it is optimal to weld massive parts that require maximum heating depth.

AC welding typically produces a lot of 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 alternating current electrodes is considered the highest for RDS.

Explanation of symbols

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

GOST

Top line - Т11-XXX-Y-ZN:

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

· 11 - metal yield strength in MPa;

· XXX - brand of electrodes;

· Y - electrode diameter;

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

· N - coating thickness.

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

· E-AAA - type and standard index that determine the strength characteristics of the seam;

· B - type of coating;

· C - seam position;

· D - current characteristics.

ISO

T XX Y SS 01:

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

· XX is the yield strength of the metal in MPa;

· Y - impact resistance index in MPa;

· SS - type of electrode coating;

Types of coatings

The acid coating (A) strongly melts the weld pool, making the metal susceptible to cracking as it solidifies. Currently replaced by rutile acid.

The main (B, B) coating ensures greater viscosity of the metal in the bath and uniform heating of the part. Such electrodes are intended for welding loaded structures, but they should be calcined before use to avoid the formation of pores in the metal.

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

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

Rutile-cellulose (RC) coatings inherit the positive qualities of 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.

Most popular brands

The lower the complexity of the seam, the more convenient the electrodes are to use; some literally weld themselves. These, first of all, should include the famous E46 brand MONOLITH, also known as ANO-36, popularly called “school” electrodes. It’s really easy to cook with them: the rutile-cellulose coating holds the arc well even at very low currents, the metal is transferred in small and medium drops, filling the bath well. However, such electrodes should not be used for critical structures: due to the increased silicon content, the weld loses its ductility and impact strength.

It is recommended to weld assemblies and connections operated outdoors, including metal frame structures with suspended cladding, using electrodes whose coating contains alloying additives. Such seams have a much higher yield strength, and they are subject to corrosion to a much lesser extent due to their low hydrogen index. An example of such a brand is OK-48. They have a base coating and melt the metal to a viscous-liquid state, setting the optimal degree of heating, and are suitable for welding in any position. If a penetration of 12 mm or higher is required, it is recommended to pre-weld the seam with organic-coated electrodes such as ANO-7 and ANO-8.

For welding structures with oscillating types of loads and pressure vessels, OK 61.35 electrodes are used. They have a basic coating, the metal is very viscous when melted, and the seam is practically insensitive to intercrystalline corrosion.

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