Who invented the welding electrode

How to choose electrodes for welding with an inverter

Electric arc welding is performed using a transformer or inverter apparatus. The second option is more popular in everyday life due to its compact size and low weight. Any of these units works using electrodes.

What does a welding electrode consist of?

The basis is a metal rod. Depending on the purpose, it can be:

Melting. It is made of steel electrode wire or a special alloy. A special paste is applied over the metal rod - coating (coating).

The composition of the coating includes various chemical elements and additives, with the help of which the correct configuration of the welding seam is formed. In addition, thanks to the coating, a stable burning of the welding arc is maintained.

Non-melting. Electrodes of this type do not participate in the formation of a seam, but serve only as a source for the occurrence of a welding arc. Made from refractory materials. The most common is tungsten rod.

The non-consumable electrode itself (as its name suggests) remains intact during work. To form a weld, a filler material is supplied to the melt zone, in the form of a wire made of the same metal as the workpiece.

Tungsten rods are used for inverter welding of aluminum. The work is carried out in an environment of neutral gases, for example argon.

Both considered options refer to piece electrodes, that is, each of them is a separate element of a certain length. There are also continuous feed electrodes - the so-called welding wire.

It is fed into the contact zone with the workpiece mechanically. The seam is formed due to its melting and flowing into the bath. Since the wire is a conductor, it ensures the operation of the welding arc. There is no coating provided for such an electrode, so all elements to create the correct weld are embedded in the alloy.

To saturate the welding zone with the necessary additives and chemical elements, flux-cored wire was created, which is a thin tube with the necessary composition in the middle.

This wire is used in semi-automatic inverter welding machines. An electrode in the form of a wire (monolithic or filled with flux-cored wire) is located inside and is fed into the welding zone automatically; the operator only gives a command to turn it on.

Popular: Rutile electrodes – quality or mass availability?

Operating principle of the inverter

To obtain a large welding current, a huge transformer is required. It is inconvenient to transport and maintain. Unlike a welding transformer, the inverter operates as a high-power switching power supply.

The conversion of alternating voltage at the input to direct current of the desired output value occurs in several stages:

• alternating current 50 Hz voltage 220 volts rectified;
• direct current is converted (inverted) into high-frequency alternating current;
• the voltage is reduced using a compact high-frequency transformer;
• AC current is rectified and supplied to the output terminals of the inverter.

At the same time, the value of the secondary rectified current is high enough to perform any welding work.

The inverter circuit is built on powerful transistors operating at direct current. A transformer operating at high frequencies (60-80 Hz) takes up much less space and, accordingly, has less weight compared to a conventional welder.

Due to the applied circuit, with the same operating current, the inverters have a size and weight that allows the device to be carried by one operator, which is especially important when working at different heights.

Many old-school welders, accustomed to working on welding transformers the size of washing machines, blame inverters for constantly sticking the core.

These statements are unfair. Professionals who know how to work on any equipment know why the electrode sticks when welding with an inverter. The reason is the damp coating. After 5-10 attempts, the coating dries out from the high temperature of the short circuit, and the arc ignites perfectly.

The coating has a porous structure and absorbs moisture well. If you are using electrodes from a package that has been opened for a long time, they must be calcined before starting work.

If you know how to cook correctly, all you have to do is select the electrodes according to the designation on the package. There are no special consumables for such welding machines. Welding electrodes for an inverter are no different from any others.

Therefore, when selecting consumables for welding, one must be guided only by the conditions of their use. All you need to know is what current the inverter produces, the location of the seam and the name of the metal you will be working with.

Popular: Welding aluminum at home with an inverter

How to cook with electrodes using an inverter, the correct selection of consumables

For domestic use, complex welding is not used. As a rule, simple materials are used as blanks - steel pipe, profile or angle. Often the steel sheet of a car body is restored. Sometimes you have to cook stainless steel - for example, when repairing a washing machine or a broken pan.

The composition of the core of the piece electrode is selected according to the type of metal from which the workpiece is made. That is, from structural steels and alloys based on them. For most household work, you do not need to have an assortment of dozens of varieties of electrodes. It is enough to remember 3-4 brands that are considered universal and are great for beginners.

Professionals recommend these consumables to novice welders, since they have average characteristics and do not require special working conditions. In addition, the brands offered are easily compatible with all types of inverter devices.

Rutile electrodes MP-3

Ask any welder what consumables he started training with - and you will get the answer: “MR-3”. This brand is ideal for a beginner. Ignition occurs instantly, even if you made a slight mistake with the inverter parameter settings.

The bath is protected by additives from the coating; special effort is not required to control its position. If you can’t “catch the arc” the first time, just calcinate the electrodes at a temperature of 160°-190° for 30-50 minutes. You can weld in any position of the welding seam, except vertical from top to bottom.

The quality of the surface does not matter; corrosion or moisture on the surface is not a problem. If you picked up an electrode holder for the first time, it should contain an MP3.

Basic coating UONI 13/55

The most common welding consumables. Manufacturers recommend them for use on metals with a high carbon content. The durable seam resists impact loads well and has a high tensile strength coefficient. In Russia, these electrodes are also popular because the seams withstand low temperatures well.

UONI 13/55 operate on direct current with reverse polarity, fully compatible with inverters.

The excellent characteristics of the seam are somewhat overshadowed by disadvantages during use. To ignite the arc, the open circuit voltage must be at least 65-70 volts. Electrodes do not cook well on a dirty and unprepared surface. Before starting work, the welding site must be thoroughly cleaned.

Rutile electrodes ANO-21

A popular brand of tinsmiths from car service centers. There is no better consumable for working on thin steels with a high carbon content. The arc ignites instantly, the thin metal is protected from through burning, and the seam is fine-scaled. Accordingly, careful processing after welding is not required.

The second most popular application is welding thin-walled pipes. This brand is well known to plumbers and gas workers.

They operate on both AC and DC current, which is suitable for inverters. Before use, it needs to be heated at a temperature of 120°-130° for an hour.

Working with stainless steel - OK 63.34

OK 63.34 grade is suitable for welding stainless steel products. This type of metal can be welded with other electrodes, but the quality of the weld will be disgusting and it will rust. These rods form an even seam with a finely wavy surface. The connection with the main surface is smooth, the seam is not subject to corrosion.

There are no requirements for the type of current; the open circuit voltage for igniting the arc is at least 60 volts.

  Selecting the welding mode for manual arc welding

Metal surfacing

This type of welding work is used when it is necessary to restore a worn part or a broken hole.

Surfacing requires special skills, so beginners should not take on this work.

To restore the volume of metal, special electrodes for surfacing steel will be required. This is a whole group of brands whose names contain the letter “H”. For example - TsNIIN-4 or OMG-N.

These brands differ in a number of parameters, such as deposition rate or weld position. But all of them provide a qualitative increase in the thickness of the workpiece without loss of metal strength.

In conclusion, a video on how to properly weld with an inverter and what electrodes to use for welding. Analysis of situations using examples.

Source: https://steelfactoryrus.com/kak-podobrat-elektrody-dlya-svarki-invertorom/

Characteristics of welding electrodes - detailed information

A welding electrode is a metal (or non-metallic) rod that has a special coating. It is a consumable material used during welding work. Today we will look at the technical characteristics of electrodes that affect their properties.

Electrode characteristics

The parameters that we will analyze directly affect the purpose of the electrodes, their technological properties and the reliability of the connections they make.

Chem. metal composition

The main factor when choosing electrodes for future work is the composition of the metal you plan to work with. Depending on the alloy and type of steel, the mechanical and technical properties differ - strength, toughness, etc. These parameters affect how the product or part will behave during welding.

To choose the right electrode, it is necessary that its coating and composition be as similar as possible to the composition of the metal being welded. In this case, the seam will be strong and reliable.

Chem. coating composition

Among the general classification, there are 4 main types of electrode coating:

• Basics. Consists of magnesium and calcium carbonates.
• Rutile. It contains rutile, silica, magnesium and calcium carbonate, ferromanganese.
• Pulp. Includes organic resins, talc, ferroalloys, cellulose.
• Sour. Contains oxides of iron and manganese.

The most common are basic and rutile coatings. They are suitable for most materials, both in industry and in private use. Specialized electrodes can have a combined coating when special properties are required from the resulting metal.

The composition of the coating affects factors such as:

• arc stability;
• metal viscosity;
• detachability of slag crust;
• connection formation.

Deposition factor

You probably noticed that when describing certain electrodes, the deposition parameter is always indicated. It shows the amount of molten electrode that was used to form the seam. In fact, this parameter means the efficiency of the electrode.

Based on the deposition rate, experienced craftsmen can easily determine how many materials will be needed for a certain amount of work, how long it will take to weld, and which welding position is best to choose.

Speaking of surfacing, it is important to note one detail. During welding and melting of the electrode, not all of its mass is used to form the seam. Some part splashes, burns out and evaporates. This is affected by the coating, the magnitude of the current and its polarity. That is, the coefficient. surfacing reflects the amount of metal that is used to form a weld without loss.

Diameter

Diameter is another important parameter that you should pay attention to when selecting consumables. Depending on the thickness of the product being welded, the diameter of the electrode also increases. The grade of steel, its composition, the shape of the edges and the type of welded joint also play a role here.

Manufacturers offer different electrode diameters. The length also differs. Manufacturers indicate different parameters and possible applications for their electrodes.

When choosing the appropriate diameter, you need to know the following:

• electrodes with a diameter of 1 mm. used for working with steels 1.5 mm thick;
• 1.6 mm - for working with metal with a thickness of more than 2 mm;
• 2 mm are suitable for products with a thickness of 2 mm at a current of up to 70A;
• 2.5 mm are used for parts up to 3 mm thick, with current up to 100A;
• Electrodes with a diameter of 3 mm are very popular - they can be used for steels up to 50 mm thick;
• 4 mm are used for conventional and professional welding machines when working with structures up to 1 cm thick;
• rods with a diameter of 5 mm or more, are used only with special welding equipment.

Using these parameters, you can easily select electrodes for the planned work. These are average values. More detailed properties can be found on the packaging. Manufacturers describe in detail the conditions for using their products.

Calcination temperature

Calcination of the electrodes is necessary in order to reduce the amount of moisture contained in the electrodes. Without calcination it will not be possible to obtain a high-quality connection. In addition to the loss of welding properties, the electrodes will be very inconvenient to work with. Electrode preparation is carried out in several ways.

The simplest and most effective method of calcination is a special oven. The thermostat and insulated walls will allow you to maintain the temperature for the required time. The electrodes are heated evenly and will be completely ready for work.

There are also “folk” methods. They are suitable for household work and in cases where the quality of welding is not of great importance. Setting the desired temperature and keeping it constant for a certain period of time is not easy at home. The most suitable option for calcining electrodes at home is an oven. It is not recommended to use open fire or gas as drying will not be effective.

Different brands and types of electrodes have their own requirements for calcination time and temperature. Each manufacturer indicates the exact parameters for calcining the rods.

Weight of deposited metal

This parameter is useful when calculating the consumption of electrodes per 1 meter of seam. The parameter is determined by the formula: N = G * K, where

• N is the consumption of materials per 1 m of seam;
• G is the mass of deposited metal in a 1 m long weld;
• K - coefficient transition from metal mass to material consumption.

Temporary resistance

Tensile strength refers to the parameters of the weld. This property determines the resistance of the resulting joint to deformation and destruction. Another definition of this parameter is the ability of a metal to withstand a certain stress.

Different materials have different strength indicators specified in GOST. Real values ​​may differ from theoretical ones, but they cannot be ignored.

Depending on the types of electrodes, they can work with different steels and alloys that have different strengths.

Impact strength

This is another mechanical parameter of the joint obtained by welding. Impact strength reflects the resistance of a metal to external loads. When choosing rods, it is imperative to take this characteristic into account, since it determines the durability of the connection and the product as a whole.

Relative extension

This property reflects the ability of the seam to be plastic under static loads. This parameter is often applied to steels E42, 46 and 50.

Electrode rod material

The basis of the electrode is the welding wire. A coating is applied to it. During welding, the rod melts under the influence of current and fills the weld pool. This is how the seam turns out.

There are 3 main types of wires:

• Carbon. It contains up to 0.12% carbon. It is used to work with steels with low and medium carbon content.
• Alloyed. It is made from alloy steel and is used for welding products made from steels with low alloy levels, as well as for heat-resistant materials.
• Highly alloyed. Used to work with chromium, chromium-nickel compounds, stainless steel, etc.

The composition of the welding wire should be as similar as possible to the composition of the material you are working with.

Conclusion

All the characteristics and parameters we talked about today affect the use of electrodes and the efficiency of the connection. Depending on the structures and parts you are working with, you can choose the best consumables that will provide not only a high-quality seam, but also make it possible to work comfortably and quickly.

Experienced professionals recommend selecting electrodes with the best properties. This will save you from unnecessary problems during operation and further operation of the products.

Source: http://instrument-blog.ru/svarka/harakteristika-svarochnyh-elektrodov-podrobnaya-spravka.html

Electric welding

February 13, 2015.
Category: Electrical engineering.

There are two types of electric welding: 1) arc and 2) electric resistance welding.

Arc welding

Electric arc welding was invented by the Russian engineer N. N. Benardosn in 1882.

Nikolai Nikolaevich Benardos (1842 – 1905), in addition to electric welding and soldering of metals, invented a method for electrolytically coating the hulls of iron ships with copper. N.N. Benardos is the designer of a combined gas-electric soldering iron. He was the first to use an electric arc to cut metals under water. N. N. Benardos received the title of honorary electrical engineer.

Electric arc welding uses the heat generated by an electric arc. When welding using the Benardos method, one pole of the voltage source is connected to a carbon rod, and the other pole is connected to the parts that need to be welded (Figure 1). A thin metal rod is inserted into the flame of an electric arc, which melts, and drops of molten metal, flowing down onto the parts and solidifying, form a welding seam.

Figure 1. Electric welding using the Benardos method (with a carbon electrode)

In 1891, Russian engineer N. G. Slavyanov proposed another method of electric arc welding, which became most widespread. Nikolai Gavrilovich Slavyanov (1854 - 1897) worked at the Votkinsk plant and in Motovilikha (near the city of Perm). In 1893, at the World Exhibition, N. G. Slavyanov received a gold medal for the method of electric welding under a layer of crushed glass (flux).

Electric welding according to the Slavyanov method is as follows. The carbon rod is replaced by a metal electrode (Figure 2). The electrode itself melts, and the molten metal, solidifying, connects the parts to be welded. When the electrode is used, it is replaced with a new one.

Figure 2. Electric welding according to the Slavyanov method (with a metal electrode)

Before welding a part, it must be thoroughly cleaned of rust, scale, oil, and dirt using a chisel, file, or sandpaper.

Figure 3. An example of a weld resulting from the use of electric arc welding

To create a stable arc and obtain a durable seam, metal electrodes are coated with special compounds. Such coating also melts during operation during melting of the electrode and, filling the highly heated surfaces of the parts being welded, prevents them from oxidizing.

Time-lapse footage of arc welding in action:

Electric resistance welding

If you put two pieces of metal close together and pass a strong electric current through them, then due to the release of heat at the point of contact of the pieces (due to the high transition resistance), the latter will warm up to a high temperature and weld.

Figure 4. Contact electric welding

Currently, electric welding, both arc and resistance welding, has firmly entered the industry and has become very widespread. They weld sheet and angle steel, beams and rails, masts and pipes, trusses and boilers, ships, and so on. Welding is used to perform new and repair old parts made of steel, cast iron and non-ferrous metals.

electric welding by resistance method:

Scientists and inventors in our country have developed many new methods of using electric welding. Professor K.K. Khrenov proposed a method of underwater electric welding, which was widely used in the construction of the Saratov-Moscow gas pipeline. Automatic welding, proposed by Academician E.O. Paton, allows you to weld metals very quickly and with high quality in mass production. Academician V.

P. Nikitin designed a welding machine that allows welding using the now most common alternating current. The device has a special part - an oscillator, the purpose of which is to generate alternating current of high voltage and very high frequency, which ensures stable arc burning when welding thin and thick metal parts.

When electrical circuits are closed and opened by a switch or circuit breaker, as well as contacts of devices and devices are closed and opened, an electric spark that occurs between the contacts, and often the following electric arc, melts the metal, and the contacts burn or weld, disrupting the operation of the installation. This phenomenon is called electrical erosion (from the Latin word “erogo” - “gnaw out”). When a spark appears, it seems to “gnaw” the metal. To combat a spark, sometimes a capacitor of a certain capacity is connected between the contacts parallel to the spark gap.

Engineers B. R. Lazarenko and I. N. Lazarenko used the property of an electric spark to “gnaw metal” in the electrical erosion installation they designed. The operation of the installation is basically as follows. One wire from a voltage source is connected to the metal rod.

Another wire is connected to the workpiece, which is in oil. The metal rod is made to vibrate.

An electric spark that occurs between the rod and the part “gnaws” the part, making a hole in it that is the same as the cross-sectional shape of the rod (hexagonal, square, triangular, and so on).

Source: https://www.electromechanics.ru/electrical-engineering/619-electric-welding.html

Existing types of electrodes, their classifications and characteristics

Currently, there are a huge number of technologies: from submerged arc and powder welding to cold welding. All these types of electrodes differ from each other in the process, but the current is supplied to the part in the same way everywhere, namely with the help of welding wires. In this article we will talk about their types and applications.

An electrode is a short piece of wire coated with a protective layer.

Wire and coatings can be made of various types of material. The choice of material, in turn, depends on the nature of the parts being welded.

What are electrodes needed for?

They are usually used for joining cast iron and steel, non-ferrous metals, but can also be used for cutting them. Now they can be cooked in almost all spatial positions.

There are a huge number of varieties of rods, each is made for its own specific task, so all brands are divided into certain classes.

So what brands of electrodes are there? What types of electrodes are there for welding?

So, now let’s find out what types of welding electrodes exist.

First of all, let's start with the fact that there are melting and non-melting electrodes for welding. Consumable electrodes not only transmit current to the part, they also, by melting, enter into a chemical bond with the molten metal and ensure the connection of the parts. Non-consumable rods provide current supply to the parts being connected, and additives are supplied separately. They are made from various types of refractory materials, such as graphite and tungsten.

In addition, groups of electrodes are divided into metallic and non-metallic. The second brand of welding electrodes includes graphite and carbon rods.

They have good conductivity and cope well with welding, cutting and surfacing, conduct current well, and have a high melting point. They are used together with an additive, which can be applied to the arc during welding, or can be placed on the area being joined immediately.

The characteristics of welding electrodes include such advantages as reusability and non-sticking to the surface of the workpiece.

In turn, metal types of welding electrodes consist of a core. They have special coatings that ensure high quality welds, improve the performance properties of the product after work and prevent harmful inclusions from entering the weld pool.

The gas-forming coating may include elements such as starch, pyrolusite and others.

This method increases the productivity of the process due to the use of a large current, the formation of a protective film on the metal surface and thereby preventing the entry of atmospheric air into the welding zone, a more stable arc.

Classification of welding electrodes

Let's move on to the question of what types of welding electrodes there are. Let us dwell on the classification of electrodes by purpose.

In order to know the characteristics of certain rods, there is the concept of marking, which indicates the various characteristics of welding electrodes and other data. It is important to know the thickness of the rods. This is necessary for its correct selection when working with a product of a certain thickness. Description, classification and labeling are usually indicated on the packaging.

Must be provided:

1. stable arc burning and easy ignition;
2. uniform melting of the coating;
3. uniform coating of the seam with slag;
4. easy removal of slag from the seam;
5. absence of pores, cracks and lack of penetration.

The purpose of the electrodes largely depends on the composition of its metal core. During manufacturing, a number of factors are taken into account that influence the quality of the seam:

1. classification by purpose;
2. direct purpose of a particular type of alloys and metals;
3. spatial location of work and conditions of work;
4. thickness of parts and structures;
5. highly specialized characteristics of the seam (bending, tensile strength, oxygen saturation, fluidity of the liquid seam, etc.).

The marking is taken into account by the relevant standards and assortments. The rod of a certain marking must comply with all technical conditions, the marking on the package must coincide with the contents qualitatively and quantitatively. The classification of electrodes by purpose is characterized by the metal on which welding work will be carried out.

• U - low-alloy and carbon dioxide steels: E6, E55, E46, E42 and others;
• L - alloy steels: E70, E85, E100 and others;
• T - alloyed heat-resistant steels: E09M, E09MH and others;
• B - high-alloy steels with special properties: E12Kh13, E10Kh17T and others;
• N - surfacing of surface layers with special properties: E10G2, E11GZ, E16G2ХМ and others.

Types of welding wires

Wires can be divided into four types: aluminum, copper-plated, stainless steel and flux-cored. Let's look at the features that characterize these types of wires.

Aluminum wires are used when it is necessary to combine aluminum with silicon or aluminum with manganese.

Stainless steel wire can be useful in cases where it is necessary to connect nickel-plated, chrome-plated stainless steel metals.

Copper-plated wires are used in cases where it is necessary to connect low-carbon and low-alloy steels. Such wires improve the quality of the weld, support the combustion of the welding arc, and prevent splashing of molten metal.

And finally, powder cores are used in shipbuilding, where the use of other types of wires is unacceptable. It differs from those listed in that the previous ones weld the product in a protective gas environment, while powder ones do not.

It is worth mentioning submerged arc welding, where instead of a shielding gas medium, a flux is used, which can be elements such as boric acid, borax, fluorides and chlorides. It protects the weld pool from harmful impurities and gases that have a detrimental effect on the metal.

Speaking in more detail about the purpose of the coating, it must ensure stable combustion of the welding arc and obtain metal at the seam with specified properties, such as impact strength, corrosion resistance, ductility, strength and others.

The slag, in turn, serves to protect the molten metal that has not yet solidified from the ingress of oxygen and nitrogen, which are harmful inclusions and interfere with the manufacturability of the part. Also, the slag shell significantly reduces the rate of weld solidification, allowing non-metallic and gas inclusions to escape from the weld pool.

The components that form the slag are: dolomite, manganese ore, titanium concentrate, quartz sand, chalk and many others.

Alloying of the welding seam is carried out to add special properties to the product. Alloying components are: chromium, tungsten, molybdenum, nickel, manganese and others. Metal alloying is also done with wire, which already contains the elements necessary for this, but most often alloying a weld is achieved by introducing alloying components into the composition of the application.

Sometimes, to increase the productivity of the welding process and to increase the deposited metal over a period of time, iron powder is added to the coating. Its introduction increases the technological properties of the rod, namely, it facilitates the ignition of the arc, reduces the cooling rate of the metal, improving welding at low temperatures.

The types of electrodes for coating are as follows:

• A - with acid application containing oxides of manganese, silicon, iron and titanium. Group A electrode can be used when welding steel; There are no spatial restrictions for brand A electrodes.
• B - with an application based on calcium carbonate and calcium fluoride; Brand B electrodes should not be used for welding in a vertical position.
• C - with a cellulose coating, which also includes organic substances that create arc protection during combustion and form a thin layer of slag;
• R - with rutile coating, which is aimed at reducing metal spattering, arc stability and the formation of seams in all spatial directions;
• Zh- is indicated when the coating contains more than 20% iron powder;
• P - other types of coating.

There are also types of electrodes for coating with a mixed type shell; they are designated by two letters at once.

There are types of electrodes based on their use in a specific spatial position. They are also marked, namely with the following digital codes:

Some rules for using electrodes

Their safety must be observed. For high-quality and safe operation, its geometry must not be damaged, its weight and mass must coincide with the data on the packaging, and slag crusts must be easily separated from the seam. Everything must be sealed, and the packaging must prevent moisture from getting inside. The electrodes must be dry; moisture ingress on them leads to dampening of the coating, and therefore to a deterioration in the welding process.

They can be dried in specially equipped ovens at a given temperature of 260 degrees Celsius, and after drying they must be sealed to prevent water from re-entering them. Also, moisture does not have the best effect on the characteristics of the coating; molten metal can splash heavily. Moisture can cause pores, cracks, cavities and other defects to form.

It is not recommended to weld bent rods with damaged coating.

Many characteristics are listed in tables. The table is a convenient and visual way to obtain information about the characteristics of materials, brands of welding electrodes and much more.

Currently, manual arc welding is the most common. Electrodes for manual welding are similar to a metal rod.

This type of welding is easier to use than many other types, it is compact, allows welding in hard-to-reach places, it can be used to work with cast iron, steel, and many non-ferrous metals, it is easy to use and does not require large material investments.

The disadvantages of this type of connection include the fact that the quality of the seam directly depends on the qualifications of the worker, rather low efficiency compared to other types of welding, harmful working conditions for workers, and others. For manual arc welding, special welding inverters are used. Electrodes for manual welding are manufactured in accordance with the requirements of GOST 9466.

In conclusion, we can say that today there is a huge range of types of electrodes and their applications, and welding is still an important part of many construction, production, and installation works. There are a huge number of them, they differ in brands, thicknesses, chemical composition and other characteristics.

It is important to know which rods can be used for various types of work in order to achieve maximum results and end up with a high-quality product or part.

This type of work is attracting more and more new specialists; scientists continue to work on improving the technological process, because the demand for welding work is quite high.

Source: https://svarkaed.ru/rashodnye-materialy/elektrody/sushhestvuyushhie-vidy-elektrodov.html

Non-consumable electrode welding for arc and argon arc welding, refractory electrodes

Non-consumable electrode arc welding is carried out in a protective atmosphere of inert gas and is one of the highly effective methods of performing arc welding by melting metal.

This technology is used in most cases to work with metal structures made of aluminum, magnesium, as well as their alloys, stainless steel, nickel, copper and a number of other metals with non-ferromagnetic qualities.

Types of non-consumable electrodes

Non-consumable electrodes are used for arc welding of metal structures. This is a consumable material for welding work, which does not have a metallic nature and properties inherent in metals. A similar method of welding operations was invented a long time ago by the hands of N. N. Benardos.

Types of welding electrodes.

Today, when making connections to metal structures, three main types of non-consumable rods are used:

1. A carbon non-consumable electrode is actively used in air-arc cutting of metals in order to eliminate various types of defects from the surface of products.
   In this case, welding must be carried out at currents of no more than 580 Amps. Also, such welding consumables are used to create connections between metal parts in thin-walled structures made of steel and non-ferrous metals. Carbon welding electrodes can be round or flat, folded along the weld line or fed into the weld pool. They can be used with or without an additive, which is determined by the welding technology.
2. Graphite rods are relevant for welding non-ferrous metals, as well as their alloys.
   But they are especially often used when working with copper wires. Graphite consumables are affordable and quite common on the domestic market, as they are characterized by a number of undeniable advantages. Among them: low wear, high temperature resistance, excellent machinability.
3. A tungsten welding electrode is made in the form of a rod with a diameter of 1-4 mm and is most often used in production and everyday life.
   This consumable material is characterized by high refractoriness, that is, it melts at higher temperatures than other types of rods. It allows you to weld a variety of metals without the use of gas protection. Although it is quite possible to carry out welding with a tungsten electrode under such conditions, if necessary. Depending on the composition, products are divided into several groups: lanthanated, ytriated, thoriated, standard.

All described types of electrodes for welding work are classified as non-consumable, since during welding work the rod either does not melt at all or melts insignificantly.

In any scenario, the material of the rod is practically not involved in the process of formation of the deposited metal and welded joint.

Welding with non-consumable electrodes

Gas shielded welding diagram.

Non-consumable electrodes are actively used in large enterprises:

• if necessary, weld thin sheet metal;
• for carrying out welding work with steels of all classes, non-ferrous metals, as well as their alloys;
• if necessary, obtain high-quality welded joints of dissimilar metals.

Advantages of non-consumable electrode welding:

• high arc stability, regardless of current polarity;
• the ability to obtain seams with a base metal share of 0-100%;
• the ability to adjust the chemical composition and geometry of the joints when changing the feed speed, inclination angle, profile, and brand of filler material.

The following points are considered to be the disadvantages of this welding method:

• poor energy efficiency indicators;
• the need to use special devices to ensure the initial initiation of the arc;
• high cooling rate of manufactured seams.

But to fully characterize non-consumable electrode welding, it is important to understand the technological essence of the process. The operation is carried out by supplying protective gas through a nozzle into the arc zone that burns between the consumable and the product.

The gas performs a protective function, protecting fireproof welding electrodes and molten base metal from the negative influence of active atmospheric gases. The edges of the product being welded melt under the influence of the heat of the arc and form a weld, crystallizing.

When using a welding machine and non-consumable electrodes, it is important to set the polarity correctly. It can be direct or reverse. In the first case, you need to set the mass to minus, the holder to plus. In the second, the mass is set to plus and the holder to minus.

Brand and purpose of non-consumable electrodes.

The shape of the welded metal depends on the correct choice of polarity mode:

• working with direct current with straight polarity will create a deep and narrow weld;
• a wide and shallow weld can be achieved by selecting constant current and reverse polarity.

The shielding gas for argon-arc welding using electrodes must certainly demonstrate inertness to the working metals, therefore, when working with tungsten electrodes, argon, helium, or a mixture of argon and helium are used as such substances.

If welding work is carried out over copper wires or using copper electrodes with a hafnium insert, you can use nitrogen.

If you have to work with metal of great thickness, then you can ensure the melting of the base metal and obtain the actual geometric parameters of the weld by welding along the gap or by cutting the edges with the addition of an additive.

Results

The use of non-consumable electrodes for arc welding when working with metal structures made of aluminum, magnesium, their alloys, nickel, stainless steel, copper and a number of other non-ferromagnetic metals allows us to obtain truly strong and durable welds.

This is extremely important for such production areas as metallurgy, electrochemical industry and electrothermal production.

Source: https://tutsvarka.ru/vidy/svarka-neplavyashhimsya-elektrodom

Marking of welding electrodes and their interpretation

When working with manual arc welding, you are constantly working with electrodes. This element of the welding process is not as simple as it seems and has its own extensive classification. Today you can select products to suit any needs, based on the metals being welded, the type of equipment, the required properties of the seam and many auxiliary parameters. Below you will learn about the classification of coated electrodes and their designation.

What types of electrodes are there?

Electrodes applicable for manual arc welding are divided into consumable and non-consumable. Rods that melt during welding are made of cast iron, steel, copper or other metal, depending on the material. They play the role of an anode or cathode, and also act as a filler material. They can be covered or uncovered.

The coating in consumable rods performs many functions, from holding the arc to forming a gas cloud that prevents oxidation of the weld. Non-consumable electrodes for welding are made from various refractory materials - graphite, tungsten or coal. They serve to ignite and hold the arc, and filling the seam with additives is carried out using manual supply of fusible material.

What does a consumable electrode consist of?

Consumable electrodes for manual arc welding consist of an inner rod and an outer layer.

According to the requirements of Gosstandart, when creating consumable welding electrodes, a variety of steels are used: carbon, with a large or small number of impurities; copper, aluminum, nickel and other non-ferrous alloys are also used.

The composition of the rod is determined by the material being welded, since both metals must fit together. The exception is cast iron, which can be welded with both steel and copper and iron electrodes.

Like the rod, the outer layer is made taking into account the metal being welded, which is why its composition may vary slightly. But despite this, it invariably performs the following functions:

• promotes arc retention;
• produces slag that envelops the weld pool, melting the mineral components of the coating;
• produces a protective gas that appears as a result of the combustion of organic components of the coating.
• performs deoxidation or alloying of metal.

We recommend! Design and use of oxygen cylinders

Classification of coated electrodes

Considering the long list of all possible variations of coating, alloy and other parameters of coated electrodes, for a more convenient search for the desired type of rods, they received an extensive classification. Types of welding electrodes are divided based on the following characteristics:

By purpose:

• alloys with a small proportion of impurities and carbon alloys;
• material with a large number of ligatures;
• alloys with enhanced strength and unique properties;
• surfacing electrodes with unique properties.

Type - the value of the final seam, characterized by tensile strength, temporary or point mechanical impact.

Welding electrode grades are a unique value assigned by the manufacturer for the internal classification of products. That is why the marking of welding electrodes with the same parameters, but from different manufacturers may be different.

The thickness of the outer layer - based on their thickness ratios, the outer layer is classified into thin, medium thickness, thick and the thickest based on the size of the central rod.

Type of current – ​​electrodes of direct current, alternating current with direct or reverse connection.

The composition of the coating is divided into a welding electrode with an acidic, basic, cellulose, rutile, layer with an increased concentration of iron, spraying consisting of various layers.

According to the permissible positions, the rods are divided into products permissible for work in: · any positions; · all except vertical, directed downward; · lower and vertical, directed upward;

· lower.

Based on the quality or condition of the seam, after working with the rods, the electrodes are divided into three groups.
Products of better quality belong to the first group. Thickness is a parameter indicating the diameter of the steel base; it can range from 1.6 to 12 mm.

To figure out which electrodes are presented in front of you, you should study their markings. Each package contains information about 9 main characteristics in accordance with GOST 9466-75.

1. Types coated electrodes for welding. High-strength steels, with a large proportion of carbon, high or low percentages of alloys, are welded with electrodes marked starting with the symbol E - electrode, then there are numbers indicating the maximum permissible tensile loads (kgf_mm2), at the end there is an index A - indicating increased resistance of the seam to plastic and impact loads. For example: E 42, E 50, E46 A, E 60, etc.

   Heat-resistant and high-alloy steels: symbol E, numbers after the dash indicating the amount of carbon, followed by letters and numbers indicating a specific chemical element (A - nitrogen, M-molybdenum, F - vanadium, etc.) and its amount in hundredths . Chemical components are arranged in descending order of their quantity in the product. For example: E-09M; E-10ХЗМ1БФ; E-30G2ХМ, etc.

2. Brands of electrodes for welding
   Brands are an individual parameter and depend solely on the manufacturer.
3. Diameter
   The thickness of the inner part of the coated electrode ranges from 1.6 to 12 mm; in everyday life, thicknesses of 3-5 mm are most often used.
4. PurposeManufactured to work with carbon steels and with a low number of impurities, as well as strength up to 60 kgf/m2, electrodes are marked with the letter - U; Alloyed structural steels with a tensile strength above 60 kgf/m2 are welded with products marked - L; Products for steels with low the coefficient of thermal conductivity is marked with the letter - T; Metals with a large proportion of impurities and unique properties can be welded with products marked - B;

   Surfacing layers with unique characteristics are produced by products marked - N.

5. Coating Thickness
   A value indicating the ratio of the thickness of the coating to the inner rod. If this ratio is less than 1.2, then the product is marked with the symbol M and classified as thinly coated; the middle layer ranging from 1.2 to 1.45 is marked with the symbol C; thick - from 1.45 to 1.8 are marked with the symbol D and finally the thickest, the ratio of which is more than 1.8, is marked with the mark G.
6. Basic properties of the weld
   The exact properties of the alloys, for each type these values ​​are their own and indicate the strength, percentage composition of impurities, operating temperature of the weld and a number of other indicators. These values ​​can be found in the corresponding tables with interpretations.
7. Type of electrode coating A – acid coating. B – calcium fluoride. C – cellulose. R – rutile. G – high iron content.

   There are also mixed types of electrode coatings, which are marked with several letters based on the composition.

8. Marking of spatial positions1 – all, 2 – everything except vertical, directed downwards; 3 – lower, plus vertical (bottom-up movement);

   4 – exclusively lower.

9.  Type of welding current and connection – Index 0 electrodes for direct current and reverse connection; – index 1,4, 7 – indicates products for any kind of voltage and any connections; – indicators – 2,5,8 – any current, but the connection must be direct;

   – indexes – 3,6,9 for any currents and reverse connection.

We recommend! How many electrodes are in a pack?

Manufacturers of welding electrodes

Below are the three best manufacturers of welding, coated electrodes in Russia:

1.  NPP "Welding of Eurasia". Over more than 70 years of history, the company has managed to master the full cycle of electrode production and currently produces all types of electrodes - consumable, welding, for alloy steels and many others.
2. JSC "Electrode Plant" The manufacturer is famous for its products, which are supplied to the largest machine-building plants in the country; the company also produces products for the average consumer. Professional welders note the ease of use and quality of this company’s products.
3. NPO Spetselektrod LLC. The products of this company include more than 50 different brands of consumer rods up to 6 mm thick. The production also accepts individual orders.

Don’t forget about the world leaders, the top three:

1.  Esab is a company with a century-old history and products recognized as the best in the world. These Swedish electrodes are known on all continents as the highest quality.
2. Kobe Steel is a Japanese company that has gained popularity by supplying their products to oil production companies.
3. Klöckner & Co SE is a German company producing steel and welding consumables. Welding electrodes from this company are very popular and widely used in Russia.

Source: https://svarkagid.ru/materialy/klassifikatsiya-elektrodov-dlya-svarki.html

The main types of welding electrode coatings that you definitely need to know

The coating of welding electrodes is a homogenized mass of mixed chemical compounds applied to a special metal rod.

the task of such substances is to ensure the required properties of the weld and promote correct, uninterrupted combustion of the arc during welding. Depending on the final goals, certain types of electrodes with certain properties are produced.

Their diversity and assortment are constantly updated on the market. Let's take a closer look at the most important varieties.

Cellulose electrodes

Such coatings are made from cellulose (up to 50%), which consists of organic materials, where wood flour is mainly used. The composition may also include ferroalloys, resins of organic origin, and talc. Cellulose electrodes are thin, form a small amount of easily removable slag and are most suitable for positional welding (when working with vertical seams, the slag does not slide down).

Good results are obtained with one-sided welding in any position, when welding the root of a seam on pipelines. In this case, the reverse seam bead is smooth and relatively neat. When heated, the electrodes dissociate into hydrogen and carbon dioxide, which in turn serve as shielding gases. Typically a constant current source is used. With the help of stabilizers for cellulose electrodes, alternating current can be used.

According to GOST, they correspond to the following types of electrodes: E 42, E 46 and E 50.

Flaws

The weld metal contains a relatively high amount of hydrogen, which reduces the ductility of the weld, and therefore cold cracks are likely. Characteristic splashes.

Rutile coated electrodes

As you know, rutile is a titanium mineral. For this type of electrode, the coating uses a titanium dioxide (TiO2) concentrate applied to steel rods. It produces an acidic slag and provides gas protection from hydrogen, nitrogen oxides and carbon. These electrodes are used for low-carbon steels in any spatial position.

In the GOST classification, mechanical properties are comparable to types E 42 and E 46. The addition of a small amount of cellulose to rutile electrodes provides an additional reserve for gas protection. Sometimes a small addition of cellulose to rutile will further improve performance, a combination called rutile-cellulose coating (RC).

In addition, there can be combinations with basic and acidic coatings (RB and RA respectively).

Peculiarities. Compared to acid-based electrodes, rutile “brothers” when welding produce metal that is more resistant to cracks, they produce less spatter and a stable, strong burning of the welding arc at alternating current. Relatively not susceptible to rust, oxidation, and moisture.

Rutile electrodes produce easily separated slag and perform well when welding vertical seams. Porosity is possible in rare cases when welding technology is violated, for example, if too thick electrodes are used for thin metal or there are gaps in T-joints.

They perform remarkably well in areas with short seams, where frequent breaks and repeated ignitions of the arc are necessary.

Weak sides

Rutile electrodes exposed to moisture can be used only after 24 hours (preliminary calcination will be required for about an hour at temperatures above two hundred degrees Celsius). It is undesirable to use them for welding structures exposed to high temperatures and creep.

Acid coated electrodes

This type of electrode coating contains metal oxides, including iron oxide, silicates and manganese oxides, which produce acidic slag. According to GOST, they correspond to types E 38 and E 42. Direct and alternating current can be used.

 Due to the high oxygen content, acidic electrodes increase the temperature, making the metal highly fluid. On the one hand, the listed features contribute to quick welding, but on the other hand, they can lead to the appearance of pores, low strength of the weld, and undercuts.

 To level this out, some deoxidizing agents are added to improve the mechanical properties and the ability of the slag to be easily removed.

Flaws

An extended arc, the presence of rust and oxides significantly increase the likelihood of hot cracks and pores in the weld. Acidic electrodes increase the hydrogen content in the weld pool. They are toxic and have increased splash formation.

Basic electrodes or low hydrogen electrodes

The base electrode variety contains calcium carbonate, magnesium carbonate, calcium fluoride and other minerals (such as fluorspar). These electrodes must be kept dry and properly warmed before use. Gas protection includes carbon dioxide with low levels of hydrogen and oxygen.

 Hydrogen control provides protection from atmospheric exposure, making the electrodes suitable for high- and low-alloy steels, for steels with low carbon content. When welding under the influence of high arc temperatures, dissociation of carbonates occurs, which ultimately contributes to an increased basicity of slags and the appearance of a protective gas environment with virtually no hydrogen evolution.

Additionally, calcium fluoride binds the hydrogen component. Because of these features, the variety received its second name - calcium fluoride electrodes. They are indispensable for structures with a rigid base, for hardening steels prone to cold cracks, and also form seams that are not prone to rapid aging.

Low-hydrogen electrodes are used in manual arc welding regardless of spatial position.
The seams can be of considerable thickness. Type in accordance with GOST 9467-75 on mechanics of deposition: compared with E42A - E50A.

Weak sides

Pores may appear if the metal being welded has rust or oxidation. The arc when burning is less stable than that of other types of electrodes. Mainly used with direct current. For alternating, you will need potash or special potassium-sodium compounds combined with heating of the electrodes (up to 400 °C).

Electrodes containing iron powder

Iron powder is added to all types of coatings to improve the efficiency of electrodes. Additional iron powder increases the deposition rate. This reduces the voltage, allowing the cellulose electrodes to handle alternating current. In addition, the additive controls the viscosity of the slag. This property is very useful in positional welding.

conclusions

Let us summarize briefly in tabular form.

The coating of welding electrodes differs in its parameters, properties, and scope of application. We examined the main types of coatings, identified the main advantages and disadvantages. We hope that the material will be as useful as possible for you, our dear readers.

Source: https://blog.svarcom.net/news/osnovnye-vidy-pokrytij-svarochnyh-elektrodov-kotorye-obyazatelno-nuzhno-znat.html

Types, brands and features of electrodes for manual arc welding

There are many methods for joining parts, but manual arc welding has earned particular popularity. It is applied through the use of single welding electrodes.

In the process of manual welding of metal parts, electrodes play an important role. Depending on the brands chosen and properly configured equipment, you can get a high-quality seam, even in hard-to-reach areas.

Classification by material of production

What types of electrodes are there? As you know, all welding consumables for manual arc welding are divided into fusible and non-fusible types. Fusible elements include: welding tools made of cast iron, aluminum, copper, steel. It all depends on the type of metal surface being welded. The metal rod can act as both anode and cathode, and can serve as an additional component in the welding field.

Infusible materials include coal, tungsten and graphite. They perform only a primary function, and an auxiliary wire is used during the welding process. Tungsten rods are actively used in manual arc welding in an inert gas environment.

According to GOST 9466, rods during the welding process can differ in several functional characteristics.

By purpose

Based on GOST 9466 and GOST 9467, electrodes are divided into categories:

• For welding metal surfaces (steel) with low to moderate carbon content. The tensile strength is at the level of 600 MPa. Indicated in the description as the letter designation – “U”.
• For joining alloy and heat-resistant steels. Mark "T".
• For alloy iron with a resistance of 600 MPa. Designated by "L".
• For fusing external layers with the desired characteristics. Mark "N".
• For high-alloy (with a high content of additives) steels with special properties. Marked "B".
• For joining metal surfaces with plastic parameters. Designated "A".

According to the thickness of the coated substance

The classification of electrodes when welding surfaces can also be carried out according to the thickness of the coated layer. These values ​​depend on the section. There are several types:

• Thin shell "M". The thickness of the coating varies at 20% of the diameter.
• Layer of moderate thickness "C". The thickness is approximately 45% of the element's cross-section. This is the most common option.
• Thick shell "D". The coated layer reaches 80% of the double radius of the tool. Ultra-thick layer “G”. The shell thickness is more than 80% of the diameter.

According to the cleanliness of the coating and location in space

Layering can be either pure or mixed with other materials, that is, it can contain several components. It can be: acidic (A), basic (B), cellulose (C), rutile (R) and other types (P).

Individual arc welding electrodes are not suitable in some positions because they are excessively fluid. To indicate this parameter, the package contains a clause about application in space:

• “1” – you can work in absolutely any plane;
• “2” – all positions are allowed, except vertical;
• “3” – Ceiling position is excluded during operation;
• “4” – you can only work in horizontal planes.

If the welding device, electrodes and protective equipment are selected correctly, then all work on manual welding of metal surfaces will be safe, and the seam will be reliable, high-quality and durable.

Marking, decoding

It happens that electrodes for welding dissimilar steels have many letters and numbers, so many beginners in welding do not understand their essence. Let's consider the electrode "E-46 LEZANO21 UD E 43 1(3) RC13". In this title:

• E-46 is a typical component used for steels with low and moderate carbon content;
• LEZANO21 – brand of electrode for manual welding;
• “U” – the purpose of the element, that is, for low-alloy (with a low content of additives) and carbon iron;
• “D” – thick layer of coating;
• “E” – classified as fusible;
• “43” – tensile strength maximum – 430 MPa. This indicator corresponds to GOST 9466-75;
• “1” – conditional elongation is at the level of 20%;
• “3” – room temperature is recommended to preserve impact strength;
• “RC” - the letters stand for a combination of rutile-cellulose layering; “1” - you can work in any plane;
• “3” – applied current for DC welding, observing reverse polarity. You can also use alternating current, but this will require a welding transformer.

This is what the decoding of the markings of electrodes for welding metal surfaces looks like.

Coating features

A welding rod for manually joining metal surfaces is made from a special measuring wire with a protective layer applied. The coating plays an important role in the cultivation of the welding area, helping to protect the area from external environmental influences and ensure a stable arc.

The containment includes:

• Process stabilizers. They provide a stable arc thanks to aggregations of alkaline earths and alkaline metals. They are practically incapable of ionization. Among such metals are potassium, less active sodium and calcium.
• Slag formers. Thanks to these elements, a protective shell of slag appears in the welding area, which prevents oxidation processes from developing. These components include some minerals and ores, for example, granite.
• Gas formers. Their role is to provide reliable gas protection of the welding area. The released gases create a protective shell in the contact area. Gaseous substances are divided into inorganic and organic elements. Prominent representatives of these components are marble, magnesite, starch, and wood flour.
• Elements that change the composition of the metal and deoxidizers. Their use is due to the fact that in certain situations it is necessary to change the composition of the metal or get rid of oxygen dissolved in the alloy. In addition, deoxidizing elements are capable of reducing welded metals in the form of oxides in the working area. Such substances include manganese, titanium, silicon and their alloys with iron.
• Binding agents. These elements bind powdery substances and give them integrity. Liquid glass is a prominent representative of this category.
• Shape modifiers. Such elements give the coating additional plastic characteristics. Among such substances are dextrin, mica and many others.

The popularity of manual welding of metal is determined by the simplicity of the procedure, as well as minor financial investments with a high-quality level of the process. In manual arc welding, different types (brands) of electrodes are used.

In accordance with the type of metal being welded, the consumable component is also selected in order to achieve maximum identity of the tool used and the product being prepared. In addition, there are many factors that influence the operating conditions of the bonding process.

This environment determines the choice of electrode for manual arc welding of metal surfaces.

Primary requirements

Consumables used for welding or surfacing can be divided by area of ​​sale and various production characteristics. For example, manual arc welding can be classified according to the mechanical parameters of the seam joint, the method of applying metal to the product, and the physical parameters of the slag.

When carrying out welding work, the electrodes are subject to the requirements established by GOST 9466-75:

• must guarantee good arc burning and high-quality seam joints without pores and cracks, especially for welding pipelines at home. Thus, electrodes are used for welding with alternating current;
• a metal of a special composition must be formed in the working area;
• melting is carried out evenly, dispersing over both sections of the metal being welded;
• there should be no strong metal spattering, thereby ensuring good performance;
• the slag formed should come off easily;
• high coating strength;
• must retain its original properties for a long time;
• minimum level of harmful emissions during welding work; increased mechanical resistance to possible impacts.

Manual arc welding with coated electrodes is carried out through the use of auxiliary components, in the form of a cellulose or rutile coating. Basically, such rods are used for welding work with steel.

Components used for production

Based on GOST, for the production of metal rods of consumable electrodes, dissimilar grades of steel are used, namely carbon, alloyed and high-alloyed. Metal wire is designated in a special way. The presence of the designation “Sv” on the brand of welding electrodes means the element is of a welding type. If it indicates a number, it means the percentage of carbon.

After the number there is a coding of alloying components and their percentage in the metal composition. For example, a metal product contains 0.10% carbon, 1% chromium, silicon, 2% manganese, then the marking of electrodes for welding is as follows - Sv-10ХГ2С. A similar model was created according to all the rules of GOST 9466-75.

The structure of the wire and the metal product being welded must be mutually consistent.

To connect non-ferrous metals, the electrode must be made of copper, nickel, ductile aluminum or bronze. But it is worth considering that cast iron parts are connected not only with steel electrodes, they can be connected with copper-iron types of rods. Due to the heterogeneity, carbon is released during welding, which significantly increases the strength characteristics. These manual arc welding electrodes typically consist of 10% iron and 90% copper.

Welding is impossible without the use of electrodes. Their importance is extremely high, since the quality of the seam of the cultivated surfaces depends on the optimal choice of consumables.

A wide variety of brands of electrodes for manual arc welding indicates the wide purpose of the elements.

This makes it very important to understand the electrode designations for manual arc welding because it helps you understand what types of electrodes are required to join metal and make the right choice.

Download GOST

GOST 9466-75 Coated metal electrodes for manual arc welding of steels and surfacing. Classification and general technical conditions

GOST 9467-75 Coated metal electrodes for manual arc welding of structural and heat-resistant steels. Types

Source: https://oxmetall.ru/svarka/tipy-marki-elektrodov

Types of electrodes for welding

To get a good result in the form of a high-quality weld, before starting welding work, you must carefully study the materials required for production. You need to understand the types of electrodes, because universal products for welding do not yet exist. Each type is used for a specific material and under certain conditions.

Basic criteria for selecting welding electrodes

Products for welding work primarily pay attention to its diameter, its appearance - melting or non-melting, the polarity and type of electric current, the type of coating and the location of the seam.

When choosing welding electrodes, it is necessary to take into account the shape of the edge of the metal sheet, its brand and electric current parameters. Such an important parameter of products as diameter is determined by the thickness of the materials being joined.

The thinnest rods with a diameter of 0.1 cm are used when welding with a current of 20 to 25 A metal sheets up to 0.015 cm thick. Products with a thickness of 0.3-0.4 cm are the most common and are used for welding metals less than 0.10 cm thick.

In this case, a current of no more than 220 A is used.

The larger the diameter, the more powerful the welding equipment used. The maximum diameter of the products is 1.2 cm. For everyday tasks, 3 mm electrodes are used. If the rod size is less than 2 mm, the electrode is used to connect thin sheets of metal.

In industry, the “four” is more often used, and electrodes thicker than 5 mm are used in construction, shipbuilding and bridge building, and in other large industries.

Stainless steel and aluminum are joined using tungsten electrodes, using alternating current to produce a better quality weld. Carbon steel products are connected by rutile-coated electrodes.

Source: http://themechanic.ru/vidi-elektrodov-dlya-svarki