Welding rail p75 with rolled metal which electrode. Rail welding: methods and their main features. Methods for welding rail joints

The installation of railway lines is carried out by two methods: prefabricated and welded. The second is preferable because prefabricated joints reduce the speed of rolling stock. Welding of rails is carried out by several methods. When choosing a method for mounting seamless lines, the weldability of the material and the cost of work are taken into account. The most common: contact and aluminothermic welding, there are other types. Each one should be mentioned separately. Joints are welded using special equipment.

The railway profile is made from high-carbon steels, characterized by poor weldability. During heat treatment, cracks form on the metal, internal stresses arise. When welding rail lashes, this is unacceptable, web defects can cause an accident.

To work you need:

professional equipment;
quality consumables;
control devices that check the integrity of the seam.

To form a strong connection, thick-walled beams must be welded to the full depth. After welding the joint, it is necessary to level the surface so that the seam does not collapse.

Rail types

To select a welding method, the chemical composition of the alloy is taken into account. For each type of profiles, GOST defines steel grades.

Name	Purpose	Steel grades used for manufacturing
Railway standard	Issued for main roads	RP50, RP65, RP75.
Railway industrial	Used for short distances.	RP50, RP65, RP75.
Railway narrow gauge	They are mounted in mines, on access narrow-gauge railways.	P8, P11, P18, P24.
Mine for mine conductors	They are used for jointless wide-gauge sections, switches	R33, R38, R43
frame	Necessary for installation of intersections of lines.	PP65.
Crane	Designed for the movement of overhead and construction cranes.	KR70, KR80, KR100, KR120 and KR140.
witty	Necessary for turnouts, circular support devices.	OP43, OP50, OP65 and OP75.
Trams with gutters	They are used only for tram tracks, they are designed for a small load.	T58 and T62
Counter-rail	Mounted in dead-end sedimentation tanks.	RP50, RP65, RP75.
Antennae	Are issued for crosspieces with a continuous rolling surface.	UR65

Methods for welding rail joints

When choosing a technology, the weldability of steels, their fluidity, and ductility are taken into account. An important factor is labor costs, the cost of equipment. Taking into account all the components, they decide how to weld the rails.

For sealing joints, the following technologies are used:

electric arc;
electrocontact;
aluminothermic;
gas press.

At enterprises, thermite welding of rails is more often used, less often contact welding. Each technology has its advantages.

Arc

Welding of rails using electrodes is used for joints and lashes. In the bathroom, it is possible to obtain a strong connection. The ends are placed at a slight elevation above the sheet with a gap of 14-16 mm in a special bath that holds the melt. An electrode with a diameter of 5 or 6 mm is placed vertically in the joint. When a high-frequency alternating or direct current of direct polarity is supplied with a power of 300–350 amperes, depending on the thickness of the profile, the melt gradually fills the entire joint. The diffusion layer is created over the entire section. For welding rails, electrodes with the main type of coating are used:

domestic UONI 13/45 and UONI 13/55,
Japanese LB 52U.

They are pre-calcined: for 2 hours they are kept at a temperature of 180 - 230 ° C.

Advantages of electric arc welding:

no need to use flux, the coating creates a layer of slag above the bath, it prevents oxidation;
no preliminary cutting of the ends is required;
no additional effort is required to form a tight connection;
availability, transformers, rectifiers and professional inverters are used as a current generator.

After cooling the bath, the joint is cleaned, the scale is removed, and the surface of the rail head is leveled.

Thermite

The method is based on the ability of aluminum to reduce iron oxide with a large release of heat. mastered over a century ago. When thermite is set on fire, a temperature of 1200 to 2000°C is created in the working area, depending on the chemical composition of the alloy. The reduced iron flows into a mold that matches the profile of the rail.

In addition to iron and aluminum oxide, thermite includes alloying additives, small pieces of metal (they slow down the chemical process). The slag formed during the melt floats, it is removed after the metal has cooled.

The most important advantage of the method is the high speed of thermite welding of rails. It is used for hardened and cold rolled beams. It is used in the installation of main railway lines and lashes.

Gas press

Welding of rail joints by this method is carried out on ductile steels. The temperature in the junction zone of the ends rises due to the shear energy. It is released at high pressure. A high-quality connection is formed due to the homogeneity of the diffuse layer. For tight joining of the rails, the end is cut with a rail cutter. The metal is preserved with 4-carbon chloride or dichloroethane; the metal does not oxidize under the composition. The joint is heated to a viscosity temperature, under a 10–15-ton pressure of a hydraulic press, the layers shift, the ends melt, and a diffuse layer is formed.

The main advantages of the gas pressure method:

homogeneity of the chemical composition;
lack of scale, the process takes place inside the profile;
the ability to connect a profile of any configuration and thickness.

Electrocontact

Automated technology is based on the heating of the joint due to a penetrating electric arc that occurs under the influence of high currents of low voltage. Electrocontact welding is carried out by self-propelled complexes MSGR-500, MS-5002, K-190 directly at the place of laying or with a slight displacement of the branch. Replaceable contact heads are used for different types of rail profile. The work is carried out by the method of continuous reflow or pulse heating of the rails.

Quality control of rail joints

Traffic safety depends on the strength of the joints, therefore, regardless of the method of welding, rail joints are checked by any of the non-destructive testing methods. The seams made by manual welding equipment are especially carefully checked. In addition to the structure, the evenness of the rail head, on which the wheel rests during movement, is checked.

Welding of rail joints is in high demand today. As you know, when the rolling stock passes prefabricated joints, they begin to get upset at a high speed. In this case, the smooth running disappears, due to which the upper coating of the railway track is destroyed. And this option will help correct the situation.

Main characteristics

It is required to lay rail tracks that have welded joints on any type of track, resulting in a seamless rail.

The rail thread is torn precisely in the places where the joint is formed. Such a gap, even with the installation of butt plates, has a great influence on the rigidity of the structure, and subsidence begins to increase.

As a result, when the rolling stock passes through the rail joint, the wheel hits the end head of the receiving rail. Due to numerous blows to the butt joints, the undercarriage of the cars, as well as the laid rails, begins to wear out quickly. Due to strong impacts of the wheelset on the running rail, rail heads are chipped and crushed. Typically, such defects are found 60 cm from the junction. The rails begin to break in the bolt holes, the linings are bent, the butt bolts are deformed. All of the above disadvantages do not apply to a seamless path, and it has several positive qualities:

almost 30% reduction in the cost of maintenance of the rail track;
energy is saved significantly, fuel consumption is reduced by about 10%;
increases the service life of the upper tracks,
rolling stock can operate much longer;
passengers experience greater comfort when the train moves;
the operation of auto-blocking and electrical circuits becomes more reliable.

Due to such positive qualities, the seamless version was adopted by all the main railway lines in the world.

Sometimes the choice of a particular type depends on the cost of work and productivity. Such a choice entails the appearance of welding joints in especially critical structures, the quality of which is at a very low level.

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To obtain an excellent weld, a material with good weldability is required. Basically, weldability characterizes the properties of the metal, the existing reaction to the welding process, as well as the ability to obtain such a welding joint that will meet all specified technological requirements.

When the parts are made of a material that is freely weldable, no special conditions are required to obtain a high-quality seam. But for parts made of poorly weldable material, additional technological conditions are required. Sometimes a special type of welding is used, which is much more expensive and more complicated. Moreover, the execution of works requires strict adherence to the technological process.

Welding of rails is in demand today, as the rail thread breaks and the undercarriage of the cars wears out quickly.

The composition of steel for rails includes a lot of carbon, almost 82%. This material belongs to the group of materials with poor weldability. When welding, cracks may appear, which is completely unacceptable on the rails. They concentrate stress, which can lead to the destruction of the butt joint and the collapse of the composition.

Today, two types of welding of rail joints are known:

contact;

aluminothermic.

It has become widespread, however, it has several serious drawbacks, restrictions when repairing railway tracks is carried out:

welding requires special rail welding machines, which are very expensive;

duration of equipment delivery and its subsequent evacuation;

to carry out the work, it is necessary to involve numerous teams;

for lack of a large amount of time, it is necessary to constantly perform work without observing the technological process, as a result of which the joint is of very poor quality;

it is impossible to weld the joint directly in the place where the arrows are translated.

Contact welding of joints loses to aluminothermic welding of rails. For it you need to have:

complex and very expensive equipment;

numerous brigade;

breaks in train traffic.

Aluminothermic welding of rails is done very quickly. The operation takes about half a minute. If you count the preparatory work and the final processing of the weld, it takes about 45 minutes.

I must say that such welding allows you to simultaneously weld several joints, as a result, the time spent on work is reduced.

Three people are needed to weld the joint. Their training takes place in the shortest possible time. The mass of the used equipment reaches 350 kg. For welding, when aluminothermic welding is used and other special operations are carried out, autonomous fuel supply sources are used.

To carry out aluminothermic welding of rails, engineers created portable miniature equipment that can operate offline right in the floor.

Technologists were able to choose a certain composition of the thermite solution and its granularity. This helped to achieve a thermite reaction in which no explosions occur, no decay is observed, and the most optimal speed and the desired temperature of all materials involved in the reaction are maintained.

Aluminothermic welding consists of several basic technological steps:

initial high-temperature heating;

final welding of rails.

Welding of rails by the second method - flashing with preliminary intermittent heating consists of an intermittent heating stage, a continuous flashing stage; stages of upsetting and welding, stages of cooling of welded joints. In this method, in contrast to the first method, heating of the metal of the rails is carried out by repeated cyclic closing and opening of the rail ends. Electrocontact welding provides the highest quality of welded joints. The quality of welded joints is determined by the degree of plastic deformation and heating of the rail metal. In this regard, the priority is the obligation to strictly ensure the welding modes approved by the Main Directorate of the track of the Ministry of Railways.

7.3. Arc welding

In electric arc welding, the rails are connected by the metal of the electrode, which is melted from the heat of the arc discharge.

Electric arc welding of joints does not require the application of sedimentary pressure. For this welding, alternating current from a transformer or direct current from a mobile welding unit is used.

The best method of electric arc welding is the bath method, in which the ends of the rails, cut perpendicular to the longitudinal axis, are installed without a fracture in the plan, and in the profile with an elevation of 3-5 mm, and in this position they are fixed with a gap of 14-16 mm.

An electrode is inserted between the ends, through which a current of 300-350 amperes is passed. The molten metal of the electrode fills the gap between the ends along the entire section of the rail.

To prevent the molten metal of the electrode from spreading, inventory copper molds are used to close the gap from below and from the sides. Welded joints are ground around the entire perimeter of the rail. The quality of the welded joint depends on the electrodes and their coating, the constancy of the liquid state of the metal until the end of the welding process, and the thoroughness of the seam processing.

Electric arc welding is used only for rails laid on station tracks, except for main and receiving-departure ones.

7.4. Gas pressure welding

Gas pressure welding provides metal connection at a temperature

below the melting point with the application of pressure.

The main advantage of gas-pressure welding of rails is the high quality of the joint and the obtaining of a homogeneous metal structure in the joint zone, therefore this type of welding is especially beneficial when applied to heavier types of rails.

Before welding, the ends of the two rails are attached tightly to each other and together with the joint, the ends of both rails are simultaneously cut with a circular saw on a rail-cutting machine or with a mechanical hacksaw, which ensures the tightness of the ends and the purity of the metal. Immediately before welding, the ends of the rails must be thoroughly washed with carbon tetrachloride or dichloroethane. Preparation before welding consists in preheating the ends of the rails.

To heat the rail, multi-flame burners of the MG-50R type are used,

MG - 65R, MG - 75R. Multi-flame burner type MG - P65 is shown in Figure 1.3.

Fig. 7.3: Multi-flame burner MG-R65 (a) and its barrel (b):

1 - upper part of the burner; 2 - pads with holes for gas; 3 - the lower part of the burner; 4 - gas pipeline; 5 and 9 - pipelines for running water; 6 - gas bracket connecting 1 and 3; 7 - gas distribution chamber; 8 - cord with nipple; 10 - extension connecting the barrel with the mixing chamber; 11 - mixing chamber; 12 - burner barrel; 13 and 14 - fittings for supplying gas to the barrel.

The ends of the rails are clamped with a hydraulic press and heated to a temperature of 1200 0 C by a system of multi-flame burners oscillating along the joint (50 oscillations per minute). At the same time, the rails are compressed with the force set by the calculation (10 - 13 tons) until a draft of a given value (about 20 mm) is obtained.

For welding, universal gas-pressing machines SGP - 8U or MGP - 9 are used.

After welding, the joint is processed, and then it is normalized.

7.5. Aluminothermic welding

The creation of high-speed highways and a seamless track sets high quality standards for rails, especially at their junctions. Aluminothermic welding of rails fully meets these standards.

Aluminothermic welding of rails is intended for joining together in any combination of volume-hardened, surface-hardened and non-thermally hardened rails.

Welding of joints of rail lashes and joints (except insulating) of turnouts laid on wooden or reinforced concrete sleepers and beams can be carried out on the main, receiving-departure, station and hump tracks of the railways of the Russian Federation, on the access roads of industrial enterprises, as well as in the subway .

This process is based on the thermite reaction, discovered in 1896 by Professor Hans Goldschmidt, which is a chemical reaction to reduce pure iron from its oxide using aluminum with the release of a large amount of heat:

Fe 2 O 3 + 2Al => 2Fe + Al 2 O 3 + 849 kJ

The thermite reaction occurs in the crucible within a few seconds after the thermite portion is ignited, consisting of a mixture of aluminum powder, iron oxide, steel particles that dampen the reaction, and alloying additives necessary to obtain steel of the desired quality. The reaction takes place at a temperature above 2000 o With the final layer-by-layer separation of the reaction products: liquid steel (bottom) and light slag (top).

In Russia, VNIIZhT together with foreign companies Snaga (Slovakia), Electro-Termite (Germany), Reltech (Czech Republic and France) perform work related to thermite welding of rail elements in the area of connecting tracks. When laying a seamless track, the thermite method of rail welding (Fig. 1.4.) plays a leading role. At present, in the turnout area, it is the main method of connecting rails. It is a cost-effective technology with great application flexibility. In most cases, welding can be carried out without closing the stage. The technology of the company "Electro-Termite", having received the greatest distribution in comparison with other companies, represents two main methods of electro-thermite welding on the Russian market, namely the so-called SoBoS method (SoWoS) and the SkFau method (SkV) (Fig. 1.5) .

When carrying out installation and repair work on sections of the railway track, as well as in similar conditions associated with the laying of rail threads, special welding technologies are used.

Features of rail welding technologies are expressed in increased requirements for the operational reliability of joints, as well as their resistance to mechanical stress.

Welding of rail joints belongs to the category of especially important activities, the organization and conduct of which is impossible without the involvement of equipment and modern welding mechanisms.

The main types of welding technologies used in the installation and repair of rails are:

electrocontact welding;
electric arc method;
thermite processing (aluminothermic welding of rails);
modern gas-pressure welding.

Each of these methods has certain advantages and disadvantages. For a more complete acquaintance with them, we will consider each of the listed welding methods in more detail.

Electrocontact method

The electrocontact approach to connecting rail joints is based on their strong heating and subsequent melting by means of an electric arc, which is formed by a significant low voltage current.

To implement the method, special machine systems are used that operate in automatic mode (MSGR-500, MS-5002 or K-190, for example).

The rails to be processed before welding are laid either directly on the tracks, or with a slight offset inside the branch or outside the track (at a distance of about 260 centimeters from its axis).

At the same time, the welding mechanism itself moves along the thread being restored, that is, it is a self-propelled rail welding station.

In the process of its operation, replaceable contact heads of various types are used, providing the necessary welding modes (continuous melting or intermittent heating of contacts).

Arc method

Non-contact arc welding is one of the most common methods used when mating the joints of rail threads.

According to this approach, the rails are first laid with a small gap, after which their ends are welded with the metal of the electrodes melted by means of an arc discharge. This type of non-contact welding does not require the application of excess sediment pressure and is realized using alternating or direct currents coming from a mobile welding station.

The most effective way to implement arc welding of rails is the so-called "bathroom" method, according to which the rails cut in advance across the longitudinal axis are laid strictly along the track line with a slight elevation and with a gap of approximately 14-16 millimeters.

Between the ends of the rail blanks laid in this way, a working electrode is inserted, followed by passing a current of about 300-350 amperes through it.

As a result of such an impact, the molten mass spreads evenly over the gap and completely fills it. To prevent it from flowing outward, the gap between the rails is closed with special blocking fences. Upon completion of welding, the resulting seams are ground over the entire joint area.

Thermite processing

Aluminothermic technology has been time-tested. The basis for the use of thermite welding of rails is a reducing reaction that occurs when the base (aluminum) comes into contact with another component - iron oxide.

The resulting metal (reduced iron) at operating temperatures of about 2000 degrees is poured into a special fire-resistant mold that matches the geometry of the welded rails.

This reaction is accompanied by the release of a significant amount of thermal energy.

Welding rails using the thermite method began a very long time ago (since the middle of the 19th century), but since then this type of welding has been called aluminothermic due to the use of aluminum.

It is important to note that the described chemical reaction after the ignition of a special high-temperature fuel (thermite) lasts only a few seconds.

In addition to the two considered components (iron and aluminum oxides), alloying additives and small steel particles are introduced into the composition of the working welded mixture, slightly slowing down or damping the ongoing process. Additives are necessary in order for the steel in the welding zone to acquire the required qualities and parameters characteristic of most rail products.

When considering the features of this type of welding process, it should be noted that upon completion of the reaction, the total chemical mass is divided into two fractions: liquid metal and light slag that floats into the upper part of the mold.

Termitan technology allows to articulate the following types of travel products:

surface-hardened rail blanks;
volume-hardened joining parts of rails,
rails that have not undergone special heat treatment in any combination.

This type of welding ensures compliance with the requirements of the main standards for high-speed rail lines, in terms of compliance with welding technology standards.

Gas press method

This welding technology is based on the connection of metal rail joints at relatively low temperatures (noticeably below the melting limit), but at a sufficiently high pressure.

The main advantages of the gas-pressing method include the homogeneity of the material structure in the welding zone, as well as the high strength of the resulting joint.

Thanks to the listed advantages, this method can effectively “cook” even very heavy and dimensional railway products. Before welding, the ends of such rails are tightly joined to one another, after which, using a special tool (rail cutter with a circular saw or a mechanical hacksaw), they are simultaneously cut.

As a result of the preparatory operations, the required tightness of the fit of the end parts of the rails with a high purity of the metal interface is ensured.

In addition, immediately before welding, the ends are treated with dichloroethane or carbon tetrachloride. At the stage of preparing the rails for welding, their ends are heated to the required temperature by means of special combined burners, which ensure that a sufficient temperature is obtained.

After thorough heating, the ends of the rails are clamped by means of a specially designed hydraulic press and continue to heat up to 1200 degrees.

In the process of welding, the bodies of the burners are slightly displaced relative to the joint being processed (make small oscillatory movements). The frequency of such periodic movements, as a rule, does not exceed 50 oscillations per minute.

Simultaneously with these movements of the gas burner, the rails are compressed by a hydraulic press with a force of 10 to 13 tons, the exact value of which is determined by special calculations. According to the results of such processing, the metal to be welded at the junction is deposited by about 20 millimeters.

To implement the described technological chain, special gas-pressing equipment (universal machines) is used.

Upon completion of the entire complex of gas welding operations, the finished joint is carefully cleaned of slags, and then brought to a normal appearance (they say that it is being “normalized”).

So, the considered key methods for welding rail joints are applied in accordance with the technical requirements and conditions for carrying out repair and restoration measures.

Of all the approaches, aluminothermic welding stands out as the one that best meets modern requirements for non-contact restoration of rails or laying of railway lines. It is the thermite method that is most often used in the construction and repair of modern transport routes.

The owners of the patent RU 2270739:

The invention relates to arc welding methods and is used primarily for manual arc welding of railroad rails. The method for welding rail joints includes installing rails with a gap between the edges being welded, introducing a consumable electrode into the gap and welding using molds installed at the welding site at a current strength that ensures the formation of a liquid pool in the entire volume of the gap. The edges of the rails or the edge of one of the rails are preliminarily machined, which includes making a transverse cut along the vertical plane from the head to the beginning of the rail sole, making a horizontal cut along the end surface of the rail perpendicular to the previously made cut, and chamfering the end surface of the sole with blunting at the base of the rail foot. When a liquid bath is formed in the root of the weld, the edges of the base metal of the rails are additionally melted. This will make it possible to obtain a weld with mechanical properties equivalent to those of the base metal, which will increase the service life of the rails. 2 ill.

The invention relates to arc welding methods, mainly used for manual arc welding of railway rails.

A known method of welding rail joints, in which the welding of rails are manual arc method (SU 78136, B 23 K 9/02, 1942).

In the known method, the rails are installed with a gap between the edges to be welded from 9-14 mm, depending on the selected electrode diameter, so the weld is obtained mainly due to the melting of the electrode material. The welded edges heat up so much that a common pool of molten metal is formed, which is maintained in a liquid state during the entire welding period. Graphite plates, the inner surface of which is made according to the shape of a rail, can serve as molds. The size and shape of the reinforcement of the weld depends on the size and shape of the corresponding recess that is made in the mold.

The ends of the rails are cut with a rail cutter along a plane perpendicular to the axis of the rail. Bevel edges before welding do not produce.

A large gap between the ends of the rails of the order of 9-14 mm does not allow welding the edges of the sole of the rails, therefore, a forming lining is used to form the reverse side of the weld root. The weld is obtained mainly due to the melting of the electrode material, the molten mass of which fills the gap between the ends of the rail sole and the forming lining.

The most significant disadvantage of this method is the presence of a large gap between the ends of the rails. The molten electrode metal is a natural bridge between the rails to be welded, along which the arc moves from the edge of one rail to the edge of the other. The welded joint obtained in this way has a coarse-grained structure due to overheating of the electrode metal and, as a result, lower mechanical properties than those of the base metal. In the fusion zone of the rail edge with the molten mass of the electrode metal, there is a high probability of occurrence of defects such as lack of fusion, slag inclusions, and pores.

The technical objective of the present invention is to improve the mechanical properties of the weld by reducing the gap between the ends of the rails to a size that allows welding the metal of the sole of the rails and obtaining a weld with mechanical properties that are equivalent to those of the base metal.

The method according to the invention consists in the fact that the edges of the rails or the edge of one of the rails are preliminarily machined, while a transverse cut is made along the vertical plane from the head to the beginning of the rail sole, and then a horizontal cut is made along the end surface of the rail perpendicular to the previously made section, and at the end of the sole, a chamfer is chamfered with a bluntness at the base of the rail sole, rails with a gap are installed, an electrode is inserted into the gap and welding is carried out using molds at the welding site at a current strength that ensures the formation of a liquid pool in the entire volume of the gap, and the liquid pool in the root of the seam is obtained by melting the edges of the base metal.

The differences of the proposed method of welding rail joints are that the edges of the rails or the edges of one of the rails are preliminarily machined, while a transverse cut is made along the vertical plane from the head to the beginning of the rail foot, and then a horizontal cut is made along the end surface of the rail perpendicular to a previously made cut, and at the end of the sole, a chamfer is removed with a bluntness at the base of the rail sole, and a liquid bath at the root of the seam is obtained by melting the edges of the base metal.

The essence of the proposed method is illustrated by drawings.

Figure 1 shows a drawing when machining the edge of one of the rails, figure 2 - the edges of the rails.

In Fig.1 marked: 1 - rail (without edge processing), 2 - rail with a prepared edge, 3 - blunting, 4 - gap between the edges, α - angle between the edges.

In Fig.2 marked: 2 - rail with a prepared edge, 3 - dullness, 4 - the gap between the edges, α - the angle between the edges.

The angle α between the edges lies in the range of 30-60°.

Welded railway rails type P65. In mechanical workshops, distances are measured for a piece of rail 3 m or more in accordance with TU 32 TsP-670-88 and the edges of the rail are prepared from both ends for installation in place of the defective rail. In this case, a transverse incision is made along a vertical plane from the head to the beginning of the rail sole. Then, a horizontal cut is made along the end surface of the rail perpendicular to the previously made cut, and at the end of the sole, a chamfer is removed at an angle of 45° with a bluntness of 2 mm at the base of the rail sole. Markings are made on the rail from which the defective section is removed. A defective piece of rail is cut off, equal in size to the prepared one, and a piece of rail with edges prepared for welding is installed in this place. The gap between the rails was 2 mm (see Fig. 1). The ends of the rails before welding are cleaned to a metallic sheen.

Under the sole of the welded rails, a copper lining forming the reverse side of the seam is installed and fixed with a clamp. The root of the seam is welded with an electrode of the UONI - 13/65 brand, with a diameter of 3 mm, a current of 140-160 A, followed by filling the gap between the ends of the rail foot with an electrode of the UONI - 13/65 brand, with a diameter of 5 mm, a current of 250-280 A.

Lateral copper molds are installed on the neck and head of the rails and fixed with a clamp. The neck and head of the rail are welded with electrodes of the UONI - 13/65 brand, 5 mm in diameter, current 250-280 A.

The proposed method makes it possible to obtain a weld with mechanical properties that are equivalent to the properties of the base metal, while the obtained mechanical properties of the weld increase the service life of the rails to the service life of the rails installed on the track without welding.

A method for welding rail joints, which includes installing rails with a gap between the edges to be welded, introducing a consumable electrode into the gap and welding using molds installed at the welding site, at a current strength that ensures the formation of a liquid pool in the entire volume of the gap, characterized in that mechanical processing the edges of the rails or the edge of one of the rails, including making a transverse cut along the vertical plane from the head to the beginning of the rail sole, making a horizontal cut along the end surface of the rail perpendicular to the previously made cut and chamfering the end surface of the sole with a bluntness at the base of the rail sole, and forming liquid bath at the root of the seam is carried out by melting the edges of the base metal of the rails.

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