Rail manufacturing technology.

The first task in the production of rails is to obtain an ingot that is uniform along its entire length. After solidification, the ingots are delivered to a heating furnace, where they are heated to rolling temperature. Then the ingots, delivered to the bloomers on special carts, are passed through the rolls with their upper ends first; here the ingots are strongly compressed 4 times by slowly rotating rollers. To remove contaminated metal, the head and tail ends of the bloom are cut off; The bloom is divided into two parts, each of which in turn is divided into two, three or four rails, depending on the length and cross-section of the profile for which they are intended.
Data regarding the weight and type of rail, type of steel, manufacturer, month and year of rolling are applied to one side of the rail journal in the form of raised letters; the letters are rolled out by the lower rollers during the last pass of the rail. Letters are also added to the mark indicating that the rails are made of steel with a medium manganese content using controlled cooling, that they have been heat treated and that their ends are hardened. Since the serial numbers of heats and ingots are preserved after a steel spill, the number of the heat and ingot is also indicated on the rails. These data are stamped on a stamping machine on the opposite side of the journal while the rail is still hot. The ingots are rolled with their head ends forward; the rails are sequentially marked with the letters A, B, C, D, etc.

After rolling, while the steel has not yet cooled, the rolled strip is cut into pieces of the required length.

The next operation is to pass the rails through a series of rollers, which bend the rails so that, after cooling them to ambient temperature, they are perfectly straight.

After cooling, the axis of the rails, like other hot-rolled profiles, is slightly bent, as a result of which the rails need to be straightened in the correct presses. The ends of the rails are cleaned of burrs formed when sawing the rails in a hot state, and ground with rotating grinding wheels.
Typically, two or three bolt holes are drilled at each end of the rail, depending on the length of the butt plates used; however, if the rails are designed to be welded into long strands, the ends are left undrilled.

Before the rails are loaded for shipment to consumers, they are divided into groups depending on the carbon content of the metal, the quality of rolling, the structure of the steel and the deviation of their length from the standard; After this, the ends of all rails, except the low carbon rails, are painted in one of five easily distinguishable colors to make it easy to find the desired rails when distributing them. The distribution of rails into groups, marking and loading are carried out in accordance with the “Marking with the distribution of rails into groups” and “Loading” of the AREA Specifications for Open Hearth Steel Rails given below.

A rail is a metal beam with an original cross-section. It is used to create a support along which railway transport moves. For the first time, rails began to be manufactured in Ancient Rome, but then wood was used to make them, and the distance between them was strictly 143 cm. The installation of the rails is carried out in a parallel plane relative to each other. As a result, a “double-strand path” is formed.

The main task of the rails is to guide the wheels of the vehicle and take on the load with its subsequent distribution to the lower elements of the upper track. In the case of using trains in areas where movement is impossible without electric traction, the rails play the role of a current conductor, and for areas that use automatic blocking, the rails act as a conductor.

Material of manufacture

In most cases, carbon steel is used to make rails. The quality of this material is influenced by several factors, for example, the microstructure and macrostructure of the steel, its chemical structure etc. The presence of carbon gives the rail greater durability and reliability.

However, excess carbon in steel can have a negative impact. With its excessive amount, fragility increases significantly. That is why, when adding carbon, it is worth taking care to ensure that the structure of the steel is as strong as possible.

Other substances are also used to improve the quality of the starting material. Recently, they have increasingly resorted to treating rails with manganese. This increases the metal’s resistance to mechanical damage, making it more durable and tough. Adding silicon to steel increases its wear resistance and hardness. Titanium, vanadium and zirconium can also be used. These microelements can significantly improve quality characteristics steel.

Under no circumstances should sulfur and phosphorus additives be added, as they make the steel more vulnerable to breakage and increase brittleness. Very often, cracks and fractures can be observed in parts made with the addition of these substances.

It was already discussed above that steel has its own microstructure and macrostructure. Perlite is used as the main material for the first structure. Its shape resembles plates containing ferrite. You can achieve a homogeneous composition of steel by hardening it, that is, treat it at very high temperatures. high temperature. Hardening increases the wear resistance, durability, reliability, rigidity and toughness of the metal. For the macrostructure, the presence of excess substances or voids is unacceptable.

Physical characteristics of rails

The actual profile of the rails was not always like this. It has endured changes over time. History remembers corner, double-headed, mushroom-shaped, wide-footed and other rails.

The design of a modern wide-sole rail includes a sole, a head and a neck, which acts as a connecting element between these two parts. The central part is made slightly convex so that the load from the wheels is transferred to the central area of ​​the rail. The junction of the neck with the sole and head have smooth shapes. To relieve tension from the neck, it is made in the form of a curve. The wider the base of the rail base, the higher its lateral stability.

There are several standard sizes rails For Russian Federation It is common to produce rails 12.5, 25, 50, 100 m long.

It is also possible to produce rails of shorter length. They are used on uneven sections of the railway track. The length of the continuous track is at least 400 m and can reach the haul length. The higher the length of the rail, the less resistance to vehicle movement and, accordingly, its wear. The saving of steel when switching to a continuous welding track reaches 4 tons per 1 km of track. This is possible due to the absence of fastening elements in the area of ​​rail joints.

When calculating the power of a material, it is necessary to take into account such a parameter as specific gravity per 1 m of rail. It is usually measured in kilograms.

Another element of the railway track is sleepers. They play the role of a fastening element. Thanks to development modern technologies It became possible to produce sleepers not only from reinforced concrete and wood, but also from steel or plastic.

When calculating the cost of one rail, its specific weight, overall parameters (length and width), hardness and degree of wear resistance are taken into account.

Rail types

In order to choose the right type of rails, it is necessary to calculate the load on the line and the average speed at which vehicles will move along it. For example, let's take a massive rail with a lot of weight. It has a positive effect on the wear resistance of sleepers and reduces the economic costs of maintaining the line by increasing its durability.

Today there are the following types of rails:

• Railway. This type is considered the most popular and in demand. The weight of 1 meter of such a rail is 50-65 kg, length – 12.5 or 50 m.
• Narrow gauge. Used when it is necessary to create a narrow inter-rail space. This type of rail is widely used in mining and other restricted traffic areas.
• Mining. With their help, jointless tracks are laid. They are also very popular in the industrial sector.
• Trams. The name speaks for itself. Not designed for heavy line traffic. These rails weigh relatively little, which leads to rapid wear.
• Crane. They are used in places where it is necessary to create paths for moving a crane.
• Crane Such rails are considered the heaviest. In some cases, laying in several rows at once is allowed.
• Frame. They are used in places where transfer mechanisms are built.
• Counter-rail. Used when working in the upper structures of railway tracks.
• Witty ones. The scope of application is similar to the counter-rail type. The type of sharp rails OR43 can be distinguished separately. It is used for the construction of railway tracks.

Where can I buy these types of rails? We recommend buying from reliable suppliers. In Yekaterinburg, rails can be purchased at trading company"Rail-Kit". The company sells railway products high quality from leading domestic factories that meet GOST standards.

Rails are classified according to several parameters:

• The presence of holes intended for connecting elements(bolts).
• Method of steel smelting.
• Quality. According to this parameter, rails are divided into heat-strengthened and non-heat-strengthened.

These characteristics directly affect the cost of the rail.

Legend

Each rail has markings consisting of several groups of numbers and letters. Each letter means a specific parameter:

• A – rail type.
• B – quality category.
• C – grade of steel used.
• D is the length of the rail.
• E – presence of holes for bolts.
• F – GOST.

For example, the marking of the rail P65-T1-M76T-25-3/2 GOST R 51685-2000 indicates that this is a railway type rail of category T1. For its manufacture, M76T steel was used. The length of the rail is 25 m. It has 3 holes for bolts at each end. Complies with the specified GOST standard.

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Purpose of rails and requirements for them

Basic load-bearing element track superstructure - rails. They are steel bars of special sections along which rolling stock moves. The standard and generally accepted rails on all roads in the world are wide-solid rails.

(Fig. 1) consists of three main parts:

• heads;
• soles;
• neck connecting the head to the sole.

The rails are the most important element superstructure of the track. They are intended:

• directly perceive pressure from the wheels of the rolling stock and transmit these pressures to the underlying elements of the upper track structure;
• guide the wheels of the rolling stock as they move;
• in areas with automatic blocking, serve as a conductor of signal current, and in electric traction - as a conductor of reverse power current. Therefore, rail threads must have the necessary electrical conductivity.

Basic rail requirements are that they must be stable and durable; have the longest service life; ensure train safety; be convenient and inexpensive to operate and manufacture.

Rice. 1 - Wide base rail

In more detail, the purpose and economic considerations determine the following requirements for the rail:

1. To ensure the safety of trains with large axle loads at maximum speeds, the rails must be heavier. At the same time, to save metal and ease loading, unloading, and changing, these same rails must have a rational and, if possible, the least weight.
2. For better resistance to bending under a moving load, the rails must be sufficiently rigid (have the highest moment of resistance). At the same time, to avoid hard impacts of the wheels on the rails, which could cause breakage of individual parts chassis rolling stock, as well as flattening and even bending of rails, it is necessary that the rails be sufficiently flexible.
3. In order for the rails not to break due to the shock-dynamic effects of the wheels of the rolling stock, the material of the rails must be sufficiently viscous. In view of the concentrated transfer of pressure from the wheels over very small areas at the points of contact between the wheels of the rails, it is required that the metal of the rails does not wrinkle, does not wear out, lasts longer and is sufficiently hard.
4. To ensure sufficient adhesion between the rails and the driving wheels of locomotives, it is necessary that the rolling surface of the rails be rough. To reduce the resistance to movement of the remaining wheels - cars, tenders and supporting wheels of locomotives - it is necessary that the rolling surface of the rails be smooth;
5. To standardize the elements of the superstructure of the track, leading to simplicity and reduction in the cost of their maintenance, it is necessary that the number of types of rails be the smallest. In the interests of saving metal, it is unthinkable that rails of the same type should be laid on all railway lines, regardless of traffic load, axial loads and train speeds. The number of rail types should be minimal but reasonable.

Thus, the requirements and conditions that rails must satisfy are extremely important, necessary and at the same time contradictory. All this makes it extremely difficult to solve the rail problem in general. Its solution is one of the most important tasks of transport science and technology.

Rail material

Modern rails are rolled only from steel ingots. Steel is produced in converters using the Bessemer method or in open hearth furnaces. Bessemer steel is obtained by blowing molten cast iron with oxygen (15-18 minutes). In this case, carbon and some impurities burn out. Open hearth steel is made from cast iron and steel scrap in large ovens with a capacity of 200 to 1500 tons for several hours. This steel is cleaner and less cold brittle than Bessemer steel. Rails heavy types(P65 and P75) are rolled only from open hearth steel.

The quality of rail steel is determined by its chemical composition, micro- and macrostructure. The chemical composition of domestic rail steel is characterized by percentage additions to iron (see table below).

Carbon increases the hardness and wear resistance of rail steel. However, the higher the carbon content, the greater, other things being equal, the brittleness of the steel and the more difficult it is to cold straighten the rails. Therefore, a more uniform distribution of metal over the cross section of the rail is required; it must be maintained more rigidly chemical composition, this is especially true for phosphorus and sulfur.

Manganese increases the hardness and wear resistance of steel, providing it with sufficient toughness.

Silicon improves the quality of steel, increasing the hardness of the metal and its resistance to wear.

Phosphorus And sulfur- harmful impurities, they make steel brittle: with a high phosphorus content, the rails become cold-brittle, with a high sulfur content - red-brittle.

Arsenic slightly increases the hardness and wear resistance of rail steel, but its excess reduces impact strength.

Microstructure installed under a microscope with a magnification of 100-200 times. The components of ordinary rail steel are ferrite, which consists of carbon-free Fe, and pearlite, which is a mixture of ferrite and cementite.

The study of the microstructure of rail steel shows that it acquires the ability to significantly resist wear and toughness with a sorbitol structure, which is obtained as a result of special heat treatment.

Currently, volumetric hardening of rails is most widespread. It increases ductility and toughness, increases fatigue strength and resistance of rails against the formation of transverse fatigue fractures. The operational durability of such rails is 1.3-1.5 times higher than the operational durability of non-hardened rails. According to technical and economic calculations, the use of volumetrically hardened rails per 1 km of track on average per year provides significant monetary savings.

The most important factor for the quality of rail steel is its macrostructure(the structure is fractured when viewed with the naked eye or with a magnifying glass). The steel must have a homogeneous fine-grained structure without slag, hair, film, or traces of non-uniform distribution of chemical additives across the cross-section. Quality improvement is achieved by strict adherence technical specifications and continuous improvement of steel manufacturing and rail rolling technology. The density of rail steel is taken to be 7.83 t/m3.

Rail shape and dimensions

Rail profile

The service properties of rails are mainly characterized by their mass per 1 m length, cross-sectional profile (Fig. 2) and mechanical characteristics the metal from which they are made. To increase resistance to vertical forces, the rail is shaped like an I-beam, top shelf which ( rail head) is adapted for contact with the wheels of rolling stock, and the lower ( rail base) - for fastening to supports. The vertical wall connecting the head and sole is called neck.

Rice. 2 - Main parts of the rails

Rail profile is due to its interaction with the wheels of the rolling stock and the design of the elements of the superstructure of the track. A typical profile of modern wide-foot rails is shown in (Fig. 3).

The rolling surface of the head is always made convex to ensure the most favorable transmission of pressure from the wheels. For rail types P75, P65 and P50, larger radius R 1 of this surface is taken equal to 300 mm. Toward the faces, the curvature changes to a radius R 2 equal to 80 mm. In P43 type rails, the rolling surface of the rail head is outlined by one radius R 1 .

Rice. 3 - Modern wide-foot rail

The rolling surface mates with the side faces of the head along a curve with a radius r 1 (Fig. 3), close in size to the radius of the fillet of the bandage. In rails of types P75, P65 and P50 r 1 equals 15 mm.

The side edges of the head are either vertical or inclined. For rails of types P75, P65 and P50 this inclination is (1: k) is taken to be 1:20. The lateral edges of the head tend to mate with the smallest lower radii r 2 equal to 1.5-4 mm. This is done to ensure that the supporting surface for the overlays is as large as possible. For the same reasons, the radii are assumed to be the same r 6 and r 7 .

The supporting surfaces for the linings are the lower edges of the head and the upper edges of the rail base. Currently, the most common angles α are those at which tan α = 1: n for rails of types P75, P65 and P50 is 1:4.

The mating of the lower edges of the head with the neck should provide a sufficient supporting surface for the lining and the smoothest transition from a thick head to a relatively thin neck in order to reduce local stresses and uniform cooling of the rails during rolling. In rails of types P75, P65 and P50, r 3 = 5÷7 mm and r 4 = 10÷17 mm.

The neck of a modern rail has a curved outline with a radius R w (from 350 to 450 mm for domestic rails), which best ensures a smooth transition from the neck to the base and head.

The connection between the neck and the sole is made with a radius r 6, the value of which is dictated by the same considerations as the values ​​of the radii r 3 and r 4. The transition to the inclined upper surface of the sole for rails of types P75, P65 and P50 is made along a radius r 5 equal to 15-25 mm.

On railways The Russian Federation uses rails of types P75, P65 and P50 (Fig. 4), having a mass of 74.4; 64.6 and 51.6 kg/linear. m. Rails of the P65 type are now predominant when laying; on particularly heavy-duty lines - thermally strengthened rails of the P75 type. They are made 25 meters long.

Rice. 4 - Standard rail profiles: A- type P75; b- P65; V- P50

Rail length

On the roads of the world, they are striving to make wider use of long rails and welded rail strands. Due to this, the number of joints is reduced, which improves the conditions for interaction between the track and the rolling stock, and provides a great economic effect. For example, if instead of rails of the P65 type with a length of 12.5 m, rails of the same type, but with a length of 25 m, are laid, then by reducing the need for butt fastenings, 3,902 tons of metal will be saved for every 1000 km. In addition, reducing the number of joints by approximately 10% will reduce resistance to train movement, reduce wear on rolling stock wheels and reduce the cost of ongoing track maintenance.

Standard length modern rails in different countries it ranges from 10 to 60 m: in the Russian Federation 25 m; in Czechoslovakia 24 and 48 m, in the GDR and Germany 30, 45 and 60 m; in France 18, 24 and 36 m; in England 18, 29 m; in Japan 25 m; in the USA, 11.89 and 23.96 m. In the Russian Federation, rails 12.5 m long are rolled in limited quantities for turnouts.

In addition to standard length rails, shortened ones are also used for laying curved sections of track on internal threads. In the Russian Federation, such rails are shortened by 80 and 160 mm, and with a length of 12.5 m - by 40, 80 and 120 mm.

Mass (weight) of rails

The main characteristic giving general idea about the type and power of the rail - is its weight, expressed in kilograms per linear meter.

Determining the optimal rail weight- the task is extremely difficult, since it depends on a large number of factors: axle loads, train speeds, load intensity, quality of rail steel, rail profile and others.

Rail weight determined from the following considerations:

• the greater the load on the axle of the railway carriage, the speed of trains and the load density of the line, the greater, other things being equal, should be the mass of the rail With;
• the greater the mass of the rail q, the lower, other things being equal, the operating costs on heavily loaded lines (for track maintenance, for resistance to train movement).

Currently, there are various proposals for determining the mass of a rail empirically, depending on a limited number of factors. Professor G. M. Shakhunyants proposed to determine the mass of the rail depending on the type of rolling stock, the load load of the line, the speed of trains and static load to the locomotive axis according to the expression

Where A- coefficient equal to 1.20 for cars and 1.13 for locomotives;

T max - freight intensity, million t km/km per year;

υ - train speed for which the track design is calculated, km/h;

The numerical values ​​included in the formula can be taken from Table 1.2

Undoubtedly, the formula given above does not reflect the complexity of the relationship between factors influencing the choice of rail weight. However, it makes it possible to make a decision as a first approximation quite reasonably.

The final mass of the rail are selected based on strength calculations and economic feasibility. The weight of standard rails in the Russian Federation is 44-75 kg/m. Their main characteristics are given in (Table 1.3) and indicated in (Fig. 5). P43 rails are rolled in limited quantities for turnouts.

Rice. 5 - Basic dimensions of a modern rail (to table 1.3)

On the railways of other countries, the rails have a mass, kg/m:

• USA - 30-77;
• England:
  • two-headed - 29.66-49.53;
  • wide-footed - 22.37-56.5;
• France and Belgium - 30-62;
• GDR and FRG - 30-64.

Economic efficiency of using heavy rails

Effect of using heavy rails lies in their durability, reduced material consumption, reduced resistance to train movement and reduced costs for ongoing track maintenance.

According to VNIIZhT, if we take a P50 type rail as a base, then an increase in its mass by 1 kg reduces labor costs for current track maintenance by 1.5-1.8% and reduces material consumption to 1.4%.

A heavier rail distributes the pressure of the rolling stock wheels over a larger number of sleepers, as a result of which the pressure on each sleeper decreases, mechanical wear slows down and their service life increases. At the same time, the dynamic pressure on the ballast is reduced, abrasion, crushing of ballast particles and its contamination are reduced.

As the weight of the rails increases, the need for middle and lifting track repairs arises less often. Heavy rails can carry more cargo. So, P50 rails are 15%, and P65 are 45% heavier than P43 rails, but P50 rails during their service life can carry 1.5 times more tonnage, and P65 is 2 times more than P43. With an increase in the mass of rails, the consumption of metal per unit of tonnage passed through decreases and the costs of replacing rails (major repairs) are reduced, resistance to train movement and traction costs are reduced.

In economic calculations for choosing the type of rail, preference is given to the rail for which the annual sum of the given construction and operating costs is ∑ E pr with a normalized payback period t n is the smallest. It is determined by the formula

Where A- construction costs (cost of laying rails);

B i - operating costs i-ro year.

The payback period for additional capital investments in laying heavy rails is short - usually 1.5-4.5 years. Since it is very profitable to use heavy rails, in the Russian Federation their average weight is ( q cf) is constantly increasing.

Rail service life

Expected rail service life determined both for the expedient management of track maintenance (for example, to know the frequency of changing rails), and for their technical and economic assessment.

The service life of rails is a function of their operation under rolling stock, the type and power of the rails, the characteristics of the superstructure and rolling stock, the operating conditions of the track and the technology of rail manufacturing.

Rails fail due to wear and defects. They should be removed from the path when worn to a certain permissible amount; This factor is used to determine the service life of the rails. Allowable wear z 0 (Fig. 6), the rail heads are installed in such a way that the cross section of the rail after wear by the area ω 0 provides permissible stresses, and so that when the wheel tires are worn, the ridges do not touch the nuts and bolt heads at the rail joints or parts of the double-headed linings protruding behind the rail head.

Rice. 6 - Cross section of the rail head (permissible wear area is shaded)

According to the picture

ω 0 = bz 0 - ∆,

Where b- width of the rail head;

z 0 - normalized limit wear of the rail head, accepted in the Russian Federation according to PTE;

∆ - takes into account the difference in the outline of the head and an imaginary rectangle, which is taken equal to 70 mm 2.

T = ω 0 / β,

where β is the specific wear of the cross section of the rail head from the passage of 1 million tons of gross cargo, mm 2.

The value of β is determined for specific rail service conditions, performing traction calculations and taking into account the quality of rail steel. For approximate calculations, you can use the average network values ​​β avg (mm 2 / million tons gross) from the table

Since wear of volume-hardened rails occurs 1.3-1.5 times slower than non-hardened rails, the value of β cf for the former should be adjusted by a coefficient α equal to approximately 0.65-0.5.

Thus, knowing ω 0 and β avg, we can find the tonnage T, which the rails in question can miss over their entire service life. Moreover, if the cargo intensity (annual tonnage) T g of a given line is known and constant, then the service life of the rails in years on this line can be found as follows:

But since the load on our railways increases every year, the service life of the rails on a given line is based on the operating time of the past tonnage

Where T 1 , T 2 , T 3 , …, Tt- respectively tonnage in the first, second, third, t th year after laying the rails.

Despite the increase in the wear resistance of rails, they have to be replaced before reaching standard wear due to a single failure due to defects. Failure of rails due to defects occurs both due to violations or imperfections in manufacturing technology, and due to the conditions of their operation.

When establishing the service life of rails, they are taken as the permissible total single failure due to defects: P50 - 6 pieces, and P65 and P75 - 5 pieces per 1 km of track or the largest annual yield for these rails - 2 pieces. for 1 km.

Rail service life between major repairs ways in million tons gross based on a single defect yield of rails T od G.M. Shakhunyants proposed to determine by the formula

where λ р is a coefficient taking into account the quality of rail steel, the length of non-hardened rails is λ р = 1, and for volume-hardened rails λ р = 1.5;

A term that takes into account the influence of path curvature and lubrication; at R≥ 1200 m A= 0 and at R < 1200 м A= 800; in the absence of lubrication of the side faces of the rail heads and wheel flanges, α lube = 1, when lubricated with graphite-molybdenum pencils or for graphite grease based on grease, α lube = 0.2;

A term that takes into account the influence of the length of the rails (lash);

R dn - average tonnage standard load on the rail from the axis of the wheel pair, established in 1964 when adopting the standard service life of unhardened rails (for P50 - 350 million tons of gross cargo, for P65 - 500 million tons of gross cargo), equal to rails P50: R dn = (1 + 0.012υ i) q ok = (1 + 0.012 50) 14 9.8 = 228.6 kN and for P65 rails: P dn = (1 + 0.012 60) 18 9.8 = 303.8 kN;

R c is the tonnage-weighted average load on the rail from the axis of the wheelset, kN;

q p - rail mass, kg/m;

γ norms - normative meaning permissible single removal of rails due to defects (P50 - 6 pieces, P65 and P75 - 5 pieces per 1 km of track);

q ok - average load on the rail from the axle of the wheelset, depending on the type of rail.

Of the two values ​​found using the formulas given above, the smaller one should be taken for calculation.

Limiting the service life of rails based on their single output cannot be considered normal, therefore the main task- carrying out measures to increase the service life of rails according to their capacity until full design wear. This can be achieved by improving the quality of rail metal, including through heat treatment; the use of seamless track with welded rail strands of increased length; surfacing of worn rail ends; improving the design of the track superstructure as a whole; the use of lubricators that lubricate the side faces of the rail head in curves; improving the current maintenance of rails and the track as a whole.

After expiration established service life in the places of initial laying, the rails are removed from the track, sorted, subjected to repair and welding at rail repair enterprises, and again laid on the track, but with more easy conditions operation, where they pass about another 2/3 of the initial standard tonnage.

Important measures to extend the service life of rails along the way are grinding their heads with rail grinding trains to remove irregularities and surface damaged metal layer from the rolling surface, surfacing rail ends, lubricant rails in curves to reduce lateral head wear.

The service life of conventional high-carbon rails is 2-3 times compared to foreign ones, and thermally strengthened rails are 3-4 times longer; however, this is not enough, since the intensity of use of railways in our country is 6-10 times greater than abroad. Therefore, scientific research is underway to create even stronger and more durable rails.