We have a constant need for rails. AREA recommendations for rails

rails designed for the movement of rolling stock railways and underground, tram, locomotives and trolleys of mine transport and monorail roads, crane trucks, cranes and other mobile, rotary and rotating structures.

rails- these are the elements of the upper structure of the track, laid on the supports and fastened to them and to each other, form a rail track, directly perceive the pressure of the wheels of the rolling stock.

In Russia, rails are produced by the Kuznetsk and Nizhny Tagil metallurgical plants. Rails have factory marks.

Latest GOST R 51685-2000 for railway rails provides four types rails R50, R65, R65K(for curves) and R75, according to quality categories rails are provided:

• B - heat-strengthened top quality;
• T1 and T2 - heat-strengthened;
• N - non-heat-strengthened.

A special rail has been introduced in the new GOST R65K for laying curved sections of the track in the outer rail threads. Their main difference lies in the outlines of the head. Its side faces in the upper part have a slope of 3.5:10, which reduces the intensity of lateral wear of the rails.

There are a number of requirements for rails:

• straightness in the vertical and horizontal planes must be ensured;
• tolerances are established in the dimensions of the transverse profile;
• the chemical composition and hardness of rail steel were determined;
• unacceptable defects specified metallurgical production and non-metallic line inclusions, etc.

Finished rails at the factory are subject to acceptance, continuous flaw detection and branding.

On the neck along the axis of each rail (on the same side where the convex signs are rolled out), the melting number is applied in a hot state in 2 places along the length of the rail at a distance of at least 1.0 m from its ends (the melting number of group 1 rails must begin with the letter P); designation of the serial number of the rail.
Stamps applied to the neck of a hot rail must be 12 mm high and deepened into the body by 0.8 ... 1.5 mm. The distance between signs should be 20...40 mm.

As the tonnage develops during operation, various damage, deformations, fatigue defects etc.

Modern requirements of Russian railways to rails

At present, rails and wheels for rolling stock of railway transport are manufactured from high-carbon pearlitic steels of the same class with a similar chemical composition, partly at the same or close to each other metallurgical enterprises. The vast majority of rails and wheels fail during operation mainly due to contact fatigue, wear, crushing and normal fatigue.

As a result of many years of work carried out by Russian Railways in relation to metallurgical enterprises producing rails and wheels, the quality of the latter is steadily increasing. In recent years, the reconstruction of steel-smelting production at the Nizhny Tagil Iron and Steel Works has been almost completed, and the modernization of production at the Novokuznetsk Iron and Steel Works is being actively carried out. This allowed both enterprises, beginning in 2003, to completely switch to the production of new generation rails in terms of steel quality, which differs from rail steel of the late 90s in the following indicators:

The output of the 1st grade in a length of 25 meters is 96-97% versus 76-78%;

The length of the lines of non-metallic inclusions is 0.5 mm versus 4-6 mm;

Improving the straightness of the rails;

A sharp decrease in the content of harmful impurities and oxygen.

Five years of work in accordance with GOST R 51685-2000 showed that both metallurgical plant successfully mastered the production of T1 category rails, as well as rails of increased straightness between T1 and B for high-speed combined traffic (SS), low-temperature reliability (NK and NE), as well as increased wear resistance and contact endurance (IE and IK), produced according to special specifications.

However, despite the successes achieved, a comparison of the quality of Russian rails produced by NTMK and NKMK with foreign samples shows the leadership of foreign samples. The conducted studies showed that 80% of the resource of the most representative lots of domestic production was equal to 500 million tons of gross cargo. Under the same operating conditions, the rails made in Japan and France showed a resource of 1000 million tons of gross cargo.

The total annual demand for rails for the Russian railway network is estimated to be about 600,000 tons, and the annual need for category B rails is about 400,000 tons. The demand for railway rails with a length of 50 m or more is 90% of the total supply. In 2004, 3,400 km (88%) of the total volume of enhanced overhaul (3,870 km) was a seamless track, where it is more economically feasible to lay rails 50 m or more in length.

The implementation of all the plans outlined by metallurgists and railroad workers will make it possible to increase the resource of rails to 1000-1500 million tons of cargo in straight lines and up to 300-700 million tons in curved sections of the track.

Rail transport in Russia is of particular importance. Given the gigantic distances, this is practically the only way to transport goods. And in big cities, trams and metros allow you to bypass traffic jams. Naturally, rails become a part of our life - such transport saves time on the road, brings us interesting goods from other parts of the country. And the child-schoolboy is helped to clearly explain what parallel lines are. And despite the creation of various futuristic competitors like a magnetic cushion and a vacuum tube, rails will definitely be out of competition for at least another half a century.

Demand triggered modernization

When we look at rail transport, we primarily see rolling stock - locomotives, wagons, trams. And all the improvements in recent years and decades associated with this type of transport, we note precisely in the rolling stock. The old trams are being replaced by new ones, low-floor, modern, and most importantly - not rattling all over the street. In the lexicon of the three Russian capitals (main, northern and Olympic), the words "peregrine falcon", "swallow" and "swift" are more often related to the railway, and not to ornithology. Large-scale modernization affected not only passengers, the fleet of freight cars in Russia is now one of the youngest in the world, new, innovative, more spacious and less often requiring repairs are replacing old cars. Locomotives are becoming more powerful and more environmentally friendly.

Behind all this technical abundance, it is easy to miss the element, without which all locomotives and wagons, in fact, become meaningless metal structures - rails. Meanwhile, the rail products themselves have also experienced certain metamorphoses throughout their history. For example, in the middle of the 19th century cast iron was replaced by Bessemer steel - a method introduced by the Englishman Henry Bessemer, which consists in the oxidation of impurities contained in cast iron. And it, in turn, was replaced by steel obtained by the open-hearth method, named after the French engineers Emil and Pierre Martin (smelting was carried out in special "regenerative" furnaces of the Siemens brothers, where the heat of exhaust hot gases was used to heat the air). The last two methods have been in demand over the past century, but at the beginning of the 21st century, the requirements for rail products manufactured by domestic manufacturers have changed significantly. 15 years ago, in 2003, the main consumer of rail products in Russia (then, by the way, the main customer - the Ministry of Railways of the Russian Federation was transformed into Joint-Stock Company"Russian Railways") outlined its new wishes. Metallurgists needed to improve the quality of steel. This led to the fact that in 2003 the largest and at that time the only Russian manufacturer rail products "Evraz" (in different years the company supplied to Russian Railways from 0.5 million to 1 million tons annually) switched to the production of rails from electric steel. After that, the company introduced out-of-furnace processing and vacuum treatment of steel and began to make rails from continuously cast billets.

"This revolution in steelmaking allowed us to increase the rail resource by 50%. If earlier the gamma resource (operational durability of rails), determined during field tests at the VNIIZhT experimental ring (Shcherbinka, Moscow Region), was 500 million tons, then later we managed to raise this figure by one and a half times - up to 750 million tons," said Gennady Yunin, adviser on the production technology of rail products at Evraz. As a result, in 2008, Russia began producing rails from steel that is clean in terms of non-metallic inclusions, gas saturation and harmful impurities, and this was already a world-class product.

Another important parameter is the "geometry" of the rails, the requirements for straightness and accuracy of profile manufacturing. The so-called velvet (seamless) path began to develop at an accelerated pace in the 21st century. If earlier the rails were connected by overlays with joints every 25 meters, now they began to be welded into lashes up to 800 meters long. Such lashes are made at rail welding enterprises and welded together already at the place of laying on the way. This requires the precise geometry of the rails in order to join them and obtain a quality welded joint.

“We introduced heat strengthening of rails by volumetric hardening in the late 60s in Nizhny Tagil, in the 70s in Novokuznetsk, and this also gave an increase in the service life of heat-strengthened rails compared to raw rails,” said Gennady Nikolayevich. However, volume-hardened rails in the 21st century were no longer so pleasing to railway workers - the technology contributed to the formation of high residual stresses in the rails, which reduced their contact fatigue strength and wear resistance. The rails were hardened over the entire cross section, so all components (head, neck and sole) had high hardness - and this is not necessary, since the rail head directly interacts with the rolling stock and experiences high contact fatigue stresses, which must have sufficient hardness to ensure high operational stability. The structural strength of the rail is provided by the neck and sole in the non-heat-strengthened state.

The desire to reduce the number welded joints led to the fact that the railroad wanted to switch to the use of 100-meter rails. Evraz agreed with Russian Railways on a plan for the further reconstruction of its rail production - the company replaced rolling mill, introduced new rolling technology and heat strengthening method. Since the spring of 2013, Evraz has been producing 100-meter rails of a new generation in Novokuznetsk - differentially heat-strengthened. “Thus, we met the requirements of Russian Railways and were able to export rails up to 100 meters long, meeting modern requirements for steel cleanliness, profile manufacturing accuracy and straightness, with an optimal complex mechanical properties providing high operational stability," Yunin summed up.

Export to be considered

Foreign manufacturers of rail products believe that 100 meters is not the ultimate dream. The Japanese, such as Nippon Steel & Sumitomo Metal Corporation (NSSMC), are already exporting 150-meter rails to the US. For such supplies, the company built special ships. Logistics plays an important role here. Novokuznetsk is not located on the sea coast, which means that 100-meter rails are transported throughout Russia along the same rails - by rail. But for export, Evraz still supplies products up to 25 meters long. The company is currently working on a scheme for loading long rails.

“At the same time, we have already received a certificate of conformity from Deutsche Bahn (the German railway concern - Kommersant-Nauka), but they ask for rails 60 and 90 meters long,” Evraz said. “Now we are thinking through the necessary logistics to compete for European consumers with two main players in this market - Voestalpine AG (Austria) and ArcelorMittal (registered in Luxembourg).It took two years to obtain a certificate in Germany: they do not have their own experimental test site (as, for example, in Shcherbinka near Moscow, where in a short a period of time you can "roll" a high turnover), and such tests are carried out at special experimental sites. At the same time, a certificate that allows you to supply products to Deutsche Bahn serves as a certain quality mark, a company with such a certificate can supply products all over the world. Although everywhere Of course, it has its own specifics.

In India, customers sometimes combine requirements for rails: some parameters are ordered according to their standard, and some - according to European standards. Here, more stringent requirements are imposed on the level of residual stress in the rails. In addition, many customers order only two tests - at the beginning and end of contract deliveries. And the Indians are asking to test separately every 20th heat.

The Brazilians, in turn, impose special requirements on the chemical composition - for example, on a higher proportion of chromium. So they want to get stronger rails than European standards. This is due to the fact that Brazilians have developed heavy traffic (trains weighing more than 7 thousand tons pass through the network).

But the Egyptians do ask for double pile tests of rails.

Such a test consists in the fact that a load weighing 1 ton is dropped onto the rail from a height of 5 meters. So, Egyptian consumers ask this test to be repeated twice.

"About 15 million tons of rail products are produced annually in the world.

At the same time, the European and American markets "digest" only 1 million tons per year. Another 1 million is consumed by Russia, 5 million are made by the Chinese themselves. In other countries, there are not such strict requirements for the length of the rails. For example, we supply 18-meter rails to Egypt and Taiwan, and 24- and 25-meter rails to Brazil and India, respectively, including for the subway, the requirements for the railway and the subway are usually identical. But trams are a slightly different story, steel for tram rails has a different chemical composition, the product is not as strong as railway rails, which is not required for this type of transport - the loads are much lower than on the railway. Although the first applications from customers are already appearing for heat strengthening of rails for tram tracks," said Gennady Yunin.

From general to specific

It is worth noting that over the years, engineers have tried to come up with various ways to get away from rail transport. One alternative was maglev trains. But we must understand that this method of transportation was invented 40 years ago in Germany. And then, 20 years later, this idea was implemented in China - such a train runs between Shanghai and the local airport at speeds up to 350 km/h. But this is, in fact, the only embodiment of a fairly ambitious idea.

American Elon Musk proposed an even more daring project called Hyperloop - traveling in a vacuum tube at speeds up to 1200 km / h. But industry experts agree that if the project succeeds and spreads around the world, it will not happen until half a century later. Until then, the demand for rails will be stable.

30 years ago, the Ministry of Railways of the USSR consumed 2.5 million tons of rails annually (application in the State Planning Commission - for 2.9 million tons). Now RZhD consumes about 1 million tons - even without taking into account Kazakhstan, Ukraine and other former republics that consume rails on a less modest scale, on average it turns out that over 30 years the demand has decreased by about half. Over the next 30 years, the need will continue to decrease in terms of the "1520 space" (countries united by the 1520 mm railway gauge).

Despite ambitious plans to build in Russia - both the so-called Northern Latitudinal Railway (the main line in the Yamalo-Nenets Autonomous Okrug), and the expansion of the Baikal-Amur and Trans-Siberian Railways, the network will increase in the future, but the need for rail products will nevertheless decrease. It is formed mainly due to retiring rails. And every year, despite the growth of loads and speeds, the margin of safety and life cycle, which gives the increase in the quality of the rails, will grow faster.

There is also active construction of railways abroad. China has doubled the length of its routes in 20 years - by 70,000 km. India also has plans to seriously increase the length of the network, in 2018-2019 about 1 thousand km of new tracks will be laid here, and the intensity of construction will continue to grow in the coming years. And taking into account such trends, even despite the improvement in the quality and durability of rails, the difference between the world demand for such products (14 million tons) and real production facilities(15 million tons) is not so great, and this margin of safety may well run out.

"In the future, we expect demand for different types rails for various conditions operation. But for now, the picture is somewhat different. Now they have mastered and have the opportunity to produce four categories of rails: general purpose, increased wear resistance and contact endurance, high-speed combined movement and low-temperature reliability. But in recent years, in the portfolio of Russian Railways orders, the overwhelming advantage has been with general purpose rails. So far, customers want more versatility from our products. Although specialized (and, accordingly, more expensive) rails will last longer in the areas intended for them. Here economic effect not limited to extended service life. It should be borne in mind that the less often defective rails are removed and repairs are carried out with a continuous replacement of rails, the fewer traffic stops are required in these sections, their throughput and carrying capacity increase, which ensures a higher freight turnover. And this is a direct benefit for Russian Railways," Yunin said.

And products continue to evolve in accordance with the requirements of the time. Currently, a new Evraz product, DT400 IK rails, which are distinguished by high strength and wear resistance, is undergoing the certification procedure. These rails are designed for special conditions operation - for heavy traffic and for difficult sections of track with steep curves with a radius of less than 650 meters. Ordinary general-purpose rails serve in such heavy sections with a cargo density of 150 million gross tons per year at the most for seven to ten months. And the service life of the DT400 IC is expected to exceed a year. Compared with leading foreign analogues, Japanese rails are on small radius curves for about 15 months. Russian product must compete with them. Also certified are rails for high-speed highways, taking into account the maximum speed of up to 400 km / h.

By the way, Russian Railways share a point of view regarding the need for specialization of rails. According to Gennady Nasonov, Chief Engineer of the Central Directorate of Infrastructure of Russian Railways, it is really more expedient to use specialized rails, taking into account the requirements due to the location, climate zone, traffic intensity and other factors.

“It is absolutely certain that high-speed highways require special rails. And the construction of the Northern Latitudinal Railway will require rails that are not so resistant to high-speed conditions, but those that can function for a sufficient time in conditions of constant low temperatures. Individual Requirements must be presented to the rails to be laid in areas where heavy traffic is planned to be used. In addition, the Russian Railways network has a certain number of low-intensity lines carrying less than 8 million tons of cargo per year. We believe that the rails should be appropriate in such sections, too," a Russian Railways representative told Kommersant-Nauka.

According to him, this will allow differentiating budgets and infrastructure maintenance requirements. By the way, Evraz notes that the right service can further increase the service life of the rails.

“For the foreseeable future, we want to offer our customers a turnkey service: not only the supply of products, but also welding, laying and maintenance of rails throughout the entire life cycle.

This, from our point of view, is a very promising line of business," Evraz concluded.

Brain Konstantin

Page 2 of 10

The purpose of the rails and the requirements for them

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

(Fig. 1) consists of three main parts:

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

The rails are the main element the upper structure of the track. They are intended:

• directly perceive the pressure from the wheels of the rolling stock and transfer these pressures to the underlying elements of the superstructure of the track;
• direct the wheels of the rolling stock during their movement;
• in areas with automatic blocking, serve as a conductor of signal current, and in case of electric traction - reverse power current. Therefore, rail threads must have the necessary electrical conductivity.

Main rail requirements consist in the fact that they must be stable and durable; have longest term services; ensure the safety of train traffic; be convenient and inexpensive to operate and manufacture.

Rice. 1 - Wide sole 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, with maximum speeds rails should be heavier. At the same time, in order to save metal and facilitate loading, unloading, changing, these same rails should have a rational and, if possible, the smallest weight.
2. For better resistance to bending under a moving load, the rails must be sufficiently rigid (have the highest modulus of resistance). At the same time, in order to avoid hard impacts of the wheels on the rails, which can cause breakage of individual parts of the running gear of the rolling stock, as well as flattening and even breaking of the rails, it is necessary that the rails be sufficiently flexible.
3. In order for the rails not to break from the impact-dynamic effects of the wheels of the rolling stock, the material of the rails must be sufficiently viscous. In view of the concentrated transmission of pressure from the wheels over very small areas at the points of contact of the rail wheels, it is required that the metal of the rails does not crumple, 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 - wagons, tenders and supporting wheels of locomotives - it is necessary that the 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 rail types be the smallest. From the interests of saving metal, it is unthinkable that rails of the same type should be laid on all railway lines, regardless of the traffic density, axial loads and train speeds. The number of rail types should be minimal but reasonable.

Thus, the requirements and conditions that the rails must satisfy are extremely important, necessary and at the same time contradictory. All this greatly complicates the solution of 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 according to the Bessemer method or in open-hearth furnaces. Bessemer steel is obtained by blowing molten iron with oxygen (15-18 min). In this case, carbon and part of the impurities burn out. Open-hearth steel is made from cast iron and scrap steel in large kilns with a capacity of 200 to 1500 tons for several hours. This steel is cleaner and less cold-brittle than Bessemer steel. Rails of 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 the steel of domestic rails is characterized by iron additions as a percentage (see the table below).

rail type	steel grade	Carbon	Manganese	Silicon	Phosphorus	Sulfur	Arsenic	Tensile strength, MPa (kgf / mm 2), not less than	Relative extension, %
R75(R65)	M-76	0,71-0,82	0,75-1,05	0,20-0,40	≤0,035	≤0,045	≤0,15	885(90)	4
P50	M-75	0,69-0,80	0,75-1,05	0,20-0,40	≤0,035	≤0,045	≤0,15	765(88)	5

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 steel and the more difficult cold straightening of rails. Therefore, a more uniform distribution of the metal over the cross section of the rail is required, the chemical composition must be more strictly maintained, especially for phosphorus and sulfur.

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

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

Phosphorus And sulfur- harmful impurities, they give steel brittleness: with a high content of phosphorus, the rails are cold-brittle, with a high sulfur content - red-brittle.

Arsenic somewhat increases the hardness and wear resistance of rail steel, but its excess reduces the toughness.

microstructure installed under a microscope with a magnification of 100-200 times. The components of conventional rail steel are ferrite, which is composed of carbon-free iron 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 significant wear resistance and toughness with a sorbitol structure, which is obtained as a result of special heat treatment.

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

The most important for the quality of rail steel is its macrostructure(structure in a fracture when viewed with the naked eye or with a magnifying glass). The steel must have a homogeneous fine-grained structure without slag, hairline, captivity, traces of a non-uniform distribution of chemical additives over the cross section. Improvement in quality is achieved by strict adherence to technical specifications and continuous improvement of the technology of steel production and rolled rails. The density of rail steel is assumed to be 7.83 t/m 3 .

The shape and dimensions of the rails

Rail profile

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

Rice. 2 - The main parts of the rails

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

The tread surface of the head is always made convex to ensure the most favorable pressure transfer from the wheels. For rail types P75, P65 and P50 larger radius R 1 of this surface is taken equal to 300 mm. Towards the faces, the curvature changes to a radius R 2 equal to 80 mm. In rails of the R43 type, the tread surface of the rail head is outlined by one radius R 1 .

Rice. 3 - Modern wide sole rail

The tread surface is mated 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 is equal to 15 mm.

The lateral faces of the head are either vertical or oblique. For rails of types P75, P65 and P50, this slope (1: k) is taken equal to 1:20. The side faces of the head tend to mate with the smallest lower radii r 2 equal to 1.5-4 mm. This is done so that the bearing surface for the pads is the largest. For the same reasons, the radii are assumed to be the same r 6 and r 7 .

The supporting surfaces for the overlays are the lower faces of the head and the upper faces of the sole of the rail. At present, the most common angles α are those for which tg α = 1: n for rail types P75, P65 and P50 is 1:4.

The conjugation of the lower edges of the head with the neck should provide a sufficient support 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 R75, R65 and R50, r 3 = 5÷7 mm and r 4 = 10÷17 mm.

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

The conjugation of the neck with 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 the radius r 5 equal to 15-25 mm.

On the railways of the Russian Federation, rails of types R75, R65 and R50 are used (Fig. 4), having a mass of 74.4; 64.6 and 51.6 kg / rm. m. Prevailing when laying now are rails of the P65 type; on especially heavy lines - thermally hardened rails of the R75 type. They are made in lengths of 25 meters.

Rice. 4 - Standard rail profiles: A- type R75; b- P65; V- P50

Rail length

On the roads of the world, they are trying to make wider use of long rails and welded rail lashes. Due to this, the number of joints is reduced, which improves the conditions for interaction between the track and the rolling stock, and gives a great economic effect. For example, if instead of rails of the R65 type 12.5 m long, rails of the same type, but 25 m long, are laid, then by reducing the need for butt fastenings, 3902 tons of metal will be saved for every 1000 km. In addition, reducing the number of joints by about 10% will reduce the resistance to train movement, reduce the wear of the rolling stock wheels and the cost of the current maintenance of the track.

Standard length contemporary 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 the FRG 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 rails of standard length, shortened rails are also used for laying curved sections of the 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 that gives a general idea of ​​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: axial loads, train speeds, traffic density, 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 vehicle, the speed of trains and the load density of the line, the greater, ceteris paribus, 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 freight-loaded lines (for the maintenance of the track, for the resistance to the movement of trains).

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 density of the line, the speed of trains and the static load on the axle of the locomotive by the expression

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

T max - traffic density, mln. t km/km per year;

υ - the speed of trains, 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 above formula does not reflect the complexity of the interrelation of factors influencing the choice of rail weight. However, it makes it possible to make a decision in the order of the first approximation quite reasonably.

The final mass of the rail are chosen on the basis of calculations for strength and economic feasibility. The mass 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). R43 rails are rolled in limited quantities for turnouts.

Rice. 5 - The main dimensions of the 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 soles - 22.37-56.5;
• France and Belgium - 30-62;
• East Germany and Germany - 30-64.

Economic efficiency of heavy rails

The effect of using heavy rails consists in their durability, reducing the consumption of materials, reducing the resistance to the movement of the train and reducing the cost of the current maintenance of the track.

According to VNIIZhT, if a rail of the R50 type is taken as the base, then an increase in its mass by 1 kg reduces labor costs for the current maintenance of the track by 1.5-1.8% and reduces the consumption of materials to 1.4%.

A heavier rail distributes the pressure of the wheels of the rolling stock to more sleepers, as a result of which the pressure on each sleeper is reduced, mechanical wear is slowed down and their service life is increased. At the same time, the dynamic pressure on the ballast is reduced, abrasion, grinding of ballast particles and its pollution are reduced.

With an increase in the mass of rails, there is less need for average and lifting repairs of the track. Heavy rails can carry even more cargo. So, R50 rails are 15%, and R65 45% heavier than R43 rails, but R50 rails can pass 1.5 times the tonnage during their service life, and R65 is 2 times more than R43. With an increase in the mass of rails, the consumption of metal per unit of tonnage throughput decreases and the cost of replacing rails (overhaul) is reduced, the resistance to movement of trains and traction costs are reduced.

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

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

B i - operating costs i-ro year.

The payback period for additional capital investments for 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 mass ( q cf) is constantly increasing.

Rail service life

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

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

Rails fail due to wear and defects. They should be taken out of the way when worn by a certain allowable amount; this factor determines the service life of the rails. Permissible 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 the allowable stresses, and that when the wheel rims are worn out, the ridges do not touch the nuts and bolt heads in the rail joints or for parts of the two-headed lining protruding for the rail head.

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

As per picture

ω 0 = bz 0 - ∆,

Where b- width of the rail head;

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

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

T = ω 0 / β,

where β - 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 with traction calculations and taking into account the quality of rail steel. For approximate calculations, you can use the average network values ​​of β cf (mm 2 / million gross tons) from the table

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

Thus, knowing ω 0 and β cf, you can find the tonnage T, which the rails in question can miss over their entire service life. Moreover, if the traffic density (annual tonnage) T r 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 traffic density on our railways is increasing every year, the service life of the rails on a given line in terms of the operating time of the past tonnage

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

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

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

Rail service life between overhauls way in million gross tons based on a single rail run out due to defects T od G. M. Shakhunyants proposed to determine by the formula

where λ p is a coefficient that takes into account the quality of rail steel, the length of non-hardened rails λ p = 1, and for body-hardened λ p = 1.5;

A term that takes into account the influence of the curvature of the path and lubrication (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 head and wheel flanges α lub = 1, when lubricated with graphite-molybdenum pencils or for graphite lubricant based on grease α lub = 0.2;

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

R dn - the average tonnage standard load on the rail from the axle of the wheelset, 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 R50 rails: R dn = (1 + 0.012υ i) q ok \u003d (1 + 0.012 50) 14 9.8 \u003d 228.6 kN and for R65 rails: P dn \u003d (1 + 0.012 60) 18 9.8 \u003d 303.8 kN;

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

q p - rail mass, kg/m;

γ norms - normative value allowable single removal of rails due to defects (P50 - 6 pcs., P65 and P75 - 5 pcs. per 1 km of track);

q ok - the 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 above, the smallest should be taken for calculation.

The limitation of the service life of rails by their single exit cannot be considered normal, therefore, the main task is to take measures to increase the service life of rails according to their power to full design wear. This can be achieved by improving the quality of the rail metal, including through heat treatment; the use of a seamless track with welded rail lashes of increased length; surfacing of worn rail ends; improving the design of the track structure as a whole; the use of lubricators that lubricate the side faces of the rail head in curves; improving the current maintenance of the rails and the track as a whole.

After the expiration established service life in places of initial laying, the rails are removed from the track, sorted, repaired and welded at rail repair enterprises, and put on the track again, but with easier operating conditions, where they pass about 2/3 of the initial standard tonnage.

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

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

For many years rails have been manufactured according to Specifications; however, due to improvements in the field of metallurgy, as well as in connection with the changing needs of the railways, it turned out to be necessary to revise the Specifications. Changes to the Specifications were made only after a thorough study of this issue by representatives of the AREA Rail Committee in conjunction with representatives of the Technical Committee of the American Institute of Iron and Steel. Specifications for open-hearth steel rails, as amended, are given below.

SPECIFICATIONS FOR OPEN STEEL RAILS

1. Introduction

Examination and testing of rails are carried out at rail rolling mills before the rails are sent to consumers; factories must be equipped with equipment that can be used to determine the quality of the produced rails.

1. Chemical composition

Definition process chemical composition steel is described below. The number of elements that make up the steel must remain within the following limits:

The last three ingots of each ladle. You can check the composition of steel by both chemical and spectrographic analysis. The average results of the analysis of the steel of each ladle must comply with the requirements set forth in Part 2. At the request of the inspector, samples are provided for the control analysis of the steel.

1. Plasticity of steel and its ability to resist impact

a) The ductility of rail steel and its ability to resist impacts are determined on a standard AREA impact tester. Samples of rails with a length of 1.22 to 1.83 m are cut from the head of the rails A of the second, middle and last ingots of each heat. The temperature of the prototypes should not exceed 38 ° C. The distance between the supports on which the prototypes are laid, for rails weighing less than 52.6 kg / linear meter. m should be 0.91 m, for rails weighing from 52.6 to 69.4 kg / linear. m - 1.22 m and for rails heavier than 69.4 kg / rm. m-1.42 m.
Samples of rails are placed on supports with their heads up and subjected to one blow from a free-falling woman; the height of the woman's fall depends on the weight of the rail.


b) If all samples withstand the impact without breaking them between the supports, then all the rails of this heat are considered accepted and are subject to a final examination, which consists in checking the condition of their surface, cross-sectional dimensions and finish.
c) If any sample breaks outside the supports, then the test is considered invalid and re-testing of samples taken from the head of the same rails is carried out.
d) If one of the three samples taken in accordance with clause "c" of part 5 breaks, then all rails A of this heat are rejected.
Then samples are cut from the lower end of the same rails A or from the upper end of rails B of the same ingot and tested in accordance with paragraph "c" of Part 5. If one of the samples breaks, then all rails B of this heat are rejected.
Then, from the lower end of rails B or from the head end of rails C, three additional sample, which are tested in accordance with paragraph "c" of Part 5; if none of the samples fails, then the remaining part of the melt is accepted for examination and the state of the rail surface, the cross-sectional dimensions and the finish of the rails are subjected to verification. If at least one of these samples breaks, the entire melt is rejected.
7. The condition of the metal inside the rail
a) On prototypes, cut off from the head ends of the upper rails of all ingots of each melt, which have passed the tests on a pile driver in accordance with paragraph "c" of Part 5, a notch is made into which a correct hammer is inserted; then the sample is placed under Hydraulic Press, which presses on the flat head of the right hammer with a force of 544 kg and breaks the sample. The quality of a rail is determined by examining the fracture. If sunsets, metal delaminations, shells, foreign inclusions are found in the fracture of the prototype, and the metal structure is light and fine-grained, then such rails are classified as X-rails.
b) If, by agreement with the customer, it is planned to examine samples of rails taken from all ingots (with the exception of X-rails), by applying notches and breaking them, then these tests are performed in the following order.
Prototypes taken from the head ends of the top rails of all ingots of each heat meeting the requirements of Part 5 are notched and the rails are broken so that the condition of the metal inside the rail can be checked. If an internal defect is found in the fracture, then a sample is cut off again from the head end of the upper rail; a notch is made on the sample and it is broken again. If a crack, free from internal defects, is at such a distance from the end that allows a rail of the permissible length to be obtained after finishing, then this rail, as well as other rails of this ingot, are considered accepted. If it is impossible to obtain a rail of sufficient length, then the rails are rejected and a sample is cut out from the lower end of the rail, which characterizes the second rail of the ingot. The second and next ingot rails are tested in the same way.
Samples with notches to be broken are taken from the upper ends of the rails at distances set by the rail manufacturers, and if it is necessary to obtain a break free from any defects, the last sample is allowed to be taken at such a distance from the end at which the finished rail will have a minimum allowed length.
Internal defects of the rails can be rolls, metal delaminations, voids, foreign inclusions in the metal, or a clearly distinguishable light or fine grained structure; when testing with the destruction of the sample, these defects become visible.
Shortened rails obtained from the tests described above are not included in the number of 11°/0 rails specified in Part 10.

1. Rail classification

Rails No. 1. Rails No. 1 must be free from damage and from all kinds of defects.
X-rails These rails are described in paragraph "a" of part 7.
Rails #2. These include the following rails:
(a) Free from superficial defects of such quantity and quality as to prevent an inspector from declaring them fit for service;
b) entering the straightening presses with sharp curvatures or deflections, the average ordinate of which is more than 152 mm per 11.89 le;
c) on which there is no stamp.

1. Ingot cutting

A certain amount of metal is removed from the upper and lower ends of the ingot, sufficient to ensure that the ingot is free from harmful segregation and cavities.

1. Rail length

The standard length of the rails shall be 11.89 m at a temperature of 16°C. It is allowed that 11°/0 of the total number of rails present in a given batch have a shorter length varying in steps of 0.305 m from 11.58 to 7.62 m. The allowable deviation from the theoretical length of the rails is 9.52 mm; 15°/0 rails of the whole batch may have a deviation in length equal to 11.11 mm.

1. Cross section of rails

The cross section of the rails should correspond as closely as possible to the templates and drawings provided by the customers. Permissible deviations from the theoretical height of the rail are + 0.79 mm and -0.40 mm. The width of each half of the sole may deviate from the theoretical width of 1.59 mm, provided that the deviation from the total theoretical width of the sole also does not exceed 1.59 mm. No deviations from those dimensions of the cross section of the rail, on which the compliance of the rail sinus with the butt plates depends, are not allowed; the only exception is the template for checking the rail sinus, approved by the customer; the size of the template in the horizontal direction can vary within 1 mm.

12. Rail weight
In the rails of the entire batch, a deviation from the calculated weight of the section is allowed in the amount of up to 1 / 2 ° / o

1. Drilling bolt holes

According to the drawings provided by the customers, round bolt holes must be drilled in the rails. It is allowed to increase the diameter of the hole not more than

1. mm. Tolerances in the dimensions that determine the position of the bolt hole are 0.79 mm.
2. rail finishing

a) All rails must have a smooth head surface, their axis must be straight; twisting, waviness and curvature of the rails are not allowed. In a straightening press, supports for rails must have a flat surface, no hollows are allowed on the supports, and bent or twisted supports are not allowed. The distance between the supports should be approximately 1.52 m. To straighten the ends of the rails, additional supports with a distance between them less than 1.52 m can be used. If you put the rail head up on a horizontal surface, then it is allowed that its ends are slightly raised, provided that the bending of the ends will be uniform, and the average ordinate of the deflection will not exceed 31.75 mm over a length of 11.89 m. The ends of the rails must be sawn in a square; in this case, deviations of not more than 0.79 mm are allowed, and for rails weighing 69.4 kg / n ^ g. m and above - no more than 2.38 mm; end burrs must be completely removed.
b) If the rails presented for inspection do not meet the requirements set forth in parts 13 or 14, paragraph "a", it is allowed to correct them at the factories, provided that after the correction the rails will fully meet the requirements for them.
c) If in the end or in the bolt hole of any of the finished rails the defects specified in paragraph "a" of part 7 are found, then the end of such a rail must be filed or broken off until healthy metal is reached; thereafter, the rails may be accepted as short rails No. 1 or 2 in accordance with the requirements set out in parts 8 and 10. To determine the condition of the metal inside the rail, fracture samples are provided to the inspector.

1. Rail marking

Rice. 1. Inspection of the rails at the loading area of ​​the rail rolling plant and their distribution into groups
A brand rolls out on one side of the neck; the mark must remain clearly visible at all times while the rail is in service; The stamp is rolled out in accordance with the following requirements:
a) The data rolled out on the neck and their location must correspond to the type mark below. The form of letters and numbers is set by the manufacturer, for example:

b) The heat number, the rail letter and the ingot number are placed on the neck of each rail in the place where they cannot be closed by butt plates. It is desirable that the number of the ingot corresponds to the ordinal number of the mold. The data stamped in the stamp and the order of their arrangement must be the same as shown on the type stamp:
63345 I ABCDEFGH I 17
(heat number) I (rail letter) | (bar number)
c) The head rails are usually designated with the letter A, and the following letters with the letters B, C, D, E, etc.
If the volume of metal removed from the head of the ingot is very large, then the first rail can be denoted by the letter B or the following letters in order, depending on the amount of metal removed. The outline and dimensions of the letters and numbers of the brand must be as shown below:
ABCDEFGHIJKHLMNO 15.88 mm 1234567890 mm or IM 15.88 mm
Rails are loaded onto platforms by an overhead electromagnetic crane.
Rails manufactured with controlled cooling, weighing more than 49.6 kg / rm. m, are designated by the letters CC (control cooled rails), which are part of the hallmark. Rails made with controlled cooling, having a weight of 4C.6 kg1po. m and less (with the exception of the section type 100 RE), are designated by the same letters CC, also included in the brand or stamped in a hot state on the neck of the rail.

1. Adjustable rail cooling

a) All rails are cooled in the usual way on racks and during their movement to the boxes until their temperature drops to 538 - 385 ° C, after which the rails are immediately loaded into the boxes.
b) Before loading, the temperature of the rails is determined using pyrometers; the temperature is measured on the tread surface of the head no closer than 304.8 mm from the end of the rail.
c) In order to avoid bending the rails and to minimize the need for cold straightening, the rails must be handled very carefully when moving them from rack to box and when removing them from the box.
d) After the loading of the box is completed, it is immediately closed with a lid and left in this position for at least 10 hours. After removing the lid, unloading of the box does not begin until the temperature top row rails will not drop to 149°C or below.
E) After that, the temperature is measured between the outer and neighboring rail of the lower row at a distance of not more than 914.4 mm and not less than 304.8 mm from the end of the rail. By changing the temperature in this place judge the rate of cooling.
f) The box must be so protected and insulated that the control temperature when cooling the rails weighing 49.6 kg / rm. m and above could not fall below 149 ° C 7 hours after the bottom row of rails was laid in the box; for rails weighing less than 49.6 kg "rm, the above time interval is 5 hours. If for some reason these requirements cannot be met, then the rails can be considered manufactured with controlled cooling in the case when the temperature is at a distance of 304, 8 mm from the end of the rail, located approximately in the center of the middle rail pack, will not fall below 149 ° C before 15 hours.
g) In accordance with the form 401-D of the AREA Instructions, the consumer receives a complete record of the processes occurring in each box.
h) If the rails do not meet the specified requirements, then the letters CC are removed from each brand.
i) The letters CH may be hot-stamped on the neck in front of the heat number to indicate that these rails are manufactured with slow cooling and that they have hardened ends.
17. Marking of rails with their distribution into groups
(Fig. 77)
a) The ends of rails No. 2 are painted white and the number 2 is embossed on both ends.
b) The ends of the X-rails are painted brown, and the letters X are embossed on both ends.
c) The ends of rails A are painted yellow.
d) The ends of rails No. 1 with a length of less than 11.89 m are painted green.
e) All melting rails with a limiting (upper) percentage of carbon or differing from it by no more than 0.05% are assigned to one group and both ends are painted blue.
Each rail must be painted only one color according to the order in which the above points follow.
18. Loading
The rails must be handled in such a way that any possibility of damage to them is excluded; rails should be loaded into separate wagons according to their classification (low carbon #1 rails, #1 high carbon rails, #2 rails and X-rails).
For the implementation of separate loading of rails, their marking is not required in more detail than the one given above.

1. Rail rolling process

The entire rail manufacturing process must be state of the art. It is assumed that it is possible to obtain a completely killed steel and that at any stage of the manufacture of rails, the experience of individual plants is taken into account.

1. Acceptance and payment of rails

a) In order for the proposed rails to be accepted, they must meet all the requirements of this Specification.
b) Rails No. 2 can be accepted in quantities up to 8°/0 of the entire lot.
c) Accepted rails are paid according to their actual weight and subject to the restrictions set out in part 12.

SUPPLEMENT TO SPECIFICATIONS

Since the use of long welded rails has already passed the experimentation stage, there was a need for some modification of the Specification for open hearth rails, aimed at making these rails more suitable for butt welding. So, for example, in rails intended for welding, there is no need to drill bolt holes, with the exception of those rails that will be at the ends of long welded lashes. The presence of bolt holes in long welded rails can lead to the appearance of cracks near them; in addition, during the pressure welding process, the distances between the bolt holes will change. It is much more expedient if such rails are produced without bolt holes at the ends. It is desirable that only rails of higher quality are welded and that the ends of such rails are not hardened or painted.
In order to summarize all of the above requirements and create a permanent guideline that can be followed when ordering butt weld rails, additions to the existing Rail Specification have been developed by the dedicated AREA Long Welded Rail Committee. Additional Specifications have been reviewed and approved by representatives of the AREA Rail Committee and the American Iron and Steel Institute Technical Committee. In 1955, additional Specifications were adopted as materials of the Manual, in the following form.

AREA SPECIFICATIONS FOR THE MANUFACTURER OF RAILS INTENDED FOR BUTT WELDING

1. a common part

Except as noted below, all butt weld rails must be manufactured in accordance with the latest AREA Specification; the length of the rails must be 11.89 m. the rails must be manufactured with controlled cooling.
2. Order for rails
a) The order for rails should indicate not the number of rails (in pieces), but their total weight.
b) The order must specify (in tons) the desired number of rails with bolt holes in the right and left ends, as well as the number of rails without bolt holes. The left and right ends of the rail are determined by the front side on which the stamp is applied.
c) In order to provide the required number of rails (in tons) suitable for butt welding, it is necessary to produce more rails than indicated in the order, in case a part of the rails in accordance with part 3 is not recognized as suitable for butt welding .

1. Rail classification by manufacturer

a) Unless otherwise stated, A-rails, X-rails, and No. 2 rails are not included in the tonnage of butt-weld rails.
b) Unless otherwise stated, short rails (rails less than 11.89 m long) are not included in the tonnage of rails intended for butt welding.
c) Rails that are not included in the tonnage of rails intended for butt welding are accepted by the consumer in accordance with paragraphs. "b", "d" and "e" of part 4.

1. Bolt holes

a) In accordance with the requirement of the customer, in this batch of rails there must be rails in which bolt holes are drilled only at the left end.
b) If the order provides for rails with bolt holes in the right and left ends, then the number of such rails must be increased compared to that specified in the order.
c) A certain number of rails to be supplied by the customer must be made without bolt holes at the ends.
d) Unless otherwise stated, A, Short and X-rails are drilled from both ends.
e) Rails that, when inspected on inspection racks, are classified as rails No. 2 and have bolt holes only at the right or left end or do not have bolt holes at all, are accepted without returning them to the finishing shop for drilling holes.

1. Finishing the ends of the rails

a) In accordance with the latest AREA Specification, the ends of all hot-sawn rails are milled or ground until the length of the rails is correct; the surface of the end of the rail must be perpendicular to the axis of the rail.
b) If hardening of the ends of the rails is envisaged, then only those ends that have bolt holes should be hardened and chamfered; at the same time, the letters CH are knocked out on the rail.
c) Ends are not hardened and chamfers are not removed at the ends of rails that do not have bolt holes. In the event that the order provides for a certain number of rails without bolt holes, but with hardened ends, the letters CH can also be placed on such rails.
V. Rail markingNext

As noted, needs depend on the number of use values, their rarity, and the possibility of reproducing them. Since a person does not need a given object (good) in general, but a certain amount of it, the need for it is satisfied in accordance with the law of saturation of needs. This is the first law named after its author, the German economist Hermann Gossen (1810-1858) (“The Development of the Laws of Human Interaction”, 1854). Gossen's first law says: as a need is satisfied, its value falls, or as the amount of consumed goods increases, its utility decreases.
To illustrate this law, Böhm-Bawerk gives the following example. A lone settler lives in the forest. He gathered five sacks of grain for the next harvest. What is their significance to this person? One bag of bread is needed so as not to die of hunger, the other is needed to maintain health and strength. He uses the third bag for fattening poultry, the fourth for making vodka, and the fifth for food for a parrot, which he keeps for fun. All bags have the same value. But if they are arranged in descending order of value for the settler, then the first bag of grain has the highest value: it is necessary to save the life of the settler. This highest value can be estimated at 10 points. The utility of the second bag will be rated somewhat lower, say, 8 points. The usefulness (or value) of the rest should be evaluated in b, 4 and, finally, 1 point.
Thus, as utility decreases, the subjective value of sacks of grain decreases. The transition to the saturation of the demand for grain does not occur immediately, but gradually, as if by steps. The utility of each new unit (batch) of the good (commodity) decreases.
The term “marginal utility” is used to denote the utility added by each successive, final portion of a commodity. The usefulness of each new unit that comes to a person's disposal depends on the similar units already in his possession. The need for new units (parts, shares) with an increase in their number gradually decreases. Marginal utility is the increase in total utility with an increase in the total number of goods per unit (part, share).
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“When a certain amount of an item has been received, we are indifferent to the further amount, or even disgusted. Each subsequent application will usually evoke less intense feelings than the previous application. Then the utility of the last share of the item usually decreases in some proportion or as some function of the total amount received”3.
If the classics were mainly interested in “average”, “weighted average” values, then the Austrians focused on the dynamics, increment or decrease of economic parameters.
We note once again that, according to the Austrian school, the consideration of utility should be approached, as it were, from two sides. One thing is the general utility of goods (bread, diamonds, gasoline) in accordance with their properties, another thing is the utility of a particular product that a given consumer needs; it does not remain the same, each time it is evaluated differently. There is a difference in approach here. If one can freely and as much as one likes one or another good, then their usefulness will not be assessed as if there were a limited number of these goods. The concrete utility of goods is changeable, mobile.
The distinction between the total (cumulative) utility of a good (goods) and its specific (marginal) utility is necessary for analyzing consumer behavior.
So, the marginal utility of each individual good (commodity) is quite specific and at the same time subjective. The usefulness of the first jug of water is very high: if at least one jug of water is missing, you can become thirsty. The usefulness of the fifth or sixth jug is much less: water will be used to water flowers or wash the floor. As for the tenth jug, it may turn out to be superfluous in general. In a home wardrobe, it is enough for its owner to have, for example, eight pairs of boots; the rest will only take up space in the closet and may go out of fashion before they are worn.
Diminishing utility helps to understand what determines (from the perspective of the consumer) the real value of a good:
its greatest, average, or least utility. The theory presented by the Austrian school states that specific utility is determined by the smallest, or marginal, utility, that is, the least important of all possible goods that can be satisfied with the available quantity of goods. Pre-
45
specific utility - the utility of the last part (unit) that came at the disposal of the consumer.
The buyer is ready to pay more for the first, the only pair of boots for him, than for the eighth. He needs the eighth pair less than the first. This feature is also taken into account by the manufacturer, who studies the degree of saturation of the market with goods.
Gossen's first law (the law of saturation of needs) has that practical value that it reflects the relationship between a decrease in marginal utility and a decrease in the demand curve (fall in demand). The demand curve can be derived as the derivative of the marginal utility curve.
The assessment of usefulness is subjective. Utility decreases as the volume, quantity of goods increases and increases as this volume decreases. If the consumer loses one of the units at his disposal, then he will refuse to satisfy the least important need. If a car owner loses one out of three cans of gasoline, or if the price of gasoline increases so much that instead of three he can only get two cans, then this person will refuse the least important trips, such as trips to a friend, but will still go shopping in a car . If, due to a malfunction in the water supply, the water supply is reduced, the consumer will stop using water for watering the lawn, but will continue to use it for cooking and washing clothes.
Everyone has their own scale of needs. There are the most and least urgent. Everyone constantly compares and chooses in what sequence, in what volume to purchase goods and pay for services. People combine and compare values. You have to pay for goods and services, and you have to make a rational choice between goods that satisfy some need and monetary payment for the purchase of goods.
Needs evolve and new ones emerge. The need to travel by tram or metro is transformed into the need to travel by personal car. The need to have an album of photographs is complemented by the desire to acquire a personal film library. The range of needs in quantity and quality is expanding utilities etc.
The resources available to society are always limited. Today, not everyone is able to buy Personal Computer or car. Not everyone manages to have convenient and comfortable housing. The society lacks
46
native resources, productivity is still low, losses are high. From the limited and lack of resources follows the need for their economical spending, limiting needs and choosing the most appropriate options. The choice is made between different needs, between more important and less important needs.
Economic science and economic practice deal not only with average, aggregated values, but also with marginal, minimum or maximum. Goods and services are compared and valued as use values. It would, of course, be absurd to add or compare tons and meters, rails and cotton as such. But you can compare what is more important to a person, a company - 1 ton of cement or a roll of linoleum, a set of carpentry or plumbing equipment.
In a real market situation, people not only evaluate utilities, but also exchange them. The exchange gives a win to each of its participants. Otherwise, no one would be engaged in the exchange. When the marginal utility of the acquired object is compared with the lost utility of the commodity offered in exchange, a kind of equality of mutual benefits sets in, an equivalence of the values ​​involved in the exchange transaction is achieved.
IN modern society the exchange is made through money. Money and prices, expressed in monetary units, act as commensurators of use values. The utilities of the commodities involved in the exchange must correspond to prices.