TW201410877A - Method for producing bainitic rail steel - Google Patents

Abstract

In a track part, in particular a rail for rail vehicles, made from low-alloy steel, the steel in the rail head of the track part comprises a ferrite portion of 5-15% by volume and a multiphase bainite structure consisting of upper and lower bainite portions.

Description

Method for producing toughened rail steel

The present invention relates to rail components made of low alloy steel, and in particular to rails for rail vehicles.

Furthermore, the present invention relates to a method of producing a rail component from a hot rolled section, and an apparatus for carrying out the method.

Recently, in order to enhance the efficiency of rail transportation, the load weight and the traveling speed of railway transportation have continued to increase. The railway track is thus subject to an increased wear and tear operation and therefore must be of a higher quality to withstand higher loads. Specific problems involve severely increased wear, especially in rails that are installed in corners, and damage due to material fatigue, which occurs mainly at the driving edge that constitutes the main point of contact between the track and the wheel in the curve, which will result in rolling Contact fatigue (RCF) damage. Examples of RCF surface damage include dry head cracking (rolling fatigue), peeling (flaking), crouching (plastic surface deformation), slip waves, and wrinkles. These types of surface damage will shorten track life, increase noise emissions and operational obstructions. In addition, the chance of such an increase in failure will increase with the growing traffic load. The direct result of this development is to increase the demand for track maintenance. However, the increased maintenance requirements are inconsistent with the ever-decreasing repair window. The higher the column Car density can greatly reduce the amount of time it can work on the track.

Although the above types of damage can be eliminated by grinding at an early stage, the track must be replaced when severe damage has occurred. Therefore, many attempts have been made in the past to improve wear resistance and RCF damage resistance to increase the life cycle of the track. In addition, this can also be achieved by introducing and using toughened rail steel.

Bainite is a structure which can be formed by constant temperature transformation or continuous cooling during heat treatment of carbon-containing steel. The toughening system is formed at a temperature and a cooling rate in a range between a temperature and a cooling rate required for separately forming a perlite and a martensite. Unlike the case of the Matian bulk structure, the inversion procedure in the crystal lattice and the diffusion procedure are joined together in this case, thus implementing different transformation mechanisms. The tough body does not have a characteristic structure because it depends on the cooling rate, the carbon content, the alloying element, and the resulting formation temperature. Like the corrugated body, the toughening system consists of the phase of the fat granules and the cementite (Fe3C), but is different in shape, size and distribution from the cortex. Basically, the toughening system can be distinguished into two main structural forms, namely, an upper tough body and a lower tough body.

A track material is known from AT-407057 B, in which the structural transformation of the Worth field is clearly formed only in the range of the lower tough body, thus giving the contoured rolled material a hardness of at least 350 HB, in particular 450 To 600HB.

The toughened substrate structure can also be obtained by a higher portion of the alloying component, such as a higher chromium content of 2.2 to 3.0% by weight, such as It is described in the document DE 1020060308915 A1 and DE 102006030816 A1. However, the high portion of alloying components can involve undesirably high cost and complex welding engineering tasks. DE 20 2005 009 259 U1 also describes a tough, high-strength orbital component of high-alloy steel, which in particular comprises a high-alloy portion of manganese, niobium and chromium. In the case of this high alloy steel, the formation of the toughener can be triggered by a simple means of cooling in still air. Conversely, low alloy steel can only achieve tough body formation with controlled cooling.

Thus, for example, DE-1533982 describes a method for heat treating a track, wherein the track system, which still has a rolling temperature, is removed by the riser after leaving the roll table and submerged in fluidization with the track head down. Maintaining a constant temperature in the bed where it is cooled, wherein the temperature of the deformed crystal structure is selected between 380 and 450 ° C at the temperature of the fluidized bed and the orbital remains in the fluid depending on its temperature Obtained in the chemical bed between 300 and 900 seconds.

Another method for producing high-strength orbits from low-alloy steels having a toughened structure to achieve resistance to fatigue damage due to rolling contact is known from EP-612852 B1. The head of the track is subjected to accelerated cooling from a range of Worth field at a rate of 1 to 10 ° C/s until a cooling interruption temperature of 500 to 300 ° C is reached. After rapid cooling, the track head is further cooled to almost room temperature by applying heat to recover heat or forced cooling at a rate of 1 to 40 ° C/min.

Although the formation and propagation of cracks in the track head can be alleviated by the above measures, the occurrence of cracks cannot be prevented.

Accordingly, the present invention is directed to the enhancement of rail components, particularly rails, which are made of low alloy steel for cost reasons, and for rolling engineering reasons, no rolling contact is produced even under the effect of increasing wheel load. Fatigue damage, and especially cracks on the running edge or running surface. Furthermore, wear resistance can be increased to ensure a service life of more than 30 years. Finally, the track component can be perfectly welded and also has other material properties similar to those found to date in the track construction, such as similar electrical conductivity and similar coefficients of thermal expansion.

The present invention further aims to provide a simple production method characterized by shortening the processing time (eliminating the annealing stage), high reproducibility, and high efficiency. The method is suitable for producing long tracks, for example having a length of more than 100 meters, wherein constant material properties are ensured over the entire length of the track.

In order to achieve this object, the invention according to the first aspect provides a rail member of the type mentioned in the preamble which is further developed such that the steel in the rail head of the rail member contains 5 to 15 volume percent of the fat body. Part and multi-phase metamorphic structure composed of upper and lower metamorphic parts. Due to the combination of the fat body structure and the tough structure, excellent toughness and high hardness can be achieved. The fertilizer granule structural component is used as a plastic carrier and prevents cracks that may form from extending into the material to become a dry head. The granule portion imparts a continuous network to the overall structure with the intertwined metamorphic body. In this context, it is desirable to be able to achieve a percolation threshold to achieve this configuration (cluster) of adjacent regions. The fertilizer granules are preferably needle-shaped granules. Different from non-needle structure, and different from wave body The structure of the needle-like structure is characterized by high tensile strength and wear resistance. The acicular granules have a microstructure characterized by needle crystals or granules which are not uniformly oriented but are presented in a completely unoriented form which will have a positive effect on the toughness of the steel. The non-directional configuration of the particles causes the individual particles to interlock with each other, and the combination with the multi-phase metamorphic body can effectively prevent the formation and propagation of cracks. In particular, it is thereby ensured that cracks (head cracks) which may be formed on the surface do not grow into the depth of the material, as in the case of, for example, a corrugated structure. The track components will therefore only be subject to wear so that they can be accurately determined during use and any further observation of crack formation can be dispensed with.

A further decisive influence is the presence of multi-phase metamorphic bodies comprising upper and lower metamorphic portions. The upper toughening system is formed in an upper temperature range of the toughening structure and has a needle-like structure similar to the Matian bulk. In the temperature range above the metamorphic structure, there are favorable diffusion conditions to allow carbon to diffuse to the grain boundaries of the granule body. Therefore, irregular and interrupted sulphur carbon crystals can be formed. Due to the irregular distribution, the structure often has a granular appearance, so that the upper tough body is sometimes referred to as a granular tough body. The lower toughening system is formed by continuous cooling at a constant temperature and in a temperature range below the formation of the toughening body. By forming a fat granule, the Worth field is rich in carbon, and by further cooling, the Worth field is converted into a fat body, a swarf carbon body, a needle-like metamorphic body, and a masculine body. Toughening will reduce internal stress and increase toughness.

The mixing ratio between the lower and upper metamorphic bodies can vary substantially within a wide range of limitations depending on the individual functional requirements. Mixed ratio The choice will especially determine the hardness of the steel. In the context of the present invention, the portion of the upper tough body is preferably from 5 to 75 volume percent, especially from 20 to 60 volume percent, and the portion of the lower toughener is from 15 to 90 volume percent, especially from 40 to 85 volume percent.

The fertilizer granule portion is preferably from 8 to 13 volume percent.

The structure of carbides from the Worth Field is a prerequisite for a complete metamorphic transformation. Since the carbide carries a large amount of carbon, it constitutes carbon sinks that extract carbon from the Worth field. If the carbide is prevented or prevented from being formed, for example, as an alloying element, a large number of Worthfield bodies cannot be transformed. These Worthfields then become partially or completely present after being quenched to room temperature and become a residual Worth. The amount of residual Worth is determined by how much the starting temperature of the field is degraded in the remaining Worth field. In the context of the present invention, it would be advantageous to leave as few parts of the Worth and/or the granules as possible. In connection with this, the present invention preferably provides that the steel in the track head of the track component contains <2 volume percent of the residual 麻田散体/Worthian body portion.

As just indicated, low alloy steels are used in accordance with the present invention to minimize cost and improve weldability. In general, in the context of the present invention, the low alloy steel preferably comprises cerium, manganese and chromium, and optionally vanadium, molybdenum, phosphorus, sulfur and/or nickel as alloying constituents.

The steel in the context of the present invention may be referred to as low alloy steel if it does not have any alloying component present in portions greater than 1.5 weight percent.

Can be achieved by low alloy steel with the following reference analysis Specific good results:

0.4 to 0.55 weight percent carbon

0.3 to 0.6 weight percent bismuth

0.9 to 1.4 weight percent manganese

0.3 to 0.6 weight percent chromium

0.1 to 0.3 weight percent vanadium

0.05 to 0.20 weight percent of molybdenum

0 to 0.02 weight percent phosphorus

0 to 0.02 weight percent sulfur

0 to 0.15 weight percent nickel

If the track member has a tensile strength above 1150 N/mm ² in the head region, a particularly good suitability for the high load track segment will preferably be provided. Furthermore, the track member has a hardness of more than 340 HB in the head region.

According to a second aspect, the present invention provides a method of producing the above-described rail member, by which the rail member can be produced from a hot rolling section, wherein the rail head of the rolling section is rolled hot after leaving the roller table Immediately subjected to controlled cooling, which comprises accelerated cooling in a first step until a first temperature at which a fertilizer body is allowed to form is reached, and the first temperature is maintained in a second step to cause formation of a fat body, and In the third step, the temperature is further cooled in a temperature range allowing the formation of the multi-phase metamorphic body until the second temperature is reached, and the second temperature is maintained in the fourth step. This controlled cooling is preferably performed by immersing at least the track head in the liquid coolant, as is well known in the art.

This first step preferably starts at a temperature of 740 to 850 ° C, especially about 790 ° C, and preferably ends at a temperature of 450 to 525 ° C. The cooling carried out during the first step must be controlled in such a way as to reach the extent of the granules, and subsequently the plastomers are formed in a time-to-temperature transition diagram, wherein in particular no transitions occur in the wavy phase. To this end, the accelerated cooling in the first step is preferably performed at a cooling rate of 2 to 5 ° C/s. In order to achieve this cooling rate, it is preferably carried out in such a manner that the rail member is completely submerged in the coolant during the first step.

In the second step, it is preferred to maintain a temperature of 450 to 525 ° C, while a portion of the granules (especially a portion of the acicular granules, which is important for the use characteristics) is 5 to 15%, especially It is formed in a volume fraction of 8 to 13%, more specifically about 10%. The maintenance of the temperature is preferably achieved during the second step, wherein the track member is held in a position removed from the coolant.

In a third step, further controlled cooling is performed for the desired limitations of the fat body portion, thus resulting in the formation of a mixture of upper and lower metamorphic structures (heterogeneous tough bodies). The temperature range in which the tough body is formed preferably occurs in a range between 450 to 525 ° C and 280 to 350 ° C, that is, in the stage of formation of the tough body, the track head of the rail member is cooled from 450 to 525 ° C to 280 to 350 ° C. This third step is preferably extended by a period of 50 to 100 seconds, especially about 70 seconds. In the stage of formation of the tough body, the track member is preferably immersed into the coolant only by the track head.

When the temperature of the rail member is subsequently maintained in the range of 280 to 350 ° C in the fourth step, the hardness of the rail member will eventually follow the temperature. It is fixed by the action of the position, wherein it is avoided to fall below the starting temperature of the granules (usually about 280 ° C), because there will be too many granules in the temperature range, which may form fragile structural components. The maintenance of the temperature during the fourth step is preferably ensured by periodic head immersion, i.e., the track members are periodically immersed in the coolant and removed from the coolant.

Since the temperature range of the toughness phase formation and the starting temperature of the matrix are determined by the alloying elements of the respective steels and their respective percentages, the values of the first temperature and the second temperature must be given for the respective steels. Determine accurately beforehand. The temperature of the track is continuously measured during controlled cooling, wherein the cooling and maintaining steps begin and end, respectively, when the respective temperature thresholds are reached. Since the surface temperature of the track changes with the total length of the track member, but the cooling is performed uniformly for the entire track member, it is preferable to detect the temperature with a plurality of measurement points distributed over the length of the track member. And the method of forming a temperature average to control the controlled cooling is performed.

In the stage of formation of the tough body, the Worth field body is transformed into a tough body as completely as possible. This occurs below the temperature at which the wave body is formed, as long as the temperature at which the granules are started is simultaneously constant temperature and continuously cooled. By slowly turning over the Worth field, a strongly supersaturated carbon crystal with a cubic space-centered crystal lattice is formed, except for grain boundaries or crystal defects. Due to the higher diffusivity in the cubic space centered carbon, the carbon is precipitated as spherical or ellipsoidal spheroidal carbon crystals in the granules. Carbon can also diffuse into the Worth field and form carbides.

In the context of the present invention, the cooling and temperature maintenance during the third and fourth steps are carried out in a manner to form a multi-phase metamorphic body. In the first sub-step, the continuous cooling is performed at a lower rate than the cooling rate in the second sub-step, wherein the temperature is suddenly lowered until the second temperature is reached. During the first substep, a preliminary upper tough body is formed. After the sudden cooling, the second temperature is maintained in the fourth step while forming the lower toughening body. The duration of the second temperature during the fourth step will determine the extent to which the lower tough body is formed.

The upper toughening system consists of needle-shaped granules in the form of a block. Between the individual granule needles, there is a more or less continuous film of carbide extending parallel to the axis of the needle. In contrast, the lower toughening system consists of a fat granule sheet in which carbides are formed at an angle of 60° with respect to the axis of the needle.

The coolant undergoes a three-stage quenching process during controlled cooling by means of a liquid coolant. In the first stage (i.e., the vapor film stage), the temperature on the surface of the track head is so high that the coolant will be rapidly evaporated while forming a thin insulating vapor film (Leidenfrost effect). In addition to this, the vapor film stage is strongly dependent on the vapor forming heat of the coolant, the surface characteristics (e.g., size) of the track member, or the chemical composition and configuration of the cooling bath. In the second stage (i.e., the boiling stage), the coolant will come into direct contact with the hot surface of the track head and begin to boil immediately, which results in a high cooling rate. The third stage, that is, the convection stage, begins when the surface temperature of the track components has dropped to the boiling point of the coolant. In this range, the cooling rate is substantially affected by the flow of the coolant. The effect of the rate.

During controlled cooling provided by the present invention, the coolant is preferably in the vapor film stage during the first step. The cooling system during the third step is controlled to cause the coolant to initially form a vapor film on the surface of the track head and then boil on the surface for further better processing. Thus, a transition from the vapor film stage to the boiling stage occurs. The vapor film stage extends over the length of the first sub-step described above, wherein a preliminary upper toughening body is formed. After the boiling phase has been reached, the temperature will suddenly drop to a second temperature, i.e. preferably to 280 to 350 °C.

The transition from the vapor film stage to the boiling stage typically occurs in a relatively uncontrolled and spontaneous reaction. Since the track temperature experiences a specific production-related temperature difference over the entire length of the track member, problems arise in the transition from the vapor film stage to the boiling stage in different length regions of the track member at different times. This will result in a non-uniform crystal structure and therefore uneven material properties throughout the length of the track member. In order to reconcile the time from the vapor film stage to the boiling stage over the entire length of the track, a preferred mode of operation is provided during which the rupture film, gaseous pressure medium, such as nitrogen, is applied along the entire length of the track member during the third step. Supply to the track head to break the vapor film along the entire length of the track member and trigger the boiling phase.

This is especially so that the state of the coolant during the third step is monitored along the entire length of the rail member and the rupture film, gaseous pressure medium is present as long as the initial appearance of the boiling phase occurs in one of the lengths of the rail member The way to supply the track head for processing.

The rupture film, gaseous pressure medium is preferably supplied to the track head for about 20 to 100 seconds after the start of the third step, especially for about 50 seconds.

According to another aspect of the present invention, there is provided an apparatus for implementing the above method, comprising a cooling tank corresponding to the length of the rail member and filled with a coolant, and a lifting and lowering device for the rail member for guiding the rail a temperature measuring device for immersing the component in the cooling bath and lifting it from the cooling tank, for measuring the temperature of the rail member, a pressure medium generating means for injecting the pressure medium into the coolant, for controlling the coolant And a control device, wherein the measured value of the temperature measuring device is fed to the control device, and the control device is connected to the rising and falling device for controlling the rising and falling operations, and the measured value is based on the temperature Means for controlling the temperature of the coolant, and further interacting with the pressure medium generating means.

In a preferred form, a sensor for detecting coolant boiling on the surface of the track head is provided, the sensor measurement being fed to the control device to activate the sensor based on the sensor measurement Pressure medium generation means. In particular, a plurality of sensors can be provided to detect coolant boiling on the surface of the track head, the sensors being distributed over the length of the cooling bath.

In a preferred embodiment, the sensor measurements of the plurality of sensors are fed to the control device, and the control device is activated when at least the sensor has detected coolant boiling on the surface of the track head. The pressure medium generating means.

The control device is advantageously configured to perform controlled cooling comprising accelerating cooling in a first step until a first temperature allowing the formation of a fat body is reached, and maintaining the first temperature in a second step to cause a fat body The formation is further cooled in the third step in a temperature range that allows formation of the multi-phase metamorphic toughness until the second temperature, and the second temperature is maintained in the fourth step.

The control device may in particular be configured to reduce the temperature of the track head to a first temperature of 450 to 525 ° C at a cooling rate of 2 to 5 ° C/s in a first step to bring the temperature of the track head in a second step The first temperature is maintained and the temperature of the track head is lowered to a second temperature of 280 to 350 ° C during the third step, preferably for a period of 50 to 100 seconds, especially for a time of about 70 seconds.

The control device is preferably configured to activate the pressure medium generating means during the third step.

1, 2, 3, 4, 5‧‧ points

Figure 1 is a schematic diagram of the time-temperature transition of low alloy steel.

Fig. 2 is a view showing the fine structure of the first embodiment of the present invention.

Fig. 3 is a view showing the fine structure of the second embodiment of the present invention.

In the following, the invention will be explained in more detail by way of illustrative embodiments.

Low alloy steels with the following reference analysis are formed by hot rolling the track into a standard track profile:

O.49 weight percent carbon

0.36 weight percent 矽

1.11% by weight of manganese

0.53 weight percent chromium

0.136 weight percent vanadium

0.0085 weight percent molybdenum

0.02 weight percent phosphorus

0.02% by weight of sulfur

0.1 weight percent nickel

Upon exiting the roll table, the track immediately undergoes controlled cooling with rolling heat. This controlled cooling will be illustrated with reference to the time-temperature transition diagram shown in Figure 1, with the straight line indicated by 1 indicating the cooling process. This cooling procedure starts at a temperature of 790 °C. In the first step, the track was immersed in the cooling water bath with its entire length and its entire section, and was adjusted to a cooling rate of 4 ° C/s. After about 75 seconds, the surface temperature of the track head was measured to be 490 ° C, which has reached point 2 and the track has been removed from the cooling bath to maintain the temperature for about 30 seconds to achieve needle-shaped fat body formation. . When point 3 is reached, the track is again submerged into the cooling bath and cooled until point 4. At point 4, the initial boiling of the cooling water is detected on the surface of the track head, and compressed air is supplied to the track head to break the vapor film surrounding the track head and initiate a boiling phase over the entire length of the track. The onset of this boiling phase caused a sudden drop in the temperature of the orbital head, which was aborted when the temperature reached 315 (point 5). By periodically immersing the head, the temperature of the head can be maintained for a certain period of time. Multiphase state This is determined by the combination of the tough structure, which will be understood from the following examples.

Example 1

In the first exemplary embodiment, the low alloy steel having the following reference analysis is formed by hot rolling the traveling track into a standard track profile:

0.49 weight percent carbon

0.36 weight percent 矽

1.11% by weight of manganese

0.53 weight percent chromium

0.136 weight percent vanadium

0.0085 weight percent molybdenum

0.02 weight percent phosphorus

0.02% by weight of sulfur

0.1 weight percent nickel

The following fine structure is achieved in the orbital head by the above controlled cooling: about 10 volume percent of needle-shaped fertilizer bodies, about 74 volume percent of upper toughness, about 16 volume percent of lower toughness, <1 Volume percent of the Ma Tian bulk - residual Worth field.

This fine structure is shown in Figure 2.

Due to the upper portion of the toughening body, a lower hardness of the orbital head than in the subsequent second exemplary embodiment can be achieved. The following material properties were measured.

Hardness: 347HB

Tensile strength: 1162MPa

0.2% drop strength: 977MPa

Burst stretch: 14.4%

Notched impact test:

Test at +20 ° C: 110 J/cm ²

Test at -20 ° C: 95 J/cm ²

The crack grows da/dN.

Test at ΔK=10 [MPa√m]: 8.9 [m/Gc]

Test at ΔK=13.5 [MPa√m]: 15.8 [m/Gc]

Where m/Gc=meter/gigacycle

Wear resistance:

(AMSLER test: 10% slip, 1200N positive force)

Material wear: 1.72mg/m ²

Compare R260 material wear: 1.79mg/m ²

Fracture toughness: 39MPa√m

Example 2

In the second exemplary embodiment, the same low alloy steel as in Embodiment 1 is employed and formed by hot rolling a traveling track into a standard track profile. Controlled cooling similar to that of Example 1 was performed, but the temperature in the fourth step was longer than that of Example 1. Obtaining the following subtle structure in the orbital head: about 10 volume percent of needle-like fat bodies, about 15 volume percent of upper toughness, about 75 volume percent of lower toughness, <1 volume percent of 麻田散体 to residual Worth field.

This fine structure is shown in Figure 3.

The following material properties were measured.

Hardness: 405HB

Tensile strength: 1387MPa

0.2% drop strength: 1144MPa

Rupture stretch: 12.6%

Notched impact test:

Test at +20 ° C: 100 J/cm ²

Test at -20 ° C: 75 J/cm ²

The crack grows da/dN.

Test at ΔK=10 [MPa√m]: 9.5 [m/Gc]

Tested at ΔK=13.5 [MPa√m]: 16.5 [m/Gc],

Where m/Gc=meter/gigacycle

Wear resistance:

(AMSLER test: 10% slip, 1200N positive force)

Material wear: 1.55mg/m ²

Compare R260 material wear: 1.79mg/m ²

Fracture toughness: 36MPa√m

1, 2, 3, 4, 5‧‧ points

Claims (34)

A track component made of low-alloy steel, in particular for rail vehicles, characterized in that the steel system in the track head of the track component comprises 5 to 15 volume percent of the fat body portion and from top to bottom A multi-phase tough structure composed of a toughened body portion. The rail member according to claim 1, wherein the upper toughener portion is 5 to 75 volume percent, especially 20 to 60 volume percent, and the lower toughener portion is 15 to 90 volume. Percentage, especially 40 to 85 volume percent. The rail member according to claim 1 or 2, wherein the fertilizer granule portion is 8 to 13 volume percent. The rail member according to claim 1, 2 or 3, wherein the fertilizer system has needle-shaped fertilizer bodies. The rail member of claim 4, wherein the multi-phase toughening system is sandwiched between the needle-shaped fertilizer structure. A rail member according to any one of claims 1 to 5, wherein the steel in the rail head of the rail member contains <2 volume percent of the residual Ma Tian bulk/Worth field portion. The rail member according to any one of claims 1 to 6, wherein the low alloy steel comprises bismuth, manganese and chromium, and optionally vanadium, molybdenum, phosphorus, sulfur and/or nickel are used as the alloy. Ingredients. The rail member of claim 7, wherein none of the alloying components is greater than 1.5 weight percent. The rail member according to any one of claims 1 to 8, wherein a low alloy steel having the following reference analysis is used: 0.4 to 0.55 weight percent of carbon 0.3 to 0.6 weight percent of lanthanum 0.9 to 1.4 weight percent Manganese 0.3 to 0.6 weight percent chromium 0.1 to 0.3 weight percent vanadium 0.05 to 0.20 weight percent molybdenum 0 to 0.02 weight percent phosphorus 0 to 0.02 weight percent sulfur 0 to 0.15 weight percent nickel. The scope of the patent application rail member according to any one of items 1 to 9, wherein the rail member has a tensile strength R _m of greater than 1150N / mm ² in the head region. The rail member according to any one of claims 1 to 10, wherein the rail member has a hardness higher than 340 HB in the head region. A method for producing a rail member according to any one of claims 1 to 11, wherein the rail head of the rolling section is after leaving the roller table The rolling heat is immediately subjected to controlled cooling, which comprises accelerated cooling in a first step until a first temperature allowing the formation of a fat body is reached, and the first temperature is maintained in a second step to cause a fat body Formed, and in the third step is allowed to enter a temperature range that allows the formation of multi-phase metamorphic bodies The step is cooled until the second temperature is reached, and the second temperature is maintained in the fourth step. The method of claim 12, wherein the first step begins at a temperature of from 740 to 850 °C, especially about 790 °C. The method of claim 12, wherein the first temperature is 450 to 525 °C. The method of claim 12, 13 or 14, wherein the second temperature is 280 to 350 °C. The method of any one of claims 12 to 15, wherein the accelerated cooling in the first step is performed at a cooling rate of 2 to 5 ° C/s. The method of any one of claims 12 to 16, wherein the third step is extended for a period of 50 to 100 seconds, especially about 70 seconds. The method of any one of claims 12 to 17, wherein the temperature is detected at a plurality of measurement points distributed over the length of the track member and a temperature average is formed, the temperature average being used This controlled cooling is controlled. The method of any one of claims 12 to 18, wherein the controlled cooling is performed by immersing at least the track head in a liquid coolant. The method of any one of claims 12 to 19, wherein the cooling during the third step causes the coolant to initially form a vapor film on the surface of the track head and then boil on the surface The way is controlled. The method of claim 20, wherein during the third step, a rupture film, a gaseous pressure medium, such as nitrogen, is supplied to the track head along the entire length of the track member to follow the track. The entire length of the part breaks the vapor film and triggers the boiling phase. The method of claim 21, wherein during the third step, the state of the coolant is monitored along the entire length of the rail member, and as long as the initial appearance of the boiling phase in one of the lengths of the rail member When present, the rupture film, gaseous pressure medium is supplied to the track head. The method of claim 21 or 22, wherein after the start of the third step, the rupture film, gaseous pressure medium is supplied to the track head for about 20 to 100 seconds, especially about 50 seconds. The method of any one of claims 12 to 23, wherein the track member is completely submerged in the coolant during the first step. The method of any one of claims 12 to 24, wherein the track member is held in a position removed from the coolant during the second step. The method of any one of claims 12 to 25, wherein the track member is immersed in the coolant only by the track head during the third step. The method of any one of claims 12 to 26, wherein the track member is periodically immersed in the fourth step The coolant is removed from the coolant. A device for carrying out the method according to any one of claims 12 to 27, comprising a cooling groove corresponding to the length of the rail member and filled with a coolant, and a lifting and lowering device for the rail member a temperature measuring device for immersing the rail member in the cooling tank and lifting it from the cooling tank, for measuring the temperature of the rail member, a pressure medium generating means for injecting the pressure medium into the coolant, Means for controlling the temperature of the coolant, and a control device, wherein the measured value of the temperature measuring device is fed to the control device, and the control device is associated with the rising and falling device for controlling the ascending and descending operations, The means for controlling the temperature of the coolant with the function of the temperature measurement and further interacting with the pressure medium generating means. The apparatus of claim 28, wherein a sensor for detecting coolant boiling on a surface of the track head is provided, the sensor measurement value being fed to the control device to The function of the sensor measurement initiates the pressure medium generation means. The device of claim 29, wherein a plurality of sensors are provided to detect coolant boiling on the surface of the track head, the sensors being distributed over the length of the cooling bath. The device of claim 28, 29 or 30, wherein the sensor measurements of the plurality of sensors are fed to the control device, the control device being detected by the at least one sensor The pressure medium generating means is activated when the coolant on the surface of the track head boils. The apparatus of any one of claims 28 to 31, wherein the control device is configured to perform controlled cooling, the controlled cooling comprising accelerating cooling in the first step until reaching the allowable fat body Forming the first temperature, maintaining the first temperature in the second step to cause formation of the fertilizer body, and further cooling in the temperature range allowing the formation of the multi-phase metamorphic body to the second temperature in the third step, and The second temperature is maintained in the fourth step. The device of claim 32, wherein the control device is configured to reduce the temperature of the track head to a temperature of 450 to 525 ° C at a cooling rate of 2 to 5 ° C/s in the first step. a first temperature, and maintaining the temperature of the track head at the first temperature in the second step, and reducing the temperature of the track head to a second temperature of 280 to 350 ° C during the third step, and Jiadi is 50 to 100 seconds, especially about 70 seconds. The device of claim 32, wherein the control device is configured to activate the pressure medium generating means during the third step.