EP0693562A1 - Process and apparatus for heat-treating shaped rolled pieces - Google Patents

Abstract

Method for treatment of rolled profile material comprises straightening rolled profile (1) with plastic forming at 750-1100 degrees C temp.. Initial cooling takes place with locally equal intensity to 5-120 degrees C temp. above the Ar point of the material. This is followed by cooling which has equal intensity in the longitudinal direction of the profile, but varies along the circumference of the profile cross section to ensure a martensitic-free fine pearlitic structure. Final cooling takes place with locally equal intensity down to room temp.. Also claimed is the appts. for carrying out the above heat treating, novel in that is has a preparatory section (A), a second cooling section (B) and a final cooling section (C). <IMAGE>

Description

The invention relates to methods for the heat treatment of profiled rolling stock, in particular of railway or railroad tracks, with increased heat dissipation of parts of the profile surface during cooling from the gamma region of the iron-based material, in which (in the) desired cross-sectional area (s), in particular in the head area of rails, a conversion into a fine pearlitic structure with increased strength, in particular increased abrasion resistance and increased heat takes place and, if necessary, a deformation or bending due to thermal distortion of the rolling stock, in particular the rail, perpendicular to the longitudinal axis when cooling to room temperature, in particular after a structural change in the (in) the cooled cross-sectional area (s), reduced, preferably essentially avoided, and increased rigidity and flexural fatigue strength of the rolling stock can be achieved.

Furthermore, the invention relates to a device for the heat treatment of profiled rolling stock, in particular driving or railroad tracks, consisting essentially of at least one preparation area for the rolling stock on the roller table, with a rolling stock positioning device, a cooling treatment area, with devices for partial heat dissipation with high intensity from the surface of the rolling stock and a final cooling area for cooling the rolling stock to room temperature as well as storage, transverse transport, holding and manipulation means.

Finally, the invention is concerned with a profiled rolling stock, in particular a driving or railroad track, consisting of a rail head with an at least partially pearlitic structure, a rail foot and a web between the rail head and the rail foot.

Profiled rolling stock, in particular driving or railroad tracks, is or are mostly made of iron-based alloys with contents of in% by weight C 0.4 to 1.0, Si 0.1 to 1.2, Mn o, 5 to 3, 5, optionally on Cr to 1.5 and others Alloy elements with concentrations below 1%, the rest iron and manufacturing-related impurities. Due to the usual dimensions, for example with a weight of 30 to 100 kg / m, and the resulting ratio of cross-section to circumference of rails, the rolling stock is cooled from the forming heat in still air, for example on cooling beds and the like. the slow cooling due to a transformation of the structure from an austenitic to a coarse pearlitic structure, possibly with ferrite components. The materials mentioned above with the above structure have a hardness in the range from 250 HB to 350 HB.

An increase in traffic volume and larger axle loads as well as the desire to improve the durability of railroad tracks in practical use led to a large number of proposals to increase the strength and wear resistance of the material. In this case, more favorable or improved material properties with a hearing value of 400 HB and higher can be achieved by heat treatment and / or by alloying measures.

However, rails should be in the field, e.g. to form bumpless route or Multiple lengths, be easy to weld, so that alloying measures to increase the hardness or strength and toughness of the material of the welding problems can usually only be carried out to a small extent and are expedient with a heat treatment tailored to the composition of the steel (DE -C 3 446 794, EP-B-0187904. EP-B-0186373). For economic reasons, too, such processes have not proven themselves on a larger scale.

In order to increase the usage properties of rails and turnout parts made of the materials mentioned at the beginning, it is possible, as the person skilled in the art knows, to set a fine pearlitic material structure by means of a thermal tempering treatment. It is important to set appropriate cooling conditions or cooling rates when cooling from the austenitizing temperature. For example, EP-B-0293002 proposes a practically isothermal structural transformation after an initially high cooling intensity of the material at approx. 530 ° C. From DE-OS-2 820 784 it is also known to carry out a hardening of rails with a certain composition in boiling water and to achieve a desired cooling intensity for setting a fine pearlitic structure by means of additives and movement measures.

According to AT-PS-323 224, it has already been suggested that rails with a homogeneous fine pearlite structure be used with a selected alloy by using certain cooling parameters, e.g. a cooling rate between 10 and 20 ° C / sec to a temperature of 550 ° C at the most. However, the above measures have the disadvantage that the same cooling intensity of the surface, depending on the mass concentration of the rolled profile, can result in different cooling speeds and microstructures in the zones near the surface, and that expensive precautions often have to be taken to prevent unwanted local microstructures or material properties, especially a Excessive hardness and embarrassment, to be avoided in parts of the rail that are primarily subjected to bending.

In many cases, it has also been proposed to specifically set a heterogeneous microstructure in the cross section of a rail, in accordance with the respective stresses. From DE-C-3 006 695, for example, a method is known according to which a conversion in the entire cross-section is effected from the rolling heat by cooling the rail, after which the head of the rail, in particular by inductive heating, is reactivated and then hardened. Furthermore, according to WO 94/02652, it was proposed to cool the rail head up to a surface temperature between 450 and 550 ° C. in a coolant with a specially adjusted cooling intensity and thereby to bring about a fine pearlitic structure in it. A device for hanging hardening of rails in accordance with DE-C-4 003 363 is suitable for such a treatment.

Inhomogeneous cooling across the cross section of profiled rolling stock can, however, lead to curvatures or deviations from the straightness at room temperature. To avoid this disadvantage, it has been proposed (DE-A-4 237 991) to hang rails on a cooling bed, preferably upside down transport or cool, but a targeted formation of a heterogeneous structure across the cross-section is hardly possible.

All previously known methods and devices have the disadvantage in common that in the production of profiled rolling stock, although in limited areas or with regard to individual process steps, they provide quite effective solutions, but that the overall problem is solved satisfactorily in the economical production of high-quality long rails special quality properties can not be shown.

Here, the invention seeks to remedy this and aims to provide a new method, by means of which profiled rolling stock with particularly advantageous usage properties can be produced, while eliminating the disadvantages of the known types of manufacture. Furthermore, it is an object of the invention to provide a device, in particular for carrying out the method, and to design a rolling stock, in particular a rail, for the highest stresses.

The aim is achieved in a generic method in that the rolling stock, in particular the rail, with an average temperature of at most 1100 ° C, preferably at most 900 ° C, but at least 750 ° C, in its longitudinal direction with plastic shaping straight , is brought and held in the aligned state in the transverse direction, and in a first step the cooling of the rolling stock or the rail balancing it or this to a temperature of below 860 ° C., preferably of approximately 820 ° C., in particular from 5 to 120 ° C, above the Ar₃ temperature of the alloy with the same local cooling intensity, preferably essentially by radiation in still air, is allowed to cool, whereupon in a second step of cooling the rolling stock in the longitudinal direction with locally essentially the same, seen in cross section extensively different, heat withdrawn and the cooling intensity in min at least one zone on the circumference of the profiled rolling stock is enlarged, the greater cooling intensity (s) in the area (s) having a large ratio of cross section to circumference or having a high ratio Volume fraction based on the surface or with a high mass concentration and / or those with a locally high temperature of the rolling stock, in particular the rail, is / are assigned and the area (s) is / are brought to the conversion temperature with such an increased cooling rate. under which cooling conditions a martensite-free fine pearlitic structure is formed, after which the cooling to room temperature is carried out in a subsequent step with the same local cooling intensity, for example in still air. It is important that the rolling stock is aligned in a plastic shape and that this is done in a temperature range between 750 ° C and 1100 ° C. Temperatures lower than 750 ° C, as has been found, can lead to a partially elastic bend with deviations from a straight orientation and consequently to inhomogeneous cooling intensity in the longitudinal direction of the rail. Rolled material temperatures of over 1100 ° C usually cause the austenite grains to grow or form coarse grains, which can ultimately adversely affect the material properties. Starting from a just aligned rolling stock, it has proven important for the formation of a fine pearlitic area with a cross section that is uniformly set in the longitudinal direction, that the rolling stock is held and, in a first step of cooling, cools down to a temperature of below 860 ° C. with the same local cooling intensity is left. On the one hand, a local inhomogeneity of the temperature distribution in the longitudinal direction, which may be caused by a resting on a transverse transport device in places, can be compensated, on the other hand, an axially symmetrical or centrically symmetrical temperature distribution in the cross section of the profiled rolling stock is set, thereby stabilizing its straightness. It is particularly advantageous to carry out this balancing cooling to a temperature of 5 ° C to 120 ° C above the Ar₃ temperature of the alloy in order to create favorable conditions for a partial transformation of the structure into a fine pearlitic structural shape in parts of the cross section. The Ar₃Temperature is the temperature at which a conversion of the gamma lattice into the alpha lattice of the alloy at a cooling rate of 3 ° C / min. begins.
A cooling of the rolling stock with an essentially the same in the longitudinal direction, seen in cross section with extensively different, intensity of heat removal is known per se. However, it is important to assign the areas with increased cooling intensity of the surface to the mass concentration of the rolling stock. In connection with a straight alignment, a compensating cooling and adjustment of a symmetrical temperature distribution and an assignment of the cooling areas, a cooling speed different over the cross-sectional areas in the longitudinal direction of the rolling stock can be kept essentially the same. It is important to adjust the size of the cooling rate with which the intended area of the rolling stock is brought to the transition temperature by measures known per se. As can be seen in Figure 3, a time-temperature conversion diagram of an alloy with a certain composition, which is familiar to a person skilled in the art, at higher cooling rates of the Ar₃ temperature, for example curves c and d, martensite components are formed in the structure, whereby the material does have a higher Takes on hardness, but loses much of its elasticity and has a higher risk of breakage and its intended use is no longer possible. Low cooling rates, eg curve h, result in a coarse pearlitic, soft structure. It is therefore important to set the local cooling rates so high that martensite formation is avoided in any case during a conversion, but a fine pearlitic structure arises in the area of the increased cooling intensity. After a complete structural transformation, in order to reduce or essentially avoid bending of the rolling stock, it is brought to room temperature with the same local cooling intensity.

It is particularly advantageous if the heat treatment after hot deformation of the rolling stock with a degree of deformation of 1.8 to 8%, preferably 2 to 5%, in the last pass at a temperature of at least 750 ° C. and at most 1050 ° C. from the hot forming heat is carried out. A final deformation with a degree of deformation or a reduction in cross-sectional area of 1.8 to 8% brings about a favorable austenite grain refinement if the deformation takes place in a temperature range from 770 ° C to 1050 ° C. As has been shown, degrees of deformation lower than 1.8 cause a particularly strong coarse grain or grain growth in places larger deformations than 8% cause a strong temperature increase in central or Interior areas obviously due to released forming energy, which locally causes structural inhomogeneities and can cause quality disadvantages.
With regard to the preservation of largely straight or axially aligned rolling stock after cooling to room temperature and in particular to rails having increased rigidity and resistance to bending fatigue, it is of great advantage if, in the second step of cooling, the cooling intensity in two or more zones on the circumference of the profiled Rolling stock is enlarged. This means that a higher hardness and higher strength of the material can be achieved in several areas near the surface of a cross-sectional area by a finer pearlite structure of the structure. When the rolled material is subjected to bending, in which the cross-sectional zones furthest away from the neutral fiber or zero line have the greatest stresses, it is now possible to form at least two of these peripheral zones with greater strength. In the case of a splint, it has been found that the fracture toughness of the material in the foot area can also be increased.

The part of the rolling stock which has the highest mass concentration, for example the head of the rail, is immersed in a dipping process or immersed in a cooling liquid, and at the same time the rolling stock part (s) intended for increased cooling are reduced with less Mass concentration, for example, the foot of the rail, heat is removed by means of lower cooling intensity, for example compressed air or air-water spraying. With such a procedure, formation of a high internal stress state and thermal distortion of a rolling stock can be counteracted.

In order to avoid disadvantageous martensite formation with the iron-base alloys mentioned at the beginning and to achieve a fine pearlite structure of the structure, it is advantageous if the size of the cooling intensity, in particular the composition of the cooling liquid for immersion cooling, is set in such a way that in the temperature range of 800 ° C. cooling to 450 ° C zone near the surface, in particular of the immersed part, is essentially achieved at 1.6 to 2.4 ° C./sec, preferably at approximately 2.0 ° C. This cooling rate is also preferred for economic reasons, because when a desired quality of the rolled product is reached, a short cooling time is required in the second step and a high throughput can thus be achieved.

To minimize the curvature, it has proven to be advantageous if, in the case of profiled rolling stock with a T-shaped cross-sectional area, as is the case, for example, at the foot of a railroad track, the zone or surface opposite the web with increased intensity, preferably by means of compressed air or by means of Air-water mixture, is cooled. In the sense of an improvement in the long-term properties, it has turned out to be particularly favorable if the surface zone opposite the web is formed with increased cooling intensity essentially symmetrically to the web axis and laterally delimited.

Furthermore, if an increased cooling intensity of the areas of the cross section of the profiled rolling stock that are distal with respect to a mass concentration or a web opening is avoided and / or these areas are protected from increased heat removal or at least briefly warmed, it is possible to have a structure in the rolling stock edges with the same or less material strength adjust. Surprisingly, this reduces the risk of breakage, in particular in the case of intermittent and / or changing permanent loading of the rolling material.

Particular dimensional stability can be achieved if the cooling intensity on the surface of the profiled rolling stock, in particular the rail, is set such that the zones in which the conversion of the gamma structure takes place during cooling are essentially symmetrical and / or parallel to neutral plane, preferably concentric to the center of gravity or to the center of gravity of the cross-sectional area.
In order to achieve an essentially completely identical local cooling intensity in the longitudinal direction and to keep the heat transfer into the cooling medium stable, it can be provided according to the invention that the rolling stock, from which based on the cross section, a part is immersed in a cooling liquid in a plunge pool, while the cooling is moved in the longitudinal direction in the longitudinal direction relative to the cooling liquid container or plunge pool and / or at least in the time in which a part of the rolling stock is immersed in the cooling liquid is subjected to an oscillation or vibrated. These measures, as has been found, decisively improve the homogeneity of the quality achieved.

A device of the type mentioned at the outset for integrally solving the problems in the production of profiled rolling stock having special properties is characterized in accordance with the invention in that the roller table in the preparation area has a known rolling stock positioning and means for the straight or axis-aligned alignment of the profiled rolling stock with a plastic shaping thereof has a transverse transport device for a straight or axially aligned movement of the rolling stock substantially perpendicular to its axis from the preparation area to the cooling treatment area, in which area a device known per se for hardening a rolling stock, in particular the head of rails, by means of cooling liquid in a plunge pool with holding and manipulation devices and a controllable additional cooling device for intensified cooling of at least one further area of the rolling stock, in particular the foot of one Rail, are arranged and the final cooling area has a shelf for the rolling stock for cooling the same to room temperature.

It was recognized that a straight or axis-aligned alignment is important, in particular in the case of cross-section, partial or partial treatment of a profiled rolling stock. By preventing a curvature over the entire length or in partial areas of this curvature, the predetermined cooling conditions or the cooling intensities of the rolling stock, viewed in the axial direction, can be kept the same, so that differences in strength or hardness along a generatrix of the profile are eliminated. Studies have shown that different distances from the wall of a coolant container and / or from the spray cooling axis can cause disproportionate deviations in the hardness and strength values.

In the case of alignment, it is also important that the rolling stock is subjected to a plastic shaping by means of appropriate devices, in order to avoid elastic resetting into an optionally partially curved shape. An axially aligned transfer of the profiled rolling stock into a cooling area by a straight transverse transport is of great importance to avoid a message device. In addition to this, a manipulation device is provided in the cooling area, with which a takeover and holding, immersion in a cooling liquid basin or hardening of partial areas of the rolling stock as well as transfer into a final cooling area can be carried out. At least one additional cooling device can be provided for intensified cooling of further cross-sectional areas.

In a further development of the device, it is advantageous if the additional cooling device can be placed on the rolling stock and the cooling intensity thereof can be regulated, and thus a further local heat dissipation can be set in accordance with the method.

An embodiment is also advantageous, in which the additional cooling device parts for forming a local in longitudinal or. Axial direction of the rolling stock has an essentially uninterrupted transverse coolant flow and optionally has means for preventing increased heat removal from the surface (s) adjacent to the cooled surface. This makes it possible to form sharply delimited cooling zones and to exclude adjacent areas from an intensified heat removal or to form a lower material hardness in them, with the additional cooling device being designed as a pressure-run or spray cooling in accordance with a further embodiment.

The homogeneity of the hardness and strength values in the longitudinal direction of the profiled rolling stock can be further increased if the rolling stock in the cooling liquid can be moved in the longitudinal axis direction relative to the plunge pool and / or relative to the additional cooling device and / or if devices on the plunge pool and / or in the cooling liquid itself are arranged, through which the Coolant can be moved turbulently and / or vibrated. It has been found that relative movements and also oscillatory movements or pressure waves between the cooling medium and the workpiece create the local cooling intensity, uniform and advantageous tempering conditions.

A splint according to the invention, in particular manufactured according to a previously mentioned method, optionally produced in a device described above, is characterized in that in the cross section of the splint it has high material strength values and hardness in the upper region of the head, which values in the lower head region in the web and in the peripheral parts of the foot are lowered and there are increased hardness values of the material in the central area on the foot base compared to the peripheral parts and the web, whereby particularly uniform quality features are achieved if symmetrical to the main axis of the cross-sectional profile or symmetrical to the vertical axis of the rail cross-section essentially the same material hardness values are set. Such a rail has improved usage properties even under difficult loads such as high axle loads and / or high frequency of use and / or low curve radii of the route.

• Fig. 1 eine Ablaufdarstellung zur Wärmebehandlung von Schienen
• Fig. 2 eine Schiene im Querschnitt
• Fig. 3 ein Zeit-Temperatur-Umwandlungsschaubild eines Schienenwerkstoffes

The invention is explained in more detail below with the aid of drawings which illustrate only one embodiment.
Show it

• Fig. 1 is a flowchart for heat treatment of rails
• Fig. 2 shows a rail in cross section
• 3 shows a time-temperature conversion diagram of a rail material

As shown schematically in FIG. 1, a profiled rolling stock such as a rail is positioned in a preparation area A on the roller table 21 by, for example, retractable buffers or the like (not shown). By means of straightening means 22 and 23, the rail 1 is aligned in a straight line, a centering shape of the straightening means, which also corrects a vertical curvature, being advantageous. After the rolling stock 1 has been aligned, it is transversely transported via a storage area 2 into a cooling area B and accommodated in one Manipulation device with holding means 24, wherein support is to be provided during a shipment in such a way that there is no bending transverse to the longitudinal axis. In a manner known per se, the rolling stock or the rail 1 is partially introduced into a cooling liquid 37, which is located in a plunge pool 38, by means of holding means 24. It is important that the distance between the surface of the rail 1 and the wall of the immersion basin is the same on both sides over the length, the rolling stock 1 in the immersion basin 38 or in the cooling medium 37 also advantageously being used to intensify and in particular to even out a cooling intensity of a rolling stock surface can be movable in the longitudinal direction to an extent of, for example, 0.5 to 5 m. In the cooling medium 37 or attached to the plunge pool, vibration generators (not shown) can also be used which place the cooling medium in a vibration which advantageously influences the cooling intensity at a frequency of, for example, 100 to 800 / min.

Additional cooling 3 can be placed or introduced on a flat part of a rolled profile, possibly on the foot 13 of a rail 1. Such an additional cooling device can have a water 32 and an air 33 feed and can form a spray stream 31 directed onto a surface part of a rolling stock or the foot of the rail. In order to set a lower cooling intensity in the peripheral parts 132 and to form a zone with increased material hardness only in a central region 131 of a rolling stock or rail base surface, it can be advantageous to provide a coolant discharge, for example, by means of a suction device.

After a part of a rolling stock, in particular a rail 1, which is immersed in a coolant 37 and in particular opposite it is acted upon by a spray stream 31, below the transformation temperature of the material with a fine pearlitic structure, for example according to FIG. 3 to approximately 500 ° C with a cooling rate according to curve f, this can be brought in a final cooling area C to a shelf 25 for cooling to room temperature.

As shown in Fig. 2, a rail 1 according to the invention has three areas with different structure or hardness, the transitions being continuous. In the rail head 11 there is a fine pearlitic zone 111 with hardness values between 340 and 390 HB, possibly up to 425 HB, which merges downwards into a zone 112 with lower hardness, for example from 300 to 340 HB. In the subsequent web 12, which must have high toughness in practical use, hardness values of 280 to 320 HB are set accordingly. A pearlitic structure with a coarser structure or lamella formation and a hardness of 280 to 320 HB is present in the rail base 13 in the peripheral regions 132, as in the web 12. This microstructure formation and the material properties of the low hardness values largely prevent crack or break initiation. In contrast, an area 131 with increased material strength and hardness values of 300 to 350 HB and higher is formed centrally on the base 13 at the foot 13. Such a distribution of the mechanical material properties over the cross-section of a rail according to the invention has been found to result in high stability and advantageous long-term behavior, in particular under difficult conditions.

Claims (19)

Process for the heat treatment of profiled rolling stock, in particular of driving or. Railway rails, with increased heat dissipation of parts of the profile surface during cooling from the gamma region of the iron-based material, whereby in the desired cross-sectional area (s), in particular in the head region of rails, a conversion into a fine pearlitic structure with increased strength, in particular increased Abrasion resistance, and increased hardness, and if necessary a deformation or bending due to thermal distortion of the rolling stock, in particular the rail perpendicular to the longitudinal axis, when cooling to room temperature, in particular after a structural change in the (particularly) cooled cross-sectional area (s), is reduced, preferably substantially avoided and increased rigidity and flexural fatigue strength of the rolling stock can be achieved, characterized in that the rolling stock, in particular the rail, with an average temperature of at most 1100 ° C, preferably of at most 900 ° C, at least each h of 750 ° C, in the longitudinal direction of which is just aligned with plastic shaping, is brought and held in the aligned state in the transverse direction, and in a first step of cooling the rolling stock or the rail to compensate for this or this to a temperature of below 860 ° C, preferably from about 820 ° C, in particular from 5 to 120 ° C above the Ar₃ temperature of the alloy with the same local cooling intensity, preferably essentially by radiation in still air, is allowed to cool, whereupon the cooling in a second step Rolled material in the longitudinal direction with locally essentially the same, viewed in cross-section with circumferentially different, heat is removed and the cooling intensity is increased in at least one zone on the circumference of the profiled rolling material, the greater (s) cooling intensity (s) being in the area (s) with a large ratio of cross-section to circumference or with a high volume share n is (are) assigned to the surface or with a high mass concentration and / or to those with a locally high temperature of the rolling stock, in particular the rail, and the area (s) is (are) brought to the transition temperature with such increased cooling rate, under which cooling conditions a martensite-free fine pearlitic structure is formed, after which the cooling down to room temperature is carried out in a subsequent step with the same local cooling intensity, for example in still air. A method according to claim 1, characterized in that the heat treatment after a hot deformation of the rolling stock with a degree of deformation of 1.8 to 8%, preferably 2 to 5%, in the last pass at a temperature of at least 770 ° C and at most 1050 ° C is carried out from the hot forming heat. Method according to claim 1 or 2, characterized in that in the second step of cooling, the cooling intensity is increased in two or more zones on the circumference of the profiled rolling stock. Method according to one of Claims 1 to 3, characterized in that the part of the profiled rolling stock which has the highest mass concentration, for example the head of a rail, is cooled by immersion or immersed in a cooling liquid, at the same time further For increased cooling intended rolling stock (s), with a lower mass concentration, for example the foot of the rail, heat is removed by means of a lower cooling intensity, for example compressed air or air-water spraying. Method according to one of claims 1 to 4, characterized in that the size of the cooling intensity, in particular the composition of the cooling liquid for immersion cooling, is set such that in the temperature range from 800 ° C to 450 ° C cooling of the zone near the surface, in particular of the immersed zone Part, essentially at 1.6 to 2.4 ° C / sec, preferably at about 2.0, ° C / sec. Method according to one of claims 1 to 5, characterized in that in the case of profiled rolling stock with a T-shaped cross-sectional area, as is the case, for example, at the foot of a railroad track, the opposite side of the web Zone or area with increased intensity, preferably by means of compressed air or by means of an air-water mixture. Method according to one of claims 1 to 6, in particular according to claim 6, characterized in that the surface zone opposite the web with increased cooling intensity is formed essentially symmetrically to the web axis and laterally limited. Method according to one of claims 1 to 7, in particular according to claim 7, characterized in that an increased cooling intensity of the regions of the cross section of the profiled rolling stock which are distal with respect to a mass concentration or a web opening is avoided and / or these regions are protected from increased heat removal or at least briefly warmed become. Method according to one of Claims 1 to 8, characterized in that the cooling intensity on the surface of the profiled rolling stock, in particular the rail, is set in such a way that the zones in which the conversion of the gamma structure takes place during cooling are essentially parallel symmetrical and / or parallel to the neutral plane, preferably concentric to the center of gravity or to the focus of the cross-sectional area. Method according to one of claims 1 to 9, characterized in that the rolling stock, a part of which, based on the cross-section, is immersed in a cooling liquid in a plunge pool while being moved in the longitudinal direction relative to the cooling liquid container or plunge pool . Method according to one of claims 1 to 10, characterized in that at least in the time in which part of the rolling stock is immersed in the cooling liquid, this is subjected to an oscillation or is set into oscillation. Device for the heat treatment of profiled rolling stock, in particular driving or. Railway rails with increased heat dissipation of parts of the profile surface during cooling from the gamma region of the iron base material, in particular for carrying out the method according to one of claims 1 to 11, consisting essentially of at least one preparation area (A) for the rolling stock (1) on the roller table (21), with a rolling stock positioning device, a cooling treatment area (B), with devices for partial heat dissipation with high intensity from the surface of the rolling stock (1) and a final cooling area (C) for cooling the rolling stock (1) to room temperature as well as transverse transport, holding - and manipulation means, characterized in that the roller table (21) in the preparation area (A) has a rolling stock positioning device known per se and means (22, 23) for straight or axially aligned alignment of the profiled rolling stock (1) with a plastic shape thereof, a transverse transport device for a straight or axially aligned V provide the rolling stock (1) essentially perpendicular to its axis from the preparation area (A) to the cooling treatment area (B), in which area (B) a device known per se for hardening a rolling stock, in particular the head of rails, by means of cooling liquid ( 37) are arranged in a plunge pool (38) with holding and manipulation devices (24) and a controllable additional cooling device (3) for intensified cooling of at least one further area of the rolling stock, in particular the foot of a rail, and the final cooling area (C) Has storage (25) for the rolling stock (1) for cooling the same to room temperature. Apparatus according to claim 12, characterized in that the additional cooling device (3) can be set against the rolling stock (1) and its cooling intensity can be regulated. Apparatus according to claim 12 or 13, characterized in that the additional cooling device (3) parts to form a local in longitudinal or. Axial direction of the rolling stock (1) has essentially uninterrupted transverse coolant flow (31) and optionally means (34) to prevent increased heat removal from the cooled surface adjacent surface (s). Device according to one of claims 12 to 14, characterized in that the additional cooling device is designed as compressed air or spray cooling. Device according to one of claims 12 to 15, characterized in that the rolling stock (1) in the cooling liquid (37) can be moved in the longitudinal axis direction relative to the immersion pool (38) and / or relative to the additional cooling device (3). Device according to one of claims 12 to 16, characterized in that devices are arranged on the plunge pool (38) and / or in the cooling liquid (37) itself, by means of which the cooling liquid (37) can be moved in a turbulent manner and / or set in vibration. Profiled rolling stock, in particular a rail or rail (1) consisting of a rail head (21) with an at least partially fine pearlitic structure (111), a rail foot (13) and a web (12) between the rail head (11) and rail foot (13), in particular Manufactured according to a method according to one of claims 1 to 11, preferably in a device according to one of claims 12 to 17, characterized in that the cross section of the rail (1) has high material hardness in the upper region (111) of the head (11) Which values are lowered in the lower head area (112) in the web (12) and in the peripheral parts (132) of the foot (13) and in the central area (131) on the foot base surface there are increased hardness values of the material. Profiled rolling stock according to claim 18, characterized in that substantially the same material hardness values are set symmetrically to the main axis of the cross-sectional profile or symmetrically to the vertical axis of the rail cross-section.

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